NASA opts for SLS green run

After considering canceling a planned full-duration test-firing of the Space Launch System (SLS) core stage in Mississippi ahead of the heavy-lift rocket’s first flight, NASA Administrator Jim Bridenstine announced during the week that the agency will press ahead with the eight-minute test next year. He cited safety and reliability benefits for future astronauts riding on the launcher on missions to the moon. The first SLS test flight, carrying an unpiloted Orion crew capsule to lunar orbit, is set for blastoff in 2021 from pad 39B at NASA’s Kennedy Space Center in Florida. The mission is designated Artemis 1, the first flight in NASA’s Artemis program to return astronauts to the moon as a stepping stone toward eventual expeditions to Mars. NASA has planned the so-called “green run” test of the SLS core stage since the program’s genesis in 2011. For more than half a decade, workers at NASA’s Stennis Space Center (SSC) in southern Mississippi have modified and outfitted the B-2 test stand — previously used for Saturn V, space shuttle and Delta IV rocket testing — to accommodate the 212-foot-tall, 27.6-foot-wide SLS core stage. Liquid hydrogen and liquid oxygen tanks inside the SLS core stage will hold 733,000 gallons of propellant to feed four RS-25 main engines, generating more than 2 million pounds of thrust at full throttle. The RS-25 engines, supplied by Aerojet Rocketdyne, are left over powerplants from the space shuttle program. Unlike full-stage firings of previous rockets, the green run test at Stennis will use the same core stage that will fly on the first SLS launch, and not a ground test article. Once the core stage is finished at Michoud Assembly Facility, a NASA barge will haul the rocket from New Orleans to SSC for installation on the B-2 test stand. The shipment of the core stage to Stennis is scheduled around the end of the year. (Source: Spaceflight Now, 07/27/19)