It’s ‘Not’ Getting Hot in Here. Orion Heat Shield Keeps Things Cool!
Have you ever imagined how hot it would be at the Earth’s core? What about stepping on molten lava?
The Lockheed Martin Orion spacecraft is going to endure those temperatures (and higher) when re-entering the Earth’s atmosphere this December.
The upcoming Orion Exploration Flight Test-1 (EFT-1) will go deeper into space than any spacecraft built for humans has gone in more than 40 years.
During its re-entry into Earth’s atmosphere, the Orion heat shield must protect the vehicle from external temperatures of up to 4,000-degrees Fahrenheit—that’s nearly half the heat of the surface of the sun!
But … what is a heat shield?
The heat shield is the forebody or ‘wind’ facing side of an aeroshell system.
Because of its size, the aeroshell experiences tremendous entry loads as a result of the dynamic pressures from the atmosphere and the high velocity of vehicle decent. At Lockheed Martin, we have built all eight of the aeroshells that have protected NASA’s Mars-bound spacecraft, but Orion is unique. First, at 16.5 feet in diameter, it is the largest composite heat shield ever made. Second, Orion is designed for long-duration, human exploration of deep space. That means that this component will play a critical role in protecting future astronauts on their return to Earth.
Not only is the Orion heat shield the largest ever made, it also has a new resin system that can withstand higher temperatures and landing impact.
After testing it in extreme environments and simulating re-entry, the Orion team verified that the thermal insulator on the outside of the composite material could be thinner, which makes the spacecraft lighter. This allows for more supplies and science to leave Earth on the mission – weight is critical in space. 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. TenCate’s composite materials are used in commercial aircraft, radomes, satellites, general aviation, oil and gas, medical and high-end industrial applications.
How will EFT-1 test the heat shield?
During the upcoming high orbital test flight, Orion will travel a total distance of 60,000 statute miles and as far out as 3,600 statute miles above the Earth’s surface. This will generate a re-entry velocity exceeding 20,000 mph.
This mission will exercise all Orion’s re-entry systems – including testing the heat shield, jettisoning the forward bay cover and deploying parachutes – and will gauge the effectiveness of the software driving numerous functions across multiple systems.
“The team will be looking for a variety of things. We will evaluate the fluctuations between the temperatures and pressure across the shield during the re-entry, evaluate the performance of the avcoat [thermal protection coating] and we will also be looking at accelerations and strain during the water impact. We want to make any necessary adjustments for future missions,” Brian Hinde, Orion heat shield certified product engineer.
This platform will provide engineers with critical data about the heat shield’s ability to protect the crew module from this high re-entry speed as well as the 4,000-degree Fahrenheit external temperatures expected. Eleven parachutes will sequentially deploy to help slow the spacecraft to a safe splashdown, but the heat shield will be instrumental to protecting the crew and capsule from landing loads and turbulent sea conditions – which could vary significantly during different Orion missions.
Comprehensive data from this test flight will influence design decisions most critical to crew safety, ultimately lowering risks and costs for future missions to deep space.
This test flight is the first step in the journey to Mars.
Source: Lockheed Martin