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NASA proves there’s a defense against killer asteroids

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by Saswato R. Das

Credit: Pixabay/CC0 Public Domain

The stock market is dipping, inflation is on the rise and there is no end in sight to the war in Ukraine. But not all the news is bad: Our planet just got a bit safer, thanks to NASA.

In a feat previously relegated to the realms of science fiction, NASA scientists successfully deflected an asteroid from its path.

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On Sept. 26, DART, a spacecraft the size of a commercial dryer, hit a nonthreatening asteroid called Dimorphos—and proved that we humans might be capable of mounting an Earthly defense, should a killer asteroid one day head our way.

Such a scenario is not far-fetched. Every school kid knows that the reason we don’t see dinosaurs roaming the Earth is that the impact of a giant asteroid wiped them out some 66 million years ago.

In a modern example, an object—perhaps a rocky asteroid, perhaps an icy comet—the size of a 15-story skyscraper exploded over the Tunguska River in Siberia in 1908, releasing energy equivalent to approximately 12-15 megatons of TNT (about a thousand times as powerful as the atom bomb that destroyed Hiroshima).

Most asteroids and comets that enter Earth’s atmosphere vaporize quickly because of the heat produced by friction. The object in Siberia, however, got within 10 miles of the planet’s surface. It flattened 80 million trees over 230 square miles. It left no crater, but the circular pattern of immense destruction is sobering.

Evidence of such events exists all over Earth. Scientists think an explosion similar to Tunguska destroyed Tall el-Hammam, an ancient walled city close to the Dead Sea, around 1650 BC.

One tell-tale sign of a planetary asteroid impact is the presence of the mineral coesite, a variant of quartz that forms only under intense heat and pressure. Mile-wide Meteor Crater in Arizona contains a lot of coesite, as do other sites across the globe. Fortunately, collisions involving an asteroid of the size (about 100 to 170 feet across), makeup and speed that produced Meteor Crater are infrequent, happening once every few hundred years, and are much more likely to hit open ocean or empty territory than a population center.

Still, such a collision could spell the end of a city like Los Angeles, and bigger asteroids could spell the end of the human race. There are thousands of these orbiting rocks in our solar system, and quite a few are on paths that bring them perilously near Earth. NASA has been finding and tracking them for more than two decades in a program sanctioned by Congress. So far none has posed a real threat.

But because the chance is not zero, NASA has looked to develop a defense mechanism. DART (short for Double Asteroid Redirection Test) tested the feasibility of changing the orbit of an asteroid, steering it away from Earth by bumping it into a new trajectory.

DART crashed into Dimorphos at a speed of just over 4 miles per second. More than three dozen telescopes around the world were watching the impact, as were the Hubble and James Webb space telescopes and the LICIACube, an Italian spacecraft designed expressly to observe DART’s slamming into Dimorphos.

On Tuesday, when NASA announced that Dimorphos had indeed been diverted, it also revealed that its experiment worked better than had been predicted. Calculations had estimated that Dimorphos’ orbit around its larger parent asteroid Didymos, which was 11.9 hours, would speed up by 10 minutes after DART crashed into it. The actual time observed was 32 minutes.

Watching NASA’s live telecast on Sept. 26 made for fascinating viewing. DART’s camera spotted Dimorphos only an hour before impact, as a faint spot of light, and it was just five minutes before the crash that the asteroid really came into focus. In the final seconds before DART made contact, the asteroid’s surface—looking like a rocky, boulder-strewn field—filled the screen. Then, true to plan, the screen went dark and the scientists watching it sent up a cheer.

The DART mission isn’t over yet; the data it generated is still being analyzed. The results are nonetheless in: DART has to be classed among the most successful spacecraft NASA has ever launched. For the first time in the history of our species, we’ve shown we might be able to defend the planet from a massive invader from space.

2022 Los Angeles Times.Distributed by Tribune Content Agency, LLC.

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Good news for a change—NASA proves there’s a defense against killer asteroids (2022, October 17)
retrieved 18 October 2022
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After lunar flyby, NASA’s Orion spacecraft is set to splashdown on Sunday – Ars Technica

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Enlarge / Orion, the Moon, and a crescent Earth on Monday.
NASA

The Orion spacecraft swung by the Moon on Monday, flying to within 130 km of that world’s surface as it set course for a return to Earth this weekend.

In making this “powered flyby burn” to move away from the Moon, Orion’s service module performed its longest main engine firing to date, lasting 3 minutes and 27 seconds. After successful completion of the maneuver, NASA’s mission management team gave the “go” to send recovery teams out into the Pacific Ocean, where Orion is due to splashdown on Sunday, during the middle of the day.

