A 600-pound satellite hurtles towards Earth, not a plane, bird but a retired spacecraft known as the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI).
After over two decades in orbit, NASA reported on Monday that RHESSI is set to reenter Earth’s atmosphere on Wednesday, making its crash landing. While most of the satellite is expected to burn up upon reentry, there is a chance that some parts may survive the fiery return.
“The risk of harm coming to anyone on Earth is low – approximately 1 in 2,467,” stated NASA in a recent statement. First launched into its low Earth orbit in 2002, RHESSI has been instrumental in observing solar flares and coronal mass ejections, providing valuable insights into the physics of the sun’s energy bursts. With its imaging spectrometer, RHESSI has recorded over 100,000 X-ray events and captured gamma-ray images, marking a significant milestone in the field of solar observation.
In addition to its contributions to solar research, RHESSI has also aided in discoveries related to the sun’s shape and “terrestrial gamma-ray flashes,” which are bursts of gamma-rays that occur over lightning storms on Earth. However, in 2018, RHESSI was decommissioned due to communications difficulties, marking the end of its active mission.
Weighing in at 660 pounds, RHESSI is considered a relatively lightweight satellite compared to other spacecraft that have been launched into or returned from orbit.
In January of this year, NASA announced that a 38-year-old satellite weighing a staggering 5,600 pounds would be returning to Earth, following the multiple instances of Chinese rocket debris reentering the atmosphere in 2022. The issue of space debris, also known as space junk, has been a growing concern for space agencies as the number of objects orbiting Earth continues to increase.
In fact, NASA estimated in 2021 that there are approximately 27,000 pieces of space junk floating in orbit, not including the potentially disruptive and destructive debris that is too small to be tracked.
The danger of space junk is primarily reserved for spacecraft in orbit, as there have been no confirmed injuries or deaths resulting from free-falling space debris. However, the higher the orbital debris is, the longer it will take to tumble back to Earth, according to NASA. Debris at altitudes of 373 miles (600 kilometers) or less takes several years to return, while orbital decay at 497 miles (800 kilometers) may take centuries to occur.
As RHESSI hurtles towards Earth at an incredibly high velocity, scientists and space agencies closely monitor its trajectory and potential impact.
While the risk to human safety is low, NASA and other organizations continue to emphasize the importance of space debris mitigation measures to minimize the risks associated with space junk.
As technology advances and more satellites and spacecraft are launched into space, proper disposal and management of space debris remain critical to ensure the safety and sustainability of space exploration and activities.