Leonard David's INSIDE OUTER SPACE

Image credit: NASA

A veteran of Earth remote sensing is nearing its destructive reentry though Earth’s atmosphere.

Landsat 4 was launched from Vandenberg Air Force Base in California on July 16, 1982 on a Delta 3920 rocket.

Landsat 4 was built for and launched by NASA. The spacecraft was built by contractor GE Astro Space. Despite numerous operations transfers, the Earth Resources Observation and Science (EROS) Center of the U.S. Geological Survey is the record and data keeping organization of the Landsat program. 

Image credit: Joseph Remis/Satellite Reentry Observation Program group

Landsat 4 had a launch mass of 4,279 pounds (1,941 kilograms).

Joseph Remis, a leading satellite reentry expert, posts that Landsat 4 has a current decay prediction date of October 8.

First light

Landsat 4 was launched with the Multispectral Scanner (MSS) and a new advanced imaging sensor, Thematic Mapper (TM), allowing for clearer views of natural disasters from space. This was the first time that the data could be depicted as a natural color image due to the new TM sensor onboard Landsat 4.

Pre-launch photo of Landsat 4.
Image credit: NASA

Landsat 4’s first light image captured eastern Lake Erie and the cities of Toledo, Detroit, and Windsor on July 25, 1982.

The spacecraft’s period of revolution around the Earth was 99 minutes; roughly 14.5 orbits/day, offering repeat coverage of locations on Earth every 16 days.

Landsat 4 early image of Detroit.
Image credit: USGS

Trouble in orbit

But within a year of launch, the spacecraft lost the use of two of its solar panels and both of its direct downlink transmitters. The downlink of data from Landsat 4 was not possible until the Tracking and Data Relay Satellite System (TDRSS) became operational).

In 1987 the TM instrument was switched off.     

The sensors onboard the satellite collected data until late 1993, and the satellite was decommissioned on June 15, 2001.