Tag: NASA

NASA to do another static fire test of SLS’s core stage

10:52 pm

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.

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New Democrat head of House subcommittee covering NASA says he supports Artemis

9:32 am

The new Democrat head of the House appropriations subcommittee that covers NASA funding, Matt Cartwright (D-Pennsylvania), appears to support the Artemis program established during the Trump administration, though he has also indicated that he does not favor the timeline imposed by Trump to land a manned mission on the Moon by ’24.

Cartwright’s embrace of Artemis during [a] July 2020 webinar was a change from 2019 when he was one of several members reacting skeptically to a supplemental budget request from the Trump Administration after it unexpectedly accelerated the timeline for putting people back on the Moon from 2028 to 2024. He complained NASA did not even have a cost estimate for the entire effort, yet expected Congress to embrace it.

In 2018, he expressed concern about proposed cuts by the Trump Administration to NASA’s earth and space science activities especially climate programs and WFIRST (now the Roman Space Telescope). He urged NASA to follow the Decadal Surveys produced by the National Academies of Sciences, Engineering, and Medicine.

What his prior views presage now that he chairs the subcommittee remains to be seen. It is widely expected the 2024 deadline will be pushed back, perhaps to the 2028 date NASA originally planned, but Cartwright appears favorably disposed towards the agency overall.

Delaying the Moon landing by SLS forever is the real goal, so the jobs program can be extended without any risks. To actually fly might result in a failure, something that no politician wants.

In the end it will not be SLS anyway that gets Americans back to the Moon. It costs too much and is badly designed. It might fly once or twice, but after that Congress will drop it while keeping Artemis, albeit in a very different form. Instead of having NASA design and build things, the new Artemis will be built by the many companies who were awarded fixed priced contracts during the Trump administration to develop their own hardware as fast as possible and as inexpensively as possible.

The distinction is important, because the latter is more likely to succeed in a reasonable amount of time.

At the same time, with Congress on board and a Democrat in the White House, it is not surprising that the policy is immediately shifting to a slower timeline. Can’t get this done too fast! I must also add that 2028 was not NASA’s original date for its return to the Moon. Before the Trump administration took control of Artemis, NASA had wanted to complete Gateway first, which based on all of NASA’s previous schedules would have pushed a lunar landing into the 2030s. Do not be surprised if this sluggish schedule is reinstated.

In fact, with the present incompetents in charge in Washington, I fully expect China to own the Moon, while U.S. politicians brainlessly dither on how to spend pork.

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Hints that NASA will redo the SLS static fire test

9:52 am

While NASA has not yet announced any decision on whether it will redo the full static fire test of its SLS core stage — following the January 16th abort — there are hints coming from industry sources that the agency is leaning to doing another test.

According to sources at the agency, program managers are in fact leaning toward conducting a second hot-fire test in Mississippi. Due to the need to obtain more propellant at the test site, conduct minor refurbishment to the vehicle, and possibly change the erratic sensor on Engine 4, the agency estimates it will require about three to four weeks before conducting another test.

Based on that schedule, the actual Artemis 1 unmanned flight, now set for November, will likely have to be delayed one month to December, since after the static fire test it will take several months to disassembly and prep the core stage for shipment to Florida and then reassembly it and prepare it for launch. That November launch date was predicated on a successful completion of the static fire test by January.

NASA and Boeing (the lead contractor building SLS) do not have much schedule margin however. They have begun stacking the solid rocket boosters that strap-on to the core stage. Once this is done the boosters supposedly have a life span of approximately one year, which means the launch must occur by about January ’22 though I would not be surprised if NASA waives that use-by-date if it needs to.

I am in a betting mood this morning. Want to bet SpaceX’s Starship completes its first orbital flight before SLS, even though it has been in development for one tenth the time (2 years vs 20) and for one thirtieth the cost ($2 billion vs $60)? I think the odds right now are very very likely. One way or the other, the race will definitely be neck-and-neck.

