In the wake of NASA’s supremely successful inaugural test flight of the Orion deep space capsule on the EFT-1 mission in Dec. 2014, NASA is beefing up the critical thermal protection system (TPS) that will protect astronauts from the searing heats experienced during reentry as the human rated vehicle plunges through the Earth’s atmosphere after returning from ambitious expeditions to the Moon and beyond.
Based in part on lessons learned from EFT-1, engineers are refining Orion’s heat shield to enhance the design, ease manufacturing procedures and significantly strengthen is heat resistant capabilities for the far more challenging space environments and missions that lie ahead later this decade and planned further out in the future as part of NASA’s agency-wide ‘Journey to Mars’ initiative to send humans to the Red Planet in the 2030s.
On all future flights starting with Exploration Mission 1 (EM-1), the Orion crew module must withstand the higher temperatures and speeds experienced during return from more distant destinations such as the Moon, near-Earth Asteroids and Mars.
“Orion’s thermal protection system is essential to successful future missions,” said John Kowal, NASA’s thermal protection system lead for Orion, in a statement.
“As we move toward building the system for EM-1, we’ve been able to take advantage of what we learned from building and flying Orion to refine our processes going forward.”
Orion’s thermal protection system is comprised of the 16.5-foot-wide (5-meter-wide) main heat shield covering the rounded base of the capsule as well as the grid of back shell tiles bonded around the vehicle from top to bottom.
Starting with EM-1, engineers will bond Orion’s thermal protection system back shell tiles with a silver, metallic-based thermal control coating.
The back shell tiles were black colored during the two orbit, 4.5 hour long EFT-1 mission.
Orion EM-1 will launch uncrewed on the maiden test flight of the NASA’s mammoth Space Launch System (SLS). Liftoff is targeted for no later than November 2018 and SLS will be configured in its initial 70-metric-ton (77-ton) version with a liftoff thrust of 8.4 million pounds.
SLS-1 will boost the unmanned Orion on an approximately three week long test flight beyond the Moon and back.
The SLS-1/EM-1 test flight with the uncrewed will launch from Launch Complex 39-B at the Kennedy Space Center.
During EM-1, Orion will endure a more intense re-entry environment compared to the EFT-1 flight profile which flew to high Earth orbit of approximately 3600 miles altitude and experienced roughly 85% of the reentry speed.
During the EFT-1 reentry, Orion encountered speeds of 30,000 feet per second (20,000 mph) and temperatures of approximately 4,000 degrees Fahrenheit (2200 Celsius).
By contrast, Orion EM-1 “will experience a faster return from lunar velocity of about 36,000 feet per second. While the speed difference may seem subtle, the heating the vehicle sees increases exponentially as the speed increases,” say officials.
The new silver-metallic coating is “similar to what is used on the main heat shield, will reduce heat loss during phases when Orion is pointed to space and therefore experiencing cold temperatures, as well as limit the high temperatures the crew module will be subjected to when the spacecraft faces the sun.”
The coating is designed to keep Orion’s back shell in a temperature range from approximately -150 to 550 degrees Fahrenheit prior to entry and afford protection against electrical surface charges in space and during re-entry.
“You’re trying to hit this sweet spot because when you’re looking at the sun, you don’t want to get too hot, and then when you’re not looking at the sun and instead in darkness, you don’t want to lose all the heat that the spacecraft generates,” Kowal elaborated.
NASA continues to make good progress on all designing, building and testing elements of SLS-1 and Orion EM-1 as reported here including the SLS RS-25 core stage engines, assembling the SLS core stage and Orion capsule, testing the solid rocket boosters, and modifying Pad 39-B and the mobile launcher.
Orion’s inaugural mission dubbed Exploration Flight Test-1 (EFT) was successfully launched on a flawless flight on Dec. 5, 2014 atop a United Launch Alliance Delta IV Heavy rocket Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
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Learn more about Orion, SLS, SpaceX, Orbital ATK Cygnus, ISS, ULA Atlas rocket, Boeing, Space Taxis, Mars rovers, Antares, NASA missions and more at Ken’s upcoming outreach events:
Dec 1 to 3: “Orbital ATK Atlas/Cygnus launch to the ISS, ULA, SpaceX, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings
Dec 8: “America’s Human Path Back to Space and Mars with Orion, Starliner and Dragon.” Amateur Astronomers Assoc of Princeton, AAAP, Princeton University, Ivy Lane, Astrophysics Dept, Princeton, NJ; 7:30 PM.
Interesting. However, wasn’t all this researched and known during the Apollo era? Didn’t the engineers who designed the Apollo Command Module face exactly the same thermal challenges? Why spend so much money, so much time and so many physical resources on two unmanned test missions when all this was done before in the late 1960s and 1970s?
Also, has NASA released any information on the radiation measurements it made in the Van Allen belts during the first Orion test mission? If so, are the results available online?
Planes have flown across the Atlantic since Lindbergh, but a new commercial aircraft design will be test flown over that route, or similar distances, before going into commercial service.
Despite a superficial similarity, Orion is not the same spacecraft as Apollo. And while the cisclunar environment has not changed, you want to know how *this* design will perform before becoming operational.
Delphinus100 I appreciate the point you’ve made. Design and testing is necessary. However, when it comes to NASA’s manned missions, what the whole world has been witnessing for decades now is an agency that used to do amazing things pussyfooting indecisively in near-Earth orbit. First there was Constellation. Was was that supposed to achieve? Apollo reprised. Then that was cancelled by Obama — a gigantic waste of taxpayers’ money, time and effort. Now we have Orion and the SLS. So what? What are they actually planning to do with this repurposed hardware? Just mount a series of unmanned test missions? Where’s the vision and daring that used to be synonymous with NASA and thrilled the entire world? When are they finally going to do something spectacular beyond near-Earth orbit, where for decades they’ve been farting about ad nauseum like post-menopausal spinsters at a tupperware party?
I love everything that NASA does in terms of unmanned exploration of the solar system. But when it comes to manned exploration, I feel intense frustration and nostalgia for the good old von Braun days. I adore NASA, but when it comes to manned exploration, it’s clearly lost the plot. There’s no elan, no grand vision, no leadership.
Gosh, you (Robst247) and I think much alike! I have the same questions as well. I suspect this new coating was not available or used back with the original capsules, so they are testing them now. I’m very curious about the radiation issue as well.
Sometimes I suspect that NASA is used by politicians as a jobs-creation organization rather than a goal-oriented organization. This a could explain why they are willing to take the time and money to “re-invent the wheel.”
I really thought that the SpaceX Dragon would be the spacecraft of choice in the future, and I am surprised that Orion is even getting a second flight. I know the first Orion was too far along to cancel before its first flight, but this second flight comes as a surprise.
Hopefully the flight goes well, and returns info that can be used when Dragon is used as the crew vehicle.
For government high costs is the purpose while the results don’t matter. You see, a government doesn’t use its own money, it has none, government only takes other people’s money and spend it. More expensive is better because (the individuals who are) the government are middlemen who keep their share. Cheap projects are politically impossible.
Dragon is just for LEO, if SpaceX have plans for a multi-week crewed spacecraft, they haven’t told the world.
RUF — you’re comparing apples with pears. Dragon is just to get astronauts into near-Earth orbit, to that gigantic white elephant called the ISS [yawn]. Orion is supposed to take crews into ‘deep’ space. When exactly that is going to happen is anybody’s guess. As the Kinks once sang; “So tired, tired of waiting, tired of waiting for you.”