Boosting Science

Inside NASA's audacious plan to save a doomed space telescope

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NASA'S NEIL GEHRELS Swift Observatory is in a race against time. For more than 21 years the Earth-orbiting telescope has surveyed the sky for gamma-ray bursts—the most powerful and luminous explosions in the universe—and whipped around to take a closer look. But on every orbit, it collides with countless particles from the planet's atmosphere. Each impact steals a tiny bit of the spacecraft's speed, pushing it a smidgen closer to Earth. If left alone, the spacecraft will lose the race later this year and fall out of orbit, bringing a fiery end to its long scientific tenure. But NASA hopes to buy the telescope an extra decade through a longstanding space-technology dream: a mission in which a robot will gently glom on to Swift, push it up into a safer orbit, then set it free. If it works, the technique could open up new possibilities for science spacecraft more generally.

“There have been ideas like this around for a long time, and I think the technology is finally getting to the point where it's not crazy,” says Jonathan McDowell, an astronomer and space sustainability analyst.

The Swift Observatory is equipped with a Burst Alert Telescope that surveys a huge amount of the sky at once, looking for flashes of light and pinpointing their locations. When the spacecraft detects something interesting, it pivots within a minute or two to examine the spot with its other two telescopes—one catching ultraviolet and visible light and the other capturing x-rays.