{ "reviewed": "2026-11-11", "flight": { "name": "Starship Flight 4", "date": "2024-06-06", "booster": "Booster 11", "ship": "Ship 29", "reported_liftoff_local": "07:50 CDT", "liftoff_utc_minute": "12:50 UTC", "time_precision": "SpaceX states liftoff to the minute. No independently synchronized event-clock extraction has been performed here.", "reported_booster_duration_seconds": 444, "reported_ship_duration_seconds_approx": 3960, "crew": false, "orbital_status": "Near-orbital test, treated as suborbital in the FAA notice; not a completed Earth orbit or lunar journey." }, "sources": [ { "id": "operator", "family": "operator", "title": "SpaceX · Starship’s Fourth Flight Test", "url": "https://www.spacex.com/launches/starship-flight-4", "locator": "Postflight summary · 6 June 2024; visible page reviewed 11 November 2026", "review": "Summary inspected in browser; complete replay not frame-collated", "role": "Operator account; onboard video and displayed telemetry share the operator’s measurement chain." }, { "id": "license", "family": "regulator", "title": "FAA · VOL 23-129 Rev.5.3 and revision history", "url": "https://www.faa.gov/media/94826", "locator": "May 2025 document · revision history PDF pp.2–3: Rev.3 entries dated 4 June 2024", "review": "Historical revision table visually checked; later document, not the original Rev.3 instrument", "role": "Identifies the Flight 4 vehicle-configuration authorization history. A licence is not a raw trajectory measurement." }, { "id": "waiver", "family": "regulator", "title": "FAA · Near-orbital collective-risk waiver notice", "url": "https://www.federalregister.gov/documents/2024/11/07/2024-25851/waiver-of-launch-collective-risk-limit-for-a-near-orbital-trajectory", "locator": "89 FR 88338 · issued 31 July 2024; published 7 November 2024 · Background and Near-Orbital Trajectory sections", "review": "Notice text reviewed", "role": "Distinguishes near-orbital classification, the requested risk waiver and its timing; does not establish Flight 4’s detailed measured path." }, { "id": "bgr", "family": "outside", "title": "Pilger & Hupe · Infrasound signatures from powerful rocket launches", "url": "https://conferences.ctbto.org/event/27/contributions/5409/attachments/2699/5052/241107_Pilger_Hupe_ITW_RocketInfrasound.pdf#page=21", "locator": "BGR · Infrasound Technology Workshop, 7 November 2024 · slides 12 and 21", "review": "Relevant slides inspected; published processed figures, not raw station waveforms", "role": "Outside acoustic measurements reported through the International Monitoring System (IMS); event association and propagation still require a model." }, { "id": "ga-lead", "family": "outside", "title": "Nikolova, Brown & Spiliopoulos · Tracing Starship re-entries with infrasound", "url": "https://doi.org/10.1093/gji/ggag447", "locator": "Geophysical Journal International · accepted manuscript published 19 October 2026", "review": "Abstract and version notice only; full analysis and supplement not reviewed here", "role": "Follow-up reading lead. Its abstract studies six later controlled re-entries and uses public telemetry in the association framework; it is not a second raw Flight 4 reconstruction performed by Babylon." }, { "id": "faa-project", "family": "regulator", "title": "FAA · Starship project and environmental document collection", "url": "https://www.faa.gov/space/stakeholder_engagement/spacex_starship", "locator": "Current catalogue reviewed 11 November 2026; documents have separate issue dates", "review": "Public document collection located", "role": "Route to dated environmental and licensing materials; present proposals must not be projected backward onto Flight 4." } ], "events": [ { "id": "liftoff", "branch": "stack", "title": "Lift off from Starbase", "time": "07:50 CDT · 12:50 UTC, to the minute", "seconds": 0, "precision": "Reported minute, not an independently timed zero", "description": "SpaceX reports launch from Texas and a completed booster ascent burn.", "meaning": "Propulsion changes the vehicle’s momentum. A video or public speed display does not by itself supply calibrated acceleration or engine thrust.", "needed": "Synchronized launch clock, sensor definitions and time-tagged ascent state vectors.", "sources": [ "operator" ] }, { "id": "separation", "branch": "split", "title": "Hot-stage