Video Transcript: Date with a Comet
Stardust-NExT is a mission to reuse the Stardust spacecraft to further the exploration of comet Tempel 1.
Tempel 1 was the target of Deep Impact. Deep Impact discovered that this is a most interesting comet. We want to see more of the surface and we also want to see what changes have occurred since Deep Impact was there five years ago.
The primary purpose is to observe how the comet has changed; how the nucleus has changed, to compare to what it was like back in 2005 with the previous pass near the sun. We call them perihelion passes.
We also would want to extend the mapping and the observation of the nucleus to see new areas of the nucleus that we haven't seen before. So that it would help complete the mapping of the nucleus of this comet.
And then, if possible,we would like to be able to image the crater that was left behind.
The key challenges for an extended mission like this are one, dealing with the age of the spacecraft. The spacecraft is almost 12 years old. Very little fuel is left; we've used most of it already.
And then the third challenge, for a comet mission, is the navigation. One of the navigation challenges with getting close to a comet is predicting its trajectory. We know that, as they get close to the sun, comets generate a lot of activity. The jets, the outbursts, all of those change the trajectory somewhat of the comet. We have a navigation camera and we photograph where the comet is on approach, and then we take that information, turn it into trajectory corrections, to put us in the right place at the right time.
One of the challenges of designing a spacecraft to go to a comet is, how do you protect it? There's a coma that goes out in front of the comet. And that coma contains particles that could be large. We're flying by at a little over ten kilometers per second. That's somewhat on the order of 25,000 miles per hour. It doesn't take much of a particle to cause damage.
The Stardust spacecraft is a very unique spacecraft. It was built for a comet flyby. So, it was built to fly close to a comet. And because of that, it has some very robust shields on the front of the spacecraft that will be able to stop a centimeter-sized particle traveling six kilometers per second and not damage the spacecraft.
These are exciting things. They're all different. Every time we go near one we find something new, and the opportunity for discovery is absolutely momentous.