For now, at least until retrorocket controlled landings become feasible, parachutes are a pretty pretty vital pieces of hardware for spacecraft. Particularly manned vehicles where the parachute is responsible for the astronauts’ safe return from a mission. Looking ahead to its next manned program, NASA successfully tested the Orion spacecraft’s parachute over the Arizonian desert last week.
Like the Apollo spacecraft it so closely resembles, Orion will splashdown at the end of its missions. We’re actually only a couple of years away from seeing a real Orion parachute in action. The spacecraft is scheduled to make its first unmanned orbital flight sometime in 2014. Launching on a Delta IV rocket operated by United Launch Alliance, the unmanned Orion will reach a peak orbital altitude 3,600 miles above Earth’s surface – that’s 15 times farther than the International Space Station orbits. The main objective on this flight is to understand Orion’s heat shield performance at speeds associated with a return to Earth from deep space.
This is, all leading up to Orion’s ultimate mission – to send astronauts to the Moon, asteroids, and beyond. And, of course, bringing them home safely both after a mission and during an emergency abort. In either case, the parachute is a vital piece of technology to ensure a safe re-entry and landing.
Last week’s test was a drop test. A C-17 airplane carried a boilerplate Orion spacecraft – a dummy that mimics the shape, size, and weight of the real thing – over the U.S. Army Yuma Proving Ground in southwestern Arizona. The plane then dropped the boilerplate spacecraft from an altitude of 25,000 feet.
Orion’s parachute has reefing lines, lines that are cut with pyrotechnics to slow the parachute’s inflation. This moderates the speed at which it inflates, controlling the amount of initial drag and force on the parachute. The drogue chutes that increase stability during descent deployed between 15,000 feet and 20,000 feet. These were followed by the pilot parachutes that deployed the main landing chutes.
Once everything was fully deployed and inflated, Orion fell at about 25 feet per second – well below its maximum designed touchdown speed to make a soft landing on the desert floor.
This is the latest in a long string of Orion parachute tests that began in 2007 with air and ground-based tests, as well as one successful pad abort test in 2010. All of the tests build an understanding of the chutes’ technical performance for eventual human-rated certification. The main objective of the latest drop test was to determine how the entire system would respond if one of the reefing lines was cut prematurely, causing the three main parachutes to inflate too quickly. With Orion’s soft touchdown, it seems one reefing line malfunction won’t ruin a while landing.
William Gerstenmaier, associate administrator for the Human exploration and Operations Mission Directorate at NASA Headquarters in Washington pointed out how this test ties in with Orion’s overall progress. “Across the country, NASA and industry are moving forward on the most advanced spacecraft ever designed,” he said. The successful parachute test in Yuma “is an important reminder of the progress being made on Orion.”
Orion’s 2014 launch on a Delta won’t be the final configuration for the spacecraft. Because Delta wasn’t designed to launch Orion, engineers at NASA’s Marshall Space Flight Center in Huntsville, Alabama, are building adapter hardware to connect the two.
This adapter hardware will eventually connect Orion to its intended launch vehicle, the Space Launch System (SLS). This heavy lifting vehicle, when built, will be the most powerful rocket ever constructed. SLS, which will be flexible to carry both manned Orion spacecraft and cargo payload on deep space missions, is scheduled to carry an unmanned Orion into lunar orbit in 2017. Of course, there’s no shortage of speculation over whether or not SLS will ever be realized. And what that might mean for Orion isn’t entirely clear just yet.