Mars Science Laboratory Entry, Descent, and Landing System Overview

Abstract: Describes the MSL guided-entry, supersonic-parachute, powered-descent, sky-crane EDL architecture, its functional elements, and the deliberate departures from Mars Pathfinder and MER heritage. Foundational documentation of an EDL architectural lineage used to code the heritage index.


Mars Science Laboratory Entry, Descent, and Landing System

Abstract: Earlier MSL EDL system description establishing the architecture concept and its heritage and novel elements prior to flight. Provides element-level architecture detail for heritage coding.


Entry, Descent and Landing Systems Analysis Study: Phase 1 Report

Abstract: NASA systems-analysis study quantifying the decelerator and propulsion trade space for Mars payloads beyond the proven MSL mass class, identifying which EDL technologies are novel for high-mass entry. Source for the novelty side of the heritage index.


A concept for the entry, descent, and landing of high-mass payloads at Mars

Abstract: Korzun, Dubos, Iwata et al. analyze EDL architectures for high-mass Mars payloads, showing how mass scaling forces departures from flown heritage toward novel decelerators and retropropulsion. Establishes the mass-difficulty link motivating the entry- and landed-mass controls.


Entry, Descent, and Landing Performance of the Mars Phoenix Lander

Abstract: Desai et al. reconstruct Phoenix EDL performance; Phoenix reused Mars Polar Lander and Mars Surveyor 2001 heritage with documented lineage. A near-heritage case and a key reconstruction-report data point.


Mars 2020 Entry, Descent, and Landing System Overview

Abstract: Way et al. describe the Mars 2020 EDL system, which reused the MSL sky-crane lineage with incremental additions such as terrain-relative navigation and MEDLI2. Documents incremental-novelty over a proven architecture.


Mars Science Laboratory: Entry, Descent, and Landing System Performance

Abstract: Steltzner et al. report MSL EDL system performance and verification, contributing to the codified, reconstructed knowledge that the Mokyr propositional-knowledge weighting relies on.


Overview of the NASA Entry, Descent and Landing Systems Analysis Study

Abstract: Companion overview of the NASA EDL systems-analysis study, enumerating technology gaps and readiness for advanced Mars EDL. Supports identification of novel EDL elements and their maturity.


Human Mars Entry, Descent and Landing Architecture Study Overview

Abstract: Polsgrove et al. survey crewed-class Mars EDL architectures and the unavoidable novel decelerators they require. Bounds the external validity claim: crewed masses are out of the historical frame.


Human Mars Entry, Descent, and Landing Architecture Study: Rigid Decelerators

Abstract: Cianciolo et al. assess rigid decelerator options for human-class Mars EDL, detailing technology development gaps and mitigations for novel elements.


Development of Supersonic Retropropulsion for Future Mars Entry, Descent, and Landing Systems

Abstract: Edquist, Korzun, Dyakonov et al. document the wind-tunnel and analysis maturation of supersonic retropropulsion. Test case for the Mokyr propositional-vs-ungrounded novelty decomposition: novelty with deep analytical grounding.


Supersonic Retropropulsion Experimental Results from NASA Ames 9x7 Foot Supersonic Wind Tunnel

Abstract: Experimental supersonic-retropropulsion results supporting the analytical maturation of a novel EDL deceleration technology, used to weight grounded vs ungrounded novelty.


Interpreted Investigation Report: Loss of Vikram Lander During Lunar Landing Phase

Abstract: Formal investigation of the Vikram lunar lander loss during the landing phase. A coded failure outcome and an example of novel-architecture lunar EDL risk.


Fatal Software Failures in Spaceflight

Abstract: Wander catalogs fatal spaceflight software failures, a class disproportionately associated with novel or modified flight software. Relevant because EDL novelty often resides in guidance and control software, supporting the software-risk channel.


Mars InSight Entry, Descent, and Landing Trajectory and Atmosphere Reconstruction

Abstract: NTRS reconstruction of InSight EDL; InSight reused the Phoenix EDL architecture almost directly, providing one of the cleanest near-replication cases in the record. Primary reconstruction-report source.


Mars 2020 Entry, Descent and Landing Instrumentation 2 (MEDLI2)

Abstract: NTRS documentation of the MEDLI2 instrumentation that reconstructed Mars 2020 EDL aerothermal and atmospheric performance. Codified-knowledge artifact for the heritage index propositional weighting.


Reliability analysis of deep space satellites launched 1991-2020: Bulk population and deployable satellite performance analysis

Abstract: Grile and Bettinger estimate failure distributions and infant-mortality effects across deep-space and deployable spacecraft cohorts. Statistical precedent for discrete-outcome and population-level reliability modeling in the domain.


Predicting Failures and Estimating Duration of Service Life from Satellite Telemetry

Abstract: Demonstrates failure prediction and time-to-failure estimation from spacecraft telemetry, establishing hazard and discrete-outcome modeling as accepted tools for spacecraft reliability.


The Tianwen-1 Guidance, Navigation, and Control for Mars Entry, Descent, and Landing

Abstract: Yu et al. describe Tianwen-1 EDL GNC, a largely independent Mars EDL architectural lineage reaching the same outcome class. A non-US heritage-lineage data point.


Overview of the Small Lunar Lander SLIM and Its Lunar Landing Results

Abstract: Reports SLIM's pinpoint lunar landing with a novel architecture and a partially anomalous touchdown attitude. The explicit boundary case for the partial-success outcome coding rule; novelty and outcome do not map one-to-one.


Scientific rationale for Saturn's in situ exploration

Abstract: Mousis et al. discuss in-situ entry and descent exploration of Saturn-system bodies, context for the Titan Huygens descent as a target-distinct EDL data point used to probe external validity.


Master Catalogue of Lunar and Mars Exploration Missions

Abstract: Consolidated catalog of lunar and Mars exploration missions and outcomes, used to assemble the population frame of landing attempts.


2020 NASA Technology Taxonomy

Abstract: NASA taxonomy of technology areas including EDL decelerators, retropropulsion, terrain-relative navigation, and landing radar. Reference framework for classifying EDL elements as heritage or novel via TechPort TRL history.


Railroads and American Economic Growth: Essays in Econometric History (Fogel 1964)

Abstract: Fogel's foundational cliometric study constructs an explicit counterfactual to compute the social saving of railroads, showing an apparently indispensable technology can have a small marginal effect once the next-best substitute is specified. Methodological anchor for the counterfactual framing of heritage value.


Technological revolutions and techno-economic paradigms

Abstract: Perez situates technological revolutions in the Neo-Schumpeterian analysis of continuity and discontinuity in innovation. Applied alongside Mokyr's propositional-vs-prescriptive knowledge distinction to frame EDL novelty and cumulative reliability.


Social Savings

Abstract: Survey of the cliometric social-savings concept measuring the societal benefit of technological improvements relative to the next-best alternative; critically reviews Fogel's original railroad application and its descendants. Anchor for the counterfactual measurement of heritage value.


Vision-based navigation and obstacle detection flight results in SLIM lunar landing

T. Ishida; Seisuke Fukuda; Kazuki Kariya; Hiroyuki Kamata; Keiki Takadama; Hirohisa Kojima; Shujiro Sawai; Shin-ichiro Sakai

Abstract: Flight results of the SLIM lunar lander vision-based navigation and obstacle detection during its pinpoint landing; documents the novel terminal-guidance architecture and the partially anomalous touchdown, a boundary case for outcome coding.


Optimal landing site selection based on safety index during planetary descent

Abstract: Method for optimal landing-site selection using a safety index during planetary descent; relevant to terminal hazard-avoidance architecture elements coded in the heritage index.


Self-position estimation using terrain shadows for precise planetary landing

Abstract: Terrain-shadow-based self-position estimation for precise planetary landing; a terrain-relative navigation technique relevant to the novelty side of the EDL architecture decomposition.


Visual navigation based on curve matching for planetary landing in unknown environments

Abstract: Curve-matching visual navigation for planetary landing in unknown environments; a candidate novel terminal-guidance element.


Efficient adversarial attacks detection for deep reinforcement learning-based autonomous planetary landing GNC

Abstract: Adversarial-attack detection for deep-RL autonomous planetary landing GNC; illustrates the software-novelty channel where EDL guidance and control risk concentrates.


Enabling intelligent onboard guidance, navigation, and control using reinforcement learning on near-term flight hardware

Abstract: Onboard RL-based GNC on near-term flight hardware; a novel autonomy element bearing on the propositional-vs-prescriptive grounding of EDL software novelty.


Electric propulsion reliability: Statistical analysis of on-orbit anomalies and comparative analysis of electric versus chemical propulsion failure rates

Abstract: Statistical analysis of on-orbit propulsion anomalies and comparative failure rates; statistical precedent for discrete-outcome reliability modeling of spacecraft subsystems.


Safety analysis for shallow controlled re-entries through reduced order modeling and inputs' statistics method

Abstract: Reduced-order safety analysis for controlled re-entries using input statistics; a statistical-methods analogue for entry-event risk quantification.


Comparison of autorotation and propulsive landing for planetary exploration

Abstract: Trade comparison of autorotation versus propulsive landing for planetary exploration; an architecture-alternatives study relevant to the heritage-versus-novel terminal-descent element.


Ocean worlds exploration

Abstract: Review of ocean-worlds exploration including in-situ entry and descent at Titan and other bodies; external-validity context for the Titan data point.


