PASADENA, Calif. — NASA's Orion capsule, which the agency is developing to help get astronauts to Mars and other destinations in deep space, aced its first flight test on Dec. 5, 2014.
During that unmanned mission, known as Exploration Flight Test-1 (EFT-1), Orion orbited Earth twice and then came zooming back to our planet to test out the capsule's heat shield and other key technologies.
Space.com's Rod Pyle recently discussed EFT-1 here at NASA's Jet Propulsion Laboratory (JPL) with Mark Geyer, the space agency's Orion program manager, and Mike Hawes, vice president and Orion program manager for aerospace firm Lockheed Martin, which built the spacecraft for NASA. [See amazing photos from Orion's first test flight]
Space.com: How does it feel to be headed back into deep space after all these years?
Hawes: I kind of choked up at the press conference after the flight. I started [my career] when the Apollo guys were still at JSC [Johnson Space Center] and learned from them, and now I finally felt like we had done this for our generation and for the other generations behind us — something we hadn't done for 40 years … It's a human spacecraft that's going much farther than we have gone in a long time.
Geyer: We now have the capability to go to those places again, but in different ways. You think about Apollo — we only visited the equator of the moon. A very small part, and just the facing side. Orion enables missions to the rest of the moon, to asteroids and eventually to Mars. It's the piece that keeps the crew safe, gets them up and back.
Hawes: Some of the lunar science guys have done a plot where they put all of the Apollo traverses, even with the rovers. It's on the scale of the National Mall in D.C. — and we didn't even explore the entire mall, so we have not "been there and done that."
Geyer: Orion opens the moon up, opens asteroids up. It opens [Mars' moons] Phobos [and] Deimos and eventually Mars. And the human element is key. [JPL's] robots are incredible machines. But remember: When we sent a scientist to the moon, at the end, the geologist could adapt very quickly to what he found. This human element will multiply our ability to learn from wherever we go. [NASA's 17 Apollo Moon Missions in Pictures]
Space.com: You learned a lot during and after EFT-1. Can you discuss some of the upcoming changes in Orion's heat-shield design?
Geyer: Yes. Like Apollo, we used Avcoat. The structure itself is like a composite sheet, and on that is a honeycomb. You fill that honeycomb with Avcoat, with a device like a caulking gun. The material has to be a certain consistency and the right temperature, and you cure it in an oven in segments. It must also be bubble-free, and that's part of the curing.
That's how we do it today. But we're finding that there was something in the process that reduced the strength of the material. It worked fine for this flight, but it can crack. If you go to museums and look at Apollo capsules, you can see the fixes they did in the heat shields — they used plugs to fill cracks, and they routed out the seams in the heat shield and filled them in with Avcoat. When you go out past the moon, the temperature swings are much greater, and [the heat shield] is susceptible to cracking.
So, one of the solutions the team came up with is to make it in blocks. This gives you some stress relief on the seams, and the blocks are stronger than this honeycomb. So we're thinking you make blocks of Avcoat, and there is a seam that you put between these blocks. That will get the strength up. [See photos of Orion's heat shield]
Space.com: What were the issues with the splashdown air bags?
Hawes: They are part of the righting mechanism. From past history, they found that the capsule landed in "stable two," or tunnel down, about 50 percent of the time. This was not in the human missions, but in test drops. So it's an important system. We hit perfectly on this flight and didn't need them. We did have some concerns about the air bags before the flight. One of the [inflating] tanks was leaking, and we had done some late repair work, so we had an alternative method as well, where the divers put an inflatable set of bags around the capsule and upright it as well. But we need to understand what went wrong as well. You don't want the crew hanging upside down.
Space.com: There were a few 'stable two' landings in Apollo, as I recall. Why is that a problem?
Geyer: If they [the crew] have been gone for a long time — in space for a long time — hanging upside down can be dangerous. It's got to work.
Hawes: We've looked at the tanks, the connecting lines and the pyrotechnics. We know that all the valves fired and opened. We know that the tanks all evacuated. We have found in the bags that failed some small cracks in the fabric; it looks like a failure of the fabric itself. Whether that is because of the way they are packaged and come out, we're not sure, so we are looking at that now.
Space.com: Were there any other major problems?
Geyer: Really, the bags were the only thing that went wrong. What went right were the propulsion system, the guidance and navigation system, the flight computers, all the video processing, the heat shield and all the separation events. The parachutes worked well. The things we are working on improving are mainly things we learned during the build.
Going through the first flight element build — particularly in this new factory we have in place at KSC [Kennedy Space Center] in Florida — we learned a lot about that process. Even with things like welding [and] the propulsion systems inside the facility, we've learned things and are making changes. We're continuing to take mass out of the spacecraft. All the primary structures will be significantly lighter than what we just flew.
Hawes: So, for instance, that big barrel [the capsule's tunnel] is now 25 percent lighter than what we just flew. So you learn a lot by building it. Then, by getting the loads data we did from EFT-1, you can take mass out of the structure, which is huge. Every pound in the crew module that you push to the moon you have to multiply by seven — that's what it takes to get it there and get it home. That makes the service module bigger; it makes the rocket bigger. So it's a big multiplier. It's enormous.
Geyer: You get more mission capture that way. You can do more things; you can carry more science.