SLS Hot Fire Test a Success on Second Try

Today’s second test of the Space Launch System (SLS) core stage appears to be a complete success, although engineers must review all the data before making a definitive determination. The first attempt in January ended after just 67 seconds because of conservative test parameters that were set.  Not so today. The four RS-25 engines actually exceeded the 485 second goal, firing for 499.6 seconds.

This was the final test in a series of eight “Green Run” tests of the Boeing-built SLS core stage and its four Aerojet Rocketdyne RS-25 engines.  The core stage was secured to a giant test stand at Stennis Space Center, Mississippi for the test.

The RS-25 engines are left over from the space shuttle program and all flew into space before the shuttle program was terminated in 2011. Only three were needed for the reusable space shuttle orbiter, but SLS needs four.  The January test was the first time four were fired at the same time. Today was the second. All apparently went well.

During a post-test press conference, NASA SLS Program Manager John Honeycutt said all the data so far shows everything was nominal. He gave the core stage an A+ and praised SLS Stages Manager Julie Bassler, the Boeing/Rocketdyne team, and the team at Stennis Space Center for a job well done.

Praise also came from members of Congress, including Sen. Richard Shelby (R-AL), one of the driving forces behind SLS. The program is managed at NASA’s Marshall Space Flight Center (MSFC) in Huntsville, AL.  Shelby, who chaired the Senate Appropriations Committee when Republicans controlled the Senate and now is Vice Chairman, is a powerful champion for the program.

Pleased that today’s Green Run hot fire test of the @NASA_SLS core stage was successful and informative – another important milestone in our return to the moon. https://t.co/uZzqJvOn5X

— Richard Shelby (@SenShelby) March 18, 2021

Rep. Robert Aderholt (R-AL), who represents a district near MSFC and is the top Republican on the House appropriations subcommittee that funds NASA, called it exciting.

Today’s successful test of @NASA_SLS at Stennis Space Center is the exciting punctuation mark of the most rigorous testing of a launch vehicle since the Apollo program. pic.twitter.com/1euKeUoqx7

— Robert Aderholt (@Robert_Aderholt) March 18, 2021

Sen. Roger Wicker (R-MS) who represents Stennis Space Center retweeted a congratulatory tweet from Republicans on the Senate Commerce Committee, which oversees NASA. Wicker chaired the committee when the Senate was under Republican control and now is its top Republican.

Congratulations to @NASA on a successful full duration burn of the @NASA_SLS Core Stage! This is exciting news for the Artemis Program. pic.twitter.com/PnO2lhehu9

— Senate Commerce Republicans (@SenateCommerce) March 18, 2021

Several other members of Congress from both parties also offered congratulations, including Rep. Eddie Bernice Johnson (D-TX) and Don Beyer (D-VA), the chairs of the House Science, Space, and Technology Committee and its space subcommittee, who issued a joint press release.

RELEASE: Chairs @RepEBJ and @RepDonBeyer Congratulate NASA and Its Industry Partners on Successful Final SLS Core Stage Test https://t.co/WnuoUmAhuj

— Science Committee (@HouseScience) March 18, 2021

NASA has decided not to reuse the shuttle-era engines anymore, so their next journey to space on the first SLS test flight, Artemis I, will be their last.  Twelve more engines remaining from the shuttle program will power the next three SLS missions. Aerojet Rocketdyne has an almost $2 billion contract with NASA to build 18 new RS-25s for the future.

It will take about a month for engineers to get the core stage ready for shipment to Kennedy Space Center, FL. Once there  it will be integrated with the other SLS components, including two 5-segment Solid Rocket Boosters from Northrop Grumman, in preparation for Artemis I, an uncrewed test flight of SLS with an Orion spacecraft around the Moon.

The launch is about 3 years late and the agency has been hoping to get it off the pad this year.  Acting NASA Administrator Steve Jurczyk told SpacePolicyOnline.com earlier this week that the agency will know in a few weeks whether it has a “reasonable shot” to launch in November, the current plan, “or if we need to move to the right a little bit.”

The first test launch with a crew, Artemis II, is planned for 2023.  Under the Trump Administration’s plan, Artemis III would launch in 2024 and take astronauts back to the Moon for the first time since Apollo 17 in 1972.  The Biden Administration supports the Artemis program, but has not yet indicated what schedule it has in mind.

The 2024 date was chosen by the Trump Administration because it would have been the end of a second Trump term if he had been reelected, but was considered unrealistic for technical and budgetary reasons by almost everyone in the space community.

During the post-test press conference, Jurczyk said NASA has gotten “good support from the Biden Administration really across the board” not just for Artemis, but NASA’s broader portfolio including climate change, reducing the environmental impact of aviation, and inspiring students in STEM education. “I am really excited about the support we’ve gotten from the Biden Administration.”