The Mars Exploration Rovers Entry Descent and Landing and the Use of Aerodynamic Decelerators

Adam Steltzner; Prasun N. Desai; Wayne Lee; Robin Bruno

Abstract: The Mars Exploration Rovers (MER) project, the next United States mission to the surface of Mars, uses aerodynamic decelerators in during its entry, descent and landing (EDL) phase. These two identical missions (MER-A and MER-B), which deliver NASA s largest mobile science suite to date to the surface of Mars, employ hypersonic entry with an ablative energy dissipating aeroshell, a supersonic/subsonic disk-gap-band parachute and an airbag landing system within EDL. This paper gives an overview of the MER EDL system and speaks to some of the challenges faced by the various aerodynamic decelerat


Entry, Descent and Landing Systems Analysis Study: Phase 2 Report on Exploration Feed-Forward Systems

Alicia M. Dwyer Ciancolo; Jody L. Davis; Walter C. Engelund; David R. Komar; Eric M. Queen; Jamshid A. Samareh; David W. Way; Thomas A. Zang

Abstract: NASA senior management commissioned the Entry, Descent and Landing Systems Analysis (EDL-SA) Study in 2008 to identify and roadmap the Entry, Descent and Landing (EDL) technology investments that the agency needed to successfully land large payloads at Mars for both robotic and human-scale missions. Year 1 of the study focused on technologies required for Exploration-class missions to land payloads of 10 to 50 t. Inflatable decelerators, rigid aeroshell and supersonic retro-propulsion emerged as the top candidate technologies. In Year 2 of the study, low TRL technologies identified in Year 1,


Overview of the Phoenix Entry, Descent and Landing System Architecture

Abstract: NASA s Phoenix Mars Lander began its journey to Mars from Cape Canaveral, Florida in August 2007, but its journey to the launch pad began many years earlier in 1997 as NASA s Mars Surveyor Program 2001 Lander. In the intervening years, the entry, descent and landing (EDL) system architecture went through a series of changes, resulting in the system flown to the surface of Mars on May 25th, 2008. Some changes, such as entry velocity and landing site elevation, were the result of differences in mission design. Other changes, including the removal of hypersonic guidance, the reformulation of the


End-to-end Mars entry, descent, and landing modeling and simulations for Tianwen-1 guidance, navigation, and control system

Chao Xu; Xiang‐Yu Huang; Minwen Guo; Maodeng Li; Jinchang Hu; Xiaolei Wang

Abstract: Abstract On May 15, 2021, the Tianwen-1 lander successfully touched down on the surface of Mars. To ensure the success of the landing mission, an end-to-end Mars entry, descent, and landing (EDL) simulator is developed to assess the guidance, navigation, and control (GNC) system performance, and determine the critical operation and lander parameters. The high-fidelity models of the Mars atmosphere, parachute, and lander system that are incorporated into the simulator are described. Using the developed simulator, simulations of the Tianwen-1 lander EDL are performed. The results indicate that t


High Mass Mars Entry, Descent, and Landing Architecture Assessment

Bradley Steinfeldt; John Theisinger; Ashley M. Korzun; Ian G. Clark; Michael J. Grant; Robert D. Braun

Abstract: As the nation sets its sight on returning humans to the Moon and going onward to Mars, landing high mass payloads ( 2 t) on the Mars surface becomes a critical technological need. Viking heritage technologies (e.g., 70 sphere-cone aeroshell, SLA-561V thermal protection system, and supersonic disk-gap-band parachutes) that have been the mainstay of the United States’ robotic Mars exploration program do not provide sucient capability to land such large payload masses. In this investigation, a parametric study of the Mars entry, descent, and landing design space has been conducted. Entry velocity


Conceptual Modeling of Drag-Augmented Supersonic Retropropulsion for Mars Entry, Descent, and Landing

Abstract: The development of new decelerator technologies will be required as the payload mass for future Mars landing missions increases beyond the current state-of-the-art capability. This study examines the potential for supersonic retropropulsion applied on entry, descent, and landing vehicles to increase the landed payload mass. This study describes the development of a model characterizing the drag augmentation capabilities of peripheral-nozzle supersonic retropropulsion flow interactions. The model captures the dominant flow physics of pressure conservation through shock cascade structures and pr


Mars 2020 Entry, Descent, and Landing Instrumentation 2 (MEDLI2) Sensor Suite

Abstract: The Mars 2020 Entry, Descent, and Landing Instrumentation 2 (MEDLI2) sensor suite seeks to address the aerodynamic, aerothermodynamic, and thermal protection system (TPS) performance issues during atmospheric entry, descent, and landing of the Mars 2020 mission. Based on the highly successful instrumentation suite that flew on Mars Science Laboratory (MEDLI), the new sensor suite expands on the types of measurements and also seeks to answer questions not fully addressed by the previous mission. Sensor Package: MEDLI2 consists of 7 pressure transducers, 17 thermal plugs, 2 heat flux sensors, an


New Developments in Retropropulsion Testing for Mars Entry, Descent and Landing

Abstract: NASA’s plans for landing human-scale payloads on Mars in the next decade require that retrorockets be used to decelerate the atmospheric entry vehicle continuously from supersonic conditions through soft touchdown.  Conventional Mars entry vehicle architectures that include a single parachute for supersonic-to-subsonic descent are not scalable to the sizes needed to land humans  on  Mars  (~20  metric  tons). The  major  aerosciences  risks are the uncertainties in predicting aerodynamic stability and performance during powered free-flight and landing.  These risks  are influenced  partially


Overview of the NASA Entry, Descent and Landing Systems Analysis Exploration Feed-Forward Study

Abstract: Technology required to land large payloads (20 to 50 mt) on Mars remains elusive. In an effort to identify the most viable investment path, NASA and others have been studying various concepts. One such study, the Entry, Descent and Landing Systems Analysis (EDLSA) Study [1] identified three potential options: the rigid aeroshell, the inflatable aeroshell and supersonic retropropulsion (SRP). In an effort to drive out additional levels of design detail, a smaller demonstrator, or exploration feed-forward (EFF), robotic mission was devised that utilized two of the three (inflatable aeroshell and


Aerocapture Guidance and Performance at Mars for High-Mass Systems

Abstract: The objective of this study is to understand the performance associated with using the aerocapture maneuver to slow high-mass systems from an Earth-approach trajectory into orbit around Mars. This work is done in conjunction with the Mars Entry Descent and Landing Systems Analysis (EDL-SA) task to explore candidate technologies necessary for development in order to land large-scale payloads on the surface of Mars. Among the technologies considered include hypersonic inflatable aerodynamic decelerators (HIADs) and rigid mid-lift to drag (L/D) aeroshells. Nominal aerocapture trajectories were de


Mars 2020 Entry, Descent, and Landing System Software Implementation

Abstract: On February 18th, 2021, the Mars 2020 project's Perseverance Rover successfully touched down on the Martian surface after nearly eight years of development. The Mars 2020 Entry, Descent, and Landing (EDL) System largely leveraged heritage from the Mars Science Laboratory (MSL) EDL System while employing targeted technological advancements. The landing process is autonomously directed by a software behavior implemented in the rover's primary flight computer called the EDL Timeline that assumes control of the vehicle six days before atmospheric entry. This paper first walks through the basics of


Mars 2020 Entry, Descent, and Landing Software Implementation

Abstract: On February 18th, 2021, the Mars 2020 project's Perseverance Rover successfully touched down on the Martian surface after nearly eight years of development. The Mars 2020 Entry, Descent, and Landing (EDL) System largely leveraged heritage from the Mars Science Laboratory (MSL) EDL System while employing targeted technological advancements. The landing process is autonomously directed by a software behavior implemented in the rover's primary flight computer called the EDL Timeline that assumes control of the vehicle six days before atmospheric entry. In addition to performing the critical funct


Development and Testing of a New Family of Supersonic Decelerators

Abstract: The state of the art in Entry, Descent, and Landing systems for Mars applications is largely based on technologies developed in the late 1960's and early 1970's for the Viking Lander program. Although the 2011 Mars Science Laboratory has made advances in EDL technology, these are predominantly in the areas of entry (new thermal protection systems and guided hypersonic flight) and landing (the sky crane architecture). Increases in entry mass, landed mass, and landed altitude beyond MSL capabilities will require advances predominantly in the field of supersonic decelerators. With this in mind, a


Mars Entry, Descent, and Landing Instrumentation 2 Trajectory, Aerodynamics, and Atmosphere Reconstruction

Christopher D. Karlgaard; Mark Schoenenberger; Soumyo Dutta; David W. Way

Abstract: On February 18th, 2021, the Mars 2020 entry system successfully delivered the Perseverance rover to the surface of Mars at Jezero Crater. The entry capsule carried a set of instrumentation installed on the heat shield and backshell, named the “Mars Entry, Descent, and Landing Instrumentation 2.” The instruments include pressure transducers, thermocouples, heat flux gauges, and radiometers to measure the aerodynamic and aerothermodynamic performance of the entry vehicle. This paper describes the trajectory and atmosphere reconstruction results based on the pressure sensor measurements. The proc


Critical spacecraft-to-Earth communications for Mars Exploration Rover (MER) entry, descent and landing

W. J. Hurd; Polly Estabrook; C. Racho; E. Satorius

Abstract: For planetary lander missions, the most challenging phase of the spacecraft to ground communications is during the entry, descent, and landing (EDL). As each 2003 Mars Exploration Rover (MER) enters the Martian atmosphere, it slows dramatically. The extreme acceleration and jerk cause extreme Doppler dynamics on the X-band signal received on Earth. When the vehicle slows sufficiently, the parachute is deployed, causing almost a step in deceleration. After parachute deployment, the lander is lowered beneath the parachute on a bridle. The swinging motion of the lander imparts high Doppler dynami


