NASA to do another static fire test of SLS’s core stage
NASA has now scheduled a second static fire test of the core stage of its SLS rocket, tentatively scheduled for the fourth week in February.
The first test, planned to last eight minutes, shut down after only one minute when the stage’s computers decided the parameters on engine #2 were outside their conservative margins. That burn also had a sensor issue with its fourth engine.
Conducting a second hot fire test will allow the team to repeat operations from the first hot fire test and obtain data on how the core stage and the engines perform over a longer period that simulates more activities during the rocket’s launch and ascent. To prepare for the second hot fire test, the team is continuing to analyze data from the first test, drying and refurbishing the engines, and making minor thermal protection system repairs. They are also updating conservative control logic parameters that resulted in the flight computer ending the first hot fire test earlier than planned. The team has already repaired the faulty electrical harness which resulted in a notification of a Major Component Failure on Engine 4. This instrumentation issue did not affect the engine’s performance and did not contribute to ending the first test early.
Assuming this test is successful, they will then need a month to get the stage ready for shipment by barge to Cape Canaveral, where it will take several more months to get it assembled with its two strap-on solid rocket boosters, its upper stage, and the Orion capsule on top.
Right now the unmanned test flight into orbit of this entire rocket and Orion is set for November ’21. While NASA has not announced a delay, this additional static fire test puts significant pressure on that schedule.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
NASA has now scheduled a second static fire test of the core stage of its SLS rocket, tentatively scheduled for the fourth week in February.
The first test, planned to last eight minutes, shut down after only one minute when the stage’s computers decided the parameters on engine #2 were outside their conservative margins. That burn also had a sensor issue with its fourth engine.
Conducting a second hot fire test will allow the team to repeat operations from the first hot fire test and obtain data on how the core stage and the engines perform over a longer period that simulates more activities during the rocket’s launch and ascent. To prepare for the second hot fire test, the team is continuing to analyze data from the first test, drying and refurbishing the engines, and making minor thermal protection system repairs. They are also updating conservative control logic parameters that resulted in the flight computer ending the first hot fire test earlier than planned. The team has already repaired the faulty electrical harness which resulted in a notification of a Major Component Failure on Engine 4. This instrumentation issue did not affect the engine’s performance and did not contribute to ending the first test early.
Assuming this test is successful, they will then need a month to get the stage ready for shipment by barge to Cape Canaveral, where it will take several more months to get it assembled with its two strap-on solid rocket boosters, its upper stage, and the Orion capsule on top.
Right now the unmanned test flight into orbit of this entire rocket and Orion is set for November ’21. While NASA has not announced a delay, this additional static fire test puts significant pressure on that schedule.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Let‘s hope this is NASA‘s “swan song” for hardware. They need to be working on boring-but-important things like spacesuit research & development. Much like the old NACA who did cooling research for radial engines. NACA didn‘t make the engines, they improved them. NASA needs boring research, not shiny hardware.
There hasn’t been any public comment, certainly not an official schedule change, but the internal “if the test goes well and on schedule, this is the launch date we work towards” is in 2022. It’s actually past the date I thought they were allowed to keep the boosters stacked for.
The Orion capsule assembly is also at one of those “once we do this, the clock is running” points with hypergolic propellant loading, and apparently they are holding off on that, even though it’s got a longer clock at 400+ days. Doesn’t exactly inspire confidence.
The idea that Starship would reach orbit ahead of the Senate Launch System used to strike me as overexuberance, but as NASA continues to drag this thing out, I’m starting to think that the first manned SLS launch might be to a commercial space station place there by SpaceX.
I’m sure NASA will find a good reason to waive the SRB storage limit.
“Early in the program, we set very conservative limits on this parameter, to ensure the safety of the vehicle. After extensive analysis, we have determined those limits are overly conservative. The SRBs are in good shape and ready to help lift the world’s largest rocket, the ONLY rocket capable of sending the first woman to the Moon, into orbit.”
Yes, I’m angling for a NASA PAO position.
Hi David,
“There hasn’t been any public comment, certainly not an official schedule change, but the internal “if the test goes well and on schedule, this is the launch date we work towards” is in 2022. It’s actually past the date I thought they were allowed to keep the boosters stacked for.”
Eric Berger actually just dropped a comment into the SpaceLaunchSystem subreddit a couple hours ago about this:
“I asked John Honeycutt this at a news conference before the hot fire. His response was that yes, there was a one-year lifetime for the SRBs once stacking operations begin. That happened in early January.
However he also said there was likely additional analysis they could do, or mitigation, to extend the lifetime.”
