Aug. 6 (UPI) -- NASA and Boeing said Thursday they completed a crucial test of propulsion systems on the Space Launch System moon rocket in Mississippi, advancing toward a full hot-fire or "green run" of the massive vehicle's engines in October.
"We've learned that this rocket is operating very well, as designed," Mark Nappi, Boeing's green run director, told UPI in a phone interview. "There's been very few surprises. The software is of excellent quality."
Crews of technicians and workers filled the engines, pipes and chambers with safe helium or nitrogen gas to check for leaks. In September, they will use the explosive liquid hydrogen and liquid oxygen to test the engines one final time before igniting them.
The final green run hot fire in October will see the rocket's core stage fire at full power for eight minutes while locked down on the test stand at Stennis Space Center, about 40 miles northeast of New Orleans. That will be the biggest, most powerful test conducted at Stennis since the Apollo era.
Completion of the propulsion leak test means the rocket's core-stage testing is more than halfway finished, Nappi said. The rocket was built in New Orleans and shipped to Stennis in January, part of a program to develop new moon rockets that is approaching $17 billion in costs, according to a report from the NASA Office of Inspector General.
NASA wanted to finish the tests by the end of summer, but halted the process for 10 weeks due to the COVID-19 pandemic. Since restarting, there have been no additional delays, despite some days of extreme heat and the arrival of Tropical Storm Cristobal nearby in June.
"They have met a lot of challenges due to COVID and the weather," said Julie Bassler, NASA's core stage manager for the rocket.
"There's cleaning and masks always, and glasses and smocks if in close contact. We maintain six feet apart whenever possible," Nappi said.
Boeing and NASA have seen no transmission of the coronavirus among the workforce of about 200 people on site, with about 100 working remotely on the project, Nappi said.
Firing of the four Aerojet Rocketdyne RS-25 engines on the 212-foot-long, 188,000-pound core stage will produce about 1.6 million pounds of thrust, slightly less than a SpaceX Falcon 9 rocket. But the moon rocket will have boosters when it actually launches, set for 2021 -- producing nearly 8 million pounds of thrust. The goal of the first, uncrewed launch will be to send the rocket around the moon.
Vice President Mike Pence charged NASA with returning to the moon by 2024 during a speech in March 2019.