What’s so special about the Orion crew’s pressure vessel, you may ask? This will be the spacecraft that will take humans to asteroids and eventually to Mars. But before that, in 2018, the craft will fly 43,000 miles beyond the Moon and back, in an important test of all its systems.
After testing and preparation, the capsule will be placed atop NASA’s Space Launch System (SLS) rocket on Kennedy’s Launch Pad 39B for launch as part of the Exploration Mission-1 (EM-1) in 2018. ABC News says NASA and Lockheed Martin engineers will begin outfitting the pressure vessel with all the controls necessary for flight, including electrical power storage and communications, computers and flight software.
“The structure shown here is 500 pounds lighter than its Exploration Flight Test-1 (EFT-1) counterpart,’ said Mike Hawes, Lockheed Martin Orion vice president, and program manager, according to the Daily Mail. Once the final structural components such as longerons, bolts, and brackets are added, total crew module structural weight savings from EFT-1 to EM-1 will total 700 pounds.”
Before all the technology is added to the capsule, it will undergo a thorough and rigorous amount of testing to ensure all the welds are structurally sound, using phased array technology. Then will come proof-pressure testing of the fluid system welds, and then all the welds will be X-ray inspected.
About a year from now, after all the systems are powered on and the tests have been completed, the Orion will be integrated with the European Space Agency-provided service module that will provide the main propulsion system and power. The spacecraft will be fueled and stacked on top of the SLS rocket and readied for launch.
Test flight to the Moon and beyond
The test flight in 2018 will be controlled remotely, sending Orion into lunar distant retrograde orbit. This will be a wide orbit around the Moon, and is farther than any human-rated spacecraft has ever traveled from Earth. The mission will last 22 days, and will test the design and safety of Orion and the SLS for future exploration missions, says Space Daily.
NASA released a video in December that details exactly how Orion’s trip into space will unfold in 2018. Viewers can see how the spacecraft will extend solar arrays measuring 62 feet (19m) when it reaches low-Earth orbit to provide power for the spacecraft.
Then it will fire its interim cryogenic propulsion stage (ICPS). This liquid oxygen/liquid hydrogen-based system is something new, and never tried before. A course will then be set for the Moon, and when ready for a fly-by, Orion will use the Moon’s gravitational pull to gain speed and propel itself into what is called DRO, “distant retrograde orbit.” Orion will fly thousands of miles past the Moon, and be at least half a million kilometers from Earth.
In order to get back home, Orion will be using a leftover system from the now-defunct space shuttle program. It will fire its main engine to maneuver the spacecraft into position for a return to Earth. On the return trip, Orion will again fly past the Moon and start its approach to Earth. Just outside Earth, the crew capsule will detach from the service module before reentry and splashdown in the Pacific Ocean. To ensure a safe reentry and soft landing, the crew capsule has three parachutes.
Apollo 17 and Orion – How do they compare?
It has been almost 42 years since the last Apollo mission on December 7, 1972, and in that time technology has made a number of great advances. To look at them, both space capsules look about the same. One big difference is the crew size. Where Apollo carried three astronauts, Orion will carry four. The Orion capsule itself is larger, to accommodate the extra supplies needed.
Another noticeable difference is that Orion will use a solar array for power and have more advanced computer systems, something Apollo lacked. NASA has also applied some lessons learned from the past. The heat shield on Orion is the largest one ever built, measuring 16.5 feet (five meters) across, and made of a new material called Avcoat.
The special heat shield material is an epoxy novolac resin with special additives in a fiberglass honeycomb matrix. In fabrication, the empty honeycomb is bonded to the primary structure and the resin is gunned into each cell individually. Avcoat was used on the Apollo command module, but was not used on the Space Shuttle orbiters. The Avcoat used on Orion has been reformulated to meet the EPA’s environmental standards.
