LANDSAT 1 (ERTS 1)

About This Satellite

Landsat 1 launched on July 23, 1972, under the name Earth Resources Technology Satellite, ERTS-1. It began a systematic land-observation record that makes it possible to compare landscapes across decades. The catalog retains its original ERTS identity because a renamed mission is still the same tracked spacecraft.

The experimental scanner became the important instrument

The payload combined the Return Beam Vidicon camera system, RBV, with a Multispectral Scanner, MSS. RBV was intended as the main instrument, but MSS delivered more useful data. Measuring separate wavelength ranges proved valuable for distinguishing surface features that may look similar in an ordinary photograph.

A 1970s image is a historical baseline

An archived scene can show a coastline or city before later development. For a meaningful comparison, match the area, season, sensor bands, and processing level. A newer image with finer detail should not be mistaken for proof that every apparent difference is a real landscape change.

Mission reference: USGS: Landsat 1 mission history. Editorial review: 2026-09-12.

A short design life, a much longer contribution

The spacecraft was designed for one year but was not decommissioned until January 6, 1978. Its value now lies in the observations it preserved, not in taking new images. A contemporary TLE for the surviving object cannot provide a contemporary Landsat 1 picture.

Reference: USGS: Landsat 1 design life and decommissioning.

Why an 80 m instrument can have 60 m product pixels

USGS describes the historical MSS observations as approximately 80 m data, delivered on a resampled 60 m grid. Resampling changes the output pixel spacing; it does not recover finer details that the instrument never measured. Check this distinction before comparing MSS scenes with later Landsat imagery.

Reference: USGS: Landsat sensor resolution and MSS resampling.

Reading this orbital snapshot

Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 895 km at perigee to 907 km at apogee, a difference of 12 km. The orbital period is about 103.0 minutes. Eccentricity 0.00083 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 99.33 degrees implies approximate geocentric ground-track limits of 80.7 degrees north and south. This is a retrograde orbit, moving against the direction of 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 6126 · GCAT: S06126 (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