In a media teleconference held on Friday at Kennedy Space Center, NASA officials discussed the status of the next wet dress rehearsal test of the SLS and Orion spacecraft in advance of the uncrewed Artemis I lunar mission.

Tom Whitmeyer of the Exploration Systems Development Mission Directorate in Washington, D.C.; Senior Vehicle Operations Manager Cliff Lanham of Kennedy Space Center; and SLS Chief Engineer John Blevins of Huntsville’s Marshall Space Flight Center provided insights on what happened during the initial wet dress rehearsal and what has been accomplished since.

“This is a very complicated process and we have a robust vehicle, a great design, but the actual vehicle itself is a very straightforward vehicle–any time you get into loading operations with cryogenics it’s something you have to take a step at a time and learn through the process how the hardware’s behaving as well as the rocket,” Whitmeyer explained.

Lanham discussed issues encountered during the initial wet dress rehearsal, noting that one of the main issues encountered was a liquid hydrogen system leak at the tail service mast umbilical. He noted that the flange bolts had loosened over time and reported that the umbilical has been tightened, with subsequent leak tests indicating that the problem has been corrected.

Other adjustments made include replacing and testing the helium check valve and other hardware on the cryogenic propulsion stage, modifying the second stage umbilical boots, and adding additional leak detectors on the liquid hydrogen side.

NASA engineers used this delay to take additional steps to prepare the SLS for a successful flight.

“This modification also allowed us to complete some of the forward work we originally scheduled to take place in the VAB after a wet dress rehearsal,” explained Lanham, who stated that they’ve completed some work in the Orion crew module including installing some of the payloads and working on several external areas.

Upgrades and tests have also been completed on the new gaseous propellant supplier at Launchpad 39B, which Lanham described as a success.

Call to stations is currently scheduled for the evening of June 5, with first motion of the crawler planned for June 6.

“We’re going later in the evening because with the weather in Florida in the June timeframe it’s much less likely to have thunderstorms in that time.”

WDR cryoflow is scheduled for no later than June 19. Lanham stated that there are two weather days built in that could move that date slightly.

“It is Florida in June, so thunderstorms are expected, and we’ll be working with any range constraints that may come up.”

In response to a question about his confidence level with the leak repair, John Blevins of Marshall Space Flight Center expressed a high confidence. Blevins explained that the seals age with time, adding “we have good confidence that we’ve done the right process…there is one good mitigating circumstance in the event that it’s not a 100 percent solution, and it is that we can access those solutions at the pad…will it have to be tweaked? That’s a possibility, and we’ll find out shortly.”

Following the successful completion of the wet dress rehearsal, the NASA officials stated that they anticipate an August launch window. NASA’s launch calendar lists a total of 73 launch opportunities between July 26 and December 23, 2022, with the mission taking between either 26 and 28 days or between 38 and 42 days, depending on the Moon’s position in its distant retrograde orbit at the time of launch.

Four primary parameters dictate launch availability. These are specific to the Artemis I mission, with launch availability for future missions determined based on capabilities and trajectories unique to each mission.

Artemis I’s launch day must account for the Moon’s position in its lunar cycle so that the SLS rocket’s upper stage can time the trans-lunar injection burn with enough performance to precisely intercept the “on ramp” for the Moon’s distant retrograde orbit. Future, more powerful configurations of the rocket will be able to take advantage of daily or near-daily launch opportunities, depending on the orbit desired.
The resulting trajectory for a given day must ensure that Orion is not in darkness for more than 90 minutes at a time so that its solar array wings can generate sufficient electricity and so that the spacecraft can maintain an optimal temperature range.
The launch date must support a trajectory that allows for the skip entry technique planned during Orion’s return to Earth, a maneuver in which the spacecraft dips into and out of the upper part of Earth’s atmosphere much like skipping a rock on a lake. This gradually slows the capsule down, enabling final descent and splashdown, while allowing engineers to pinpoint the splashdown location.
The launch date must support daylight conditions for Orion’s splashdown to assist recovery personnel as they locate, secure, and retrieve the capsule from the Pacific Ocean.

For a full view of NASA’s launch schedule, please visit here or at https://www.nasa.gov/specials/artemis-i/