Draper Engineer Seamus Tuohy

In Their Own Words: Seamus Tuohy on Dream Chaser

Seamus Tuohy

Seamus Tuohy is the former Principle Director of Space Systems at Draper.

"Dream Chaser is a very capable vehicle. You can think of it as a mini shuttle. It doesn't have the cargo capacity that the space shuttle had, but it's a very capable vehicle. It takes off like you would normally think on a rocket, goes up vertically, goes into space, but the unique thing about it is that it's a lifting body and so it returns to Earth it actually lands like an airplane. If you could withstand going on a roller coaster ride, you could withstand the mission and Dream Chaser. NASA is very interested in it because it can carry precious cargo and science instruments and science experiments back to the laboratory quicker than anything else. That's important because as soon as you bring the experiment back to Earth it starts to feel the Earth's gravity again and you're basically ruining the experiment, ruining the result. So the fastest way you can get the experiments off of station and into a laboratory. The better for the science, the better for the results.

Dream Chaser can operate currently without humans on board. It can conduct entire missions without interaction of a pilot or co-pilot or crew on board. Obviously we're going to be watching what it does from the ground to just make sure it's doing what it's supposed to do. But it could actually do the entire mission from launch, orbit operations, to station rendezvous with station dock, separate from station when the mission’s over, reenter the Earth's atmosphere, and land—all by itself. It does use navigation systems and things like that, but there's nobody on board. The software has to be very robust to handle contingencies, things that could happen, things that are unexpected, and also things that are expected.

Humans do think very well at a very high level. However, humans are human. And so sometimes, you know, it's always nice to have a list of what you're supposed to do. Yes, I'm I'm much smarter than a piece of paper but I carry a piece of paper around with me to tell me what to remember, remind me what to buy. In that way, the automation that we put into these vehicles alleviates the humans of having to remember things.

It's also there to try to eliminate human error as much as possible. Humans will always be, for our vehicles, the highest level reasoning the things that make the mission successful. But having a lot of autonomy there allows a human to think about those things at a high level. Think about mission goals as opposed to keeping track of all the little details that are going on. The autonomy is there to be safe, to be reliable, to help the humans—whether it's a ground crew or humans on board—execute the mission in a very predictable way."