A three-armed spacecraft is rushing to the rescue of a NASA telescope that’s in danger of crashing back to Earth. Northrop Grumman launched Katalyst Space Technologies’ Link spacecraft on Friday from the Marshall Islands in the Pacific. The Pegasus rocket blasted off from the belly of a modified airplane, putting Link on course to reach NASA’s Swift Observatory in about a month. Launched in 2004, Swift is sinking faster than ever because of recent solar storms. NASA is paying $30 million for Katalyst to capture the telescope and boost its orbit so it can continue tracking the universe’s biggest explosions.