In the realm of ‘Things I Did At Work Today’, helping to develop a NASA spacecraft that is going to be used like a missile to alter the path of an oncoming asteroid has to be a highlight. NASA has been working on a spacecraft called the OSIRIS-REx which is a probe roughly the size of sports utility vehicle. The OSIRIS-REx was launched into the Earth’s atmosphere just last year with a single, explicit goal: grab some material off of an asteroid and bring it back to Earth. Now, why would NASA need an expensive probe for this mission when asteroids pelt the Earth all of the time? We’re glad that you asked.
The goal of the OSIRIS-REx was to bring back the largest sample ever of rock from asteroids. The idea here is that NASA will end up with the largest sample they’ve ever gotten their hands on, thus giving them something to look at it much more extensive detail than ever before. The goal was simple, at least on paper, but they still had to wait for the perfect target: an asteroid that they could maneuver to be within the path of OSIRIS-REx. Finally, it looks like NASA has their target: an asteroid named Bennu.
Bennu was chosen because its orbit is extremely similar to that of Earth and thus makes it an easier target for the OSIRIS-REx to lock on to. Bennu isn’t exactly locked in to the Earth’s orbit as it is roughly six degrees off-tilt. Still, that doesn’t mean that NASA is letting their target get away. The OSIRIS-REx has been orbited the Earth at a slightly faster pace and now NASA will be maneuvering their probe toward Bennu with a target collision date of this coming Friday.
Now, in order for the OSIRIS-REx to match up and collide with Benu they need to make sure that OSIRIS-REx can catch up to the projectile. In order to do this NASA had to choose one of two options: burn up precious onboard fuel by thrusting their engines or instead use Earth’s gravity to slingshot toward the Bennu. They chose option two. After the collision the OSIRIS-REx will return to Earth’s orbit with Bennu and rotate for an additional two years while it angles back toward Earth. This sounds like something straight out of a movie but really it is just the ever impressive work of the greatest scientists and technology of our existence.