Robots in Space: Dr. Gordon Roesler on the Future of Satellite Servicing

Susan Wise: Welcome to Stars Launch Pod: Space Technology and Research Sciences, brought to you by StarSciences.org, where we connect, collaborate, and accelerate. My name is Susan Wise, and I’m your host. Joining us today is Dr. Gordon Roesler, former DARPA program leader and now president of Robots in Space, his consulting firm.
Hi Gordon, and welcome to the show.

Gordon Roesler: Hi Susan, thanks for having me. I appreciate it.

Susan Wise: Let’s talk a little bit about your background, and then I’d love for you to tell us what you’re working on right now to advance the space industry.

Gordon Roesler: Sure. About 23 years ago, I joined DARPA for the first time and asked the question: what could we do to help the satellites that are up there — satellites that are never inspected, never repaired, never maintained, and never upgraded?
So, back in 2002, we started a research program to prove that one satellite could connect to another using robotics. By 2005, we had shown in the lab that it worked.

Then we started building a robotic arm that could actually fly in space — which turned out to be harder than it sounds. In 2014, they asked me to come back and build a real one: a full satellite equipped with robotic arms, cameras, tools, computers, and radios that could go out and add value to other satellites — fix them, inspect them, and add new capabilities.

That satellite is scheduled to launch in 2026. It’s been a long program — a lot of challenging technology — but very exciting.

Susan Wise: That’s amazing, because if you have a satellite up there and something happens, it just becomes space junk. And there’s more and more of that. So, it’s great that you can go up there, fix it, and keep using it.

Gordon Roesler: Exactly. Imagine someone gave you a job managing a massive building or ship worth half a billion dollars, and told you to keep it running for ten years — but you could never inspect or maintain it. You’d say, “No thanks.” But that’s exactly what we do in space today.

Susan Wise: That’s pretty amazing — and very cool. Tell me more about the robots and how they actually work. I’m trying to visualize it. Do you have someone on Earth manning the controls?

Gordon Roesler: Nope.

Susan Wise: No?

Gordon Roesler: Nope — it does it itself. Humans help it get close to its customer satellite, but the final approach and docking are done autonomously by the satellite. There’s a lot of software involved to make sure the grab is safe, to detect if something’s going wrong, and to back away if needed.

So no — it’s not someone with a joystick sitting on the ground. That would be dangerous. If the target satellite suddenly moved or fired a thruster, there wouldn’t be time for a human to react. The robot has to make those decisions by itself.

Susan Wise: So, say you finish a project up there — does the robot come back to Earth, or does it just stay in space until the next job?

Gordon Roesler: It stays in space. The project we built at DARPA was called Robotic Servicing of Geosynchronous Satellites. That means it operates in geosynchronous orbit — about 22,000 miles up — so it’s not coming back. That would take too much fuel, and there’s no safe way to re-enter the atmosphere.

But since all those satellites are in the same orbital ring, it’s relatively easy to move from one to another. We built the robot to last 10 to 15 years so it can serve multiple customers and perform many missions.

Susan Wise: That’s incredible. Have you found ways to use this technology here on Earth — maybe to do my household chores?

Gordon Roesler: (Laughs) Let’s look at it the other way around. What would it take to take a household robot or an industrial robot and move it into space? That’s extremely difficult.

Space is a vacuum — there’s nothing to cool the electronics. When the sun hits, it gets extremely hot; when it’s in shadow, it gets extremely cold. In a vacuum, electrical arcs can jump and damage electronics. Plus, there’s radiation that a home vacuum robot would never experience, and that can fry the circuits.

So, designing a robot for space is much, much harder than designing one for Earth.

Susan Wise: Talk about one of your biggest “aha” moments — when you realized, “Yes, this can really work.”

Gordon Roesler: That was around 2002. I had helped DARPA plan an experiment called Orbital Express. It sounds like FedEx, right? It was a demonstration mission where two satellites docked autonomously — no ground commands — and used robotic arms to replace a battery and a processor module.

