Space

Largest heat shield ever constructed installed on NASA's Orion spacecraft

Largest heat shield ever const...
The heat shield, attached to the underside of the Orion spacecraft (Photo: NASA)
The heat shield, attached to the underside of the Orion spacecraft (Photo: NASA)
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Artist's impression of Orion in orbit during its maiden test flight (Image: NASA)
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Artist's impression of Orion in orbit during its maiden test flight (Image: NASA)
The heat shield, attached to the underside of the Orion spacecraft (Photo: NASA)
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The heat shield, attached to the underside of the Orion spacecraft (Photo: NASA)

NASA scientists have installed the largest heat shield ever created for the intention of atmospheric re-entry, onto the crew module of its next generation spacecraft, Orion. The shield, made of the same base material as that which protected Apollo-era astronauts from re-entry conditions over four decades ago, is set to be tested to the extreme later this year as Orion's maiden flight blasts off.

The Orion spacecraft is set to be the first deep-space vehicle capable of extending manned space flight to destinations such as Mars and beyond. For this to be possible, Orion must boast a heat shield capable of withstanding the intense pressures of re-entry into Earth's atmosphere. "It is extremely exciting to see the heat shield in place, ready to do its job," states Mark Geyer, program manager for the Orion spacecraft. "The heat shield is such a critical piece, not just for this mission, but for our plans to send humans into deep space."

To conquer this mammoth challenge, NASA scientists have installed a five-meter (16-ft) wide heat shield onto the crew module of the Orion spacecraft. The shield was built by Lockheed Martin and is constructed from Avcoat ablator, which is comprised of silica fibers with an epoxy-novalic resin filled in a fiberglass-phenolic honeycomb.

The heat shield is protected from the frigid temperatures of outer space by a coating of reflective silver tape, and upon contact with Earth's atmosphere, is designed to slowly erode, channeling heat away from the crew module in the process. The protective measure will need to withstand temperatures exceeding 4,000 ºF (2,204 ºC) during Orion's maiden test flight, roughly five times the heat experienced by missions returning from the International Space Station (ISS).

Artist's impression of Orion in orbit during its maiden test flight (Image: NASA)
Artist's impression of Orion in orbit during its maiden test flight (Image: NASA)

NASA selected Avcoat ablator as the main component for Orion's heat shield back in April 2009. Previously used as the material of choice for the Apollo missions, Avcoat was one of eight options considered to protect NASA's next-generation spacecraft. Avcoat was selected in a close contest with another ablator, PICA. Both materials are tested and viable options for heat dissipation, with PICA currently in service as the re-entry shield for the Soyuz spacecraft. A modified composition of the material has also been chosen to protect SpaceX's newly announced Dragon V2, set to begin servicing the ISS in 2017.

"The biggest challenge with Avcoat has been reviving the technology to manufacture the material such that its performance is similar to what was demonstrated during the Apollo missions," explains John Kowal, Orion's thermal protection system manager. "Once that had been accomplished, the system evaluations clearly indicated that Avcoat was the preferred system."

Orion's maiden flight is designed to test the shield under the kind of pressures that the capsule would be expected to withstand upon re-entry returning from beyond low-Earth orbit (aka Mars). To simulate this, the spacecraft will be launched 3,600 miles (5,794 km) above the Earth's surface, resulting in an atmospheric re-entry speed of roughly 20,000 mph (32,187 km/h).

Over the coming months, the service and crew modules will be joined and tested, after which Orion will be moved to Cape Canaveral for pad integration, and finally launch, some time in December this year.

