When a satellite reaches the end of its life, it has only two destinations. It can either be maneuvered into a graveyard orbit, a kind of purgatory for satellites, or it plunges to its destruction in Earth’s atmosphere. The ESA’s ERS-2 satellite took the latter option after 30 years in orbit.
ERS-2 was an Earth Observation satellite launched in 1995. It was scheduled to last three years but lasted much longer. In March 2,000, a computer and a gyro failed, and the mission continued but suffered some data degradation. Other equipment failures followed, and the mission finally ended in 2011. ERS-2 was destroyed during reentry into Earth’s atmosphere on February 21st, 2024. But unlike other satellites, the destruction of ERS-2 was caught on camera. The Tracking and Imaging Radar (TIRA) at the Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR in Germany captured images of the satellite’s demise.
A full-size model of ERS-2. Image Credit: By Poppy – Self-photographed, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1393904
TIRA has a 34-meter tracking antenna, and on February 19, 20 and 21, the facility tracked the satellite for a few minutes while it travelled overhead. A GIF of these images shows ERS-2 tumbling through the sky and its solar array coming loose.
The images show the solar array coming loose the day before ERS-2 re-entered the atmosphere.
These are more than just interesting images for space buffs. Authorities would like to be able to predict a satellite’s time and place of re-entry so they can plan for it. When they predict a re-entry, they treat it as one object until almost the end. If the solar array on ERS-2 was loose and moving independently from the satellite body a day before re-entry, the satellite would’ve interacted with the atmosphere differently, changing the time and location of its re-entry.
ERS-2 actually re-entered the atmosphere slightly later than initially predicted. Analysts are examining the re-entry data to determine if the solar array buckling was related to the delayed re-entry. The results of their analysis could help experts make more accurate forecasts for future satellite re-entries.
There are no records of a re-entry causing any injury or damage, and NASA says that fewer than a half-dozen of their large pieces of orbital debris re-enter each year. “Since the beginning of the space age in 1957, there has been no confirmed report of an injury resulting from re-entering orbital objects,” according to NASA.
Re-entry is hard to predict, but with so many satellites and other large pieces of debris in orbit, it’s becoming more important to predict where and when they’ll re-enter. Image Credit: International Association for the Advancement of Space Safety
That doesn’t mean that a satellite re-entry can’t be dangerous, though. Back in 1978, a Soviet nuclear satellite named Kosmos 954 re-entered Earth’s atmosphere. It exploded over northern Canada and spread radioactive debris across parts of Nunavut, Alberta, and Saskatchewan. To this day, one indigenous leader from the region claims that radioactivity from the crash is responsible for higher cancer rates among his people, but scientists say that’s extremely unlikely.
Plenty of objects have struck Earth after re-entry. In 1997, parts of a Delta 2 launch vehicle landed near Georgetown, Texas. One of the pieces weighed 250 kg or over 550 lbs. It landed in an empty field but could’ve caused enormous damage if it had struck a building or other infrastructure.
This is the main propellant tank of the second stage of a Delta 2 launch vehicle, which landed near Georgetown, TX, on 22 January 1997. This approximately 250 kg tank is primarily a stainless steel structure and survived reentry relatively intact. Image Credit: NASA ODPO.
NASA is concerned about re-entry and space debris and has an Orbital Debris Program Office (ODPO) at the Johnson Space Center. ODPO is charged with measuring Earth’s orbital environment and helping develop mitigation methods for the debris problem. They use software tools to compute re-entry survivability and to predict any possible risks.
The non-profit corporation Aerospace.org keeps a database of objects that have re-entered Earth’s atmosphere. You can see it here.