The catch was that the customer satellite had to be specially designed to be serviced — with the right ports and modules. My “aha” moment was asking: What can we do for satellites that weren’t designed to be serviced?

The first idea was simple — just dock with them and move them. Why is that valuable? Because when a satellite fails or runs out of fuel, we can move it out of its working orbit into a “graveyard” orbit, reducing debris. We can also use up every last drop of its fuel to extend its life.

Today we’re even working on refueling satellites directly — but that original insight came 23 years ago.

Susan Wise: That’s exciting — wow! Over the years, I’m sure you’ve had plenty of challenges. What stands out as one of the biggest, and how did you overcome it?

Gordon Roesler: The biggest challenge was convincing people it was possible. Early on, in the 2000s, many said, “That technology’s too hard,” or, “There’s no business case for it.”

Fast-forward to 2022 — the White House Office of Science and Technology Policy issued a national strategy for on-orbit servicing, assembly, and manufacturing. They outlined what NASA, the Department of Defense, and others would do.

So, 20 years after that “aha” moment, we saw a national commitment to the very thing we’d been pushing for. That was when I thought, “Okay — my work here is done.”

Susan Wise: And with more and more satellites going up all the time, there’s definitely a growing need for what you’re doing.

Gordon Roesler: Absolutely. There’s a need to remove large, dead satellites before they become debris — and also huge economic value in upgrading existing ones.

There’s a small company I consult for called Katalyst Space Technologies — that’s Katalyst with a “K.” They recently received a $30 million award from NASA to build a robot that will attach to the Neil Gehrels Swift Observatory, which is gradually being pulled down by the atmosphere. Their mission is to boost it back up so it can keep operating.

It’s a high-risk, challenging mission, but imagine what we’ll learn — even if it doesn’t go perfectly. In this case, we’re pushing the satellite up to keep it working, but in other cases, we could push satellites down to safely deorbit them. I’m really excited for Katalyst and their partners.

Susan Wise: When is that launch expected?

Gordon Roesler: I think they’re aiming for next year.

Susan Wise: That’s exciting! I’ll be watching that one.

Gordon Roesler: You bet.

Susan Wise: Do you have a piece of advice you’d like to share with our listeners?

Gordon Roesler: Yes — never quit. If you can see the value in something, keep talking about it. Keep telling people, “This is useful, this adds value, this will help you reach your goals.” Be persistent — keep that record player spinning. (I’m old enough to remember record players — though I guess vinyl is making a comeback!)

Susan Wise: (Laughs) And before we wrap up — I’m so grateful you shared your story with us — do you have a passion project, either past or present, that you’d like to talk about?

Gordon Roesler: Absolutely. Remember that Orbital Express experiment in 2007? It was meant to demonstrate how to do logistics in space. On Earth, our economy depends on logistics — ships, trucks, trains, and delivery services like UPS and FedEx.

In space, we don’t have that. Our “logistics system” is basically a rocket that goes up once and drops off a single satellite. My passion is to build a space logistics network — connecting low Earth orbit all the way to the Moon and every orbit in between: GPS orbits, geosynchronous orbit, the lunar Gateway at the Lagrange point, even routes to bring resources back from the Moon.

It should be a two-way network, and I believe the defense community, NASA, and the commercial space sector should all work together to build it — for everyone’s benefit.

Susan Wise: We’ll need someone directing traffic up there, too!

Gordon Roesler: (Laughs) Yes — that’s another big challenge: making sure things don’t collide.

Susan Wise: It’s getting more and more crowded, and that’s not going to change anytime soon.

Gordon Roesler: Right. The Department of Commerce is actually taking over the space traffic management mission from the Space Force, so that’s in progress.

Susan Wise: This is all such exciting work. Gordon, thank you so much for sharing your journey and insights with us. We’d love to check back in a few months and hear what’s new.

Gordon Roesler: You bet. Thanks for having me — this was a lot of fun.

Susan Wise: We really enjoyed having you. Thank you!
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