Preliminary assessment of the Mars Science Laboratory entry, descent, and landing simulation

Abstract: On August 5, 2012, the Mars Science Laboratory rover, Curiosity, successfully landed inside Gale Crater. This landing was the seventh successful landing and fourth rover to be delivered to Mars. Weighing nearly one metric ton, Curiosity is the largest and most complex rover ever sent to investigate another planet. Safely landing such a large payload required an innovative Entry, Descent, and Landing system, which included the first guided entry at Mars, the largest supersonic parachute ever flown at Mars, and the novel Sky Crane landing system. A complete, end-to-end, six degree-of-freedom, mu


Pre- and Post-entry, Descent and Landing Assessment of the Martian Atmosphere for the Mars 2020 Rover

M. A. Mischna; Gregory Villar; D. M. Kass; Soumyo Dutta; Scot Rafkin; D. Tyler; J. R. Barnes; B. A. Cantor

Abstract: Abstract This review provides an analysis of activities undertaken by the Mars 2020 Council of Atmospheres (CoA) in support of the entry, descent, and landing (EDL) of the Mars 2020 rover Perseverance in Jezero crater, Mars. The activities of the CoA were designed to evaluate the safety of early-stage landing site candidates and, later, to constrain the range of plausible conditions expected at Jezero crater during the early northern spring season of EDL, following the successful blueprint of similar councils for prior landed Mars missions. The multiyear effort of the CoA involved using a comb


A Survey of Supersonic Retropropulsion Technology for Mars Entry, Descent, and Landing

Ashley M. Korzun; Juan R. Cruz; Robert D. Braun

Abstract: This paper presents a literature survey on supersonic retropropulsion technology as it applies to Mars entry, descent, and landing (EDL). The relevance of this technology to the feasibility of Mars EDL is shown to increase with ballistic coefficient to the point that it is likely required for human Mars exploration. The use of retropropulsion to decelerate an entry vehicle from hypersonic or supersonic conditions to a subsonic velocity is the primary focus of this review. Discussed are systems-level studies, general flowfield characteristics, static aerodynamics, vehicle and flowfield stabilit


Conceptual Modeling and Analysis of Drag-Augmented Supersonic Retropropulsion for Application in Mars Entry, Descent, and Landing Vehicles

CU Scholar (University of Colorado Boulder)

Abstract: The development of new decelerator technologies will be required as the desired payload mass for future Mars landing missions increases beyond the current state-of-the-art architecture capability. This thesis examines the potential for supersonic retropropulsion applied on entry, descent, and landing vehicles to increase the landed payload mass. Supersonic retropropulsion systems use rocket thrust directed into the free stream flow to decelerate the vehicle during descent. Under certain conditions the aerodynamic drag on the entry vehicle can be preserved or augmented using supersonic retropro


Assessment of the Mars Science Laboratory Entry, Descent, and Landing Simulation

David W. Way; Jody L. Davis; Jeremy Shidner

Abstract: On August 5, 2012, the Mars Science Laboratory rover, Curiosity, successfully landed inside Gale Crater. This landing was only the seventh successful landing and fourth rover to be delivered to Mars. Weighing nearly one metric ton, Curiosity is the largest and most complex rover ever sent to investigate another planet. Safely landing such a large payload required an innovative Entry, Descent, and Landing system, which included the first guided entry at Mars, the largest supersonic parachute ever flown at Mars, and a novel and untested Sky Crane landing system. A complete, end-to-end, six degre


A Solution to Separation and Multicollinearity in Multiple Logistic Regression

Abstract: In dementia screening tests, item selection for shortening an existing screening test can be achieved using multiple logistic regression. However, maximum likelihood estimates for such logistic regression models often experience serious bias or even non-existence because of separation and multicollinearity problems resulting from a large number of highly cor related items. Firth (1993, Biometrika, 80(1),27-38) proposed a penalized likelihood estimator for generalized linear models and it was shown to re duce bias and the non-existence problems. The ridge regression has been used in logistic re


Bias, Calibration and Stability in Logistic Regression Models: A Comparative Simulation Study of MLE, Firth and Ridge Methods

International Journal of Research and Innovation in Applied Science

Abstract: Logistic regression is widely used to model binary outcomes but the traditional maximum likelihood estimation performs poorly in small samples, rare events and in cases of correlated predictors. This simulation study compared the MLE, the Firth’s bias-reduced and the ridge-penalized logistic regression across diverse sample sizes (n = 20, 100, 1000), event rates (5%, 20%, 50%) and predictor correlations (ρ = 0.1, 0.5, 0.8). The key performance metrics were estimation bias, calibration slope and bootstrap-based coefficient variability. Results show that MLE suffers extreme bias and instability


A High-Heritage Blunt-Body Entry, Descent, and Landing Concept for Human Mars Exploration

Abstract: Human-scale landers require the delivery of much heavier payloads to the surface of Mars than is possible with entry, descent, and landing (EDL) approaches used to date. A conceptual design was developed for a 10 m diameter crewed Mars lander with an entry mass of approx. 75 t that could deliver approx. 28 t of useful landed mass (ULM) to a zero Mars areoid, or lower, elevation. The EDL design centers upon use of a high ballistic coefficient blunt-body entry vehicle and throttled supersonic retro-propulsion (SRP). The design concept includes a 26 t Mars Ascent Vehicle (MAV) that could support


Mars Science Laboratory Entry Descent and Landing Simulation Using DSENDS

Abstract: The most recent planetary science mission to Mars is Mars Science Laboratory (MSL) with the Curiosity rover, launched November 26, 2011 and landed at Gale Crater on August 6, 2012. This spacecraft was the first use at Mars of a complete closed-loop Guidance Navigation and Control (GN&C) system, including guided entry with a lifting body that greatly reduces dispersions during the Entry, Descent and Landing (EDL) phase to achieve a 25 km x 20 km landing error relative to the selected Gale Crater landing target. In order to confirm meeting the above landing criteria, high-fidelity simulation of


Overview of the Mars Science Laboratory Parachute Decelerator Subsystem

Abstract: In 2010 the Mars Science Laboratory (MSL) mission will deliver NASA's largest and most capable rover to the surface of Mars. MSL will explore previously unattainable landing sites due to the implementation of a high precision Entry, Descent, and Landing (EDL) system. The parachute decelerator subsystem (PDS) is an integral prat of the EDL system, providing a mass and volume efficient some of aerodynamic drag to decelerate the entry vehicle from Mach 2 to subsonic speeds prior to final propulsive descent to the sutface. The PDS for MSL is a mortar deployed 19.7m Viking type Disk-Gap-Band (DGB)


Entry, Descent, and Landing Communications for the Mars 2020 Lander Mission

Abstract: The Mars 2020 mission was launched on July 30, 2020 and successfully landed in Jezero Crater on February 18, 2021. The challenging Entry, Descent, and Landing (EDL) sequence was observed by ground stations on Earth and by orbiters at Mars.  This paper discusses the design of the launch and arrival period to ensure maximum Earth visibility, the details of phasing the orbiting assets, and the development of the entry relay targets needed to ensure robust spacecraft telecommunications during EDL.


Entry, Descent, and Landing Operations Analysis for the Mars Phoenix Lander

Abstract: The Mars Phoenix lander was launched August 4, 2007 and remained in cruise for ten months before landing in the northern plains of Mars in May 2008. The one-month Entry, Descent, and Landing (EDL) operations phase prior to entry consisted of daily analyses, meetings, and decisions necessary to determine if trajectory correction maneuvers and environmental parameter updates to the spacecraft were required. An overview of the Phoenix EDL trajectory simulation and analysis that was performed during the EDL approach and operations phase is described in detail. The evolution of the Monte Carlo stat


2007 Mars Phoenix Entry, Descent, and Landing Simulation and Modeling Analysis

Abstract: This viewgraph presentation reviews the entry, descent, and landing of the 2007 Mars Phoenix lander. Aerodynamics characteristics along with Monte Carlo analyses are also presented for launch and landing site opportunities.


Mars Phoenix Entry, Descent, and Landing Simulation Design and Modelling Analysis

Abstract: The 2007 Mars Phoenix Lander was launched in August of 2007 on a ten month cruise to reach the northern plains of Mars in May 2008. Its mission continues NASA s pursuit to find evidence of water on Mars. Phoenix carries upon it a slew of science instruments to study soil and ice samples from the northern region of the planet, an area previously undiscovered by robotic landers. In order for these science instruments to be useful, it was necessary for Phoenix to perform a safe entry, descent, and landing (EDL) onto the surface of Mars. The EDL design was defined through simulation and analysis o


Mid Lift-to-Drag Ratio Rigid Vehicle 6-DoF Performance for Human Mars Entry, Descent, and Landing: A Fractional Polynomial Powered Descent Guidance Approach

Abstract: Defining a feasible vehicle design and mission architecture capable of reliably delivering apayload of 20 metric tons (mt) or more is a great challenge for landing humans on Mars. TheMid Lift-to-Drag Rigid Vehicle (MRV), a rigid decelerator studied in NASA’s Entry, Descent,and Landing Architecture Study (EDLAS), has shown to be a viable vehicle candidate forfuture human Mars missions. As the vehicle concept matures, models of increasing fidelity areadded to the six-degree-of-freedom (6DoF) EDL simulation. This paper presents 6DoFsimulation results using model updates for vehicle mass propertie


