Spacecraft Artemis 1 heads for landing on Sunday to complete its historic mission

Spacecraft Artemis 1 heads for landing on Sunday to complete its historic mission

Spacecraft Artemis 1 heads for landing on Sunday to complete its historic mission

NASA’s Artemis 1 spacecraft concluded a 25-day trip around the moon and approached Earth on Saturday, on track for a 25,000-mph reentry Sunday that will subject the unpiloted capsule to a hellish 5,000-degree inferno before crashing down off Baja California .

In an unexpected but richly symbolic coincidence, the end of the Artemis 1 mission, expected at 12:39 a.m., will come on the day 50 years after the last Apollo moon landing in 1972.

Testing the Orion capsule’s 16.5-meter-wide Apollo-derived Avcoat heat shield is the top priority of the Artemis 1 mission, “and it’s our number one goal for a reason,” said mission manager Mike Sarafin.

“There is no arcjet or aerothermal facility here on Earth capable of replicating hypersonic reentry with a heat shield of this size,” he said. “And it’s a brand new heat shield design, and it’s a safety-critical piece of equipment. It’s designed to protect the spacecraft and (future astronauts) … so the heat shield has to work.”

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On Nov. 28, halfway through the Artemis 1 mission, a camera on one of the Orion spacecraft’s four solar wings captured this iconic image of the blue-and-white Earth and moon (lower right).

NASA


launched November 16 during the maiden flight of NASA’s massive new Space Launch System rocket, the unmanned Orion capsule was flung from orbit to the moon for an exhaustive battery of tests, testing its propulsion, navigation, power and computing systems deep space environment.

While flight controllers continued to encounter unexplained problems with the power system, initial “funkiness” with its star followers and reduced performance of a phased array antenna, the Orion spacecraft and its European Space Agency-built service module generally worked wellwith which they have achieved almost all of their main objectives so far.

“We have collected a huge amount of data that characterizes the system performance of the power system, propulsion, GNC (guidance, navigation and control) and so far the flight control team has downlinked to more than 140 gigabytes of technical and imagery data,” said Jim Geffre, Orion’s vehicle integration manager.

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The Orion spacecraft followed a trajectory that included a close lunar flight and a subsequent engine firing to achieve the planned “distant retrograde orbit” around the moon. After half a lap, the spacecraft’s engine fired two more times to set up a second close-flyby of the moon that in turn sent the capsule on its way back to Earth for a Sunday splash into the Pacific Ocean at west of Baja California.

NASA


The team is already analyzing that data “to help not only understand performance on Artemis 1, but also plan ahead for all subsequent missions,” he said.

If all goes well, NASA plans to follow the Artemis 1 mission by sending four astronauts around the moon in the program’s second flight – Artemis 2 – in 2024. The first moon landing would follow in the 2025-26 time frame , when NASA says the first woman and the next man will set foot on the lunar surface.

The unmanned Artemis 1 capsule flew through half of an orbit around the moon that put it farther from Earth — 268,563 miles — than any previously human-assessed spacecraft. Two critical main engine firings last Monday triggered a low-altitude lunar flight that in turn put the craft on course for landing on Sunday.

NASA originally planned to take the ship west of San Diego, but a predicted cold front with higher winds and rougher seas prompted mission managers to move the landing site about 350 miles south. Splashdown is now expected south of Guadalupe Island, about 200 miles west of Baja California.

Approaching almost due south, the Orion spacecraft is traveling at 32 times the speed of sound and is expected to re-enter the observable atmosphere at 12:20 a.m. at an altitude of 400,000 feet, or about 76 miles.

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The Orion spacecraft will fly an unusual “skip entry” trajectory during its return to Earth, bouncing over calm waters off the top of the observable atmosphere before a second plunge plummets down.

NASA


NASA planners devised a unique “skip-entry” profile that causes Orion to leap over the top of the atmosphere like a flat rock skipping over calm water. Orion will plunge from 120,000 feet to about 200,000 feet in just two minutes, then climb back up to about 295,000 feet before resuming its computer-controlled fall to Earth.

Within a minute and a half of entry, atmospheric drag will generate temperatures across the heat shield reaching nearly 5,000 degrees Fahrenheit, enveloping the spacecraft in an electrically charged plasma that blocks communication with flight controllers for about five minutes.

After another two and a half minute communication breakdown during its second drop into the lower atmosphere, the spacecraft will continue to decelerate as it approaches the planned landing site, decelerating to about 650 mph, about the speed of sound, about 15 minutes after the import started.

Finally, at an altitude of about 22,000 feet and a speed of about 280 mph, small parachute parachutes will deploy to stabilize the spacecraft. The ship’s main parachutes will deploy at an altitude of about 5,000 feet, slowing Orion to a leisurely 18 mph or so before splashdown.

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An Orion mockup is towed onto the flooded well deck of a Navy amphibious docking vessel during training to prepare for Sunday’s landing and recovery of the actual Artemis 1 spacecraft after its 1.4 million-mile test flight around the moon.

NASA


Expected mission duration: 25 days 10 hours 52 minutes, covering 2.4 million miles since detonation on Nov. 16.

NASA and Navy rescue crews aboard the USS Portland, an amphibious docking vessel, will be standing by in sight of the crash, ready to secure the craft and deliver it to the Navy ship’s flooded “well deck.” to tow.

Once the deck gates are closed, the water is pumped out, leaving Orion on a modified stand, protecting its heat shield, for the journey back to Naval Base San Diego.

But first, the recovery team will be on standby for up to two hours while engineers collect data on how the heat from reentry penetrated the spacecraft and what effects that could have on crew cabin temperatures.

“We’re on track to have a fully successful mission with some bonus goals achieved along the way,” Sarafin said. “And on the day of entry, we will realize our main goal, which is to demonstrate the vehicle on return to the moon.”



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