NASA’s Artemis 1 lunar rocket remains on the launch pad, at least for now.
Artemis 1 will use NASA’s new Space Launch System (SLS) mega-rocket to send an uncrewed Orion capsule to and from lunar orbit. NASA attempted to launch the epic mission on Saturday (September 3) but stalled when it couldn’t fix a leak of supercold liquid hydrogen (LH2) in time for liftoff.
The leak occurred at the “quick disconnect,” the interface connecting the SLS main stage to the fuel line from the giant rocket’s mobile launch tower. After analyzing the problem for several days, the Artemis 1 team decided to replace the seal on the poorly functioning quick release device, the agency said in an update Tuesday evening. (will open in a new tab) (6 September).
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This work will be performed at Site 39B at the Kennedy Space Center (KSC) in Florida, where the Artemis 1 stack has been located for the past three weeks.
“Site work requires technicians to install a fence around the work area to protect equipment from weather and other environmental conditions, but allows engineers to test repairs in cryogenic or ultra-cold conditions,” NASA officials wrote in the release. Update Tuesday.
“Performing site work also allows teams to gather as much data as possible to understand the cause of the problem,” they added. “Teams may return the missile to the Vehicle Assembly Building (VAB) for additional work that does not require the use of on-site cryogenics.”
And a rollback to VAB may be required whether or not the team wants to do more repairs there. The US Space Force has certified the Artemis 1 Flight Termination System (FTS), which will destroy a rocket if it veers off course during liftoff in just 25 days. (Space Forces are watching the Eastern Range, the huge rocket launch area that includes the KSC.) That deadline will expire by Sept. 19, when the next Artemis 1 launch window opens.
Recertification requires FTS testing, which can only happen in VAB. NASA officials have said they may apply for another waiver to extend the certification period, allowing Artemis 1 to stay on site longer, but it’s not clear at this point if they will do so. (Artemis 1 has already received one such rejection from 20 days to 25.)
Saturday’s hitch was the second for Artemis 1. The first happened on August 1st. 29 was caused by a measurement showing that one of the four engines in the SLS main stage was not cooled to the proper pre-launch temperature. The Artemis 1 team quickly concluded that the reading was caused by a faulty temperature sensor and decided to continue the attempt on Saturday.
The team also fixed the LH2 leak during August. 29 tries, but this leak was much smaller than the leak the team is currently working on.
Artemis 1 has two launch windows available over the next two months. The first runs from September 19 to October 4, while the second is open from October 17 to 31. A rollback to VAB would almost certainly set Sep 19-Oct. 4 windows out of reach.
Mike Wall is the author of Out There (will open in a new tab)(Grand Central Publishing, 2018; illustrations by Carl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall (will open in a new tab). Follow us on Twitter @Spacedotcom (will open in a new tab) or on facebook (will open in a new tab).