RELAY 2

About This Satellite

Relay 2 launched on January 21, 1964 to continue experiments with television, telephone, and digital communication through an orbiting repeater. Its elliptical orbit supported communications demonstrations rather than a permanently fixed broadcast position above the equator.

The second Relay incorporated lessons from the first

NASA documents upgraded solar cells, traveling-wave tubes, power regulation, and radiation shielding on Relay 2. These changes addressed spacecraft performance and durability; the mission was not simply a duplicate of Relay 1 with a different number.

An Olympic broadcast linked spacecraft and ground stations

On January 29, 1964, Relay 2 helped transmit part of the Innsbruck Winter Olympics to the United States through stations in France and Maine. This was a demonstration of the complete relay path, not direct reception from the satellite by household television antennas.

Mission reference: NASA Historical Data Book, volume II: Relay 2 design and demonstrations. Editorial review: 2026-09-14.

Communications hardware and radiation records ended at different times

NASA's archived mission catalog describes two transponders with different failure histories: one failed in January 1967 after degraded turn-on behavior, while the other stopped operating normally in June 1967. Particle experiments also studied the trapped radiation belts. The archive identifies August 31, 1968 as the last processed-data endpoint, noting that later recorded tapes were not processed or archived. These separate dates should not be compressed into a single shutdown date for every function.

Reference: NASA NSSDC: Relay 2 transponder history and radiation-data archive limits.

A brief radio pulse did not restart the mission

James and colleagues reported in 2025 that ASKAP had detected a pulse on June 13, 2024 and localized it to Relay 2 using near-field arrival-time differences. The signal structure lasted about thirty nanoseconds after propagation correction. The researchers considered electrostatic discharge or plasma from a micrometeoroid impact plausible explanations, not an established cause. The event is evidence of a radio transient associated with the retired object, not restored telemetry, a working transponder, or an intentional message.

Reference: James et al.: a nanosecond-duration radio pulse from the defunct Relay 2 satellite.

Reading this orbital snapshot

Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 1,859 km at perigee to 7,641 km at apogee, a difference of 5,782 km. The orbital period is about 194.7 minutes. Eccentricity 0.25980 shows why a single altitude cannot describe the whole path. In a two-body approximation, perigee speed is 1.70 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 46.45 degrees implies approximate geocentric ground-track limits of 46.5 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 737 · GCAT: S00737 (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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