NASA is just days away from a crucial fuel test of its new megarocket that could make or break the space agency’s chances of launching its Artemis 1 mission to the Moon next week.
The fuel test, which NASA will attempt on Wednesday (Sept. 21), will test the repair of two hydrogen leaks on the rocket, called space launch systemPlus a new, slower way to fuel the 32-story booster on the Pad 389A Kennedy Space Center in Florida. If all goes well, NASA made a third attempt to launch the Artemis 1 SLS rocket to the Moon on September 27 after two false starts in recent weeks.
“We’re not just preparing ourselves for the September 27 launch, we’re setting ourselves up for the future of this vehicle,” Tom Whitmire, NASA’s deputy associate administrator for Common Exploration Systems Development, told reporters in a teleconference Monday (Sept. 19). “That’s why we’re taking the time and effort to make sure we understand the vehicle.”
of NASA artemis 1 The fuel test comes after two failed attempts to launch the Artemis 1 mission – with it the first uncrewed test flight of the SLS rocket Orion Capsule — on August 29 and September 3, for the first time an engine temperature issue detected bad sensor, and then Due to a massive leak of hydrogen fuel, The space agency has since repaired an 8-inch (20-centimeter) hydrogen line and a 4-inch (10-cm) shorter line.
The 8-inch line was of particular concern because it had a substantial leak during its September 3 launch attempt. Engineers soft seals replaced A small indentation was also found on both lines and even in the seal of the larger line which may or may not be caused by a piece of debris (though no debris was found on the launch pad). NASA said the tiny divot was less than 0.01 inches long (0.002 cm).
“Now, it doesn’t sound like much, but we’re dealing with hydrogen, which is the smallest particle on the atomic chart,” Mike Sarafin, NASA’s Artemis 1 mission manager, said in a teleconference. “It provides an opportunity for a pressurized gas to leak through.”
To make things easier on the SLS fuel lines, NASA will attempt what it calls a “kinder and gentler” liquid hydrogen loading process during this week’s test. This process will fuel the rocket about 30 minutes slower than normal to reduce stress on the pressurized fuel lines and seals. (It usually takes up to four hours to fuel the rocket.)
“Ultimately, we’ve mitigated everything we can think of and we’ll know, in 36 hours or 48 hours or so, how effective those mitigations are,” said NASA’s SLS chief engineer John blevins Marshall Space Flight Center in Huntsville, Alabama, told reporters.
The agency automated all but five manual commands for the refueling process, and added training for the launch team to avoid accidental excessive pressure of the fuel line such as the incident during the September 3 attempt.
During Wednesday’s Artemis 1 fuel test, NASA will fill the rocket’s core and upper stages with the 736,000 gallons (3.3 million liters) of super-chilled liquid hydrogen and liquid oxygen needed to launch. NASA officials said this is not a full dress rehearsal for the launch (the Artemis 1 Orion space capsule and twin solid rocket boosters will be unpowered) but is designed to fix fuel leaks and verify the new fueling process works.
Space Force relaxation still needed
Even if the fuel test is successful, it is not certain that NASA will be able to launch on September 27.
The space agency is currently seeking exemption from the US space force On the SLS rocket’s flight termination system, which consists of batteries that need to be checked every 25 days to make sure they are working properly. The flight termination system is a safety device designed to protect the public from flying an SLS rocket if it is to take off. Ensuring that it works correctly is required by the US Space Force, which oversees the Eastern Range for rocket launches off the coast of Florida. The 25-day period for Artemis 1 ended on 6 September.
Rechecking of the flight termination system can only be done inside the large vehicle assembly building hangar where the SLS was assembled. To do so, NASA would have to roll a 322-foot-tall (98 m) rocket off the launch pad, potentially adding to weeks of more delay.
“Right now, we are still in the process of having technical discussions with Range,” Whitmeyer said. “It’s been very productive and collaborative.” NASA has not yet received a decision on whether it will be granted a waiver and is not expected to be notified before the Sept. 21 fuel test.
If the Artemis 1 fuel test goes well and NASA is exempt from Space Force, its next launch attempt will be scheduled for September 27 at 11:37 a.m. EDT (1537 GMT). NASA will have 70 minutes to launch the mission.
A backup launch date is likely October 2, but it also depends on whether it is exempt from the Space Force and the health of the Artemis 1 launch system, Sarafin said.