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By getting into an orbit around the Moon, and back out of it again during its deep space mission, Orion has now completed four main propulsive burns. This completes a big test of the spacecraft and its propulsive service module, which was built by the European Space Agency. Although a boilerplate version of Orion made a flight in 2014, it did so without a service module.

As part of this Artemis I mission, NASA is now three weeks into a 25.5-day test flight of the Orion spacecraft. The goal is to validate the spacecraft’s capabilities ahead of a human flight of the vehicle in about two years’ time, the Artemis II mission.

Orion has met most of its main objectives to date, with only the entry, descent, and splashdown part of its mission ahead of it. The spacecraft’s heat shield must demonstrate its ability to survive reentry at a velocity of 39,400 kph. This big test will come Sunday during a fiery reentry into Earth’s atmosphere.

A minor power issue

So far, Orion’s test flight has gone remarkably well. Typically, with new spacecraft, there are issues with thrusters, navigation, or onboard avionics and more. However, Orion has had no major issues. The only real troubleshooting has involved a problem with power systems on the vehicle.

The issue has occurred with four “latching current limiters” that help route power to propulsion and heating systems on Orion. For some reason, automated controllers on Orion commanded the four current limiters to “open” when no such command was supposed to be sent. “We’re not exactly sure on the root cause of the problem, but teams are doing tests on the ground,” said Debbie Korth, the Orion Program deputy manager, during a briefing on Monday evening at Johnson Space Center in Houston.

Overall, the Orion spacecraft has performed like a champion.
Enlarge / Overall, the Orion spacecraft has performed like a champion.
NASA

This system is somewhat like a circuit breaker box in a home, and for some reason four of the breakers were opened when they were not supposed to be. This did not pose a threat to Orion, as there are backup power systems. Had a crew been on board it would have required a minor procedure to account for the problem.

In an interview after the news briefing, Korth said she did not think the glitch would have an impact on the service module that will be used for the Artemis II mission. This hardware is already built and being tested in the United States.

“I think it’s probably too early to say for sure, but ideally we will not want to perturb the Artemis II service module,” she said. “This may very well be something we can handle with software.”

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Artemis 1 Orion spacecraft aced its test flight but still hasn't tested life support – Space.com

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The Europe-built service module powering the Orion spaceship during the Artemis 1 mission is nailing its debut lunar round trip, but a key system for keeping future human crews alive is not being tested during the flight. 

The Orion capsule, which commenced the return leg of its groundbreaking journey on Thursday (Dec. 1), is currently not filled with breathable air, European aerospace giant Airbus  told Space.com. According to Airbus, which built Orion’s service module, the capsule’s life support system will only be fully put through its paces in ground-based labs before the first flight with astronauts in 2024. 

The Europe-built service module, responsible for propulsion and navigation, is the part of the spacecraft that sustains livable conditions inside Orion’s crew compartment. The service module carries water the astronauts will need during the flight and generates breathable air by mixing oxygen and nitrogen that are stored in separate tanks.

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Related: NASA’s Artemis 1 moon mission: Live updates

During the Artemis 1 mission, however, engineers are only testing the nitrogen delivery system, but fortunately, neither Shaun the Sheep, the plush toy sent for the mission by the European Space Agency (ESA), nor the three dummies occupying the Orion cockpit, mind this fact. 

“The oxygen and nitrogen delivery systems are very similar,” Airbus spokesperson Ralph Heinrich told Space.com in an email. “We carry nitrogen on board Artemis 1 and will be testing the nitrogen delivery system during the flight that’s ongoing at the moment. As the oxygen and nitrogen systems carry the same components, the test on the nitrogen distribution system will cover by similarity the oxygen delivery system. Furthermore, the oxygen system is being tested extensively on ground.”

For Airbus, the Artemis 1 mission represents a major victory. The company was awarded a contract to develop the service module, a key component of the Orion spacecraft, by ESA, based on their previous experience building the Automated Transfer Vehicle, a cargo spacecraft which used to supply the International Space Station between 2008 and 2014. During its lunar sorties in the late 1960s and early 1970s, NASA built all of the required technology at home in the United States and didn’t include any international partners.

Shaun the Sheep fortunately doesn’t mind the absence of breathable atmosphere inside the Orion capsule during the debut Artemis 1 mission. (Image credit: ESA)

The Artemis 1 service module is a culmination of ten years of work, and the Airbus team is delighted to see the craft performing with flying colors. So far, the service module has completed all of its key tasks flawlessly, including three engine burns, which first helped Orion to enter orbit around the moon, and then to subsequently leave lunar orbit to head back to Earth.

In a post-launch press conference, NASA admitted it detected 13 anomalies during the early phase of Orion’s flight, including erratic readings from star trackers that the space capsule uses to navigate.