Source: NASA

15 comments
Skipjack
Orion is so uninspired, even its heatshield. I wished, they just let the project die already.
Rt1583
@ skipjack - Unispired though it may be, it is still better than the alternative which is nothing. We saw what inspired got NASA and the taxpayer for the last 30 or so years. While the Shuttle system was useful as the transport of various systems into space, in the end it served more as an extreme environment repair/maintenance vehicle and never fulfilled one of its most important promises of being a lower cost system for manned space travel. Unfortunately, government bureaucracy and inspired can not co-exist. NASA had it's turn and ultimately failed. Until the few companies in the civilian sector that are working toward space flight can get their programs/projects/systems fully approved and functioning, the Orion is our best bet for continued space travel. I will even go sar far as to say that, even when the civilian systems come on line, Orion or its descendants will continue to have a place int the U.S. space program for quite some time.
Slaven
just a noob question, why is immediate re-entry needed after deep space mission? Wouldn't it be more simple to stop over on ISS and come back on next crew change?
Rt1583
@ Slaven - From my very basic understanding, as a layman, there is nothing that is simple to accomplish in space. The way I understand it, to dock with the ISS requires everything to be planned as part of the overall mission. You can't just arbitrarily go to one point in space and then expect to meet up with something else, at another point in space, on a whim. Everything that was purposely put into space and is still functioning properly has its own distinct orbit at its own distinct altitude to keep all of them from interacting with each other in a disastorous fashion. As a recent example of jumping from point A to point B (from the film Gravity, and which , with a high degree of certainty, wouldn't/couldn't happen in real life) - ISS orbits at about 51 degrees, at an altitude of about 420 kilometers, at about 17,300 miles per hour. Hubble orbits at about 29 degrees at, an altitude of about 560 kilometers, at about 16,800 miles per hour. In this example, to make it from Hubble to ISS you would first have to wait until their orbits intersected (or within a relatively small window of that intersection). You would then need to have enough fuel to make the maneuver and make the necessary calculations to leave point A at such a time as to get you to point B at just the right time to make contact.
VirtualGathis
@Rt1583 - You are incorrect in your statement. It was not vision or inspiration that gave us 30 years of the shuttle. It was unmitigated, blind stupidity by congress. They couldn't even follow their own plan. The shuttles we grew to know and love were prototypes. They were never intended to fly more than 15 missions between them. The originals were meant to be used to understand reusable vehicles better. Once we gathered that data they were to be reengineered for easy and quick turn around. They were even going to figure out how to carry the external tank all the way to orbit so it could be used as habitable volume in space. Then some fool sold congress on the "space plane" and convinced them to gut the shuttle budget to chase it. This meant that the redesign never happened so each and every time these prototypes flew they needed to be stripped to the chassis and rebuilt rather than merely serviced. The money was then thrown at a project that had too many new systems in it to ever succeed. Pretty much the entire vehicle was a complete long shot. The lifting body had never been tried before, the aero-spike engines hadn't ever been past pencil doodles, the fuel tanks relied on material properties the sience of the 80's had never achieved, the list goes on. So as it was destined to do it went over budget, over time, and congress killed it when the material they selected for the tanks in the draft design phase failed during vibration testing. If they had stuck to the original iterative design approach of add one new system, test, crunch the data, improve the design, add the next new system and repeat we'd be watching news of the latest space hotels being transferred to a lunar or even mars orbit by now. Instead we are rebooting the whole process and returning to 1960's tech then iterating up from the beginning.
Mel Tisdale
The thing I always remember from the Apollo missions was that re-entry was at escape velocity of 25,000 mph, which is knocking on a bit to use a technical term. They flew the capsule in by initially digging it into the atmosphere so that it could lose a lot of the speed. This, of course, raised the temperature of the heat-shield. So to give it a chance to cool down, they tilted the capsule so that it 'bounced' upwards (relative to the earth's surface below), something akin to a bouncing pebble on water. When gravity brought it back into the earth's atmosphere, it was traveling much slower, allowing a normal decent to the surface from then on. It is interesting to note that some politicians were calling for essentially the same procedure to be used to achieve lunar orbit and thus save the cost of the planned orbital burn. Unfortunately, they all refused the offer to try it out first, even though the name 'Calamity Crater' had already been reserved for the (desired) outcome.
solutions4circuits
That's it? With all the material science research going on, the best we have is what grampa came up with 50 years ago, and even then, we have to figure out how it was done? Why not just use the Apollo capsule, as is, and just retrofit the avionics? Works for another innovative US machine...the B-52 bomber
lwesson
VENTURE STAR was to be THE replacement for The Shuttle. From what I have been told by my NASA contacts, and what I have read, it was screwed up from within per engineering on purpose! And of course there are the Congressthings and $$$. A friend at NASA said that funding is hard since Congressthings are constantly trying to get voters via promises and NASA just does not get that many voters. A good friend who worked on the Shuttle --managing orbit rendezvous-- had nothing good to say per what she saw per NASA. She quit eventually. The Right Stuff, per management, imagination, follow through was/is not there, and the Federal Budget is but pocket chump change from Uncle Sugar Daddy, thus we get the Back to the Future retro Apollo redo but with a nicer comfy Sci Fi inside. The Von Braun days are long gone and even then he saw the righting on the wall. His plan was to get the US to Mars by about 1985!!! "Dave, I sense a complete failure coming..." "Yes HAL, I do too."
the.other.will
The shuttle had wings. It was not a lifting body. Lifting bodies were tested as far back as '63 in the form of the M2-F1. http://en.wikipedia.org/wiki/NASA_M2-F1 The shuttle was an example of deciding on a solution before determining whether or not it was the best route to the objective - reducing the cost of transporting people & materiel into space. A private sector effort would likely have produced a similar result given the same parameters. Orion, in contrast, is designed to accomplish a mission within current parameters, which include cost & safety. If existing tech is the best solution at the best price, it should not be discarded because it isn't sexy. Interplanetary travel poses enough new challenges to consume all the money that will be available.
owlbeyou
NASA got the short-shrift because the American Gov's been spending too much tax-payer dollars on ahem, "defense". And it doesn't look like it's abating.