NASA is developing a thermal protection system, improving the heat shield of the Orion spacecraft. Engineers are enhancing the overall system looking forward to the next spacecraft’s mission, a flight with an extreme set of conditions.
The thermal protection system is one of the most important features of the spacecraft, that has to be capable of enduring the extremely hot and fast journey from space back to Earth, protecting astronauts inside of it.
This protection system consists of Orion’s main heat shield, that slows the ship down when it reenters the Earth’s atmosphere, as well as the grid of tiles that are known as back shell. For the next mission Exploration Mission-1 (EM-1), using NASA’s Space Launch System rocket, Orion spacecraft will go to space for more than three weeks and return to our planet even faster and with harshest heat conditions than the last time.
John Kowal, NASA’s thermal protection system leader for Orion, stated that the improvements are essential towards further successful missions. He added that as they build the system for EM-1, they have taken advantage of the things they had learned from Orion, improving the process.
Getting ready for EM-1
During EM-1, the spacecraft will experience a faster return from a lunar velocity of nearly 36,000 feet per second and temperatures of approximately 4,000 degrees Fahrenheit. Last time, Orion’s reentering happened at 30,000 feet per second, and although it doesn’t seem much difference, this will potentially increase the heat conditions.
These improvements, made by engineers from all across the country on the spacecraft’s shield to perform a faster re-entry, will be applied on any of the missions planned near the moon, or in high lunar orbit for the coming years -that corresponds with the NASA’s Proving Ground program.
Also, a silver, metallic-based thermal control coating will be added to the crew module’s thermal protection system back shell tiles, according to NASA. This is very similar to the one used in the heat shield, and will reduce heat loss during stages when Orion will be faced with colder temperatures -as well as limiting the high temperatures, too. It will maintain a temperature range between -150 to 550 degrees Fahrenheit.
“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,” said Kowal, on NASA press release.
Improving the making process
Also, engineers from NASA have updated the design to improve the manufacturing process and reducing the mass of the spacecraft for further exploration missions. It changed from a monolithic outer layer to an 180-block heat shield, made simultaneously with other components to accelerate the manufacturing process.
Additionally, they found new ways of reducing the mass of the heat shield’s structure, composed by titanium and carbon fiber skin. Research teams have optimized the thickness of the skeleton underlying the structure, based on the amount of pressure received by each sector of the shield, making it resistant and lighter.