NASA has issued a warning that an old American satellite - the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) - is set to fall to Earth after spending over 20 years in orbit.
The decommissioned scientific device, designed to study solar flares and coronal mass ejections from the solar corona, was the first-ever scientific probe to use a spectrometer to study solar flares in the X-ray and gamma-ray ranges. The device itself was launched in 2002.
During its mission, the device observed more than 100,000 different events on the Sun in the X-ray range, allowing scientists to better understand how and where charged particles are accelerated in flares.
The device was also responsible for making discoveries unrelated to flares, such as clarifying the shape of the Sun and proving that terrestrial gamma-ray bursts occur more frequently during thunderstorms than previously thought.
NASA engineers shut down the 300-kilogram spacecraft in 2018 due to data transmission problems. The agency predicts RHESSI will enter Earth's atmosphere on April 19. Although most of the vehicle is expected to burn up as it moves through the atmosphere, some parts may persist. However, the risk of them hitting someone on Earth is low, at 1 in 2,467.
Despite the low risk of the RHESSI satellite causing damage upon impact, it is important to note that there is a growing problem of space debris in near-Earth space, which could pose a significant threat to space exploration.
At present, around 25,000 fragments are tracked in orbit, but many more are present that are not visible to tracking equipment. The European Space Agency estimates that around 1 million objects between 1 and 10 centimeter in size are currently moving around the planet, with around 130 million fragments from 1 millimeter to 1 centimeter on Earth.
Even small fragments can damage a satellite or spacecraft, given the speed of their movement. As such, the problem of space debris needs to be addressed before it becomes too severe to continue exploring space.