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SLS static fire abort not caused by malfunction but too-tight parameters

1:51 pm

According to NASA today the reason the SLS static fire test cut off after only one minute was because of too conservative margins set in the computer software.

In an update today, however, NASA said it was engine 2 that caused the abort. At that moment, the engines were underdoing a gimble test where they are rotated in different directions just as they must do during ascent to steer the rocket. Actuators in the Thrust Vector Control system that generate the force to gimble an engine are powered by hydraulic Core Stage Auxiliary Power Units (CAPUs). The CAPUs for engine 2 exceeded pre-set test limits and the computer system automatically shut down the test as it was designed to do, but NASA said it would not have been a problem during a launch.

According to NASA’s update,

The specific logic that stopped the test is unique to the ground test when the core stage is mounted in the B-2 test stand at Stennis. If this scenario occurred during a flight, the rocket would have continued to fly using the remaining CAPUs to power the thrust vector control systems for the engines.

Note too that another issue during the test needs resolution:

Initial data indicate the sensor reading for a major component failure, or MCF, that occurred about 1.5 seconds after engine start was not related to the hot fire shutdown. It involved the loss of one leg of redundancy prior to T-0 in the instrumentation for Engine 4, also known as engine number E2060. Engine ignition begins 6 seconds prior to T-0, and they fire in sequence about 120 milliseconds apart. Test constraints for hot fire were set up to allow the test to proceed with this condition, because the engine control system still has sufficient redundancy to ensure safe engine operation during the test. The team plans to investigate and resolve the Engine 4 instrumentation issue before the next use of the core stage.

No decision has been made yet whether they will do another static fire test before shipping the core stage to Florida for launch. They are under a time limit, as they have begun stacking the SLS rocket’s strap-on solid rocket side boosters, and those only have a life expectancy of one year once stacking has begun.

As far as I am concerned, nothing about the development of this rocket makes sense. I would never fly on it no matter how much money was offered to me, and anyone who does must know the terrible risk they take.

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SLS core stage static fire test aborts after only one minute

9:23 pm

During the crucial first static fire test of SLS’s core stage yesterday — meant to last a full eight minutes — the booster aborted the test after only one minute.

It’s still too early to know exactly what caused the early shutdown in Saturday’s engine test.

Flight controllers could be heard during the test referring to an “MCF” (a major component failure) apparently related to engine No. 4 on the SLS booster. John Honeycutt, NASA’s SLS program manager, added that at about the 60-second mark, cameras caught a flash in a protective thermal blanket on the engine, though its cause and significance remain to be determined.

Honeycutt said it’s too early to know if a second hot-fire test will be required at Stennis, or if it can be done later at NASA’s Kennedy Space Center in Florida, where the SLS is scheduled to launch the uncrewed Artemis 1 mission around the moon by the end of this year. Similarly, it’s too early to know if Artemis 1 will still be able to launch this year. “I think it’s still too early to tell,” Bridenstine said of whether a 2021 launch for Artemis 1 is still in the cards. “As we figure out what went wrong, we’re going to know kind of what the future holds.” [emphasis mine]

If this engine abort had occurred during a launch, with the two strap-on solid rocket boosters still firing (and no way to turn them off), the entire rocket would have been lost. Thus, for NASA to even consider shipping this core stage to Florida before figuring out the problem and fixing it is downright insane.

They need to figure out what went wrong, fix it, and then test again, even if if means the first unmanned Artemis flight experiences a serious delay. If they don’t then this whole program is proved to be an idiotic sham (something I have believed for about a decade), and should be shut down by Congress and the new President, immediately.

I am reporting this late because this weekend I was out in the country on a caving trip, taking a very much needed break from the truly horrible news of modern America.

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InSight scientists give up on heat sensor mole

9:25 pm

After another failed attempt earlier this month to dig with the German-made mole on the InSight Mars lander, the science team has decided to abandon all further efforts.