“Engineers will be looking into the data that’s coming back from Orion so that every single system, every single component on board of the spacecraft can be tested in one way or another before the next mission,” Sian Cleaver, the European Service module project manager at Airbus told Space.com in an interview. “So far, everything is going well. Of course, there’ll be things that can be improved or changed. There were a few things that didn’t work exactly as planned, but none of them were major issues.”

Airbus engineers are receiving a stream of data from the spacecraft including “pressure, temperature, valve position data and currents and voltages” to monitor its health, Airbus wrote in an email.

“We look at all the data throughout the whole mission, and especially during major events, like main engine firings,” Airbus wrote. “[We] make sure the system is operated within its expected and qualified range. The data is also being stored continuously, to allow post flight analyses and prepare for the next Artemis missions.”

Airbus has already delivered the next service module to NASA for testing and mating with the crew compartment for the Artemis 2 mission,which will take humans to orbit around the moon for the first time since the final Apollo flight in 1972. That mission is expected to launch no earlier than 2024, if all goes according to plan. The company has also nearly completed the assembly of the third service module, which will power the Artemis 3 mission that is expected to involve a lunar landing no earlier than 2025.

The bones of the fourth service module have also been put together and plans are in place to begin work on the fifth specimen later this month. These service modules will cover Artemis missions 4 and 5, which are expected to take off to the moon toward the end of this decade. By that time, the Lunar Gateway space station will be put together in orbit around the moon, opening a new era of regular human visits to Earth’s companion.

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“It really feels like a bit of a production line going on now at our facility,” Cleaver said. “It’s really exciting. The program is really, really moving now. We have a plan for the next 10 years, and there are also clear messages from NASA and ESA that the moon is only the first step and that the technology will be used to eventually go to Mars.”

Airbus is under contract to build the service module number six and is currently negotiating another batch of three. The service modules are single-use only and will detach from the crew capsule before it enters Earth’s atmosphere during its return. 

The Artemis 1 mission lifted off from NASA’s Kennedy Space Center in Florida on Nov. 16. The mission was a debut not only for Orion, but also for the Space Launch System mega rocket that lofted it into space. During the mission, Orion passed only 80 miles (130 kilometers) above the moon’s surface, and also broke a record for the greatest distance from Earth ever achieved by a human-rated spacecraft. By getting as far as 270,000 miles (435,000 km) from the planet, Orion surpassed the previous maximum held by the Apollo 13 mission. That mission, however, only got that far as part of a rescue operation designed to bring it back home after an onboard explosion crippled the spacecraft. 

Follow Tereza Pultarova on Twitter @TerezaPultarova. Follow us on Twitter @Spacedotcom and on Facebook

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NASA capsule flies over Apollo landing sites, heads home – World News – Castanet.net

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NASA’s Orion capsule and its test dummies swooped one last time around the moon Monday, flying over a couple Apollo landing sites before heading home.

Orion will aim for a Pacific splashdown Sunday off San Diego, setting the stage for astronauts on the next flight in a couple years.

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The capsule passed within 80 miles (130 kilometers) of the far side of the moon, using the lunar gravity as a slingshot for the 237,000-mile (380,000-kilometer) ride back to Earth. It spent a week in a wide, sweeping lunar orbit.

Once emerging from behind the moon and regaining communication with flight controllers in Houston, Orion beamed back photos of a close-up moon and a crescent Earth — Earthrise — in the distance.

“Orion now has its sights set on home,” said Mission Control commentator Sandra Jones.

The capsule also passed over the landing sites of Apollo 12 and 14. But at 6,000 miles (9,600 kilometers) up, it was too high to make out the descent stages of the lunar landers or anything else left behind by astronauts more than a half-century ago. During a similar flyover two weeks ago, it was too dark for pictures. This time, it was daylight.

Deputy chief flight director Zebulon Scoville said nearby craters and other geologic features would be visible in any pictures, but little else.

“It will be more of a tip of the hat and a historical nod to the past,” Scoville told reporters last week.

The three-week test flight has exceeded expectations so far, according to officials. But the biggest challenge still lies ahead: hitting the atmosphere at more than 30 times the speed of sound and surviving the fiery reentry.

Orion blasted off Nov. 16 on the debut flight of NASA’s most powerful rocket ever, the Space Launch System or SLS.

The next flight — as early as 2024 — will attempt to carry four astronauts around the moon. The third mission, targeted for 2025, will feature the first lunar landing by astronauts since the Apollo moon program ended 50 years ago this month.

Apollo 17 rocketed away Dec. 7, 1972, from NASA’s Kennedy Space Center, carrying Eugene Cernan, Harrison Schmitt and Ron Evans. Cernan and Schmitt spent three days on the lunar surface, the longest stay of the Apollo era, while Evans orbited the moon. Only Schmitt is still alive.

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