TELSTAR 2 (A-41)

About This Satellite

Telstar 2 launched on May 7, 1963 to extend the experiments begun with Telstar 1. Bell Telephone Laboratories built the spacecraft for AT&T. The mission combined demonstrations of active satellite communication with measurements relevant to radiation damage and the useful lifetime of electronics in orbit.

Television demonstrations also tested the ground network

NASA records the transmission of black-and-white and colour television and voice signals between stations in the United States, France, and England. Testing new ground equipment was an explicit objective. The experiment therefore involved tracking, transmitting, and receiving installations on Earth as well as the orbiting repeater; the satellite alone was not a complete communications service.

Radiation measurements belonged alongside the communications mission

The payload included proton-electron detectors, and NASA's history describes radiation effects as part of the mission's operating experience. These instruments helped investigate the environment encountered by the hardware. Their presence did not make the spacecraft an imaging observatory or mean that all received radiation readings represented a failed communication link.

Mission reference: NASA Historical Data Book: Telstar 2 characteristics, objectives and communications results. Editorial review: 2026-09-14.

The VHF timer did not switch off every path for scientific data

NSSDC records a timer-controlled VHF transmitter shutdown on May 16, 1965. Telstar 2 also provided microwave telemetry for scientific information, and the catalog notes limited subsequent collection at Andover, Maine. The VHF shutdown is therefore a specific subsystem milestone. It should not be described as reentry or as proof that every possible data path ceased at exactly the same instant.

Reference: NASA NSSDC: Telstar 2 VHF shutdown and limited later microwave telemetry.

Different detector channels sampled different particle populations

The same experiment catalog describes separate directional and omnidirectional proton measurements and electron channels with different energy thresholds. Sampling and accumulation were part of the measurement definition. A radiation plot should retain its detector, energy selection, and time interval; combining every channel into an unexplained single value would discard the distinctions that made the experiment useful.

Reference: NASA NSSDC: Telstar 2 proton and electron detector channels.

Reading this orbital snapshot

Based on TLE epoch: 2026-09-03. Estimated altitude ranges from 962 km at perigee to 10,809 km at apogee, a difference of 9,847 km. The orbital period is about 225.3 minutes. Eccentricity 0.40147 shows why a single altitude cannot describe the whole path. In a two-body approximation, perigee speed is 2.34 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 42.76 degrees implies approximate geocentric ground-track limits of 42.8 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 573 · GCAT: S00573 (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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