TIROS 4

About This Satellite

TIROS-4 launched on February 8, 1962 to improve experimental weather observations from orbit. NASA describes a new lens system intended to reduce distortion and improve resolution, alongside television cameras and radiometers. Better pictures were useful only if forecasters could receive and interpret them in time.

Tape recorders bridged gaps between receiving stations

Each camera had a magnetic tape recorder for pictures collected outside the ground network's receiving range. Capture and delivery were therefore separate steps. The spacecraft also carried an electronic clock controlling its infrared horizon sensor and magnetic orientation system; obtaining a usable picture depended on more than the lens alone.

An international network distributed the cloud pictures

NASA credits TIROS-4's improved imagery with enabling the US Weather Bureau to begin an international facsimile network for sharing cloud pictures with other weather services. This was ground-based distribution after satellite reception, not a claim that every weather office communicated directly with TIROS-4.

Mission reference: NASA Science: TIROS-4 camera improvements and weather-picture distribution. Editorial review: 2026-09-14.

The image record included applications beyond storm tracking

NASA's historical summary reports 32,593 pictures over 161 days, with declining clarity after June 14, 1962. Images supported Project Mercury weather analysis and joint US-Canadian ice reconnaissance on the St. Lawrence River. That count describes the historical output, not a guarantee that every frame has identical quality or survives in a modern download collection.

Reference: NASA Historical Data Book, table 3-189: TIROS-4 output and applications.

The radiometer archive is not a folder of camera photographs

The GES DISC product preserves recovered magnetic-tape data in the original IBM 36-bit binary format, with one orbit per file. Its five-channel instrument had a roughly 55 km nadir footprint, but channel 4 carried redundant timing rather than an independent science band. NASA also warns that degradation changed the prelaunch calibration. Reading these radiometric records requires their format and calibration documentation; a camera image viewer cannot interpret them as ordinary photographs.

Reference: NASA GES DISC: TIROS4L1FMRT format, channel functions and calibration caveat.

Reading this orbital snapshot

Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 680 km at perigee to 789 km at apogee, a difference of 109 km. The orbital period is about 99.5 minutes. Eccentricity 0.00764 indicates a nearly circular path. In a two-body approximation, perigee speed is 1.02 times apogee speed. These are mean-element estimates, not instantaneous measurements. Distance per orbit uses an ellipse approximation.

Saved build snapshot. If a valid TLE is retrieved, this explanation and the orbit panel update together. Otherwise this dated snapshot is retained.

Ground track is not sensor coverage

An inclination of 48.30 degrees implies approximate geocentric ground-track limits of 48.3 degrees north and south. This is a prograde orbit, moving in the same general direction as Earth rotation. The plotted line marks the point beneath the object. It does not represent camera coverage, radio reception, or a guaranteed visible pass.

Accuracy and missing information

The introductory record describes the build snapshot. The orbital snapshot explanation and orbit panel share any successfully retrieved TLE; check the displayed epoch. Reentered objects retain historical data only. Mission history is not rewritten by TLE updates. TLE/SGP4 positions are predictions and can change after maneuvers or updated observations. The 14-day stale-data cutoff is a display safeguard, not an accuracy guarantee. Local passes are geometric predictions, not a visibility forecast. No verified operator or mission status means unknown, not active. Do not use this catalog for collision avoidance or operational flight decisions.

Catalog sources: CelesTrak SATCAT: NORAD 226 · GCAT: S00226 (source update 2026 Sep 4 2345:57). Supplementary metadata: SatNOGS DB, retrieved 2026-09-05T12:57:25.375Z. Page assembled 2026-09-15. GCAT phase codes describe trajectory phases, not mission health.

Learn more: TLE data · Perigee and apogee · Ground tracks · JOT (Jewawud Live Orbital Map)

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