Hypersonic Inflatable Aerodynamic Decelerator Ground Test Development

Abstract: Hypersonic Inflatable Aerodynamic Decelerator (HIAD) technology readiness levels have been incrementally matured by NASA over the last thirteen years, with most recent support from NASA's Space Technology Mission Directorate (STMD) Game Changing Development Program (GCDP). Recently STMD GCDP has authorized funding and support through fiscal year 2015 (FY15) for continued HIAD ground developments which support a Mars Entry, Descent, and Landing (EDL) study. The Mars study will assess the viability of various EDL architectures to enable a Mars human architecture pathfinder mission planned for mi


Reconstructed Performance of the Mars InSight Lander's Supersonic Parachute & Comparison with the Phoenix Lander


Direct-to-Earth Communications and Signal Processing for Mars Exploration Rover Entry, Descent, and Landing

E. Satorius; Polly Estabrook; J. T. Wilson; D. Fort

Abstract: For planetary lander missions, the most challenging phase of the spacecraft-toground communications is during the entry, descent, and landing (EDL). As each 2003 Mars Exploration Rover (MER) enters the Martian atmosphere, it slows dramatically. The extreme acceleration and jerk cause extreme Doppler dynamics on the 8.4-GHz (X-band) signal received on Earth. When the vehicle slows sufficiently, the parachute is deployed, causing almost a step in deceleration. After parachute deployment, the lander is lowered beneath the parachute on a bridle. The swinging motion of the lander imparts high Doppl


Reconstruction of Entry, Descent, and Landing Communications for the InSight Mars Lander

Sanford Krasner; K. Bruvold; Jared A. Call; Paul Fieseler; Andrew Klesh; M. Michael Kobayashi; Norman Lay; Ryan S. Lim

Abstract: The Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport (InSight) spacecraft landed successfully on 26 November 2018 to conduct an exploration of the interior of Mars. To meet NASA’s requirement for communications during critical events, the InSight lander transmitted telemetry continuously throughout entry, descent, and landing. This allowed the public to witness the landing in real time. The transmissions were received by five assets: three at Mars and two on Earth. These included real-time relay of telemetry by the first deep-space CubeSats. This paper describes th


Mars 2020 Entry, Descent and Landing Instrumentation (MEDLI2)

White, Todd R.; Todd R. White; Dominic Trombetta; Helen Hwang; Bose, Deepak; Deepak Bose; Tomo Oishi; José Maria Campos dos Santos

NASA STI Repository (National Aeronautics and Space Administration)

Abstract: The Mars Entry Descent and Landing Instrumentation 2 (MEDLI2) sensor suite will measure aerodynamic, aerothermodynamic, and TPS performance during the atmospheric entry, descent, and landing phases of the Mars 2020 mission. The key objectives are to reduce design margin and prediction uncertainties for the aerothermal environments and aerodynamic database. For MEDLI2, the sensors are installed on both the heatshield and backshell, and include 7 pressure transducers, 17 thermal plugs, and 3 heat flux sensors (including a radiometer). These sensors will expand the set of measurements collected b


Proposed Analysis Process for Mars Science Laboratory Heat Shield Sensor Plug Flight Data

Ioana Cozmuta; Todd R. White; José Santos; Bernard Laub; Milad Mahzari

Abstract: The Mars Science Laboratory (MSL) mission is scheduled to enter the Martian atmosphere in August 2012. Aboard the heatshield is the MSL Entry Descent and Landing Instrumentation (MEDLI) system that includes a series of embedded sensor plugs to measure in-depth response of the thermal protection system (TPS). The general objectives of the MEDLI system are to assess the TPS performance and reconstruct the aerothermal environment experienced during entry. Some specific objectives, such as measuring TPS temperature, can be addressed with direct measurements. Other objectives, such as determining s


Comparison of Statistical Estimation Techniques for Mars Entry, Descent and Landing Reconstruction from MEDLI-like Data Sources

Soumyo Dutta; Robert D. Braun; Ryan Russell; Ian G. Clark; Scott A. Striepe

50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition

Abstract: Flight data from an entry, descent, and landing (EDL) sequence can be used to reconstruct the vehicle's trajectory, aerodynamic coefficients and the atmospheric profile experienced by the vehicle. Past Mars missions have contained instruments that do not provide direct measurement of the freestream atmospheric conditions. Thus, the uncertainties in the atmospheric reconstruction and the aerodynamic database knowledge could not be separated. The upcoming Mars Science Laboratory (MSL) will take measurements of the pressure distribution on the aeroshell forebody during entry and will allow freest


Mars Science Laboratory Flyaway Guidance, Navigation, and Control System Design

Behçet Açıkmeşe; Steven W. Sell; A. Miguel San Martin; Jeffrey Biesiadecki

Abstract: This paper describes the flyaway guidance, navigation, and control system design that was successfully used during the landing of NASA’s Mars Science Laboratory on Mars on 5 August 2012. One of the most challenging phases of the Mars Science Laboratory mission is the entry, descent, and landing that starts with the Mars atmospheric entry and ends with the rover Curiosity landing on Mars and the descent stage with the sky crane crashing to the surface. Because the two-way signal’s communication time between Earth and Mars is about 26 min and the fact that the end-to-end entry, descent, and land


Results from the Mars Science Laboratory Parachute Decelerator System Supersonic Qualification Program

Anita Sengupta; Adam Steltzner; Keith Comeaux; Graham V. Candler; Michael Barnhardt; Carlos Pantano; James Bell; JT Heineck

Abstract: In 2010 the Mars Science Laboratory (MSL) Mission will deliver the most massive and scientifically capable rover to the surface of Mars. To deliver this payload, an aerodynamic decelerator is required to decelerate the entry vehicle from supersonic to subsonic speeds, in advance of propulsive descent and touchdown on Mars. The aerodynamic deceleration will be accomplished by a mortar-deployed 21.5-m Viking-type disk-gap-band parachute (DGB), and will be the largest extra-terrestrial decelerator in the history of space exploration [1]. The parachute will deploy at up to Mach 2.2 and 750 Pa, res


Powered-descent landing GNC system design and flight results for Tianwen-1 mission

Xiangyu Huang; Chao Xu; Jinchang Hu; Maodeng Li; Minwen Guo; Xiaolei Wang; Yu Zhao; Baocheng Hua

Abstract: Abstract The powered-descent landing (PDL) phase of the Tianwen-1 mission began with composite backshell—parachute (CBP) separation and ended with landing-rover touchdown. The main tasks of this phase were to reduce the velocity of the lander, perform the avoidance maneuver, and guarantee a soft touchdown. The PDL phase overcame many challenges: performing the divert maneuver to avoid collision with the CBP while simultaneously avoiding large-scale hazards; slowing the descent from approximately 95 to 0 m/s; performing the precise hazard-avoidance maneuver; and placing the lander gently and sa


Orbit Determination and Analysis for SLIM Lander

Yoshihide Sugimoto; Hiroshi Takeuchi; Tsutomu Ichikawa; Masaya Nakano; Chiaki Aoshima

AEROSPACE TECHNOLOGY JAPAN THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES

Abstract: The Smart Lander for Investigating Moon (SLIM), developed by the Japan Aerospace Exploration Agency (JAXA), was launched from the Tanegashima Space Center on September 7, 2023 (JST), and successfully achieved Japan's first lunar soft landing and the world's first pinpoint landing on January 20, 2024. SLIM, a 700-kg class small lander launched as a secondary payload with the X-ray Imaging and Spectroscopy Mission (XRISM), represents a shift from landing at easy-to-reach locations to precise landings at desired spots. Achieving high-precision landings on gravitational celestial bodies requires a


Firth's logistic regression with rare events: accurate effect estimates and predictions?

Rainer Puhr; Georg Heinze; Mariana Nold; Lara Lusa; Angelika Geroldinger

Abstract: Firth's logistic regression has become a standard approach for the analysis of binary outcomes with small samples. Whereas it reduces the bias in maximum likelihood estimates of coefficients, bias towards one-half is introduced in the predicted probabilities. The stronger the imbalance of the outcome, the more severe is the bias in the predicted probabilities. We propose two simple modifications of Firth's logistic regression resulting in unbiased predicted probabilities. The first corrects the predicted probabilities by a post hoc adjustment of the intercept. The other is based on an alternat


logistf: Firth's Bias-Reduced Logistic Regression

Georg Heinze; Meinhard Ploner; Lena Jiricka; Gregor Steiner

Abstract: Fit a logistic regression model using Firth's bias reduction method, equivalent to penalization of the log-likelihood by the Jeffreys prior. Confidence intervals for regression coefficients can be computed by penalized profile likelihood. Firth's method was proposed as ideal solution to the problem of separation in logistic regression, see Heinze and Schemper (2002) <doi:10.1002/sim.1047>. If needed, the bias reduction can be turned off such that ordinary maximum likelihood logistic regression is obtained. Two new modificatio


FIRTHLOGIT: Stata module to calculate bias reduction in logistic regression

Abstract: The module implements a penalized maximum likelihood estimation method proposed by David Firth (University of Warwick) for reducing bias in generalized linear models. In this module, the method is applied to logistic regression. Others, notably Georg Heinze and his colleagues (Medical University of Vienna), have advocated the method for use under conditions of complete and quasi-complete separation, in which conventional maximum likelihood fails in obtaining finite estimates.