After getting the top of the mole about 2 or 3 centimetres under the surface, the team tried one last time to use a scoop on InSight’s robotic arm to scrape soil onto the probe and tamp it down to provide added friction. After the probe conducted 500 additional hammer strokes on 9 January, with no progress, the team called an end to their efforts.

This means the heat sensor, one of the two instruments carried by InSight, is also a failure, and will not be able to provide any data about the planet’s interior temperature.

From the beginning InSight appears to have been a poorly run and badly chosen project. Other than a weather station, it carried only two instruments, a seismometer and a heat sensor. Its launch was delayed two years when the French attempt to build the seismometer failed and JPL had to take over, fortunately with success. Now the failure of the German-made mole has made the heat sensor a failure.

To send a lander to Mars at a cost of a billion dollars with so little payoff seems in hindsight to have been bad use of money. Plenty of other NASA planetary missions have done far better for far less.

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U.S. and Japan formalize partnership on Gateway

8:53 am

NASA announced yesterday the signing of a formal agreement between the U.S. and Japan detailing exactly how the two countries will partner in the building of NASA’s lunar space station Gateway.

Under an arrangement with Northrop Grumman, Japan also will provide batteries for the Gateway’s Habitation and Logistics Outpost (HALO), the initial crew cabin for astronauts visiting the Gateway. Additionally, Japan is investigating enhancements to its HTV-X cargo resupply spacecraft, which could result in its use for Gateway logistics resupply.

…The agreement also marks NASA’s intent to provide crew opportunities for Japanese astronauts to the Gateway, which will be determined following additional discussions, and documented in a future arrangement.

Japan is one of the seven countries that has also signed the Artemis Accords, which covers the legal and international rights under the project. This new agreement is more technical in nature, outlining who will do what during construction.

Of course, much of this assumes that money will be forthcoming from Congress for Gateway. Right now that budget does not really exist, and its allocation remains quite uncertain.

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NASA moves up static fire test of SLS core stage

10:50 pm

NASA today announced that it has rescheduled the full duration static fire engine test of the core stage of SLS’s first stage, moving it up one day to this coming Saturday, January 16th.

During the test, engineers will power up all the core stage systems, load more than 700,000 gallons of cryogenic, or supercold, propellant into the tanks and fire all four engines at the same time.

If all goes right, that test will last about 8 minutes, the full time those engines are intended to fire during launch.

For SLS a lot rides on this test. Should anything go wrong, it will likely delay the launch, presently scheduled for November (though there are rumors this date is no longer likely). And since we now have a new administration taking power that is also linked politically with the previous Obama administration that was generally uninterested in SLS, a failure during this test could very well signal the death knell for this vastly over-budget and far behind schedule project.

For SLS to survive, this test must succeed, and fire for its full duration.

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NASA targets Jan 17th for full static fire test of SLS core stage

8:34 am

After analyzing the data from an aborted fueling dress rehearsal, NASA engineers have decided they understand and have fixed the issue that caused the abort and have now scheduled the full static fire test of SLS’s core stage for January 17th.

NASA conducted the seventh test of the SLS core stage Green Run test series – the wet dress rehearsal – on Dec. 20 at NASA’s Stennis Space Center near Bay St. Louis, Mississippi and marked the first time cryogenic, or super cold, liquid propellant was fully loaded into, and drained from, the SLS core stage’s two immense tanks. The wet dress rehearsal provided structural and environmental data, verified the stage’s cryogenic storage capabilities, demonstrated software with the stage’s flight computers and avionics, and conducted functional checks of all the stage’s systems. The end of the test was automatically stopped a few minutes early due to timing on a valve closure. Subsequent analysis of the data determined the valve’s predicted closure was off by a fraction of a second, and the hardware, software, and stage controller all performed properly to stop the test. The team has corrected the timing and is ready to proceed with the final test of the Green Run series.

…The upcoming hot fire test will fire all four of the stage’s RS-25 engines simultaneously for up to eight minutes to simulate the core stage’s performance during launch. After the firing at Stennis, the core stage for SLS will be refurbished and shipped on the agency’s Pegasus barge to NASA’s Kennedy Space Center in Florida. The stage will then be assembled with the other parts of the rocket and NASA’s Orion spacecraft in preparation for Artemis I, the first integrated flight of SLS and Orion and the first mission of the agency’s Artemis program.

