A NASA satellite that has spent over ten years exploring the Van Allen radiation belts surrounding Earth is about to make an uncontrolled reentry into the atmosphere.
While a majority of the 1,323-pound (600-kilogram) satellite is expected to burn up upon reentry, some portions might survive and reach the Earth's surface. According to a recent study, satellites of similar mass undergo uncontrolled reentries multiple times per month. These typically involve older satellites or expended rocket components.
This particular reentry is significant as it presents a higher risk to the public than what is usually accepted by the US government. Although the chances of causing harm to someone on Earth are still low, at approximately 1 in 4,200, this risk surpasses the governmental threshold of 1 in 10,000 for such reentries.
'Due to late-stage design changes, the potential risk of uncontrolled reentry increased,' a NASA spokesperson informed Ars. 'After evaluating the mission’s scientific benefits and the low risk posed, NASA granted an exemption to the standard US Government Orbital Debris Mitigation practices. In line with national policy, NASA notified the US Department of State regarding this exception.'
The satellite, named Van Allen Probe A, was launched in 2012 as a component of a dual-satellite mission aimed at studying Earth’s radiation belts. These belts, consisting of charged particles ensnared by Earth's magnetic field, play a crucial role in shielding our planet from cosmic radiation and solar storms.
Predicting satellite reentries is complex due to the variable density of the upper atmosphere. The latest prediction from the US Space Force indicates that Van Allen Probe A is expected to reenter the atmosphere early this week, with a reentry window spanning from late Monday to late Wednesday.