17.02.2026
NASA has adjusted operations of the Neil Gehrels Swift Observatory to reduce atmospheric drag and prepare the spacecraft for a planned orbit-raising mission. On Feb. 11 the mission team temporarily suspended most science activities so controllers can keep the satellite in an orientation that minimizes drag and slows its gradual loss of altitude.
Swift normally slews rapidly to observe transient targets such as gamma ray bursts with its suite of telescopes. Principal investigator S. Bradley Cenko at NASA's Goddard Space Flight Center said that while the Burst Alert Telescope will continue detecting gamma ray bursts, the spacecraft will no longer slew to follow up these events with its other instruments. This change limits Swift's ability to carry out multiwavelength observations but helps preserve the observatory for a future reboost.
Enhanced solar activity heats Earth's upper atmosphere and causes it to expand, increasing drag on spacecraft in low Earth orbit and slowly lowering their altitude over time. Swift has operated in orbit for about 21 years, and its average altitude has been steadily declining as a result of this atmospheric drag. Many missions eventually reenter the atmosphere at the end of their lifetimes, but NASA is pursuing a different path for Swift.
The agency has contracted Katalyst Space Technologies of Flagstaff, Arizona, to carry out a mission that will boost Swift into a higher orbit. The planned servicing effort aims to extend the observatory's scientific lifetime while demonstrating an orbital reboost capability that could be applied to a broader class of spacecraft. NASA sees satellite servicing and orbit-raising as an important step toward maintaining valuable space assets and reducing the need for replacement missions.
To maximize the chances of a successful reboost, Swift's average altitude must remain above about 185 miles, or roughly 300 kilometers. As of early February the spacecraft's orbit had already dropped below about 250 miles, around 400 kilometers, prompting the team to modify operations to slow the descent. By keeping the observatory in a drag-minimizing attitude and limiting slews, the mission team is working to preserve sufficient altitude for the upcoming servicing flight.
Mission planners anticipate that the reboost spacecraft will launch in the summer. Cenko said the team is transitioning Swift's operations now to provide the widest possible margin for the servicing mission. If successful, the boost to a higher orbit will allow Swift to continue its role in rapidly detecting and studying changes in the high energy universe.
Swift studies gamma ray bursts, which are among the most powerful explosions known, along with other energetic cosmic phenomena. The observatory has provided nearly daily observations of these fleeting events and has helped scientists investigate their origins and environments. Extending the mission's life would enable continued rapid-response observations and maintain a key asset for time sensitive astrophysics.
NASA encourages the public and scientific community to follow developments as the reboost mission approaches. The agency notes that the Swift mission remains an important part of its portfolio for studying the dynamic universe, even while operations are constrained to support orbital preservation. Additional information about the observatory and its science is available through the mission's web resources.
Quelle: SD
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Update: 28.05.2026
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NASA Predicts Swift Spacecraft’s Location for Boost Mission
Neil Gehrels Swift Observatory
NASA's Neil Gehrels Swift Observatory is a satellite that studies gamma-ray bursts, the most powerful explosions in the universe, and other cosmic objects and events.
NASA analysts and engineers have been closely tracking the agency’s sinking Neil Gehrel’s Swift Observatory as part of a fast-paced plan to raise it to a higher orbit.
Teams have been generating models to forecast the spacecraft’s altitude in the coming weeks and months, as Katalyst Space readies its LINK robotic servicing satellite to launch and rendezvous for the lift maneuver.
“These predictions evolve over time, based on space weather forecasts and other factors like Swift’s current height and orientation,” said Michael Shoemaker, deputy flight dynamics lead in SSMO (Space Science Missions Operations) at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “It’s also an iterative process with members of Swift’s operations team. They determine new ways to point the spacecraft to reduce drag, and we do some new computations to see how much extra time that buys them.”
All spacecraft in low Earth orbit experience drag caused by our planet’s atmosphere, which solar storms can magnify. Many satellites, like Swift, don’t have propulsion systems to maintain their orbits, so the drag gradually reduces their altitudes.
Shoemaker and his colleagues create annual predictions for dozens of spacecraft in this situation, some that are still active and others that have been decommissioned.
They use orbital data from the U.S. Space Force, solar activity research from NASA and the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center, and operational details from each satellite team.
After most models forecast that a mission will re-enter Earth’s atmosphere within two years, the team generates altitude predictions more frequently.
Swift’s November 2023 yearly model showed a split in the possibilities, with some potential re-entries falling within the two-year window, but a similar number stretched far beyond it, into the 2030s.
In 2024, the Sun reached its solar maximum phase, triggering intense space weather that was more active than expected. The activity caused Earth’s atmosphere to expand slightly and increased its drag on Swift. By early 2025, almost all the models had Swift re-entering by the summer of 2026.
NASA awarded Katalyst, based in Flagstaff, Arizona, a contract to attempt to boost Swift to a higher altitude in September 2025. The Swift team started looking for ways to slow Swift’s orbital decay to give Katalyst as much time as possible to complete the lift maneuver. For the best chance of success, Swift needs to be at least 185 miles (300 kilometers) above Earth.
Shoemaker and his colleagues started generating weekly orbital predictions, which the Swift team used to make decisions about when to halt science observations and how to steer the spacecraft to reduce drag as much as possible. This innovative new approach to operating Swift has allowed them to successfully slow its orbital decay.
According to the most recent predictions, the Swift team’s actions will likely keep the spacecraft above the critical altitude into early fall.
“We’re also working on predictions for where Swift will be when LINK is set to launch in June aboard a Northrop Grumman Pegasus rocket,” said Russell Carpenter, the deputy project manager in SSMO. “The project to re-boost Swift has generated intense interest across the flight dynamics community. The Swift team is grateful that so many people have been willing to pitch in to help with refining these predictions.”
Quelle: NASA