A retired NASA spacecraft is about to meet its fiery demise, burning up in Earth’s atmosphere after its expected free-fall from orbit later this week.
The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) spacecraft is expected to reenter Earth’s atmosphere on April 20 at around 11:30 am AEST, give or take 16 hours, NASA announced based on the most recent estimate by the Department of Defence.
The 300 kilograms satellite will likely burn up during its reentry, although some parts could survive the atmospheric plunge and make their way to the surface. NASA reassured the people of Earth, however, that the risk of harm is approximately 1 in 2,467. The space agency will continue to monitor RHESSI’s reentry to refine its predictions.
The mission launched on February 5, 2002, with the sole purpose of watching the Sun, day in and day out. RHESSI’s job was to look out for solar flares — dramatic eruptions of radiation that the Sun flings out into space (and sometimes towards Earth). “Ask any scientist who worked on RHESSI what their favourite flare is, and they’ll easily rattle off a date, as if it’s a birthday or holiday they’ll always remember,” NASA wrote in a 2018 statement.
After years of providing scientists with valuable data about our host star, the ageing spacecraft officially retired on August 16, 2018. RHESSI spent its retirement years in a stable low Earth orbit, but atmospheric drag has been tugging on the spacecraft, gradually lowering its orbit until it finally reenters through the atmosphere this week.
Throughout its mission, RHESSI observed more than 75,000 solar flares, each memorable in its own way, according to NASA. “One guy even has a most-hated flare,” solar physicist Säm Krucker is quoted as saying in the NASA statement. “He had many arguments with colleagues over it, trying to explain it, which was not always pleasurable.