An old NASA satellite is set to reenter the atmosphere tomorrow, Sunday, January 8. Though most of the satellite is expected to burn up in the atmosphere and pose minimal risk, some debris could reach the surface. NASA satellites launched today are designed to deorbit more gracefully and with less risk of creating space debris, but this satellite was launched in 1984 before guidelines were in place.
The current guidelines, updated in November 2019, require that any risk of a deorbiting satellite impacting people on Earth is less than 1 in 10,000. The old satellite doesn’t quite meet that requirement as there is marginally more risk from its impact. “NASA expects most of the satellite to burn up as it travels through the atmosphere, but some components are expected to survive the reentry,” the agency wrote in a statement. “The risk of harm coming to anyone on Earth is very low – approximately 1 in 9,400.”
The Department of Defense predicts that the satellite will reenter the atmosphere within a 17-hour window on either side of 6:40 p.m. ET on Sunday. Tracking of the satellite will continue, as it is not yet known where any debris could be expected to land.
The satellite is called Earth Radiation Budget Satellite or ERBS and weighs 5,400 pounds. Launched in 1984, it was an early tool for investigating climate change from space. Among other things, it measured the Earth’s radiative energy budget, which refers to how much energy our planet gets from the sun and how much it emits out into space. This measurement is related to climate factors such as aerosols and greenhouse gases as well as formations such as clouds and surface geography.
Running far beyond its originally planned lifespan of two years, ERBS continued to collect data until 2005 — making it a 21-year mission in total. The satellite was launched from the Space Shuttle Challenger and is notable for having trouble with deploying its solar panels when first launched. Pioneering American astronaut Sally Ride had to use a robotic arm from the Space Shuttle to shake it loose and move the panel into sunlight, allowing it to fully deploy.