New Delhi: In September last year, NASA awarded a contract to Katalyst Space Technologies to reboost the sinking Neil Gehrel’s Swift Observatory. Katalyst subsequently
revealed that the Northrop Grumman Pegasus XL rocket will be used to launch its robotic rescue mission. As part of the fast-paced plan to raise the orbit of the satellite, NASA analysts and engineers are closely tracking the Swift observatory. Teams have been generating models to forecast the altitude of the spacecraft over the coming weeks and months, as Katalyst readies its LINK robotic servicing satellite for the launch, and rendezvous and lift manoeuvre.
All spacecraft in low Earth orbit experience drag from the atmosphere of the planet, that reduces the altitude of the spacecraft. During solar storms, the increased injection of heat causes the entire atmosphere to inflate, much like a hot air balloon. During such times, the drag on the satellites increases, along with the reduction in their altitudes. The NASA teams create annual predictions of altitude loss for dozens of spacecraft in this situation, some of which are still operational, while others have been decommissioned. The team uses orbital data from the US Space Force, as well as the Space Weather Prediction Centre (SWPC) of the National Oceanic and Atmospheric Administration (NOAA).
Re-boosting Swift remains possible
Swift’s November 2023 yearly model showed a split in possibilities, with some potential re-entries falling within a two-year window, with a similar number stretching out into the 2030s. In 2024, the Sun reached its solar maximum of the ongoing Solar Cycle 25, triggering intense space weather, causing the significant expansion of the atmosphere, and increasing the drag on Swift. by early 2025, almost all the models showed Swift re-entering the atmosphere in 2026. The Swift team is looking for ways to slow the orbital decay, to provide Katalyst with more time to complete the lift manoeuvre. The teams are attempting to maintain the observatory at an altitude of at least 300 kilometres.