Performance of Firth-and logF-type penalized methods in risk prediction for small or sparse binary data

Mohammad Shafiqur Rahman; Mahbuba Sultana

Abstract: BACKGROUND: When developing risk models for binary data with small or sparse data sets, the standard maximum likelihood estimation (MLE) based logistic regression faces several problems including biased or infinite estimate of the regression coefficient and frequent convergence failure of the likelihood due to separation. The problem of separation occurs commonly even if sample size is large but there is sufficient number of strong predictors. In the presence of separation, even if one develops the model, it produces overfitted model with poor predictive performance. Firth-and logF-type penali


Mars Science Laboratory Entry, Descent, and Landing Trajectory and Atmosphere Reconstruction

Abstract: On August 5th 2012, The Mars Science Laboratory entry vehicle successfully entered Mars atmosphere and landed the Curiosity rover on its surface. A Kalman filter approach has been implemented to reconstruct the entry, descent, and landing trajectory based on all available data. The data sources considered in the Kalman filtering approach include the inertial measurement unit accelerations and angular rates, the terrain descent sensor, the measured landing site, orbit determination solutions for the initial conditions, and a new set of instrumentation for planetary entry reconstruction consisti


Comparison of Mars Atmospheric Density Estimates from Models to Measurements from Mars Global Surveyor (MGS) Data

Abstract: A recent study (Desai, 2008) has shown that the actual landing sites of Mars Pathfinder, the Mars Exploration Rovers (Spirit and Opportunity) and the Phoenix Mars Lander have been further downrange than predicted by models prior to landing Desai's reconstruction of their entries into the Martian atmosphere showed that the models consistently predicted higher densities than those found upon entry, descent and landing. Desai's results have raised a question as to whether there is a systemic problem within Mars atmospheric models. Proposal is to compare Mars atmospheric density estimates from Mar


Mars Exploration Rover Entry, Descent, and Landing: A Thermal Perspective

Abstract: Perhaps the most challenging mission phase for the Mars Exploration Rovers was the Entry, Descent, and Landing (EDL). During this phase, the entry vehicle attached to its cruise stage was transformed into a stowed tetrahedral Lander that was surrounded by inflated airbags through a series of complex events. There was only one opportunity to successfully execute an automated command sequence without any possible ground intervention. The success of EDL was reliant upon the system thermal design: 1) to thermally condition EDL hardware from cruise storage temperatures to operating temperature rang


Mars Science Laboratory (MSL) Entry, Descent, and Landing Instrumentation (MEDLI): Complete Flight Data Set

Abstract: The Mars Science Laboratory (MSL) entry vehicle (EV) successfully entered the Mars atmosphere and landed the Curiosity rover safely on the surface of the planet in Gale crater on August 6, 2012. MSL carried the MSL Entry, Descent, and Landing (EDL) Instrumentation (MEDLI). MEDLI delivered the first in-depth understanding of the Mars entry environments and the response of the entry vehicle to those environments. MEDLI was comprised of three major subsystems: the Mars Entry Atmospheric Data System (MEADS), the MEDLI Integrated Sensor Plugs (MISP), and the Sensor Support Electronics (SSE). Ultima


MSL Entry, Descent, and Landing Instrumentation: Return on Investment

Abstract: On Aug 5, 2012 the Mars Science Laboratory (MSL) Entry, Descent, and Landing Instrumentation (MEDLI) suite on MSL entry vehicle heatshield suc-cessfully returned surface pressure and in-depth temperature data.1,2 The MEDLI data has given scientists and engineers an unprecedented ability to reconstruct entry environment, atmospheric density, and flight trajectory, and flight validation of predic-tions vehicle aerodynamics and thermal protection system (TPS) performance. This presentation will dis-cuss key findings from MEDLI, some of which are being applied to improve definition of aerothermal


Approach and Entry, Descent, and Landing Operations for the Mars Science Laboratory Mission

Abstract: On August 5th, 2012, at 10:31 PM PDT, the Mars Science Laboratory (MSL) rover Curiosity landed safely within Gale Crater. Her successful landing de-pended not only upon the flawless execution of the numerous critical activities during the seven minute entry, descent, and landing (EDL), but also upon the operational preparations and decisions made by the flight team during approach, the final weeks, days, and hours prior to landing. During this period, decisions made by the flight team balanced operational risk to the spacecraft in flight with any resulting risks incurred during EDL as a result


Real-time Terrain Relative Navigation Test Results from a Relevant Environment for Mars Landing

Abstract: Terrain Relative Navigation (TRN) is an on-board GN&C function that generates a position estimate of a spacecraft relative to a map of a planetary surface. When coupled with a divert, the position estimate enables access to more challenging landing sites through pin-point landing or large hazard avoidance. The Lander Vision System (LVS) is a smart sensor system that performs terrain relative navigation by matching descent camera imagery to a map of the landing site and then fusing this with inertial measurements to obtain high rate map relative position, velocity and attitude estimates. A prot


Terrain Relative Navigation for Guided Descent on Titan

Abstract: Titan’s dense atmosphere, low gravity, and high winds at high altitudes create descent times of >90 minutes with standard entry/descent/landing (EDL) architectures and result in large unguided landing ellipses, with 99% values of  110x110 km and 149x72 km in recent Titan lander proposals. Enabling precision landing on Titan could increase science return for the types of missions proposed to date and make additional types of landing sites accessible, opening up new possibilities for science investigations. Precision landing on Titan has unique challenges, because the hazy atmosphere makes it di


Entry, Descent, and Landing Communications for the 2007 Phoenix Mars Lander

Abstract: This paper addresses NASA's requirement on the 2007 Phoenix Mars Lander to provide spacecraft communications during entry, descent, and landing on Mars to allow the identification of probable root cause should any mission failure occur. The Phoenix mission launched on 4 August 2007 and will land on 25 May 2008 on the northern plains of Mars to conduct a three-month study of the Martian environment. The paper discusses the architectural trades in designing a communications link and surveys the entry, descent, and landing communications approaches taken by previous missions. It then discusses th


Multibody Modeling and Simulation for the Mars Phoenix Lander Entry, Descent and Landing

Abstract: A multi-body flight simulation for the Phoenix Mars Lander has been developed that includes high fidelity six degree-of-freedom rigid-body models for the parachute and lander system. The simulation provides attitude and rate history predictions of all bodies throughout the flight, as well as loads on each of the connecting lines. In so doing, a realistic behavior of the descending parachute/lander system dynamics can be simulated that allows assessment of the Phoenix descent performance and identification of potential sensitivities for landing. This simulation provides a complete end-to-end ca


Human Mars Entry, Descent and Landing Architecture Study: Deployable Decelerators

Abstract: NASA’s Entry, Descent and Landing Architecture Study uses a trajectory simulation framework to evaluate various technologies and concepts of operations for human scale EDL at Mars. The study results inform agency technology investments. This paper summarizes the design assumptions and analysis of two deployable entry concepts performed in Phase 2 of the study. The entry concepts include a rigid deployable called the Adaptable Deployable Entry Placement Technology and an inflatable concept called the Hypersonic Inflatable Aerodynamic Decelerator. This paper describes the concept operations of t


The Adaptable, Deployable, Entry and Placement Technology (ADEPT) Enabling Advanced Entry, Descent, and Landing Capabilities for SmallSat Missions

Abstract: The Adaptable, Deployable Entry and Placement Technology (ADEPT) is a mechanically deployable low-ballistic coefficient aeroshell entry system which performs entry, descent, and landing (EDL) functions for a broad range of planetary destinations including Mars, Venus, Titan and Earth. The deployable system allows mission planners to develop an aeroshell design that is stowed like a folded umbrella, and yet prior to the EDL mission segment, transforms into a deployed, near-rigid low ballistic coefficient configuration.  The ADEPT architecture is scalable from a sub-1m class to 6m diameter entry


Using Firth’s Penalized Maximum Likelihood Estimation for Logistic Regression to Detect Polytomous Differential Item Functioning

Yue Xu; Corinne Huggins-Manley; Eric Wright; M. D. Miller

Proceedings of the 2025 AERA Annual Meeting

Abstract: ABSTRACT Logistic regression is one of the common methods for differential item functioning (DIF) detection and is typically estimated by maximum likelihood estimation (ML), despite the fact that ML may produce biased estimates in situations of rare event data and small sample sizes. Firth’s penalization method (PML) may address this issue. In the current study, we compared PML with ML estimation in logistic regression for polytomous DIF detection, focusing on rare event, small, and unbalanced data. The manipulated factors included item average difficulties, sample sizes, group impact, and DIF


A Comparative Study of the Bias Correction Methods for Differential Item Functioning Analysis in Logistic Regression with Rare Events Data

M. Faghih; Z. Bagheri; D. Stevanović; S. Ayatollahi; P. Jafari

Abstract: The logistic regression (LR) model for assessing differential item functioning (DIF) is highly dependent on the asymptotic sampling distributions. However, for rare events data, the maximum likelihood estimation method may be biased and the asymptotic distributions may not be reliable. In this study, the performance of the regular maximum likelihood (ML) estimation is compared with two bias correction methods including weighted logistic regression (WLR) and Firth's penalized maximum likelihood (PML) to assess DIF for imbalanced or rare events data. The power and type I error rate of the LR mod


Mars Exploration Rovers Entry, Descent, and Landing Trajectory Analysis

AIAA/AAS Astrodynamics Specialist Conference and Exhibit

Abstract: The Mars Exploration Rover mission successfully landed two rovers Spirit and Opportunity on Mars on January 4th and 25th of 2004, respectively. The trajectory analysis performed to define the entry, descent, and landing (EDL) scenario is described. The entry requirements and constraints are presented, as well as uncertainties used in a Monte Carlo dispersion analysis to statistically assess the robustness of the entry design to off-nominal conditions. In the analysis, six-degree-of-freedom and three-degree-of-freedom trajectory results are compared to assess the entry characteristics of the ca


Statistical Entry, Descent, and Landing Performance Reconstruction of the Mars Science Laboratory

