On Dec. 4, Orion will travel 3,600 miles beyond Earth—15 times further than the International Space Station. It will return to Earth at a speed of approximately 20,000 mph for a splashdown in the Pacific Ocean. The test will provide engineers with data about systems critical to crew safety, such as heat shield performance, separation events, avionics and software performance, attitude control and guidance, parachute deployment, and recovery operations to validate designs of the spacecraft before it begins carrying humans.
"EFT-1 will exercise all of Orion’s re-entry systems, including testing the heat shield. We will evaluate the fluctuations between the temperatures and pressure across the shield during the re-entry, evaluate the performance of the thermal protection coating and we will also be looking at accelerations and strain during the water impact," Rakes revealed.
She also pointed out that Orion's heat shield (16.5 feet in diameter) is the largest ever built and is capable of protecting a crew from external temperatures of nearly 5,000°F. It also has a new resin system that can withstand higher temperatures and landing impact. "Orion will have to withstand landing loads of about 300,000 to 400,000 pounds - That’s about equal to the mass of a full-size yellow school bus crashing into the ocean at 20 mph," Rakes noted. This resin was developed by the Lockheed Martin Orion thermal protection system team in partnership with TenCate Advanced Composites, a leading supplier of aerospace thermoset and thermoplastic prepregs.
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| Orion's EFT-1 flight path. Credit: NASA |
During the test flight, the spacecraft will return to Earth at a speed of approximately 20,000 mph, but when returning from deep space, the velocity is much higher. "When a spacecraft re-enters Earth’s atmosphere from deep space, it’s plummeting at 25,000 mph, or Mach 33. During a re-entry from Mars, Orion would be travelling at about 27,000 mph," Rakes said.
Last week, Orion has completed a 22-mile, 6-hour journey from the Launch Abort System Facility at Kennedy Space Center, to launch pad 37 at Cape Canaveral Air Force Station in Florida. It was lifted about 200 feet up and mated to the United Launch Alliance (ULA) Delta IV Heavy rocket that is slated to take the spacecraft for its maiden flight high above.
What's next for Orion before December's lift off? "Leading up to EFT-1 in the next couple of weeks, the rocket and Orion will be integrated and powered up, and engineers will test and verify interfaces between the two in preparation for the test flight," Rakes revealed.
Let's keep our fingers tightly crossed, because the upcoming test will be crucial for U.S. space exploration. Human spaceflight far beyond Earth commences now, when the Delta rocket is about to make a one small step lifting the Lockheed Martin's craft, making another "giant leap for mankind" possible in the near future.