LES 1

About This Satellite

LES-1 was a Lincoln Experimental Satellite launched in February 1965 to test active satellite communications. It demonstrated a small solid-state X-band transmitter, switched antenna pointing, and magnetic spin stabilization. An onboard rocket failure left it in its circular transfer orbit instead of the intended higher elliptical orbit.

The wrong orbit limited a communications demonstration

Lincoln Laboratory explains that the lower orbit did not provide sufficiently long simultaneous visibility from multiple terminals for the intended operational scenarios. LES-2 incorporated circuit changes and reached its intended orbit. Demonstrating individual electronics on LES-1 was therefore different from completing the full communications experiment under the planned geometry.

A returning beacon did not restore the original communications service

The transmitter was shut down in 1967, but amateurs detected 237 MHz UHF telemetry in 2012. That signal is distinct from the X-band communications experiment. Lincoln Laboratory suggests that degraded circuitry may have allowed solar cells to power the transmitter directly; this is a hypothesis, not a confirmed repair or a claim that all spacecraft functions recovered.

Mission reference: MIT Lincoln Laboratory: LES-1/LES-2 communications experiments and later signal detections. Editorial review: 2026-09-14.

An overhead pass can still be radio silent

Lincoln Laboratory's LES-1 monitoring page explains that transmission depends on sunlight reaching the solar panels. The spacecraft can be above a receiving station's horizon while inside Earth's shadow, leaving a geometrically visible pass without the expected radio signal. Visibility, illumination, and a working transmitter are separate conditions; a ground-track line alone establishes none of the latter two.

Reference: MIT Lincoln Laboratory: LES-1 solar illumination and reception conditions.

Not every streak in a radio plot belongs to LES-1

The monitoring station samples signals around rise, culmination, and setting, with times given in UTC. Its explanation cautions that nearby radio sources can create extra features in the spectrogram, including digital audio-radio signals. A bright line is therefore not sufficient identification by itself. The observing time, expected satellite pass, and frequency behaviour provide context for interpreting the recorded trace.

Reference: MIT Lincoln Laboratory: LES-1 observation timing and spectrogram contamination.

Reading this orbital snapshot

Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 2,780 km at perigee to 2,808 km at apogee, a difference of 28 km. The orbital period is about 145.7 minutes. Eccentricity 0.00152 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 32.14 degrees implies approximate geocentric ground-track limits of 32.1 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 1002 · GCAT: S01002 (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)

Satellite Details