Installation of heat-shielding tiles marks new phase for Orion spacecraft
The bonding of heat-shielding, waterproof tiles on NASA’s Orion spacecraft has begun, marking a key milestone and new phase in the development of the vehicle that will replace the Space Shuttle. Designed to protect the spacecraft from 5,000-degree-Fahrenheit (2,760-degree-Celsius) heat during re-entry, the tiles are being bonded to nine panels that cover the crew module, which will one day carry astronauts into deep space beyond low-Earth orbit.
A total of 1,300 tiles are being installed beginning this month, most of which are eight by eight inches (20.3 by 20.3 centimeters) in size except for those designed to cover windows, thrusters, and antennas, as those will be unique in size and design.
Each tile’s size and shape comes from computer-assisted design information. Once built, the tiles are studied with 3-D cameras, which compare the finished products with the initial design information to assure they meet required specifications before being installed on the spacecraft.
“The fact that Orion lands in the ocean, requires we replace the tiles after each mission,” said thermal protection system engineer Joy Huff of the Materials Science Branch of Kennedy Engineering at NASA’s Kennedy Space Center in Florida. “The tiles are waterproofed to protect them from freshwater, such as rain. But during re-entry, the waterproofing material burns out of the tiles, so they do absorb salt water while in the ocean, and that adds contaminants that would make their [recovery] impossible.”
Similar to those used on the Space Shuttle, the tiles are made of silica in order to protect the spacecraft’s back shell panels and forward bay cover.
Orion’s tiles are coated with a material used in the later years of the Space Shuttle program. Known as “toughened uni-piece fibrous insulation” or TUFI, this coating gives the tiles an extra layer of protection.
All the tiles being installed have been manufactured at the Kennedy Space Center’s Thermal Protection System Facility.
Expected to take several months, tile bonding is being done by technicians and inspectors who have years of experience bonding tiles on the Space Shuttles. The team includes seven or eight technicians and two quality inspectors from Arctic Slope Research Corporation, who are working in the high bay of the Neil Armstrong Operations and Checkout Building – the site where the Orion crew capsule’s pressure vessel has been under construction since February of this year.
NASA’s Orion program is being conducted through a contract with Lockheed Martin Space Systems Co. in Denver, Colorado.
After the tile bonding project is completed, the next steps for Orion will be the attachment of the crew module to the service module and installation of the crew module’s nine panels and forward bay cover.
Orion’s first flight test, Exploration Flight Test-1 (EFT-1), an unpiloted mission, was conducted on Dec. 5, 2014. The spacecraft traveled 3,604 miles (5,800 kilometers) above the Earth and returned several hours later, splashing down in the Pacific Ocean. Black tiles were used during that mission, giving the capsule a black appearance.
Orion’s next test flight, Exploration Mission-1 (EM-1), also unpiloted, will take place no earlier than Sept. 30, 2018. This time, the spacecraft will be launched from Kennedy Space Center’s Launch Complex 39B, to spend about three weeks in space some 40,000 miles (64,000 kilometers) beyond the Moon.
EM-1 will test systems needed to carry astronauts to Mars. Six days of the mission will be spent in retrograde orbit around the Moon.
The spacecraft will return using a comet-like re-entry trajectory, protected not just by the tiles but also by the most powerful heat shield ever built for a spacecraft.
Huff said the EM-1 tiles will be covered with an aluminum coating, making them appear shiny and silver rather than black.
“We’re looking forward to EM-1. SLS is the largest rocket ever built. It will help confirm we’re doing things the right way on Orion, and we’ll be another step closer to Mars,” Huff said.
Orion is designed to be 30 percent more spacious than the Apollo spacecrafts, with a launch abort system that can safely ferry the crew out of harm’s way in the event of an emergency either on the launch pad or during launch.
Orion’s first crewed test flight, Exploration Mission-2, is currently expected to take place sometime between late 2021 and 2023.
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program. Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.