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NASA’s Artemis Delays Fuel Controversy over Rocket Design

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In and around Cape Canaveral, Florida, everything related to Artemis. Colorful hand-painted banners that read “Go Artemis!” Decorate the storefronts. Large temporary street signs carry traffic warnings for launch day. Astronauts, NASA officials and aerospace industry executives are pressing down on the rails, which are rife with chatter about NASA’s groundbreaking program of human space exploration.

“We’re Going,” NASA announced in the days before the space agency attempted to launch its Artemis I mission, the first test of a massive craft called the Space Launch System (SLS) and a crew-rated spacecraft called Orion. Named after the sister of the Greek god Apollo, Artemis is NASA’s moonshot — the agency’s plan to return humans to the lunar surface and possibly eventually send them to Mars.

But first, the SLS needs to get off this planet. NASA’s two first launches, scheduled for August 29 and September 3 at the Kennedy Space Center (KSC), failed. The next attempt was tentatively scheduled for 27 September, with a possible backup date of 2 October – pending a successful tank test and launch authorization.

says Daniel Dumbacher, who oversaw the initial development of the SLS while at NASA and now serves as executive director of the American Institute of Aeronautics and Astronautics. “I’m not worried about this at all. It’s a delay, yes, but in the bigger picture of things, we’re re-establishing the launch capability that this country abandoned after Apollo.”

Now, as agency officials continue to troubleshoot the missile, the rhetoric has changed somewhat: They were quick to stress that the Artemis I was a test flight and a dangerous one at the time. The rocket is, after all, a new machine — even if its design is based on space shuttle age technology. And the spacecraft on top is new, too. If all goes well, the SLS will launch an unmanned Orion capsule on a circular flight around the moon — a prelude to a critical test of Orion’s toughness as the repatriated spacecraft attempts to survive a high-speed, fiery re-entry into Earth’s atmosphere.

The stakes are high. Together, the pair went over their budgets and were years behind on the launch pad, having already eaten about $43 billion in taxpayer dollars. And for some, NASA’s problems launching this rocket aren’t unexpected — but for a different reason.

“I’m not too surprised,” says Laurie Garver, a former NASA deputy administrator and well-known critic of Artemis instruments. “One of the reasons it’s not surprising is that the decisions they made over a decade ago locked them into this design that didn’t really focus on operability.”

The SLS and Orion is a Franken machine woven together in parts built by many of the older airlines — the result not of any mission-driven request from NASA but rather political pressure from influential members of Congress like then-Senator Bill Nelson (now Administrator of NASA) to keep the flow going. cash to their region or state. The result is an unwieldy tool based on outdated technology jokingly referred to as the “Senate Launch System” — which, combined with Orion, carries an almost unfathomably predicted cost of about $4 billion per launch. Even if the SLS gets off the driver board, along with the Orion payloads and secondary payloads, the rest of the extremely expensive group won’t be recovered. Instead, they will either be dumped into the ocean or left to drift through space.

This is in contrast to companies like SpaceX, which have prioritized reusable rockets and have so far launched five Rockets from Cape Canaveral since NASA rolled out the SLS to the platform on August 16. SpaceX’s largest reusable rocket currently in operation, the Falcon Heavy, has already flown into space three times; Depending on the specific mission profile and final orbital destination, under the most favorable conditions, the Falcon Heavy can lift about two-thirds of the payload as the SLS, with the price per launch of about $100 million.

“Companies with experience with these rockets wanted to keep working, which meant convincing policymakers to design them this way — even though everyone knows we have all these problems with these systems on the shuttle,” Garver says. “They somehow believed that taking the narrow and expensive parts of previous programs and putting them together differently would be easy and cost-effective.”

first shooting

The night before the first launch attempt, which was scheduled for 8:33 a.m. EDT on August 29, the “Space Coast” that includes KSC and the surrounding area of ​​Florida was already crowded with tens of thousands of spectators and hundreds of exhausted. Space Journalists. All eyes were on the SLS and Orion, stacked together as a 322-foot-tall white and yellow statue twinkling in the floodlights at Launch Complex 39 at KSC, where the multi-hour refueling process will soon begin. Hopes were high for the next day’s launch, but as the night went on, the problems festered, just like rainstorms wetting flooded Florida meadows every afternoon.

First came the weather delay. At about midnight, the probability of a lightning strike near the platform was too high for the team to begin refueling the rocket. After about an hour, the storms went out of range, and tank operations began. Degassing the SLS means pumping approximately 190,000 gallons of cryogenic liquid oxygen and 538,000 gallons of cooled liquid hydrogen into the main stage tank. It’s a delicate process because refrigerated fuel is notoriously difficult – and explosive.

Sure enough, the teams soon discovered a hydrogen leak at the base of the rocket—the same kind of problem they encountered during training in wet clothes and the same problem that often delayed space shuttle launches: For 30 years, NASA space shuttles purified in Averaged once per release – mostly due to hydrogen leakage.

Hydrogen, the smallest and lightest atom in the universe, is an excellent propellant, but also a master of escape. “It’s a sneaky little molecule. You can find ways to get out of things,” says Dumbacher. “The challenge with that is: With enough concentration, it can be combustible in places you don’t want it to burn.”

