Artemis I Heading Back to Launch Pad June 6 To Resume WDR Test

NASA announced today that the Space Launch System rocket for the Artemis I misson will roll back to the launch pad on June 6 in preparation for resuming the Wet Dress Rehearsal test. After three attempts to complete the test in April, the rocket was taken back to the Vehicle Assembly Building for several fixes while a contractor upgraded a system that supplies gas to purge propellant lines. Loading the rocket with propellant, a key step in the test, is scheduled for June 19. NASA will not set a date for launching Artemis I until the tests are done.

NASA is getting ready to launch SLS and an uncrewed Orion spacecraft around the Moon as soon as August, though the actual date depends on results of the tests. It is the first flight of the agency’s new Saturn V-class rocket to return astronauts to the Moon for the first time since the Apollo 17 crew left in 1972.

The SLS/Orion “stack” rolled out to the launch pad for the first time on March 17-18 for what NASA hoped would be a successful Wet Dress Rehearsal where the propellant tanks of the Core Stage and Interim Cyrogenic Propulsion Stage were loaded with fuel (hence “wet”) and two practice countdowns were conducted.

But three attempts had to be scrubbed. On April 3 it was malfunctioning fans on the Mobile Launcher needed to clear hazardous fumes. On April 4, it was a defective helium check valve on the Interim Cryogenic Propulsion Stage, ICPS, the Space Launch System’s second stage. On April 14, it was a hydrogen leak on the SLS Core Stage.

The agency ultimately decided to take the stack back to the Vehicle Assembly Building to make repairs while also giving Air Liquide, a contractor that supplies gaseous nitrogen (GN2), time to upgrade its system. Although GN2 supply problems were not responsible for any of the three scrubs, they did delay the test on April 4 and April 14.

During a media teleconference today, Cliff Lanham, senior vehicle operations manager with NASA’s Exploration Ground Systems program at Kennedy Space Center, said the upgraded system has been tested and is working well, and the various problems on the SLS and Mobile Launcher are repaired.

The plan is for “call to stations” at 6:00 pm ET on June 5 and “first motion” of the Crawler-Transporter carrying SLS/Orion attached to its Mobile Launcher at midnight June 6. The time was chosen to avoid thunderstorms that frequent Cape Canaveral this time of year.

Many test objectives were met during the first three WDR attempts. The focus now is demonstrating filling the tanks on the Core Stage and ICPS with liquid hydrogen and liquid oxygen and practicing countdowns, getting as close as 9.3 seconds before launch.

Artemis I can only launch during certain roughly-two week windows each month for a variety of reasons due to orbital dynamics and ensuring it splashes down during daylight when it returns. Which day it launches will also determine its duration, between 26 and 42 days. It will not enter lunar orbit, but will circle the Moon making either a half-lap or one-and-a-half laps.

Tom Whitmeyer, NASA Deputy Associate Administrator for Common Exploration Systems Development, confirmed today they still hope to be ready to launch in August.

If not, there are launch windows each month, though some are preliminary pending more detailed analysis. Two include dates in August.

• July 26-August 10, but not August 1, 2 or 6
• August 23- September 6, but not August 30, 31 or September 1
• September 20-October 4, but not September 29
• October 17-31, but not October 24, 25, 26 or 28
• November 12-27, but not November 20, 21 or 26
• December 9-23, but not December 10, 14, 18 or 23

SLS and Orion are years late and billions over budget. Boeing is the prime contractor for SLS and built the Core Stage, derived from the space shuttle’s External Tank and using left over Aerojet Rocketdyne RS-25 space shuttle main engines. Boeing also is the prime contractor for the ICPS, derived from the Delta IV upper stage. Northrop Grumman provides the side-mounted Solid Rocket Boosters, which are five-segment versions of the four-segment SRBs used for the space shuttle. Lockheed Martin is the prime contractor for Orion. The European Space Agency provides Orion’s Service Module, derived from ESA’s Automated Transfer Vehicle that was developed to take cargo to the International Space Station.

SLS/Orion can get astronauts to lunar orbit, but not down to and back from the surface. NASA is procuring a Human Landing System (HLS) from SpaceX through a Public-Private Partnership. A competition is underway for at least one other provider.

Artemis I is a test flight without a crew. Next is Artemis II, a test flight with a crew planned for 2024. Astronauts would return to the lunar surface in 2025 on the Artemis III mission under NASA’s current schedule.