{"id":44934,"date":"2024-08-16T00:45:43","date_gmt":"2024-08-15T16:45:43","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/nasa-acknowledges-it-cannot-quantify-risk-of-starliner-propulsion-issues-2\/"},"modified":"2024-08-16T00:45:43","modified_gmt":"2024-08-15T16:45:43","slug":"nasa-acknowledges-it-cannot-quantify-risk-of-starliner-propulsion-issues-2","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/nasa-acknowledges-it-cannot-quantify-risk-of-starliner-propulsion-issues-2\/","title":{"rendered":"NASA acknowledges it cannot quantify risk of Starliner propulsion issues"},"content":{"rendered":"

With no consensus on the safety of the Starliner crew capsule, NASA officials said Wednesday they need another week or two before deciding whether to bring two astronauts back to Earth on Boeing\u2019s spacecraft or extend their stay on the International Space Station until next year.<\/p>\n

Boeing\u2019s Starliner spacecraft, stricken by suspect thrusters and helium leaks, is taking up a valuable parking spot at the space station. It needs to depart the orbiting research complex, with or without its two-person crew, before the launch of SpaceX\u2019s next Dragon crew mission to the station, scheduled for September 24.<\/p>\n

\u201cWe can juggle things and make things work if we need to extend, but it\u2019s getting a lot harder,\u201d said Ken Bowersox, associate administrator of NASA\u2019s spaceflight operations directorate. \u201cWith the consumables we\u2019re using, with the need for the use of the ports for cargo missions, those types of things, we\u2019re reaching a point where that last week in August, we really should be making a call, if not sooner.\u201d<\/p>\n

Last week, NASA officials said they expected to make a decision in mid-August\u2014presumably this week\u2014but Bowersox said Wednesday NASA probably won\u2019t make the final call on what to do with the Starliner spacecraft until the end of next week, or the beginning of the week of August 26.<\/p>\n

\u201cWe\u2019ve got time available before we bring Starliner home and we want to use that time wisely,\u201d Bowersox said.<\/p>\n

NASA astronauts Butch Wilmore and Suni Williams launched inside Boeing\u2019s Starliner spacecraft on June 5. Their mission is the first crew test flight on Boeing\u2019s capsule before NASA clears Starliner for regular crew rotation flights to the space station. But after software setbacks, parachute concerns, and previous problems with its propulsion system, Boeing\u2019s Starliner program is running more than four years behind SpaceX\u2019s Dragon crew spacecraft, which flew astronauts to the station for the first time in 2020.<\/p>\n

,<\/p>\n

And now, there\u2019s a significant chance the Starliner crew won\u2019t come home in the spacecraft they launched in. Bowersox, a former astronaut, said NASA brought in propulsion experts from other programs to take a fresh look at the thruster issue.<\/p>\n

Engineers are still investigating the root cause of why five of Starliner\u2019s 28 reaction control system thrusters, supplied by Aerojet Rocketdyne, failed during approach to the space station the day after launch. The thrusters overheated as they pulsed over and over again to fine-tune the ship\u2019s rendezvous with the station. Tests of a similar control jet on the ground suggested a Teflon seal in an internal valve could swell at higher temperatures, restricting the flow of propellant to the thruster.<\/p>\n

Four of the five thrusters that failed before Starliner docked at the station have recovered and generated near-normal thrust levels during test-firings last month. But many engineers at NASA aren\u2019t convinced the thrusters will work normally on Starliner\u2019s journey from the space station back to Earth. These control jets are needed to keep the spacecraft pointed in the right direction when four larger rocket engines fire for the deorbit burn to steer the capsule on a trajectory back into the atmosphere for landing.<\/p>\n

Rapid pulses of the thrusters, coupled with a long firing of the four larger engines, could raise temperatures inside four doghouse-shaped propulsion pods around the perimeter of Starliner\u2019s service module. Once the deorbit burn is complete, Starliner will jettison the service module to burn up in the atmosphere, and its crew module will use a different set of thrusters to guide its reentry. Then, it will deploy parachutes to slow for landing, likely at White Sands, New Mexico.<\/p>\n

,<\/p>\n

Elevated risk<\/h2>\n

Bowersox said the outside engineers brought in from other NASA centers have, so far, largely agreed with the assessments made by the team working full time on Starliner.<\/p>\n

\u201cThere are a lot of folks out there that have worked with similar thrusters, and have seen similar issues,\u201d he said. \u201cSo we\u2019ve gotten feedback on what we\u2019re seeing, and a lot of it is confirming what we thought was causing the signatures that we were observing on orbit. It\u2019s really tough when you don\u2019t have the actual hardware to look at, when it\u2019s up in space.\u201d<\/p>\n

If NASA decides to bring Wilmore and Williams home on Starliner, Bowersox said the agency will have to accept more risk than officials originally expected. NASA officials were unable to quantify how much additional risk the thruster problem might pose to the astronauts if they rode back to Earth inside the spacecraft.<\/p>\n

\u201cIt\u2019s really taken some time to work through this and getting experts together because we don\u2019t have enough insight and data to make some sort of simple black-and-white calculation, that says this is what you should do or not do,\u201d said Russ DeLoach, chief of NASA\u2019s office of safety and mission assurance. \u201cI think that\u2019s why we bring a series of experts in from different background. [It] gives us different perspectives. That means there are different opinions. There is a lot of engineering judgement that goes into this.\u201d<\/p>\n

