NASA will attempt to launch Artemis I on Saturday; Weather Prospects Improve – Orlando Sentinel

NASA announced that it will continue to launch its $4.1 billion Artemis I rocket to the Moon on Saturday.

The two-hour launch window opens at 2:17 p.m. and teams will gather on Thursday for another review before the official countdown begins.

The Space Launch Delta 45 weather squadron on Thursday updated its forecast to predict a better chance of good weather, now 60% chance Under good conditions, up from Tuesday’s initial 40% forecast. Monday evening backup window odds of good weather increase to 70%.

“I’m optimistic we’ll have some clear air to work with during Saturday afternoon’s bid,” Mark Burger, the 45th Weather Squadron launch officer, said at a Tuesday evening news conference. “However, again, the possibility of a weather violation occurring at any point in the countdown still seemed to me fairly high.”

If it cleans up on Saturday, the next window will be on Labor Day, a 90-minute opportunity that opens at 5:12 p.m., which NASA said would still be feasible because NASA only needs a 48-hour time frame to replenish all the gases needed to refill. the tank.

The massive jumble of a Space Launch System topped by the Orion spacecraft blasted through several roadblocks Monday morning in NASA’s first shot of sending the Artemis I mission into space, but eventually an engine problem forced a scrub.

The culprit was what is known as the bleed system, which feeds cooled propellant from the primary stage to the four RS-25 engines in its base. Sensors during the bleed test that led to the aborted boot on Monday showed that one of the engines was not cooling to acceptable levels.

All four need to be temperature controlled so they don’t get overstressed with liquid hydrogen (LH2), which is cooled to minus 423 degrees Fahrenheit, when full throttle starts to flow 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 the SLS on takeoff.

Other issues included during Monday’s attempt to load refrigerant propellant, which needed to be adjusted when a potential hydrogen leak was detected in one of the secret feed lines. To deal with both issues, NASA is working to change how the countdown to Saturday begins.

“We agreed on what was called the first option, which was to change the loading procedures operationally and start cooling our engine early,” said Mike Sarafin, Artemis mission manager. “We also agreed to do some work in the pad to address the leak we saw in the secret hydrogen tail service mast.”

The teams weren’t quite sure if the engine temperature was really off target, said John Honeycutt, NASA SLS manager, and possibly a faulty sensor based on readings from other equipment at the site.

“I think we understand the physics of how hydrogen performs and not the way the sensor behaves,” he said, noting that it “does not fit with the physics of the situation.”

He said that replacing the sensor on the launch pad would be difficult and require retraction, so instead they would “go flying with the data we can access today.”

Sensors from Monday’s attempt showed that three of the four engines came within 10 degrees of a minus 420 degrees Fahrenheit target while the fourth, the engine that convinced managers to rub, was about 40 degrees warmer, Honeycutt said.

“We’ll try to launch,” Sarafin said. “And you know to enter into this earlier attempt – [Monday’s] Try – you know we said that if we couldn’t thermally condition the motors, we wouldn’t fire. This is the same situation we go to on Saturday. I don’t see it any different.”

If taken off, the rocket would become the most powerful rocket ever launched from Earth, outstripping the 7.6 million pounds of thrust produced by the Saturn V rockets for the Apollo missions to the moon.

Artemis I is supposed to send the unmanned Orion capsule on a weekly, multiple mission to orbit the moon, travel 1.3 million miles and back home as the fastest human-rated spacecraft ever, at over 24,500 miles per hour and generating nearly 5,000 degrees Fahrenheit upon entry. once again .

The goal is to test the limits of the launch system and spacecraft so that it can transition to human missions including Artemis II, a lunar orbital mission scheduled for 2024, and Artemis III, which aims to return humans including the first woman to the moon’s surface. Since 1972. This flight could come as early as 2025.

But first Artemis must get off the ground.

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