separation", "time": "Sequence reported · exact event time not extracted here", "seconds": null, "precision": "No numeric time assigned", "description": "The operator describes ignition of the upper stage’s six engines before the two vehicles separate.", "meaning": "Two flight paths now need separate clocks and identifiers. A booster readout must not be mistaken for the ship’s readout.", "needed": "Separation timestamp, vehicle-specific telemetry channels and frame definitions.", "sources": [ "operator" ] }, { "id": "boostback", "branch": "booster-return", "title": "Booster turns back", "time": "After separation · no measured timestamp transcribed", "seconds": null, "precision": "Sequence only", "description": "SpaceX reports a flip, boostback burn and hot-stage adapter jettison.", "meaning": "Engine burns and atmospheric flight shape the booster’s return path; this is separate from the upper stage’s much longer flight.", "needed": "As-flown burn start/stop times, thrust/propellant records and trajectory.", "sources": [ "operator" ] }, { "id": "booster-splash", "branch": "booster-sea", "title": "Booster splashdown", "time": "T+07:24 · operator-reported duration", "seconds": 444, "precision": "Reported to the second; clock calibration not obtained", "description": "The company reports a landing burn and soft splashdown in the Gulf of Mexico.", "meaning": "This is an operator-reported endpoint. A complete landing reconstruction needs location, velocity and independent timing.", "needed": "Position/velocity at water contact, clock alignment and separately located receiving or camera records.", "sources": [ "operator" ] }, { "id": "coast", "branch": "ship-coast", "title": "Upper-stage coast", "time": "After powered ascent · no numeric state series obtained", "seconds": null, "precision": "No altitude or speed curve supplied here", "description": "SpaceX reports that the upper stage reached its planned coast trajectory.", "meaning": "The FAA describes these near-orbital developmental profiles as suborbital. Coast does not require continuous thrust; gravity continues acting.", "needed": "Time-tagged position and velocity, altitude datum, force model and planned-versus-flown comparison.", "sources": [ "operator", "waiver" ] }, { "id": "entry", "branch": "ship-entry", "title": "Atmospheric entry and heating", "time": "Entry phase · no calibrated heat-flux series obtained", "seconds": null, "precision": "Phase only", "description": "The operator reports passage through peak heating and aerodynamic pressure with flap control.", "meaning": "A bright image is evidence of emitted light. Temperature, heat flux and structural load require calibrated instruments and a flow model.", "needed": "Thermal/pressure channels, camera calibration, heat-shield inspection evidence and uncertainty.", "sources": [ "operator" ] }, { "id": "splash", "branch": "ship-sea", "title": "Ship landing burn and splashdown", "time": "About T+01:06 · operator’s rounded duration", "seconds": 3960, "precision": "Approximate; not a second-accurate endpoint", "description": "SpaceX describes three centre engines relighting, a flip and splashdown in the Indian Ocean.", "meaning": "An ocean endpoint differs from a recovered vehicle or a demonstrated reusable turnaround. Flight 4 carried no people.", "needed": "Final trajectory, touchdown location/velocity and a separately calibrated endpoint observation.", "sources": [ "operator", "license" ] } ], "station_leads": [ { "station": "IS04", "claim": "Detailed processed example on slide 21", "raw_waveform_obtained": false }, { "station": "IS05", "claim": "Listed re-entry detection on slides 12 and 21", "raw_waveform_obtained": false }, { "station": "IS07", "claim": "Listed re-entry detection on slides 12 and 21", "raw_waveform_obtained": false }, { "station": "IS40", "claim": "Listed re-entry detection on slides 12 and 21", "raw_waveform_obtained": false } ], "gaps": [ { "id": "clock", "area": "Telemetry and clocks", "known": "The operator publishes narrative events and selected displayed data.", "missing": "Raw time-tagged Flight 4 channels, sampling rates, altitude/speed frames, rounding, filtering and video latency.", "next": "Ask SpaceX for an existing public data package or data dictionary, with source-clock and vehicle identifiers.", "test": "Align