How Will #MissionToPsyche Use Gravity to Study An Asteroid?

The way to understand how our solar system has evolved, we really have to gather more information about these planetary bodies.

Psyche is an incredibly exciting mission to study - an asteroid that is truly unique.

The reason that Psyche is unique is that it is metal rich.

We are seeing what we believe could be the core of a protoplanet.

As the science community has become interested in Psyche, there are more observations been made, and the measurement of Psyche’s density has come down over the years to something that is more, sort of, more dense than a rocky body, but less dense than it was before.

So we don’t really know what this interior structure would look like.

And gravity is the way that we are going to study the inside of this.

So gravity science is different than most of the other science investigations, because the other science investigations build an instrument and they put that instrument on the spacecraft.

The interesting thing about gravity is that we don't have a dedicated instrument to measure gravity.

What we do is use the radio signal that we use to track and communicate with the spacecraft.

We send our radio signals from Earth.

They go up to the spacecraft, and the spacecraft takes those signals and turns them around and sends them back to us to measure exactly where the spacecraft is in relation to the asteroid as we're orbiting the asteroid.

Psyche has a high-gain antenna, which gives us our highest data rate to go back to Earth.

And it also has several low-gain antennas on the spacecraft.

So using both the high-gain antenna and the low-gain antenna, we will be able to accurately track the motion of Psyche spacecraft.

So by accurately tracking the motion of the spacecraft, it can say something about the underlying gravity field.

And once you know about the gravitational variation, then you can say something about the interior structure.

We will do gravity science data collection in all four of the orbits that the mission has four orbits, A, B, C and D.

We can’t just go down to the best orbit to do gravity science because we don’t have enough knowledge yet of the gravity to find a stable orbit there.

I designed sort of a series of steps to get us from that highest altitude orbit where we wanted to be in an orbit that was completely outside of any significant perturbations.

Then we go to orbit B and that’s where we do a lot of imaging.

But in addition to doing a lot of imaging, we also collect better gravity science data.

But the most critical orbit is orbit C.

That’s where we are going to be gathering most of the critical science that we can get from gravity science.

It is a moment of pure joy when the data starts coming back.

There has never been an instance where we have gone to another planetary body and made new observations where we didn’t have fantastic discoveries.

Psyche is really going to provide a unique piece of the picture because of the fact that it is such a metal rich body.

We just can’t wait to study it.