NASA announced it would pursue the launch of its $4.1 billion Artemis I rocket to the moon on Saturday.
The two-hour launch window will open at 2:17 p.m. and the teams will meet on Thursday for a reassessment prior to an official countdown start.
The Space Launch Delta 45 weather squadron updated its forecast Thursday to predict a better chance of good weather, now a 60% chance of good conditions, up from the initial 40% forecast Tuesday. The Monday night backup window has a good weather chance of up to 70%.
“I am optimistic that we will have some clear skies to work with during the afternoon attempt on Saturday,” 45th Weather Squadron Launch Officer Mark Burger said at a press conference on Tuesday evening. “But again, the probability of a weather violation at any point in the countdown still seems pretty high to me.”
As it scrubs on Saturday, the next window will fall on Labor Day, a 90-minute occasion that opens at 5:12 p.m., which NASA said would still be feasible given that NASA only needs 48 hours to replenish all the gases. needed to refill the tank.
The massive combination of the Space Launch System and Orion spacecraft sent through several roadblocks Monday morning on NASA’s first shot to send the Artemis I mission into space, but ultimately an engine problem forced a scrub.
The culprit was what is known as the venting system, which feeds cryogenic propellant from the core stage into the four RS-25 engines at the base. Sensors showed during a bleeding test leading up to Monday’s aborted launch that one of the engines was not cooling to acceptable levels.
All four need to be temperature controlled so they don’t get stressed with the liquid hydrogen (LH2), which is cooled to minus 423 degrees Fahrenheit, when it starts flowing full throttle into the engines on takeoff.
The LH2 combined with liquid oxygen cooled to minus 297 degrees Fahrenheit provides 2.2 million pounds of thrust, which when combined with two solid rocket boosters provides 8.8 million pounds of thrust for SLS on takeoff.
Other issues during Monday’s attempt included loading the cryo-propellants, which required adjustment when a possible hydrogen leak was detected in one of the umbilical cord’s power lines. To address both issues, NASA is shifting how Saturday’s countdown will go.
“We agreed on what was called option one, which was to operationally change the charging procedure and cool down our engine earlier,” said Artemis mission manager Mike Sarafin. “We also agreed to do some pad work to address the leak we saw in the umbilical cord of the hydrogen tail service mast.”
NASA SLS manager John Honeycutt said teams weren’t quite sure if the engine temperature was really off, and that it could be a faulty sensor based on readings from other equipment at the site.
“I think we understand the physics about how hydrogen performs and not the way the sensor behaves,” he said, noting that it “doesn’t match the physics of the situation.”
He said replacing the sensor on the launch pad would be a pain and require a rollback, so instead they’re going to “fly with the data we have access to today.”
Go for launch – Space News
Point your telescope at all the space-related news, from rocket launches to advances in the space industry.
The sensors from Monday’s attempt showed that three of the four motors came within 10 degrees of a minus 420 degrees Fahrenheit target, while the fourth, the one that convinced managers to scrub, was about 40 degrees warmer, Honeycutt said.
“We’re going to try to launch,” Sarafin said. “And you know you come in this earlier attempt – [Monday’s] attempt – you know we said if we couldn’t thermally condition the motors we wouldn’t launch. And that’s the same attitude we’re going into on Saturday. I don’t see it any other way.”
If and when it takes off, the rocket would become the most powerful ever launched from Earth, surpassing the 7.6 million pounds of thrust produced by the Saturn V rockets from the Apollo missions to the moon.
Artemis I is believed to send the unmanned Orion capsule on a multi-week mission to orbit the moon, travel 1.3 million miles and return home as the fastest human-assessed spacecraft with a speed of over 24,500 mph generating nearly 5,000 degrees Fahrenheit on reentry.
The goal is to test the limits of the launch system and spacecraft so it can advance to human missions, including Artemis II, an orbital lunar mission planned for 2024, and Artemis III, which aims to send people, including the first woman to the planet. to restore lunar surface. since 1972. That flight could come as early as 2025.
But first Artemis I must get off the ground.
Follow up on Orlando Sentinel space coverage Facebook.com/goforlaunchsentinel.