a measured state with the same event, vehicle and reference frame before comparing values." }, { "id": "heat", "area": "Heat and aerodynamic loads", "known": "SpaceX reports controlled entry and live onboard views.", "missing": "A public Flight 4 calibration/uncertainty package for thermal, pressure, attitude and structural channels has not been located in this review.", "next": "Locate existing engineering results and identify which quantities were measured, modeled or inferred from imagery.", "test": "Compare predicted heating/load to calibrated flight channels without treating brightness as a thermometer." }, { "id": "acoustic", "area": "Outside acoustic measurements", "known": "BGR reports IMS detections associated with Flight 4 re-entry.", "missing": "Raw waveforms, exact detection windows, station responses, processing settings, atmospheric profiles and association uncertainties.", "next": "Ask the authors for existing waveform/data access routes and processing information, including IMS access conditions.", "test": "Trace rays through dated temperature/wind fields; test competing source locations and quantify the association uncertainty." }, { "id": "authority", "area": "Authorization and actual flight", "known": "A later FAA licence history records Rev.3; a later waiver notice explains near-orbital classification.", "missing": "The original Flight 4 authorization package, applicable conditions and corresponding as-flown compliance records are not fully assembled here.", "next": "Locate the exact dated FAA files; distinguish public copies, redactions, commercial protections and records not yet located.", "test": "Compare what was authorized with what was reported and observed. Approval alone does not validate every flight measurement." }, { "id": "trajectory", "area": "Full trajectory and endpoints", "known": "The operator reports two splashdowns with different durations.", "missing": "A numerical as-flown trajectory with covariance, both endpoint positions and separately calibrated observations has not been obtained.", "next": "Identify SpaceX flight data and any agency-held range/tracking products; then locate independent observations with clocks and geometry.", "test": "Fit held-out measurements to a documented trajectory and report residuals with uncertainty." } ], "findings": [ { "title": "Two vehicles need two evidence trails", "text": "The booster’s reported 7 minutes 24 seconds and the ship’s roughly 66 minutes describe different branches. They are not competing durations for the same object.", "sources": [ "operator" ] }, { "title": "A requested waiver is not a waiver already in force", "text": "The FAA notice says there would be no waiver decision before Flight 4; the request moved to Flight 5. The notice was issued after Flight 4. We must not use that later decision as Flight 4’s approval.", "sources": [ "waiver" ] }, { "title": "Outside sensors add an acoustic check", "text": "BGR’s slides identify multiple station detections. Babylon has not reproduced the signal processing or inferred a complete trajectory from these figures.", "sources": [ "bgr" ] }, { "title": "A technical summary is not the raw data package", "text": "The mission page supports a reported sequence. Our review has not established public availability of the full calibration, uncertainty and raw telemetry files needed to reproduce the flight.", "sources": [ "operator", "faa-project" ] } ], "acoustic_demo": { "default_distance_km": 3000, "default_effective_speed_m_s": 300, "distance_min_km": 2000, "distance_max_km": 6000, "speed_min_m_s": 250, "speed_max_m_s": 350, "default_delay_minutes": 166.66666666666666, "role": "Illustrative distance / effective-speed calculation. No measured Flight 4 arrival is fitted. Real rays bend and winds alter travel time; multiple paths may exist." }, "outreach_status": "Research questions identified · no new SpaceX, FAA or infrasound-author email drafted or sent in this study.", "boundaries": "No raw Flight 4 telemetry or IMS waveforms are included. Events without extracted timestamps remain untimed. No unpublished engineering result, full orbit, Moon mission, crew radiation assessment or atmospheric ceiling is established by this case. Independent recordings and interpretations that incorporate operator telemetry are distinguished." }