Abstract: The Mars Science Laboratory spacecraft landed an approximately 900 kg rover on Mars on 5 August 2012. Similar to past Mars missions, the spacecraft recorded inertial measurement unit data and radar altimeter measurements, but its aeroshell was also instrumented with flush atmospheric data system sensors that captured the pressure distribution on the vehicle during hypersonic and supersonic flight regimes. The rich data set enables a comprehensive postflight analysis of the vehicle’s trajectory, atmosphere, and aerodynamics. This paper demonstrates a comprehensive statistical estimation methodo


Reconstructed performance of the supersonic parachute of the mars insight lander


Mars Entry, Descent, and Landing guidance under dynamic uncertainty

Abstract: Future Mars exploration missions require improvements of one order of magnitude in landed mass and of two orders of magnitude in landing accuracy with respect to current (Mars 2020) capabilities. These stringent requirements pose significant challenges to current Entry, Descent, and Landing (EDL) guidance algorithms. In addition, the behaviour of the dynamical system is highly uncertain due to the partial knowledge of the Martian atmosphere and of its interaction with the entry vehicle. In this talk, I will give an overview of some recent advances in EDL guidance under dynamic uncertainty. Fir


Assessment of the Reconstructed Aerodynamics of the Mars Science Laboratory Entry Vehicle

Mark Schoenenberger; John Van Norman; Chris Karlgaard; Prasad Kutty; David W. Way

Abstract: On 5 August 2012, the Mars Science Laboratory entry vehicle successfully entered the atmosphere of Mars, flying a guided entry until parachute deploy. The Curiosity rover landed safely in Gale crater upon completion of the entry, descent, and landing sequence. Preflight aerodynamic predictions are compared with the aerodynamic performance of the entry capsule identified from onboard flight data, including inertial-measurement-unit accelerometer and rate gyro information, and heat shield surface pressure measurements. From the onboard data, static force and moment coefficients have been extract


Overview of the MEDLI Project

Michael J. Gazarik; Michael Wright; Alan Little; F. McNeil Cheatwood; Jeff A. Herath; Michelle Munk; Frank J. Novak; Edward Martinez

Abstract: The Mars Science Laboratory Entry, Descent, and Landing Instrumentation (MEDLI) Project's objectives are to measure aerothermal environments, sub-surface heatshield material response, vehicle orientation, and atmospheric density for the atmospheric entry and descent phases of the Mars Science Laboratory (MSL) entry vehicle. The flight science objectives of MEDLI directly address the largest uncertainties in the ability to design and validate a robust Mars entry system, including aerothermal, aerodynamic and atmosphere models, and thermal protection system (TPS) design. The instrumentation suit


Mars Science Laboratory Heat Shield Instrumentation and Arc Jet Characterization

Deepak Bose; Jose A. Santos; Erika D. Rodriguez; Todd R. White; Milad Mahzari

Abstract: The Mars Science Laboratory (MSL) Entry Descent and Landing Instrumentation (MEDLI) suite on MSL entry vehicle heatshield has returned pressure, temperature, and thermal protection system (TPS) performance data acquired during entry. This paper presents performance and characterization data of the MEDLI Integrated Sensor Plug (MISP) embedded in Phenolic-Impregnated Carbon Ablator (PICA) heatshield. The sensor is characterized in arc jet facilities at MSL flight relevant conditions. The performance of the Hollow aErothermal Ablation and Temperature (HEAT) sensor in tracking a moving temperature


Isotherm Sensor Calibration Program for Mars Science Laboratory Heat Shield Flight Data Analysis

José Maria Campos dos Santos; Tomo Oishi; Edward Martinez

Abstract: Seven instrumented sensor plugs were installed on the Mars Science Laboratory heat shield in December 2008 as part of the Mars Science Laboratory Entry, Descent, and Landing Instrumentation (MEDLI) project. These sensor plugs contain four in-depth thermocouples and one Hollow aErothermal Ablation and Temperature (HEAT) sensor. The HEAT sensor follows the time progression of a 700 C isotherm through the thickness of a thermal protection system (TPS) material. The data can be used to infer char depth and, when analyzed in conjunction with the thermocouple data, the thermal gradient through the T


Performance Characterization of Supersonic Retropropulsion for Application to High Mass Mars Entry, Descent, and Landing

AIAA Atmospheric Flight Mechanics Conference


Introduction: Recent Developments in Supersonic Retropropulsion for Mars Entry, Descent, and Landing

Karl T. Edquist; Chau‐Lyan Chang; James C. McDaniel

Abstract: Covers advancements in spacecraft and tactical and strategic missile systems, including subsystem design and application, mission design and analysis, materials and structures, developments in space sciences, space processing and manufacturing, space operations, and applications of space technologies to other fields.


Powered descent guidance strategy and algorithms for mars landing using supersonic retropropulsion

Joel Benito; Erich Brandeau; Evgeniy Sklyanskiy; Steve Sell


Entry, Descent, and Landing with Propulsive Deceleration: Supersonic Retropropulsion Wind Tunnel Testing


Supersonic vehicle configuration transitions to enable supersonic rétropropulsion during mars entry, descent, and landing


The Mars 2020 Engineering Cameras and Microphone on the Perseverance Rover: A Next-Generation Imaging System for Mars Exploration

J. N. Maki; David Gruel; Colin McKinney; M. A. Ravine; M. Morales; D. Lee; Reg G. Willson; Djuna Copley-Woods

Abstract: Abstract The Mars 2020 Perseverance rover is equipped with a next-generation engineering camera imaging system that represents an upgrade over previous Mars rover missions. These upgrades will improve the operational capabilities of the rover with an emphasis on drive planning, robotic arm operation, instrument operations, sample caching activities, and documentation of key events during entry, descent, and landing (EDL). There are a total of 16 cameras in the Perseverance engineering imaging system, including 9 cameras for surface operations and 7 cameras for EDL documentation. There are 3 ty


Parachute Models Used in the Mars Science Laboratory Entry, Descent, and Landing Simulation

Juan R. Cruz; David W. Way; Jeremy Shidner; Jody L. Davis; Richard W. Powell; D. Kipp; Douglas Adams; Anita Sengupta

Abstract: An end-to-end simulation of the Mars Science Laboratory (MSL) entry, descent, and landing (EDL) sequence was created at the NASA Langley Research Center using the Program to Optimize Simulated Trajectories II (POST2). This simulation is capable of providing numerous MSL system and flight software responses, including Monte Carlo-derived statistics of these responses. The MSL POST2 simulation includes models of EDL system elements, including those related to the parachute system. Among these there are models for the parachute geometry, mass properties, deployment, inflation, opening force, area


Wind Tunnel Test of Subscale Ringsail and Disk-Gap-Band Parachutes

Carlie H. Zumwalt; Juan R. Cruz; Clara O’Farrell; Donald F. Keller

34th AIAA Applied Aerodynamics Conference

Abstract: A subsonic wind tunnel test was conducted to determine the drag and static aerodynamic coefficients, as well as to capture the dynamic motions of a new Supersonic Ringsail parachute developed by the Low Density Supersonic Decelerator Project. To provide a comparison against current Mars parachute technology, the Mars Science Laboratory's Disk-Gap-Band parachute was also included in the test. To account for the effect of fabric permeability, two fabrics ("low" and "standard" permeability) were used to fabricate each parachute canopy type, creating four combinations of canopy type and fabric mat


Descent trajectory reconstruction and landing site positioning of Chang’E-4 on the lunar farside

Jianjun Liu; Xin Ren; Wei Yan; Chunlai Li; He Zhang; Yang Jia; Xingguo Zeng; Wangli Chen

Abstract: Chang'E-4 (CE-4) was the first mission to accomplish the goal of a successful soft landing on the lunar farside. The landing trajectory and the location of the landing site can be effectively reconstructed and determined using series of images obtained during descent when there were no Earth-based radio tracking and the telemetry data. Here we reconstructed the powered descent trajectory of CE-4 using photogrammetrically processed images of the CE-4 landing camera, navigation camera, and terrain data of Chang'E-2. We confirmed that the precise location of the landing site is 177.5991°E, 45.444


Guidance Navigation and Control for Chang’E-5 Powered Descent

Honghua Zhang; Ji Li; Zeguo Wang; YiFeng GUAN

Abstract: To achieve the goal of collecting lunar samples and return to the Earth for the Chang’E-5 spacecraft, the lander and ascender module (LAM) of the Chang’E-5 spacecraft successfully landed on the lunar surface on 1 Dec., 2020. The guidance, navigation, and control (GNC) system is one of the critical systems to perform this task. The GNC system of previous missions, Chang’E-3 and Chang’E-4, provides the baseline design for the Chang’E-5 LAM, and the new characteristics of the LAM, like larger mass and liquid sloshing, also bring new challenges for the GNC design. The GNC design for the descent an


Autonomous hazard avoidance control for Chang&rsquo;E-3 soft landing

Jie Yu; Honghua Zhang; Ming Cheng; Jun Liang; Yu Zhao; Ji Li; PengJi WANG; Li Wang

Abstract: Chang'E-3 is the first mission of Chinese soft landing on celestial body outside Earth. Chang'E-3 firstly implements the autonomous hazard avoidance of soft landing using the onboard measured image data. For the feature of autonomous hazard avoidance mission, Chang'E-3 firstly presents the relay hazard avoidance control method including the large hazard avoidance of gray-scale-safe &amp; attitude maneuver and the fine hazard avoidance of altitude-safe &amp; position-attitude maneuver. The real flight results of Chang'E-3 show that in the powered descent process the safe landing site is