The agency had been hoping to complete this test series before the end of 2020. Whether the delay will effect the planned launch date in November is unclear. I suspect they are already anticipating another postponement, in that this press release strangely makes no mention of that launch date.

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Surprisingly low number of observation proposals from astronomers for Webb telescope

4:03 pm

In preparation for the launch of the James Webb Space Telescope in ’21, the Space Telescope Science Institute (STScI) that will operate it has begun accepting observation proposals from astronomers, and has apparently discovered that the number of proposals, dubbed the subscription rate, is surprisingly low.

The stats of the James Webb space telescope cycle 1 proposal round came in the other day. In summary: an over subscription rate of 1:4. A little less even.

There was immediate spin how the stats were a good thing. Enthusiasm from around the globe! So many investigators! But that does not change that the 1:4 oversubscription is a disappointment. If I were part of the project, this would and should worry me.

If they got exactly the right number of proposals to precisely use all of the telescope’s observation time, the subscription rate would be 1. An oversubscription rate of 1.4 seems good, but in truth it is tiny compared to Hubble and other space telescopes, and horrible considering the cost of Webb (almost $10 billion, 20x what it was originally budgeted).

The author at the link provides some technical reasons for the low interest, some of which are the fault of the Webb management team (such as a very complicated proposal process) and some that are beyond their control (the Wuhan panic). He also provides suggestions that might help.

Either way, the relatively low interest I think is rooted in Webb’s initial genesis. It was pushed by the cosmological community and its design thus optimized for studying the early universe. Other astronomical fields were pushed aside or given a lower priority so that the telescope does not serve them as well.

The result is that a lot of astronomers have been finding other more appropriate and already functioning telescopes to do their work, bypassing Webb entirely. They are probably also bypassing Webb because it seems foolish to spend the inordinate amount of time putting together a proposal for a telescope a decade behind schedule that carries an enormous risk of failure once it is launched.

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Another SLS core stage abort during dress rehearsal

1:33 pm

NASA today revealed that engineers were forced on December 20th to abort at about T-5 minutes their second attempt to do a fueled dress rehearsal countdown in preparation for the full core stage static fire test.

[S]ources said the terminal countdown started at T-10 minutes and counting and ran down to T-4 minutes and 40 seconds where an unplanned hold occurred. … The criteria for how long it should take for a liquid hydrogen replenish valve to close was violated at that point in the countdown when the valve was commanded to the close position as a part of the process to pressurize the liquid hydrogen tank for engine firing. After holding at the T-4:40 point for a few minutes, teams decided the terminal countdown test couldn’t continue.

Vehicle safing and recycle sequences were then executed.

Although the countdown ran for over half of its intended duration, the early cutoff left several major milestones untested. With the countdown aborted at that point, the stage’s propellant tanks weren’t fully pressurized, the hydraulic Core Stage Auxiliary Power Units (CAPUs) were never started, the final RS-25 engine purge sequence was never run, and the vehicle power transfer didn’t occur.

NASA management is debating now whether they can proceed directly to the full core stage static fire test, where the core stage engine will fire for the full duration of a normal launch. It could be that they will decide to waive testing what was not tested on this last dress rehearsal.

If they delay the full test to do another dress rehearsal, they risk causing a delay in the fall launch of SLS, as they need a lot of time to disassemble, ship, and reassembly the stage in Florida. If they don’t delay, they risk either a failure during the full static fire test, or (even worse) a failure during that first launch.

Considering the number of nagging problems that have plagued this test program, it seems foolish to me to bypass any testing. They not only do not have enough data to really understand how to fuel the core stage reliably, they don’t even have a lot of practice doing the countdown itself. All this bodes ill when they try to launch later this year, especially if they decide to not work the kinks out now.

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