The same thread had another clarification on this as well, from a NASASpaceFlight article last summer:
One of the reasons that the EGS and SLS Programs don’t want to stack the boosters early is a time limit carried over from the Shuttle-era on how long they can stand that way. The stacked boosters have an approximately 12-month life limit, so once they are built up on the Mobile Launcher, NASA has about a year to launch Artemis 1 before they would need disassembly, inspection, and possible maintenance.
“Field Joint J-leg function and proper contact is the primary reason we have the 12 month stack life requirement,” Anderson said in an email. “The J-leg is a redundant sealing feature in the motor field joint molded into the insulation that depends on contact with the adjacent segment to create a seal when pressurized.”
Link: https://www.reddit.com/r/SpaceLaunchSystem/comments/l9g8vh/srbs_aging_out/
It does seem that this one-year timeframe is not necessarily a hard limit, but rather what it’s been certified for.
But since the launch date now looks pretty certain to be pushing hard against that 12 month certification, questions have to be asked about how confident NASA is in what it can do to stretch and mitigate that cutoff. I think they have to start doing some serious thinking about unstacking and starting over – a thought I am sure has occurred to more than a few Artemis (and NG) engineers.
Either way, redoing the hot fire seems a no brainer. Apparently pretty much all the program engineers favored doing so.
Boy, did I call it, or what?
Since the first launch will be unmanned, let’s hope it blows up and scatters debris all overt the Western Atlantic. Then the swamp dwellers will be forced to devote some serious thought about what type of space effort they want the USA to have.
Michael G. Gallagher asked: “Then the swamp dwellers will be forced to devote some serious thought about what type of space effort they want the USA to have.”
None.
Since the first launch will be unmanned, let’s hope it blows up and scatters debris all overt the Western Atlantic. Then the swamp dwellers will be forced to devote some serious thought about what type of space effort they want the USA to have.
Geesh. We already know what type of space effort the government wants the USA to have. It’s called Artemis: a manned lunar base at the lunar south pole processing volatiles for a manned trip to Mars.
Surely you jest, mkent! The $2 billion or so a year that’s being spent on Miss Piggy’s fiance could buy a lot of r&d into very useful tech. As Dave Cook said, NASA should go the NACA route.
Skunk Bucket wrote: “The idea that Starship would reach orbit ahead of the Senate Launch System used to strike me as overexuberance, but as NASA continues to drag this thing out, I’m starting to think that the first manned SLS launch might be to a commercial space station place there by SpaceX.”
A history of development related delays is why people thought, long ago, that Starship has a good chance of beating SLS to orbit. SpaceX also has delays, but it has always been serious about getting things done sooner rather than later. It is not the average modern rocket company but looks more like a company from around 1960, when we were willing to publicly blow up rockets in order to learn the lessons necessary on how to do it right.
Just as SpaceX had enough budget to lose its first three launch vehicles in the early days, many small rocket startups are willing to lose a couple of their first attempts in order to eventually get it right. It seems to me that rapid development is catching on in the space business, but a few companies still seem to move slowly. Blue Origin is one, Boeing (SLS) is another.
SLS development spending and Starship development spending are similar rates, but SpaceX is learning more about how to build and launch rapidly and inexpensively than Boeing or NASA are. Many people are more impressed with the philosophy and paradigm at SpaceX and several of the startups than they are with Boeing and most of the other heritage space companies. But then again, those startups are spending their own money, and the heritage companies tend to be spending NASA and DOD money. The difference in incentives seems to be all important.
There is more incentive to launch Starship sooner than the incentive for SLS. SpaceX and the startups have a sense of urgency, the others do not. This lack of urgency is why the development of space was so slow for the first 75 years of spaceflight, since the V2 broke the Von Karman line. Governments were in charge of spaceflight and space exploration. SLS is yet another slow and expensive government project, whose low launch rate shows only a potential for slowly expanding the exploration of space. When we let government run things, all we get is what government wants.
Five years ago, ULA had a vision for space that turned out to be a little optimistic, but then again, we were still dependent upon a practical government monopsony — and for a customer with no sense of urgency.
https://www.youtube.com/watch?v=uxftPmpt7aA (7 minutes “CisLunar 1000”)
“Economies are driven by people here on Earth, and CisLunar space is the vicinity of the Earth and the Moon, and there are potential business models that can deliver value and benefit back to humanity here on Earth.”
Rocket Lab is currently providing opportunity for many small space companies to get started in space, other smallsat launch companies will soon do this, and Starship has the promise of extending this opportunity to large companies and large projects. When We the People run things, we get what we want, and the people at SpaceX want rapid expansion into space.