ATS 5

About This Satellite

ATS-5 launched on August 12, 1969 to test gravity-gradient stabilization and meteorological imaging techniques. It reached its intended region above the equator, but arrival in orbit did not make all its experiments successful. The mission illustrates how spacecraft orientation can limit an otherwise orbiting payload.

Reaching the orbit did not restore the intended attitude

NASA describes wobbling after separation and a recovery that left the spacecraft rotating in the wrong direction. Gravity-gradient stabilization and image acquisition failed, although some other instruments functioned. An orbital trajectory and the direction in which spacecraft hardware points are different engineering problems.

A working subsystem was not evidence of a complete imaging service

NASA notes that WEFAX remained operational but transmitted no images. Its brief summary labels the mission failed; that label should not erase the separate experimental measurements documented in later research reports. Conversely, those measurements do not establish that the planned weather-imaging mission was recovered.

Mission reference: NASA Science: ATS-5 stabilization problem and failed imaging experiments. Editorial review: 2026-09-15.

Rain fading could differ between nearby receiving sites

A NASA report used ATS-5 links near 15 and 32 GHz to investigate atmospheric attenuation. In its Columbus experiment, two receiving sites about four kilometres apart encountered the strongest fading at different times as a storm moved across them. Selecting the less-attenuated site improved reception. The report also found different margins in two years of observations at Rosman, showing why one year of rain data need not represent a link's long-term requirements.

Reference: Ippolito: ATS-5 millimeter-wave propagation measurements and site diversity.

An electron emitter helped investigate spacecraft charging

Olsen and Whipple used particle detectors to study electrical potential during daylight and eclipse. Their 1977 report distinguishes ATS-5's hot-filament electron emitter from the low-energy plasma neutralizer on ATS-6. For ATS-5, the preliminary results included reducing negative potentials from thousands to hundreds of volts. That is partial discharge under the reported conditions, not complete neutralization, and it is a charge-control result rather than proof of successful orbital stationkeeping.

Reference: Olsen and Whipple (1977): active potential-control experiments on ATS-5 and ATS-6.

Reading this orbital snapshot

Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 35,984 km at perigee to 36,031 km at apogee, a difference of 48 km. The orbital period is about 1447.4 minutes. Eccentricity 0.00056 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 0.39 degrees implies approximate geocentric ground-track limits of 0.4 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 1447.4 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 4068 · GCAT: S04068 (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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