Space force

NASA needs space force blessing for SLS launch in late September

SLS on the Kennedy Space Center launch pad in Florida.

SLS on the Kennedy Space Center launch pad in Florida.
Photo: Nasa

Like a student late to submit a mission, NASA has requested a Space Force extension that would allow the space agency to make a third launch attempt of its mega Moon rocket later this month.

from NASA The Space Launch System rocket is currently being repaired following a hydrogen leak that caused a second failed launch attempt this past Saturday. The The agency is eager for a third launch attempt at the end of September and has filed a special waiver request with the Eastern Channel for that to happen, as Jim Free, associate administrator for the directorate of media, told reporters. NASA exploration systems development missions. Thursday morning.

No waiver, no launch

The Eastern Range, a branch of the US Space Force, oversees rocket launches from Kennedy Space Center and Cape Canaveral Space Force Station. The Range issues launch permits but with time restrictions to ensure public safety. Time is up for NASA’s SLS, which is currently on Launch Pad 39B at Kennedy Space Center, which means NASA needs to get the SLS back to the vehicle assembly building and test the batteries again. rocket flight termination. The system is designed to destroy the rocket in midair, if SLS wanders off during launch and threatens populated areas. The problem is that the flight termination system batteries need to be tested and recharged at regular intervals.

For the launch period that ended on Tuesday, September 6, the Eastern Channel had already issued a waiver that extended NASA’s launch authorization from 20 to 25 days. As Free explained, NASA is now requesting another waiver and asking the Range “for a few dates” in support of the Artemis 1 mission, in which SLS will launch an uncrewed Orion spacecraft on a journey to the Moon and back. NASA’s relationship with the Range remains “fantastic,” Free said, and that “our job is to…comply with their requirements.” It’s unclear whether the lineup will adhere or when it might issue a waiver, but NASA will have to make a decision on how to proceed if the space agency doesn’t respond in a timely manner, Free said. NASA wants to “be very respectful” of the Eastern Range’s decision-making on the matter, he added.

If NASA was unable to secure a waiver, SLS would have to be moved back to the VAB, allowing technicians to inspect the batteries. This scenario would likely push the third launch attempt to late October, further delaying the start of the Artemis era. Artemis 1in which an unmanned Orion capsule will circle the Moon and back, is a prelude to Artemis 2 in late 2024a similar mission with a human crewand eventually Artemis 3, in which NASA seeks to bring astronauts back to the lunar surface. The Artemis program as a whole is an effort to sustainably return humans to the lunar environment and set the stage for a crewed mission to Mars.

The dates requested are September 23 and 27, dates specially chosen so as not to conflict with NASA’s Next DART Mission, in which a probe will deliberately crash into a non-threatening asteroid in an attempt to test a planetary defense strategy. The DART team will need access to NASA’s Deep Space Network during the test, conflicting with the launch of Artemis 1. DART will crash into Dimorphos, the small asteroid moon of Didymos, on September 26, d ‘where the two non-conflicting dates proposed by the Artemis 1 team. Free said NASA was considering a third date in October, but the upcoming launch of the Mission Crew-5 to the ISS poses another potential conflict.

Pad repairs

In addition to needing the Eastern Range Special Waiver, NASA must repair and properly test his stubborn rocket, which failed to launch on the first two attempts. The first launch failed on August 29 was the result of a faulty sensor, while the second failed attempt on September 3 was caused by an unmanageable hydrogen leak. Ground crews are currently replacing a joint on the quick disconnect, which connects the mobile launcher’s liquid hydrogen fuel line to the 322-foot-tall (98-meter) rocket.

During today’s briefing, Mike Bolger, head of the ground systems exploration program, said engineers are still unsure whether the inadvertent overpressurization during Saturday’s attempt damaged the seal, but he said the added pressure did not exceed the quick-connect design specifications. The pressure in the hydrogen line is normally controlled by an automated system, but technicians on Saturday opted for manual operations. Bolger said the team didn’t have enough time to practice the procedure, so “we haven’t, as a management team, placed our operators in the best possible location.”

A tanking test that is supposedly not a launch rehearsal

Ground crews are expected to complete their repairs shortly, setting the stage for a major tanking test on Sept. 17, Bolger said. For this test, the ground crews would perform a complete filling of the central stage and the upper stage under the usual cryogenic conditions. Bolger said technicians are planning a “softer, gentler” approach to filling the rocket with ultra-cold liquid hydrogen and liquid oxygen. This “softer and gentler” approach, he later clarified, is based on experience from previous green courses and rocket launches, and that this “promising” path would allow for finer control of the process. refueling with regard to slow and fast filling procedures. .

The proposed September 17 tanking test looks suspiciously like a wet dress rehearsal, but Bolger said that’s definitely not the case, as the test won’t involve a countdown repeat. A fully wet dress is not necessary, he added, saying “we just want to get a good seal”, and that previous SLS wet dress rehearsals “have met all the requirements”. It was a suspicious comment to make, given that NASA had previously admitted to having not achieving 10% of their test goals during the last wet dress of July.

A successful tanking test would set the stage for the third launch attempt. For the proposed attempt on Friday, September 23, the two-hour launch window would open at 6:47 a.m. ET, with Orion returning to Earth on October 18. A launch attempt on Tuesday, September 27 would involve a 70-minute window that begins at 11:37 a.m. ET, with Orion crashing into the Pacific on November 5.

Again, it’s important to keep in mind that these launch dates are hypothetical until the eastern chain issues a new waiver. If a waiver is not issued, SLS will have to return to the VAB for the required new battery test. If that happens, NASA should consider a third launch window that runs from October 17 to 31.

Related: Why hydrogen leaks continue to be a major headache for NASA launches.