NASA’s Van Allen Probe A, which has been studying how our planet is protected from harmful space radiation, is expected to reenter the Earth’s atmosphere tonight. The spacecraft, weighing 600 kilograms, is likely to burn up upon reentry, but some parts are expected to survive the journey. NASA has issued a warning about a one-in-4,200 risk of harm to people due to potential debris.
The exact timing of the reentry is uncertain, with NASA estimating it around 7:45 P.M. EDT, but with a window of plus or minus 24 hours. Jonathan McDowell, an astrophysicist tracking satellites, mentioned that the spacecraft’s elliptical orbit adds to the uncertainty of its reentry time.
The Van Allen Probe A is one of two sister spacecraft launched in 2012 to study the Van Allen belts, which shield Earth from harmful space weather and radiation. The mission concluded in 2019 when the probes ran out of fuel. Unexpectedly, due to a more active solar cycle than anticipated, Probe A is reentering Earth’s atmosphere ahead of schedule.
Although NASA has not specified where the spacecraft will enter the atmosphere or where any debris may fall, both NASA and the U.S. Space Force are monitoring its path. The agency has assured that the risk to humans is low, with most parts likely to land in the ocean.
The Van Allen Probes have significantly contributed to radiation belt physics, unveiling previously unknown radiation belt features and mechanisms. Despite the potential risks associated with the reentry of Probe A, the scientific community awaits the conclusion of this chapter in space exploration.
As this is a developing story, updates may follow. For the latest news and updates on science and space exploration, stay tuned to Scientific American.