Thermal Cycle Tests of CLCC Solder Joints: Influence of Substrate, Solder, and Pad Patterns

Seisuke Fukuda; Takayuki Ishida; Tetsuhito Arakawa; Tsuyoshi Nakagawa; Hajime Murao

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES AEROSPACE TECHNOLOGY JAPAN

Abstract: SLIM (Smart Lander for Investigating Moon) of ISAS/JAXA is a demonstration mission of lunar pinpoint landing technology with a small spacecraft. The navigation cameras of SLIM require the function of the so-called global shutter in order to take lunar surface images under high orbital velocity. Since the requirement of miniaturization is also critical, we decide to use the commercial CMOS image sensor for the SLIM cameras. The package of the selected CMOS image sensor is the 48-pin CLCC (Ceramic Leadless Chip Carrier). It is known that there are some matters of concerns about reliability of th


Development and Flight Results of Guidance, Navigation, and Control for the SLIM Pinpoint Moon Landing

Takahiro Ito; Satoshi Ueda; Kentaro Yokota; Shinichiro Sakai; Ryo Hirasawa; Junji Kikuchi; Seisuke Fukuda; Yu Miyazawa

Abstract: The Smart Lander for Investigating Moon (SLIM) lander made a pinpoint Moon landing in January 2024. Its key technologies were a vision-based navigation and autonomous guidance, navigation, and control (GN&C). This paper focuses on autonomous GN&C for the SLIM's pinpoint landing. The onboard GN&C algorithm can correct a large initial state dispersion for a pinpoint Moon landing, in addition to considering thrust pointing constraint and subsurface flight avoidance for its terminal descent. The developed GN&C architecture successfully orchestrated the lander effectively to achieve the soft pinpoi


Logistic Regression for Massive Data with Rare Events

Abstract: This paper studies binary logistic regression for rare events data, or imbalanced data, where the number of events (observations in one class, often called cases) is significantly smaller than the number of nonevents (observations in the other class, often called controls). We first derive the asymptotic distribution of the maximum likelihood estimator (MLE) of the unknown parameter, which shows that the asymptotic variance convergences to zero in a rate of the inverse of the number of the events instead of the inverse of the full data sample size. This indicates that the available information


brglm2: Bias Reduction in Generalized Linear Models

Ioannis Kosmidis; Euloge Clovis Kenne Pagui

Abstract: Estimation and inference from generalized linear models based on various methods for bias reduction and maximum penalized likelihood with powers of the Jeffreys prior as penalty. The 'brglmFit()' fitting method can achieve reduction of estimation bias by solving either the mean bias-reducing adjusted score equations in Firth (1993) <doi:10.1093/biomet/80.1.27> and Kosmidis and Firth (2009) <doi:10.1093/biomet/asp055>, or the median bias-reduci


Conjugate priors and bias reduction for logistic regression models

Abstract: Logistic regression models for binomial responses are routinely used in statistical practice. However, the maximum likelihood estimate may not exist due to data separability. We address this issue by considering a conjugate prior penalty which always produces finite estimates. Such a specification has a clear Bayesian interpretation and enjoys several invariance properties, making it an appealing prior choice. We show that the proposed method leads to an accurate approximation of the reduced-bias approach of Firth (1993), resulting in estimators with smaller asymptotic bias than the maximum-li


Mars Exploration Rover Mission: Entry, Descent, and Landing System Validation

Abstract: System validation for a Mars entry, descent, and landing system is not simply a demonstration that the electrical system functions in the associated environments. The function of this system is its interaction with the atmospheric and surface environment. Thus, in addition to traditional test-bed, hardware-in-the-loop, testing, a validation program that confirms the environmental interaction is required. Unfortunately, it is not possible to conduct a meaningful end-to-end test of a Mars landing system on Earth. The validation plan must be constructed from an interconnected combination of simul


Mars2020 Entry, Descent, and Landing Instrumentation (MEDLI2): Science Objectives and Instrument Requirements

Abstract: NASAs exploration and technology roadmaps call for capability advancements in Mars entry, descent, and landing (EDL) systems to enable increased landed mass, a higher landing precision, and a wider planetary access. It is also recognized that these ambitious EDL performance goals must be met while maintaining a low mission risk in order to pave the way for future human missions. As NASA is engaged in developing new EDL systems and technologies via testing at Earth, instrumentation of existing Mars missions is providing valuable engineering data for performance improvement, risk reduction, and


Direct-to-Earth Communications with Mars Science Laboratory During Entry, Descent, and Landing

Abstract: Mars Science Laboratory (MSL) undergoes extreme heating and acceleration during Entry, Descent, and Landing (EDL) on Mars. Unknown dynamics lead to large Doppler shifts, making communication challenging. During EDL, a special form of Multiple Frequency Shift Keying (MFSK) communication is used for Direct-To-Earth (DTE) communication. The X-band signal is received by the Deep Space Network (DSN) at the Canberra Deep Space Communication complex, then down-converted, digitized, and recorded by open-loop Radio Science Receivers (RSR), and decoded in real-time by the EDL Data Analysis (EDA) System.


Comparison of OVERFLOW Computational and Experimental Results for a Blunt Mars Entry Vehicle Concept During Supersonic Retropropulsion

Abstract: Simulations of supersonic retropropulsion (SRP) flow over a Hypersonic Inflatable Aerodynamic Decelerator (HIAD) blunt-body vehicle were performed using the Overflow Computational Fluid Dynamics (CFD) solver. Simulation conditions and geometry were designed to match specific test runs in the Descent System Study (DSS) testing campaign. The relative accuracy of simulation predictions are assessed by direct comparison to experimental data. Computational predictions of the SRP flowfield and bow shock shape are compared to experimental schlieren images. Comparisons of the model surface pressure en


Guidance, Navigation, and Control for NASA Lunar Pallet Lander

Abstract: The NASA Lander Technology project is leading the development and integration of the Lunar Pallet Lander (LPL) concept. The objective is to demonstrate precision landing by delivering a payload to the lunar surface within 100 meters of a landing target. Potential landing sites are selected near the lunar pole where water may be present in permanently shadowed regions that could enable future in-situ resource utilization. The LPL is part of a sequence of missions aimed at maturing the necessary technologies, such as lunar precision landing sensors, that will enable the next generation of multi-


Mars Entry, Descent, and Landing Trajectory and Atmosphere Reconstruction

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

Abstract: Flight data from an entry, descent, and landing (ED L) sequence can be used to reconstruct the vehicle’s trajectory as well as com pute the associated uncertainty. The atmospheric profile encountered by the vehicle can also be estimated from flight data. Past Mars missions have contained instruments, such as accelerometers, gyroscopes, and radar altimeters that do not provide direct measurement o f the free-stream atmospheric conditions. Thus, uncertainties in the atmospheric reconstruction and the aerodynamic database knowledge cannot be separated. However, the upcoming Mars Science Laborator


Reconstruction of Aerothermal Environment and Heat Shield Response of Mars Science Laboratory

Deepak Bose; Todd R. White; Milad Mahzari; Karl T. Edquist

Abstract: An initial assessment and reconstruction of the Mars Science Laboratory entry aerothermal environment and thermal protection system response is performed using the onboard instrumentation suite called the Mars Science Laboratory entry, descent, and landing instrumentation. The analysis is performed using the current best-estimated trajectory. The Mars Science Laboratory Entry, Descent, and Landing Instrumentation suite in part provides in-depth temperature measurements at seven locations on the heat shield. The temperature data show the occurrence of boundary-layer transition to turbulence on


Bow-shock instability in entry, descent, and landing vehicles under high-enthalpy conditions

Adrián Antón-Álvarez; Adrián Lozano-Durán

Abstract: Laminar--turbulent transition remains a major uncertainty in the aerothermal design of entry, descent, and landing (EDL) vehicles. We show that, under high-enthalpy Mars-entry conditions, the detached bow shock and shock-generated shear--entropy layer can become unstable under freestream disturbances, leading to nonlinear breakdown and enhanced wall heating. The analysis spans freestream Mach numbers ($M_\infty$) up to 30 for both Earth and Mars at high altitude, with Mars being more susceptible. The receptivity analysis shows that disturbance amplification occurs through a three-step mechanis


Results of the Mars Pathfinder atmospheric structure investigation

J. A. Magalhães; J. T. Schofield; A. Seiff

Journal of Geophysical Research Atmospheres

Abstract: We report on a thorough analysis of the Mars Pathfinder atmospheric structure investigation (ASI) accelerometer data spanning the altitude range 161–8.9 km. Entry, descent, and landing occurred within 850 km of the Viking 1 lander and somewhat later in northern summer. The early morning entry (0300 hours) provided the first opportunity to study Mars' nighttime atmospheric structure; the close proximity to the Viking 1 site has permitted a search for changes in atmospheric structure during the 21 years between the landings. Our results confirm and refine the major features of the atmospheric st


Mars Pathfinder entry, descent, and landing reconstruction


Introduction to the Mars InSight Entry, Descent, and Landing Flight Reconstruction Virtual Collection

Myron R. Grover; Eli D. Skulsky; Matt Russell

Abstract: Covers advancements in spacecraft and tactical and strategic missile systems, including subsystem design and application, mission design and analysis, materials and structures, developments in space sciences, space processing and manufacturing, space operations, and applications of space technologies to other fields.


