NASA engineers had to work quickly to avoid another leak affecting Artemis’ latest vacuum test, just hours after an attempt to reboost the International Space Station (ISS) via the Cygnus cargo ship was aborted after a few short seconds.
The US space agency returned the massive Artemis I stack to its Florida launch pad on Monday after resolving leaks and glitches that beset its previous attempt to power the beast by April for an earlier dress rehearsal of the final countdown.
As propellant was being loaded into the rocket, controllers noted a hydrogen leak in the quick disconnect that connects an umbilical from the mobile launcher’s tail service mast to the rocket’s center stage.
Such a leak would normally trigger a wait during an actual launch. When heating and then cooling the disconnect to align the seal didn’t work, the team “devised a plan to hide the data associated with the leak.” according at NASA. The “mask” – which prevented the data from triggering a crash by the ground launch computer – allowed testing to continue.
The tanks were filled for the first time and other critical operations were checked off, including the switch from the ground launch sequencer to the automated launch sequencer controlled by the rocket’s flight software.
The wet dress rehearsal ended at 1937 EDT.
The question now is whether NASA believes it has enough test targets to validate the stack as ready for its uncrewed launch. If so, there is a chance that the big rocket will be launched at the end of the summer.
Problems also marred an attempt earlier today to reboost the ISS with the engine of Northrup Grumman’s Cygnus NG CRS-17 freighter. The test shot – scheduled for Monday at 1020 Central – was supposed to last just over five minutes, but was cut short after five seconds. The director of the Cygnus mission in Dulles, Va., said the cause of the abortion was “understood” and being investigated.
A second attempt could take place on June 25, which would potentially lead to Cygnus leaving for the station on June 28.
The need to add additional reboost options to the ISS has become more urgent in light of Russia’s invasion of Ukraine, ensuing sanctions, and saber-rattling from Roscosmos about a future where the Russian agency abandons the project. With the retirement of the US Space Shuttle and ESA’s ATV, reboost options are limited. Ignitions from Russian Progress engines are rather the norm.
Aside from Cygnus, non-Russian reboost options are limited for ISS partners. A propulsion module was proposed as a backup of the functions of the Roscosmos Zvezda service module and the Progress cargo ship, but never completed or launched. Another possibility involves the use of SpaceX’s Dragon spacecraft. ®