Squeeze the team and seal the leak. Tanks continued. Then a crack appeared in the SLS core stage insulating foam, but team members decided it wasn’t a problem and kept working. They couldn’t have been arrogant after a short time when sensors indicated that one of the rocket’s four engines was not cooling to the proper temperature during a procedure known as “chilldown,” which prepares the engines for the cold shock of supercooled liquid hydrogen. Normally, teams would bleed a small amount of -423°F thrust through the system to condition the four engines before exploding, but the number three engine didn’t seem to respond.

This was the show. Launch director Charlie Blackwell-Thompson announced a scrub action at approximately 8:40 a.m. ET, with the massive countdown clock paused at T minus 40 minutes.

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A few days later, NASA officials announced that the cooling procedure might have been OK. The team had enough data to indicate that refrigerant was flowing properly, and the engineers decided that the sensor reporting an abnormally high temperature might just be faulty. They will try again without fixing it. “Is it part of the plan… to just ignore the sensor?” asked Kristen Fisher, a CNN reporter, during a September 1 briefing. “Yes,” replied John Blevins, chief engineer of the SLS.

“It’s not uncommon to see hardware problems; it’s just one of those things the public isn’t used to seeing.”

Second moon launch

Officials have scheduled the next launch attempt for September 3, with a two-hour launch window opening at 2:17 p.m. ET. As Labor Day approaches, the weekend will attract even larger crowds—up to 400,000 people this time.

Again, the problems piled up quickly. Tanks operations began on time, but officials found out – blew them up! Another hydrogen leak almost immediately. They tried to fix it by heating the fill lines and pressing them with helium, but the leak was too big. Three times later, it’s proven beyond repair – and by 11am the team was already way behind on its timeline. With the hydrogen tank filled to only 11 percent, Blackwell-Thompson once again shot at an exfoliator.

“Every time we saw the leak, it was a significant leak that immediately exceeded our flammability limits,” said Mike Sarafin, Artemis mission manager during a post-launch briefing on September 3.

But, also during this briefing, Sarafin told reporters that a large hydrogen leak had occurred at the same junction where the manually inserted command “caused an unintended overpressure of the hydrogen transmission line” and boosted pressures to two or three times higher than it should have. also. As a result, he said, excessive pressure is likely to damage the seal at this junction.

“There was a sequence of about a dozen commands required, and this was simply the wrong valve that was ordered,” Sarafin said. “This was a manual sequencing, and it was probably the fact that we didn’t automate that specific sequencing which may be part of the reason we had unintended overpressure.”

As of press time, NASA officials have not yet conclusively linked this bug with the hydrogen leak ending the launch. They are still doing “error tree analysis” which will eventually point to the root cause of the rubbing.

“They really think about all the possible scenarios that could happen, and then they use the data and information very systematically to determine what might go wrong,” Dumbacher says. “They are doing all the right things.”

But Garver says that even if the wrong thing doesn’t cause the leak, it’s not good news. “At this point, whether or not that results in a leak is a red flag,” she says. “Don’t send wrong commands to overpress a line at this point in the game. It’s a process. It’s an action. They said it probably should have been automated – these aren’t the “Oh, yeah, we probably should have done that” type of questions on a stack valued at 43 Billion dollar. “

The third time is the charm?

NASA officials say they have now repaired several seals on the launch pad but have called for a third launch attempt from September 23 to September 27.

That timing still depends on two critical things: first, a successful repair and tank test run, currently scheduled for September 21, and second, a waiver from Space Launch Delta 45, a unit of the Space Force that gives permission for all missile launches in the eastern range. The SLS is only approved for launch through September 6. The batteries powering the onboard self-destruct system — a bomb designed to destroy a missile if it veers off course and threatens a populated area — will need recharging, which can only be done at the Vehicle Assembly Building (VAB) near the KSC’s 526-foot-tall.

A launch at the end of September would require the launch of the Delta 45, which is the responsibility of public safety, to waive the recharge requirement. If that’s a taboo, NASA will have to go back to the VAB and try the mid-October window, as a result of choosing a simplified launch plate design that doesn’t have the required cargo capacity.

“I don’t think there is an appreciation for how some of the early decisions that were made and that were constrained by the budget look today,” Dumbacher says. It refers in particular to the abbreviated launch process and the selection of frozen fuels.

“I heard that talk, OK, you’re not using a new technology. Well, I’m also going to remind people that the laws of physics haven’t changed,” says Dumbacher. The liquid oxygen and liquid hydrogen system is “what Mother Nature has provided that we can use to achieve our mission objectives. It has the energy to make large systems, large masses, large volumes orbital and on their way to the Moon and eventually to Mars.”

The problems of NASA’s recent human spaceflight come at a opportune time: September 12 was the 60th anniversary of the speech in which President John F. Kennedy famously declared, “We chose to go to the moon in this decade and do the other things, not because it’s easy, but because it’s hard.”

Yet, sixty years later, for the most respected space agency on Earth, perhaps the hardest part of getting into orbit is overcoming the forces – political rather than gravity – that keep them on Earth.

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