Artemis I Test Scrubbed Again, Ax-1 Launch Slips to Friday

Artemis I Test Scrubbed Again, Ax-1 Launch Slips to Friday

NASA’s Wet Dress Rehearsal test of the Space Launch System rocket for the first Artemis launch scrubbed for a second time today. This is the first test of all the SLS components and problems are hardly unexpected. What makes it newsworthy is how busy NASA and its two launch pads at Kennedy Space Center are these days so a delay on one impacts whatever is happening on the other. In this case it’s the launch of the first U.S.-sponsored private astronaut mission to the International Space Station, Axiom-1.

The schedule conflict between the Artemis I test and the launch of Ax-1 only became apparent in recent weeks as dates for each were adjusted for a variety of reasons. They are using NASA’s two launch pads at KSC, Launch Complex 39-A and Launch Complex 39-B. Both are part of the Eastern Range controlled by the U.S. Space Force’s Space Launch Delta-45 at Patrick Space Force Base that coordinates launches among users of NASA’s launch pads and the Space Force’s pads on Cape Canaveral Space Force Station next door.

NASA Kennedy Space Center’s Launch Complex 39 and its two launch pads, 39A and 39B. Undated photo by NASA’s Cory Huston via Wikimedia.

SpaceX leases LC-39A from NASA and uses it for a variety of launches including sending people to orbit. Some of those are for NASA-sponsored missions to the ISS and others for its own commercial customers.

The first all-commercial SpaceX crewed mission was Inspiration4 last fall, which did not visit ISS. Its first private flight to the ISS, Ax-1, is awaiting launch right now for Axiom Space, a company that not only arranges trips to space for non-NASA astronauts, but is building its own commercial space station to replace ISS.

Four people, an Axiom employee (and former NASA astronaut) and three wealthy men who are paying for the trip, are already in quarantine awaiting launch on a 10-day mission that includes eight days on the space station.

They need to get up and back in time for the next NASA-sponsored crewed launch as part of the regular six-month ISS crew rotations, Crew-4. It is this interplay among the Artemis I Wet Dress Rehearsal (WDR) test, launch of Ax-1, and launch of Crew-4 that’s the challenge. A slip in one affects the others.

NASA claimed the range for the WDR test this weekend. It began with Call to Stations on Friday with the end anticipated on Sunday. That allowed Ax-1 to launch on Wednesday.

The Space Launch System (SLS) rocket with an Orion spacecraft on top at Launch Complex 39-B during the Wet Dress Rehearsal, April 4, 2022. Photo Credit: NASA/Joel Kowsky.

The WDR test was scrubbed at about noon on Sunday, however, when both the primary and secondary fans needed to pressurize the Mobile Launcher to keep out hazardous fumes malfunctioned.

The 6-foot tall fans operate in two modes. Rated at 75 hp, they normally operate at 40 percent power, but up to 100 percent power when clearing the fumes. Launch Director Charlie Blackwell-Thompson told reporters yesterday they had been operating at normal power since Friday when test preparations began, but something went awry Sunday when they were needed at full power as propellants were about to be loaded into the rocket. Blackwell-Thompson did not know what the problem was yesterday and NASA provided little additional information today saying only that the primary fan was working and the secondary fan could operate at 80 percent capacity.

This morning test preparations resumed. NASA planned to begin “tanking” — loading cryogenic Liquid Oxygen (LOX) and Liquid Hydrogen (LH2) into the SLS core stage and upper stage — at 7:00 am ET, but an outage with the vendor of the gaseous nitrogen (GN2) needed to purge propellant lines delayed the “go for tanking” call until 10:52 am ET.

The agency is not providing live commentary of the test. The only publicly available information is occasional tweets (@NASAGroundSys) and blog posts. What can be gleaned is that a variety of other unexpected challenges cropped up as the day progressed and tanking did not actually begin until very late in the afternoon.

LOX loading finally got underway, but when they were about to begin flowing LH2, a vent valve on the Mobile Launcher malfunctioned. At that point, 5:00 pm ET, they decided to scrub for the day.

Because of Sunday’s scrub, Axiom Space had to delay Ax-1 until Friday.

As of press time, no decision had been made by NASA as to when it will resume the WDR test and what impact that could have on Ax-1.

The Ax-1 crew needs to complete their trip in time for NASA to launch Crew-4 to relieve four astronauts, three from NASA and one from ESA, currently on the space station. NASA recently delayed that launch from April 19 to April 20 as the Ax-1 launch slipped.

Both Ax-1 and Crew-4 will launch from LC-39A on SpaceX Crew Dragons. The launches cannot take place while the WDR is underway on LC-39B.

If not for that, how long the WDR takes would not matter so much. Veteran space reporter Eric Berger of Ars Technica points out that the equivalent test of the original Moon rocket, Saturn V, took 17 days.

Time will tell when the WDR is completed, which in turn will determine when the Artemis I launch itself will take place. An uncrewed test of SLS and Orion around the Moon, NASA is targeting June for that mission.

Artemis is NASA’s program to return astronauts to the Moon and someday go on to Mars. The first launch with a crew, Artemis II, is expected in 2024, but they will not land on the Moon. The first Artemis lunar landing is planned for Artemis III in 2025.

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