Interview with Attitude Control Engineer, Kevin Gilliland
What is your role on the mission?
I'm responsible for the spacecraft's attitude, or its orientation in space. We are most often controlling to keep the antenna on Earth. Occasionally, we turn toward an imaging target or toward the Sun for more power. I'm also responsible for implementing the control for any required corrections to our trajectory.
The position of Attitude Control Engineer requires working very closely with the Navigation team. Every thruster pulse required for control makes a tiny change to the spacecraft's orbit. The Navigation Team's orbit determination task, then, requires a prediction of all of these thruster pulses.
What advice would you give to someone interested in doing what you do?
Be flexible. Over the course of a long mission, the engineering tasks may evolve and, by being flexible, one can use the opportunity to learn a new spacecraft subsystem. Small teams and long missions offer a variety of challenges.
Be curious. Our operations are often very smooth and require little interaction or engineering. Occasional challenges arise that may require immediate action or may present a new problem to solve.
Who inspired you growing up?
As a boy, I was impressed by my grandfather, because he seemed to know everything and to be able to fix anything. He was a craftsman and an engineer, with a broad range of interests. Later, I learned how hard he was willing to work, that his 'knowing everything' was a result of study and practice. I see the same traits carried on by my father. Both of them inspire me to work hard, and to work at learning.
How far is the spacecraft going in space?
Stardust has been deep into space—over 250 million miles from the Sun. For comparison, Earth is about 93 million miles from the Sun. Stardust is solar powered, and has been farther from the Sun than any other solar powered spacecraft. Stardust at times flies very close to Earth: In January 2009, the spacecraft was just over 6,000 miles above the US.
Is this the only mission you’ve worked on?
I've worked on Magellan, Gallileo, Genesis, and many Mars spacecraft.
If something breaks on the spacecraft how do you fix it? Any anything ever broke?
Some of the components have on-board backup units, so, we are always ready to switch to the other side in case of a failure. We prepare, test, and rehearse for almost any failure; few components have actually failed. Most recently, our star camera was unable to operate well while pointed near the Pleiades. We switched to another mode that used gyros for rate measurement until our view was clear of the Pleiades. My Gallileo job was to help re-write spacecraft software to compress science data. The change was required when the main antenna failed to deploy.