ATS 1

About This Satellite

Applications Technology Satellite 1 was a 1966 technology demonstrator that combined communications experiments, spacecraft-engineering tests, and observations of the environment. The Spin Scan Cloud Cover Camera was one of fifteen experiments. Its weather imagery became especially influential, but describing the whole spacecraft as only a camera leaves out much of its original purpose.

The spin-stabilized body carried several kinds of hardware

The cylindrical spacecraft combined solar cells, rechargeable batteries, communications antennas, and instruments. It was initially placed near 151 degrees west over the Pacific. Its engineering configuration supported a programme of measurements and communications trials, rather than the single-purpose imaging payload a visitor might imagine from the famous Earth photographs.

Archive coverage changed while the spacecraft remained useful

SSEC describes nominal data coverage until about 1970, followed by more limited NOAA acquisition and later NASA studies comparing ATS-1 with ATS-6. A long spacecraft history does not imply a uniform, uninterrupted archive. A historical weather comparison needs the actual image dates and coverage, not simply the mission's launch year.

Mission reference: University of Wisconsin SSEC: ATS-1 experiments and observation history. Editorial review: 2026-09-14.

The spacecraft rotation helped assemble an image

NASA's processing description explains that the spin-scan radiometer acquired one line during each spacecraft revolution. A small mechanical change in elevation placed the next line beside it, and ground equipment digitized the transmitted signal in synchrony with the spin. The full disk was built through scanning, not captured as one instantaneous shutter exposure. Motion during the scan therefore matters when interpreting rapidly changing clouds.

Reference: NASA NTRS: ATS spin-scan sampling and ground data processing.

The famous ATS-1 view was not a colour photograph

NASA identifies the December 11, 1966 ATS-1 view as the first Earth photograph from geostationary orbit. Its historical comparison distinguishes this from an earlier full-disk view by Molniya 1-3 and the later colour image from DODGE. Those are different milestones. An illustration should not silently turn ATS-1's black-and-white camera into the multicolour camera flown on another mission.

Reference: NASA History: distinct full-disk, geostationary and colour-imaging milestones.

Reading this orbital snapshot

Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 35,753 km at perigee to 35,810 km at apogee, a difference of 57 km. The orbital period is about 1435.8 minutes. Eccentricity 0.00068 indicates a nearly circular path. In a two-body approximation, perigee speed is 1.00 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 5.17 degrees implies approximate geocentric ground-track limits of 5.2 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.

Is it fixed above one longitude?

The snapshot period is 1435.8 minutes. A sidereal day is about 1,436.07 minutes. Height alone does not establish a geostationary orbit: the period must match Earth rotation and the path must be circular and equatorial. This catalog uses a five-minute period tolerance for near-geosynchronous labels; near-geostationary additionally requires inclination at most 1 degree and eccentricity at most 0.01. These are browsing categories, not evidence of station-keeping or a fixed longitude.

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 2608 · GCAT: S02608 (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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