On August 2, Boeing said it \u201cremains confident in the Starliner spacecraft and its ability to return safely with crew.\u201d NASA officials haven\u2019t expressed the same confidence.<\/p>\n

\n

\"\"<\/p>\n

Astronauts Suni Williams (left) and Butch Wilmore (right) inside a Starliner simulator at NASA\u2019s Johnson Space Center in Houston.<\/p>\n

Credit:
\n NASA\/Robert Markowitz<\/p>\n<\/figure>\n

At a so-called Program Control Board meeting earlier this month, NASA managers asked representatives of various teams involved on the Starliner program whether they were ready to give the green light for Boeing\u2019s spacecraft to return to Earth with its two-person crew. Many of the board members said no, prompting NASA to postpone a meeting of senior agency officials in a Flight Readiness Review that would have decided on a formal \u201cgo\u201d or \u201cno go\u201d for Starliner\u2019s voyage home.<\/p>\n

,<\/p>\n

\u201cI will tell you how I took the question that I heard,\u201d DeLoach said. \u201cIt really was, \u2018Do you feel like you have all the data you would need now to make a good decision?\u2019 To me, most people were at no, we need a little more work, and that\u2019s why we\u2019re continuing to work it. There were a few people that seemed to already be there (at a yes).\u201d<\/p>\n

Bowersox said engineers will attempt to model the behavior of the valve with the bulging Teflon seal over the next week and its effects on thruster performance. Managers will evaluate the modeling data, along with other test results, at another Program Control Board meeting as soon as next week. Then, NASA leadership will convene a Flight Readiness Review chaired by Bowersox. If there\u2019s no consensus out of that review, the final decision could go to NASA\u2019s most senior civil servant, Jim Free, or NASA Administrator Bill Nelson.<\/p>\n

There is some level of risk with extending the stay of Wilmore and Williams on the International Space Station and returning them to Earth on a SpaceX Crew Dragon spacecraft early next year. If that happens, the astronauts will spend eight months or more in orbit, and things can go wrong during spaceflight. Their original flight plan called for an eight-day stay at the outpost.<\/p>\n

If NASA opts to undock Starliner from the space station without the astronauts aboard, there will be a short period of time when the only way for Wilmore and Williams to come home is on the SpaceX Dragon spacecraft currently parked at the station. In that case, the Dragon capsule would have to reenter the atmosphere with a crew of six, as opposed to the normal complement of four astronauts. Wilmore and Williams would not wear pressure suits for the trip back to Earth.<\/p>\n

,<\/p>\n

If this is how NASA proceeds, two SpaceX-made launch-and-entry spacesuits for Wilmore and Williams would launch on the following Dragon mission in late September. This Dragon spacecraft would launch with a crew of two, rather than four, for a five- or six-month expedition, leaving empty seats for the Starliner astronauts to occupy when it comes back to Earth next year.<\/p>\n

\u201cThe challenge in this situation is the alternative plan raises risk, we\u2019ve got increased risk on the baseline plan, and we always knew that a test flight potentially was a bit higher risk than return with a vehicle that has a lot of flights under its belt,\u201d Bowersox said.<\/p>\n

Wilmore and Williams haven\u2019t spoken with reporters since July 10. Joe Acaba, chief of NASA\u2019s astronaut corps, said Wednesday the Starliner astronauts were aware of the risks and uncertainties associated with a test flight of a new spacecraft.<\/p>\n

\u201cI\u2019ve spoken quite a bit with Butch and Suni,\u201d Acaba said. \u201cThey are receiving a lot of information that we are reviewing here on the ground. I do ask for their opinion, but when I talk to them, they are relying on us on the ground to analyze the data and to come up with a decision. And they will do what we ask them to do, and that\u2019s their job as astronauts.\u201d<\/p>\n

Both astronauts have lived on the space station for six months before, but on those missions, they knew how long they would be in orbit when they left Earth.<\/p>\n

Wilmore\u2019s wife, Deanna, told the CBS affiliate in Knoxville, Tennessee, near the family\u2019s hometown, that she is preparing for her husband to be away for Christmas, their 30th wedding anniversary, and their daughters\u2019 school activities. \u201cWe probably don\u2019t expect him until February, February or March,\u201d she told WVLT-TV.<\/p>\n

\u201cYou just sort of have to roll with it and expect the unexpected,\u201d she said.<\/p>\n","protected":false},"excerpt":{"rendered":"

With no consensus on the safety of the Starliner crew capsule, NASA officials said Wednesday they need another week or two before deciding whether to bring two astronauts back to Earth on Boeing\u2019s spacecraft or extend their stay on the International Space Station until next year. Boeing\u2019s Starliner spacecraft, stricken by suspect thrusters and helium […]<\/p>\n","protected":false},"author":1,"featured_media":44936,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[670,524,1545,717,190,1306],"class_list":["post-44934","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","tag-boeing","tag-commercial-crew","tag-human-spaceflight","tag-international-space-station","tag-nasa","tag-starliner"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/44934"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=44934"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/44934\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media\/44936"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=44934"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=44934"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=44934"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}