NASA continues to make steady progress towards the first missions of the Orion spacecraft and the Space Launch System (SLS) rocket that will lead the next steps of human exploration to the Moon and beyond, extending human exploration farther into space than ever before. Exploration Mission-1 will be the first integrated test of Orion, SLS, and the supporting ground systems launching from Kennedy Space Center in Cape Canaveral, Florida in 2020, and will pave the road for future missions with astronauts.
Crew Capsule – Orion
Engineers at NASA’s Kennedy Space Center in Florida recently installed the heat shield that will protect the crew module for Exploration Mission-1 from the searing 5,000 degree heat it will experience upon reentry through Earth’s atmosphere. Before installing the heat shield, engineers first completed the majority of the work to assemble the Orion crew module. Thousands of components like Orion’s windows, avionics, wire harnessing and parachutes that make up more than 30 subsystems have been integrated and tested through evaluations like thermal cycle testing, proof tests on propulsion lines and functional tests to ensure systems work as planned.
Testing on a structural test article in Denver for sound and vibration evaluations has confirmed Orion can withstand the intense noise and shaking that launch on the SLS rocket will produce. At sea, NASA and the Department of Defense have honed the procedures and skills they will use to recover Orion upon splashdown in the Pacific Ocean. Flight controllers also conducted tests to ensure that Orion can communicate with mission control through NASA’s satellite network in space.
The Rocket – Space Launch System
NASA’s Super Guppy airplane delivered the second piece of SLS flight hardware to Kennedy earlier this year. The Orion stage adapter not only connects the Orion vehicle to the SLS, but will also be loaded with 13 small satellites on the first mission. Engineers at NASA’s Michoud Assembly Facility are seeing a surge of activity, as the five major structural pieces of the SLS core stage are completing final outfitting and assembly. Assembly of the forward and intertank are complete, and the liquid oxygen and hydrogen tanks are nearly complete as well. The structural test article for the hydrogen tank will ship to Marshall in several weeks for testing that will push, pull and twist the hardware to simulate the forces of flight. Teams have also been applying the thermal insulation to the flight hardware for protection due to extreme temperatures it will face during launch.
Engineers at Marshall are putting the finishing touches on the 30-foot-tall launch vehicle stage adapter that will connect the core stage to the interim cryogenic propulsion stage, which was delivered to KSC last year. It will be stored at Marshall until needed for integration, and NASA’s barge Pegasus will deliver it to Kennedy. The SLS booster team in Utah has finished eight of the ten solid rocket motor segments and will complete the last two segments before the end of the year. When needed for integration, they will be delivered to Kennedy where they will join booster parts, such as the aft and forward skirts being prepared there.
Kennedy Space Center – Ground Systems
Workers at Kennedy also continue to ready NASA’s modernized spaceport in Florida for blast off of the rocket and spacecraft. Earlier this year, engineers completed construction on the main flame deflector at the launch pad and conducted a countdown simulation. Over the summer, software teams completed critical updates to use for command and control from the firing room to support the first mission.
In August, engineers installed the final umbilical on the mobile launcher. For the first time since the mobile launcher has been modified for the SLS, the massive tower rolled out atop the crawler-transporter 2 to Launch Pad 39B in late August for a fit check that verified all physical connections between the launcher and pad systems before rolling into the Vehicle Assembly Building for testing.
Challenges Ahead
The teams have made significant progress building hardware for the first mission and there is still a lot of challenging work ahead. With an aggressive schedule for the remaining work, engineers must ensure safe and reliable operation of SLS, Orion, and the ground systems that support human spaceflight to the Moon and beyond.
By the end of the year, the SLS team at Michoud will join the first three structures to form the forward section of the 212-foot-tall core stage, including the recently completed forward skirt, and connect them with the flight computers. Technicians will also finish outfitting the engine section where the four RS-25 engines will be attached. The engine section is packed with internal systems that make it challenging and intricate work. It will then be connected to one of the largest fuel tanks ever built, the 130-foot-long liquid hydrogen tank, to form the aft section of the core stage. Then the forward and aft sections of the core stage will be assembled to form the whole stage, which will then be outfitted with the four RS-25 engines that are already complete and waiting for integration. NASA will ship the integrated core stage on the Pegasus barge to NASA’s Stennis Space Center near Bay St. Louis, Mississippi, for a major performance test in 2019, called the “green run” test, when all four engines roar to life and burn simultaneously while the stage is securely held down by the recently refurbished B2 test stand.
At Kennedy, teams are preparing for the arrival of the European-built service module which will power, propel and cool Orion in space and provide air and water to its future crews. The module is an integral part of human deep space exploration success and brings international collaboration to missions to the Moon and beyond. Once the powerhouse for the spacecraft arrives, technicians will stack the elements together, joining propulsion lines, avionics and other connections before shipping the stack to NASA’s Plum Brook Station in Sandusky, Ohio for testing in 2019.
The mobile launcher will undergo about seven months of testing of the new work platforms, power systems, air conditioning systems, communication systems, including cameras, and pneumatics systems. Test conductors will also operate the launcher’s umbilical arms remotely from inside the Young-Crippen Firing Room, and the launch team will conduct a terminal countdown demonstration later this fall. The flame trench at the launch pad is nearly complete, and two more wet flow tests are scheduled in the fall and spring.
Hardware for the Second Flight and Beyond
NASA also is making progress in preparation for future missions with astronauts. The underlying structure of the Orion crew module, called the pressure vessel, for the first crewed flight was shipped in August to Kennedy, where teams have already started assembly. The agency tested Orion’s parachute system for the final time in mid-September, bringing NASA another step closer to verifying the spacecraft is ready to bring crews home in any scenario. Engineers at several NASA centers have helped build and power on the crew module for a test of Orion’s launch abort system as other elements of the test vehicle are prepared for the test, which will verify the crew can be carried to safety in an emergency during launch.
The SLS teams are also building components for the second flight and testing engines in support of future crew and planetary missions. The engine section and forward skirt structures have been built for Exploration Mission-2. All the barrels and domes for the liquid oxygen tank have been welded as well as three of the five barrels for the liquid hydrogen tank. Half of the solid rocket motor sections for the boosters on the second mission are cast and being outfitted. Stennis has continued with a new series of RS-25 test firings to evaluate the performance of new designs and manufacturing techniques to significantly lower the production cost of future engines. The most recent test marked the seventh test of a 3D-printed pogo accumulator and the third test of a main combustion chamber fabricated using a bonding technique designed to save time and money.
The foundational work by NASA and its contractors around the country sets the stage for an even busier period ahead, when Orion and SLS will be integrated, tested, and rolled out to the launch pad as one of the final steps before Exploration Mission-1. The first in a series of increasingly complex missions, Exploration Mission-1 will demonstrate our commitment and capability to extend human existence to the Moon and beyond with a flexible, reusable and sustainable infrastructure to support exploration for decades to come.