NOV. 15, 2022—The countdown clock has started ahead of NASA’s third launch attempt of the Artemis I mission to the Moon, currently set for 1:04 a.m. ET on November 16. Flight controllers were called to their stations at 1:24 a.m. ET yesterday morning, starting the nearly two-day countdown clock for the Space Launch System rocket, now standing tall at historic Space Launch Complex-39B.
This launch attempt comes after significant delays due to impacts from two hurricanes and repairs after the Aug. 29 and Sept. 3 attempts were scrubbed due to hydrogen loading problems. While the hydrogen problems were repaired and tested during a tanking test on Sept. 21, Hurricane Ian forced a return to the VAB for the safety of the rocket.
After recertification of the Flight Termination System (FTS) and further repairs and checkouts, Artemis I rolled back out to the launchpad on Nov. 4, only to be hit by a second storm, Hurricane Nicole. NASA officials made the call to keep the rocket at the launchpad, due to uncertainties in being able to safely roll back the rocket before the storm picked up. Winds remained beneath structural limits throughout the storm, with the rocket suffering some minor damage.
Almost all of the damage caused by Hurricane Nicole has been fixed on the pad. One issue remains, involving a 10-foot strip of RTV (room-temperature vulcanizing) silicone rubber sealant along Orion’s aeroshell that was partially loosened by the storm’s force. The strip is not critical for flight, however, teams were still concerned about transporting unnecessary debris. The issue was closed at yesterday’s Mission Management Team meeting, with the decision that the risk was within acceptable limits pre-set for launch and with no dissenting opinions.
Assuming an on-time liftoff tomorrow, Artemis I’s Orion spacecraft will embark on a 25-day mission into a lunar Distant Retrograde Orbit and back to Earth. This is a “short-class” mission, in contrast to the original 40+ day long-class missions that were enabled by the August/September launch window. Orion’s goals and objectives will remain the same, and the difference between the mission classes should not result in a significant reduction of data.
If the launch scrubs for any reason, backup opportunities are available through Nov. 27, with the exception of the 20th and 21st due to Orion eclipsing constraints. If the rocket has a significant amount of propellant loaded by the time of the scrub, the launch will very likely delay to the 19th or 25th, both dates that have been called out by NASA as primary backup opportunities.
If a hold but not a scrub is called in the countdown, teams still do have a few options in order to restart the count. During the terminal count, the team can hold at T- 6 minutes for the duration of the two-hour window, without having to recycle. Past that, a hold can be called as late as T- 33 seconds with a recycle to the 10-minute mark. However, once the automated launch sequencer takes over, any abort is a scrub for the day. This is mostly equivalent to the Space Shuttle’s RSLS abort mode.
Based on tomorrow’s timeline, Orion would be set to splash down on December 11 at 12:40 p.m. ET, after spending about two weeks around the Moon. For a successful Artemis I mission to be called, four objectives must be met, in order of importance:
- Prove Orion’s heatshield can withstand a re-entry from a lunar return.
- Demonstrate operations and facilities during all mission phases
- Retrieve and recover Orion after splashdown
- All other supplemental objectives.
At the time of writing, Artemis I remains on time for liftoff at 1:04 a.m. ET, ready to launch for the first in a series of increasingly complex missions to build a foundation for a return to human deep space exploration.
Go Orion, Go SLS, Go Artemis I!
Article written and edited by Lavie Ohana.