Artemis 1 spacecraft closes in on Earth for Sunday splashdown

Artemis 1 spacecraft closes in on Earth for Sunday splashdown

Space

By William Harwood


CBS News

Sunday splashdown: Artemis 1 spacecraft heads to the launchpad


Sunday splashdown: Artemis 1 spacecraft heads to the launchpad

00:18

NASA’s Artemis 1 spacecraft completed a 25-day journey around the moon. It was closing in on Earth Saturday. The unpiloted capsule will be subject to a hellish 5,000-degree fire before splashing down off Baja California.

The end of the Artemis 1 mission will be 50 years after the last Apollo moon landing in 1972. This is an unexpected, but highly symbolic coincidence.

Mike Sarafin, mission manager, stated that testing the Orion capsule’s 16.5-foot-wide Apollo derived Avcoat heat protection is the mission’s top priority.

He stated that there is no aerothermal facility or arc jet capable of reproducing hypersonic reentry using a heat shield this large. It is a new design heat shield, and is a critical piece of safety equipment. It is designed to protect (future astronauts), and the spacecraft. The heat shield must work.

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Halfway through Artemis 1’s mission, on November 28, a camera mounted to one of Orion’s four solar wings captured this iconic view (lower right) of the blue-and white Earth and moon.

NASA


Launched November 16 The unpiloted Orion capsule was launched from Earth orbit to the moon on the first flight of NASA’s new Space Launch System rocket. It was subject to extensive tests that tested its propulsion, navigation, and power systems in deep space.

Flight controllers encountered still-unsolved problems with the Orion spacecraft’s power system, initial “funnies” with its star trackers, and degraded performance of a phased antenna. However, Orion and its European Space Agency-built, service module were able to overcome these issues. Overall, it worked wellThey have achieved almost all of their major goals to this point.

Jim Geffre (Orion vehicle integration manager) stated that “We’ve collected an enormous amount of data characterizing the system performance from the power, the propulsion and GNC (guidance navigation and control), and so far, flight control has downlinked more than 140 gigabytes engineering and imagery data.”

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The Orion spacecraft took a track that included a close lunar flyby, followed by an engine firing to reach the “distant retrograde orbit” about the moon. After a half-lap, the spacecraft’s engine fired twice again to initiate a second close flyby with the moon. This, in turn, sent Orion back to Earth for a Sunday splashdown at the Pacific Ocean west coast of Baja California.

NASA


He said that the team is already analysing that data to help “not only understand Artemis 1’s performance, but also play forward for all future missions.”

If all goes according to plan, NASA will follow the Artemis 1 mission and send four astronauts around Earth in its second flight, Artemis 2. This flight will take place in 2024. NASA predicts that the first moon-landing will occur between 2025 and 26 when NASA announces that the first woman and the second man will step foot on the lunar surface.

The Artemis 1 capsule, which was unpiloted, flew half of its orbit around the moon. This distance took it farther than any human-rated spacecraft — 268,563 mile — and was more than any other human-rated spacecraft. Two crucial firings of the main engine set up a lunar flyby at low altitude last Monday, which, in turn, set the craft up for splashdown Sunday.

NASA had originally planned to bring it down west of San Diego. However, a cold front predicted with stronger winds and rougher seas forced mission managers to move the landing area south by 350 miles. Splashdown will now be south of Guadalupe Island, about 200 miles west from Baja California.

The Orion spacecraft is approaching from almost due south and is expected to return into the visible atmosphere at an altitude approximately 400,000 feet (or about 76 miles) at 12:20 p.m.

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The Orion spacecraft will fly a unique “skip entry” path during its return to Earth. It will skip off the top of the discernible atmospheric atmosphere like a stone, before taking a second plunge to splashdown.

NASA


NASA planners created a unique “skip entry” profile that will allow Orion to skip across the top of calm water like a flat stone. Orion will fall from 400,000 feet down to around 200,000 feet in two minutes. Then, it will climb back up to approximately 295,000 feet before returning to Earth.

Within one minute and a quarter of entry, atmospheric friction will produce temperatures across the heat shield that reach nearly 5,000 degrees Fahrenheit. This will envelop the spacecraft in an electricly charged plasma, which will block communications with flight controllers. It will take about five minutes.

After another two-and a half minutes of communications blackouts during its second drop into lower atmosphere, the spacecraft will continue to decelerate as it closes in on the target landing site. It will slow down to around 650 mph, approximately the speed sound, within 15 minutes.

Finally, the small drogue parachutes that will stabilize the spacecraft at around 22,000 feet altitude and a speed of around 280 MPH will deploy. The main parachutes of the ship will deploy at an elevation of approximately 5,000 feet. This will slow Orion down to around 18 mph for splashdown.

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During training for Sunday’s splashdown of the actual Artemis 1 spacecraft, an Orion mockup is towed into the well deck of a Navy amphibious Dock vessel.

NASA


Expected mission duration: 25 days 10 hours 52 minutes, covering 1.4 million miles since blastoff November 16.

NASA and Navy recovery crews from the USS Portland, an amphibious Dock vessel, will be on-hand at splashdown to secure the craft and tow the craft onto the Navy ship’s “well deck.”

After the deck’s gates have been closed, the water will be pumped from Orion, leaving it on a custom stand to protect its heat shield for the return trip to Naval Base San Diego.

First, engineers will collect data about how much heat was absorbed into the spacecraft by the heat of reentry and any effects that may have on the crew cabin temperature. This can take up to two hours.

Sarafin stated that “we are on track for a fully successful mission with some bonuses objectives that we’ve reached along the way.” “And on entry day we will achieve our priority one objective, that is, to demonstrate the vehicle at lunar landing conditions.”

William Harwood


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Since 1984, Bill Harwood has been full-time covering the U.S. Space Program. He was first the Cape Canaveral bureau chief of United Press International and is now a consultant for CBS News. He covered 129 spacecraft missions, every interplanetary flight after Voyager 2’s orbit of Neptune, and scores of military and commercial launches. Harwood, who is based at the Kennedy Space Center in Florida and co-author of “Comm Check. The Final Flight of Shuttle Columbia”, is an avid amateur astronomer.

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