Insight Entry, Descent, and Landing Pre-Flight Performance Predictions

Robert W. Maddock; Alicia M. Dwyer-Cianciolo; Daniel Litton; Carlie H. Zumwalt


MEDLI2: MISP Inferred Aerothermal Environment and Flow Transition Assessment

Chun Yin Tang; Milad Mahzari; Dinesh Prabhu; Hannah S. Alpert; Brett A. Cruden

Abstract: View Video Presentation: https://doi.org/10.2514/6.2022-0552.vid The Mars Entry, Descent, and Landing Instrumentation 2 (MEDLI2) sensor suite on the Mars2020 mission contained multiple sensors on the aeroshell to measure the aerothermal environment during entry into the Martian atmosphere. These sensors performed superbly and successfully returned forebody and aftbody heating measurements. Analysis of MEDLI2 data indicated flow transitioning from a laminar to turbulent state on the heatshield. No evidence of flow transition was observed on the backshell. Two methods were used to estimate flow


Aerothermal Analysis and Environment Predictions for the Mars Sample Retrieval Lander (SRL)

Suman Muppidi; Dinesh Prabhu; David Saunders; Ryan McDaniel; Rathakrishnan Bhaskaran; David Kinney; Kaelan Hansson; Alireza Mazaheri

Abstract: Mars Sample Retrieval Lander (SRL) is the next mission to Mars, and an integral part of the proposed Mars Sample Return (MSR) Program. Aerothermal analysis of the SRL capsule takes advantage of the design and analysis of the Mars Science Laboratory and the Mars 2020 missions, findings from the MEDLI and MEDLI2 heatshield instrumentation campaigns, and developments in predictive capabilities over the last 20 years. In particular, SRL is being designed to enter Mars atmosphere at velocities as high as 8 km/s, which would be the highest for a Mars entry, and is expected to encounter additional sh


Aerodynamic and Aerothermal Environment Models for a Mars Entry, Descent, and Landing Systems Analysis Study

49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition


Conceptual Modeling of Supersonic Retropropulsion Flow Interactions and Relationships to System Performance

Abstract: Supersonic retropropulsion is an entry, descent, and landing technology applicable to and potentially enabling high-mass missions required for advanced robotic and human exploration on the surface of Mars. For conceptual design, it is necessary to understand the significance of retropropulsion configuration on an entry vehicle’s static aerodynamic characteristics and the relation of this configuration to other vehicle performance metrics. This investigation developed an approximate model for the supersonic retropropulsion flowfield to assist in evaluating the impact of design choices on the ve


Modeling, simulation and validation of supersonic parachute inflation dynamics during Mars landing

Daniel Z. Huang; Philip Avery; Charbel Farhat; Jason Rabinovitch; Armen Derkevorkian; Lee D Peterson

Abstract: A high fidelity multi-physics Eulerian computational framework is presented for the simulation of supersonic parachute inflation during Mars landing. Unlike previous investigations in this area, the framework takes into account an initial folding pattern of the parachute, the flow compressibility effect on the fabric material porosity, and the interactions between supersonic fluid flows and the suspension lines. Several adaptive mesh refinement (AMR)-enabled, large edge simulation (LES)-based, simulations of a full-size disk-gap-band (DGB) parachute inflating in the low-density, low-pressure,


Powered descent aerodynamics for low and mid lift-to-drag human mars entry, descent, and landing vehicles


Design of a Novel Hypersonic Inflatable Aerodynamic Decelerator for Mars Entry, Descent, and Landing

Nathaniel Skolnik; Hiromasa Kamezawa; Lin Li; Grant Rossman; Brandon Sforzo; Robert D. Braun


Advanced High-Temperature Flexible TPS for Inflatable Aerodynamic Decelerators

Joseph Del Corso; F. McNeil Cheatwood; Walter E. Bruce; Stephen J. Hughes; Anthony M. Calomino

Abstract: Typical entry vehicle aeroshells are limited in size by the launch vehicle shroud. Inflatable aerodynamic decelerators allow larger aeroshell diameters for entry vehicles because they are not constrained to the launch vehicle shroud diameter. During launch, the hypersonic inflatable aerodynamic decelerator (HIAD) is packed in a stowed configuration. Prior to atmospheric entry, the HIAD is deployed to produce a drag device many times larger than the launch shroud diameter. The large surface area of the inflatable aeroshell provides deceleration of high-mass entry vehicles at relatively low ball


A Light-Weight Inflatable Hypersonic Drag Device for Planetary Entry

Abstract: The author has analyzed the use of a light-weight inflatable hypersonic drag device, called a ballute, (balloon + parachute) for flight in planetary atmospheres, for entry, aerocapture, and aerobraking. Studies to date include missions to Mars, Venus, Earth, Saturn, Titan, Neptune and Pluto. Data on a Pluto lander and a Mars orbiter will be presented to illustrate the concept. The main advantage of using a ballute is that aero deceleration and heating in atmospheric entry occurs at much smaller atmospheric density with a ballute than without it. For example, if a ballute has a diameter 10 time


ASPIRE2: The Mars Sample Retrieval Lander's Supersonic Parachute Test Program


Implementing Planetary Protection Measures on the Mars Science Laboratory

James N. Benardini; Myron T. La Duc; Robert A. Beaudet; Robert Koukol

Abstract: The Mars Science Laboratory (MSL), comprising a cruise stage; an aeroshell; an entry, descent, and landing system; and the radioisotope thermoelectric generator-powered Curiosity rover, made history with its unprecedented sky crane landing on Mars on August 6, 2012. The mission's primary science objective has been to explore the area surrounding Gale Crater and assess its habitability for past life. Because microbial contamination could profoundly impact the integrity of the mission and compliance with international treaty was required, planetary protection measures were implemented on MSL har


Findings from the Supersonic Qualification Program of the Mars Science Laboratory Parachute System

Anita Sengupta; Adam Steltzner; Allen Witkowski; Graham V. Candler; Carlos Pantano

Abstract: In 2012, the Mars Science Laboratory Mission (MSL) will deploy NASA's largest extra-terrestrial parachute, a technology integral to the safe landing of its advanced robotic explorer on the surface. The supersonic parachute system is a mortar deployed 21.5 m disk-gap-band (DGB) parachute, identical in geometric scaling to the Viking era DGB parachutes of the 1970's. The MSL parachute deployment conditions are Mach 2.3 at a dynamic pressure of 750 Pa. The Viking Balloon Launched Decelerator Test (BLDT) successfully demonstrated a maximum of 700 Pa at Mach 2.2 for a 16.1 m DGB parachute in its AV


Supersonic Testing of 0.8 m Disk Gap Band Parachutes in the Wake of a 70 deg Sphere Cone Entry Vehicle

Anita Sengupta; Mark P. Wernet; James W. Roeder; Richard Kelsch; Allen Witkowski; T. W. Jones

Abstract: Supersonic wind tunnel testing of Viking-type 0.8 m Disk-Gap-Band ( DGB ) parachutes was conducted in the NASA Glenn Research Center 10'x10' wind-tunnel. The tests were conducted in support of the Mars Science Laboratory Parachute Decelerator System development and qualification program. The aerodynamic coupling of the entry-vehicle wake to parachute flow-field is under investigation to determine the cause and functional dependence of a supersonic canopy breathing phenomenon referred to as area oscillations, characteristic of DGB 's above Mach 1.5 operation. Four percent of full- scale parachu


Fluid Structure Interaction of Parachutes in Supersonic Planetary Entry

Anita Sengupta; L. A. Hall; Mark P. Wernet

Abstract: A research program to provide physical insight into disk-gap-band parachute operation in the supersonic regime on Mars was conducted. The program included supersonic wind tunnel tests, computational fluid dynamics and fluid structure interaction simulations. Specifically, the nature and cause of the area oscillation phenomenon were investigated to determine the scale, aerodynamic, and aero-elastic dependence of the supersonic parachute collapse and re-inflation event. A variety of non-intrusive, temporally resolved, and high resolution diagnostic techniques were used to interrogate the flow an


Development of models for disk-gap-band parachutes deployed supersonically in the wake of a slender body

Clara O’Farrell; Suman Muppidi; Joseph M. Brock; John W. Van Norman; Ian G. Clark

Abstract: The Advanced Supersonic Parachute Inflation Research and Experiments (ASPIRE) project will investigate the supersonic deployment, inflation, and aerodynamics of Disk-Gap-Band (DGB) parachutes in the wake of a slender body. The parachutes will be full-scale versions of the DGBs used by the Mars Science Laboratory in 2012 and planned for NASA's Mars 2020 project and will be delivered to targeted deployment conditions representative of flight at Mars by sounding rockets launched out of NASA's Wallops Flight Facility. The parachutes will be tested in the wake of a slender payload whose diameter is


A historical summary of the design, development, and analysis of the disk-gap-band parachute

Abstract: The Disk-Gap-Band (DGB) parachute was originally developed in the late 1960's by Clint Eckstrom for high-altitude meteorological rocket applications. It was designed as a balance between drag and stability with a relatively simplistic design and low packing volume. Due to its demonstrated high-altitude performance and design features, the DGB was selected as a candidate for Viking precursor test programs such as the Planetary Entry Parachute Program (PEPP) and the Supersonic Planetary Entry Decelerator (SPED), in which the parachute was tested at high altitude supersonic conditions similar to


Supersonic Tests of the Double Gap Disk-Gap Band Parachute and Fluid Structure Interaction Simulation

J Stephen Lingard; John C. Underwood; Matthew G. Darley; Lionel Marraffa; Luca Ferracina

23rd AIAA Aerodynamic Decelerator Systems Technology Conference


Preliminary Design of the Supersonic Disk-Gap-Band Parachute for Sample Retrieval Lander

Katie J. Siegel; Clara O'Farrell; Jeremiah Rowan; Kirin Peterson; Charles Lowry