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Hall of Shoulders

Space Strategy

Jonathan McDowell

Jonathan McDowell is known for The launch and orbital object catalog (GCAT), space activity statistics, and the empirical re-derivation of the edge of space (the Karman line).. This is a neutral research artifact. It cites only sources actually retrieved in the research sweep logged in Section 2. No citation is fabricated; where an abstract was not machine-retrievable, the source is characterized from its verified title, authorship, and venue only.

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48

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Citations

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FTS5 Chunks

48

Retrieval index

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Memberships

Review Lens

Adversarial questions for candidates

The falsifiable questions this brain puts to a dissertation candidate. They seed the pre-Conclave initial review whenever a candidate's topic matches the Space Strategy lens.

  1. 1

    Catalog reconciliation: "State your satellite/debris population numbers and name the catalog of record. How do your counts reconcile with operator-declared figures and with the independently tracked object population, and what is the tracking floor (smallest object size/altitude) below which your numbers are unverified?" (Tests F1/F6; falsified if the candidate cannot name a catalog or quantify its completeness — McDowell 2020; Murtaza et al. 2020.)

  2. 2

    Boundary justification: "Your architecture/policy assumes space begins (or sovereignty ends) at a specific altitude. Justify that boundary from the observed orbital behavior of objects there, not from convention. Why is your altitude defensible given the ~80 km vs 100 km debate and the VLEO migration of new constellations?" (Tests F2; falsified by a convention-only answer — McDowell 2018; Bittencourt Neto et al. 2022; Muirhead et al. 2025.)

  3. 3

    Capacity is not a constant: "Give the carrying capacity of the orbital shell your proposal targets, the model behind it, and the risk-rate it assumes. Does your capacity number account for thermospheric contraction from greenhouse-gas trends and the consequent change in debris lifetimes?" (Tests F4/F5; falsified if capacity is treated as fixed or atmospheric coupling is omitted — D'Ambrosio & Linares 2024; Parker, Brown & Linares 2025.)

  4. 4

    Own-externality accounting: "Quantify the observable externality your own system imposes — satellite brightness/trail contamination, added conjunction load, and launch/re-entry emissions — using measured magnitudes and rates, not qualitative assurances." (Tests F3/F4; falsified by hand-waving — McDowell 2020; Borlaff et al. 2025; Ryan et al. 2024.)

  5. 5

    Trend, not snapshot: "Show your claim against the launch/activity time series, not a single-year snapshot. Where is the inflection in your data, and is your governance instrument calibrated to the post-megaconstellation regime or to a steady state that no longer exists?" (Tests F4; falsified if the candidate reasons from a static assumption against an inflecting series — McDowell's Space Report practice; Ryan et al. 2024; OECD 2020.)

Core Concepts & Space Translation

The catalog as ground truth (the General Catalog of Artificial Space Objects / GCAT and the launch log)

McDowell's foundational practice is the maintenance of a comprehensive, openly published census of every launch and every catalogued orbital object, with consistent definitions of what counts as a "launch," an "object," a "payload," and an arrival "in orbit." The catalog is the empirical substrate of his published analysis (McDowell 2020, *ApJL*; DOI 10.3847/2041-8213/ab8016, which works directly from the LEO satellite population). The reviewer's first instinct, inherited from this practice, is to ask of any claim: *what does the catalog actually show, and is your number reconcilable with the observed object population?*

Space translation

See Space Applications below for how this framework translates to contemporary space governance, drawn directly from the dossier's applied-literature review.

Empirical, data-derived boundaries rather than conventions (the edge of space)

McDowell's most cited single result re-derives the boundary between airspace and outer space not from a round-number convention but from the observed orbital data: the perigee distribution of catalogued objects and the lowest sustained free orbits (McDowell 2018, *Acta Astronautica*; DOI 10.1016/j.actaastro.2018.07.003). He argues the practical lower edge of orbital space sits near 80 km, not the conventional 100 km Karman line. The transferable principle: definitions used in law, policy, and engineering should be anchored in measured physical behavior of the object population, not in tradition or political convenience.

Space translation

See Space Applications below for how this framework translates to contemporary space governance, drawn directly from the dossier's applied-literature review.

Population-level brightness and observability (the satellite as an observed object)

Because McDowell treats satellites as objects with measured orbital and physical parameters, he can compute population-scale observational consequences. In the Starlink paper he models the number of *illuminated* satellites as a function of latitude, season, and time of night, predicting naked-eye visibility of hundreds of satellites at twilight at mid-latitudes (McDowell 2020; DOI 10.3847/2041-8213/ab8016). This astronomer's-eye accounting has since been extended to the Gen2 constellation (Muirhead, Crisp & McGrath 2025, *AJ*; DOI 10.3847/1538-3881/adfbef) and elevated to a space-based-astronomy threat assessment (Borlaff, Marcum & Howell 2025, *Nature*; DOI 10.1038/s41586-025-09759-5).

Space translation

See Space Applications below for how this framework translates to contemporary space governance, drawn directly from the dossier's applied-literature review.

Activity statistics and trend accounting (launches, payloads, and the megaconstellation inflection)

McDowell's *Space Report* is, at its core, longitudinal statistics: launches per year, payloads per launch, objects added to the catalog, and the structural break the megaconstellation era represents. The transferable framework is that the trajectory of space activity is a measurable time series, and policy must be calibrated to the observed inflection, not to a steady-state assumption. The atmospheric-emissions inventory of the megaconstellation era (Ryan et al. 2024, *Scientific Data*; DOI 10.1038/s41597-024-03910-z) is the kind of downstream accounting this framework enables.

Space translation

See Space Applications below for how this framework translates to contemporary space governance, drawn directly from the dossier's applied-literature review.

The orbital shell as a finite, measurable resource (toward space environmentalism)

By cataloging objects by altitude shell, McDowell's data makes legible the idea that specific bands of LEO are filling up. This empirical legibility is the precondition for the "space environmentalism" program (Lawrence et al. 2022, *Nature Astronomy*; DOI 10.1038/s41550-022-01655-6) and for quantitative carrying-capacity work (D'Ambrosio & Linares 2024, *JSR*; DOI 10.2514/1.a35729; Parker, Brown & Linares 2025, *Nature Sustainability*; DOI 10.1038/s41893-025-01512-0). The reviewer treats "how full is this shell, and by what measure?" as a first-order question.

Space translation

See Space Applications below for how this framework translates to contemporary space governance, drawn directly from the dossier's applied-literature review.

Definitional rigor and reconciliation as the discipline's hygiene

Underlying all of the above is McDowell's insistence on precise, reproducible definitions and on reconciling competing counts (operators' claims, official catalogs, sensor limitations). The catalog only works because the categories are stable and the discrepancies are tracked. For a reviewer, this is the sharpest tool: it exposes any candidate whose population numbers, capacity claims, or "edge of space" assumptions are asserted rather than reconciled against the observed record.

Space translation

See Space Applications below for how this framework translates to contemporary space governance, drawn directly from the dossier's applied-literature review.