Data Methodology & Trust Standards

Every number in our comparison engine is cited, confidence-scored, and editor-reviewed. This page explains exactly what that means — where our data comes from, how we assign confidence levels, when we update, and how you can flag errors.

How we source data

We follow a strict primary-source waterfall. Each tier is only used when sources above it are unavailable or unverifiable:

1Agency and manufacturer user guides, technical datasheets, and official press kits (NASA, ESA, JAXA, ISRO, CNSA, SpaceX, ULA, etc.)
2Official financial filings — SEC EDGAR 10-K/10-Q, UK FCA disclosures, and equivalent regulatory documents.
3Peer-reviewed literature indexed in NASA ADS, arXiv (astro-ph), or similar scholarly archives.
4Operator press releases and mission blogs directly from the spacecraft or vehicle team.
5Established analyst reports — BryceTech, Euroconsult, McKinsey Space Practice, PwC Space.
6Established space journalism (SpaceNews, Spaceflight Now, NASASpaceFlight) with traceable primary-source attribution.

We never fabricate figures or estimate where sources are unavailable. When a manufacturer has not disclosed a figure, it appears as undisclosed — never as a guess.

Confidence levels explained

Every data entry in our comparison tables carries one of three confidence badges. The badge reflects the strongest source tier found for that figure.

High confidence

At least one source is a NASA, ESA, JAXA, ISRO, or CNSA primary publication; an SEC EDGAR filing; or peer-reviewed literature.

Medium confidence

Sources include the operator's own press releases or established analyst aggregators (BryceTech, McKinsey Space, PwC, Euroconsult, etc.).

Low confidence

Only trade press or secondary aggregators — no agency-primary or operator-primary source found. Treat as indicative only.

CitedFigure format

Every verifiable figure in our data layer is stored as a structured object rather than a plain string:

{ value: "150 t", asOf: "2025-10-14", sourceIdx: 2 }

valueThe figure as it appears in the source — preserved verbatim, including units.
asOfThe ISO date the source was published or last updated — not when we added the data. This is the date we show in UI as "confirmed as of."
sourceIdxZero-based index into the entry's sources[] array. Source superscripts (like ¹²³) in comparison tables link to the full bibliography at the bottom of each entry page.

Update cadence

Active missions

Reviewed when agencies publish mission updates — typically monthly for major missions such as Perseverance, LRO, and active orbital telescopes.

Active rockets & spacecraft

Reviewed quarterly or after significant events: a new flight, an anomaly, a vehicle retirement, or a manufacturer data release.

Historical data

Reviewed annually or when new archival material becomes available (e.g., declassified documents, post-mission reports, new scholarly literature).

Staleness flag

All entries display a "Last verified" date. Entries where that date is more than 12 months in the past are flagged for re-verification before the next publish cycle.

How to report errors

Found a wrong number? We take accuracy seriously. If you have a primary-source citation that contradicts a figure on this site, please let us know:

→GitHub: Open an issue in our public repository with the figure, the page URL, and your source citation.

→Email: data@spaceodysseyhub.com — include the page URL, the incorrect value, and the source that contradicts it. We aim to respond within 48 hours.

All verified corrections are reflected in the per-vertical changelog shown at the bottom of each comparison page.

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