A newly released plot of the Hubble Space Telescope’s altitude shows just how quickly the observatory has descended in recent years.
The post on Bluesky by astronomer Jonathan McDowell is a stark reminder that Hubble is heading back to Earth, possibly sooner than previously thought, as its orbit decays.
Hubble was launched into low Earth orbit in 1990, carried in the payload bay of Space Shuttle Discovery. While it remains capable of pointing its instruments and has returned breathtaking imagery over more than three decades in orbit, it cannot raise its altitude.
Because there is still a tenuous atmosphere at that altitude, LEO is actually somewhat self-cleaning, which is why so many satellites (including Hubble) will reenter relatively quickly unless regularly boosted, making Kessler Syndrome of low concern.
Kessler syndrome is a much more serious risk in MEO and GEO, where orbits can take decades to millenia to decay naturally.