Space Stuff and Launch Info

[mfb]

For the Space Shuttle, it was said that the solid rocket boosters have to launch within one year after stacking as the fuel shifts down over time. SLS uses the same boosters and should have the same constraint. The boosters were stacked in February/March 2021. The one year estimate might have been conservative, but using boosters outside their specifications is not a good idea. I expect NASA has studied this more recently, and I guess they concluded it's still okay. Unstacking the solid rocket boosters would add months of delay.

 

[sophiecentaur]

within one year after stacking as the fuel shifts down over time.

They should treat them like power fire extinguishers and photocopier cartridges. Shake them and turn them up the other way, every now and again. Alternatively, lay them down and constantly roll them slowly around their axis - like readymix concrete.

 

[gleem]

Boeing has successfully built and tested a composite cryogenic fuel tank about 4.3 m in diameter suitable for the SLS. https://www.engineeringnews.co.za/a...d the oxygen is, by definition, the oxidiser).

If it replaces the standard metal tank it could increase the payload of the rocket by as much as 30%.

Remember Musk tried to make a composite tank but opted for SS instead.

 

[hutchphd]

Is software included to make it handle just like the older tank?

OK that was mean. But I remain affronted.
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[Astronuc]

I am very fond of Gene Cernan's assertion that Apollo was a piece of the 21st century grafted onto the 20th

I found the following while looking for information on rocket nozzles and the F1 engine.

https://history.nasa.gov/SP-4206/sp4206.htm
https://history.nasa.gov/SP-4206/contents.htm

Section III Fire, Smoke, and Thunder: The Engines, Chapter 4 CONVENTIONAL CRYOGENICS: THE H-1 and F-1
https://history.nasa.gov/SP-4206/ch4.htm

 

[berkeman]

https://history.nasa.gov/SP-4206/sp4206.htm

Thanks Astro, great stuff. It's funny how primitive the web page presentation is in the link above. It's like it was done early in the Internet days, and not updated since. Still, it's not too bad to navigate, and has great info in it.

 

[hutchphd]

Atmosphere got too big for ion drive:

 

[mfb]

SpaceX lost up to 40 recently launched satellites due to a solar storm.

Starlink satellites go to very low initial orbits to mitigate space debris concerns (the deployment mechanism and potentially bad satellites reenter quickly) and to carry more satellites per launch. That means the satellites experience significant drag until they raised their orbit. The most recent launch happened when a solar storm hit Earth, increasing the density of the atmosphere. SpaceX expected the satellites to survive, but most of them did not.
It should not have a big impact on the constellation or the company - one extra launch is maybe two weeks of delay in the project. No risk to other satellites or the ground - nothing flies that low and the satellites fully burn up on reentry. NASA studies the event to learn more about the upper atmosphere.

The launch was delayed by bad weather and a ship entering the exclusion zone. Without that delay the satellites would have been higher by the time the solar storm hit Earth, and it's likely they would have survived better.

Some more details from SpaceXEdit: What a timing. Was already writing this post when you linked the video.

In other news, Starship has been stacked again, this time using the launch tower. We should get an update very soon.

 

[hutchphd]

As Scott Manley explained it they didn't have enough control authority margin in the 50% heavier atmosphere, with solar panel extended, to orientate. Can't point panels and can't aim ion thrusters...by by. Drag is likely doubled (at least) by the density increase of 50% I guess

EDIT :Also watched live video of Astra second stage pitching into a rotation at second stage ignition. Ooops. Too bad

 

[mfb]

50% higher density should be 50% more drag. Stay in safe mode until the density goes down again, then start raising the orbit - at least that was the idea. But if the orbit degrades too fast that doesn't work.

Astra's rocket fails to reach orbit. It looks like the stage separation or the ignition of the upper stage lead to an uncontrollable spin. They do launch fast, but their track record is bad so far.

Edit: After some more video watching: Astra's sequence is main engine cutoff, fairing separation, and then second engine ignition. The fairing goes around the payload and the second stage. It looks like the whole fairing or one half of it didn't separate properly. The second stage decoupled from the first stage, crashed into the fairing, and started to spin.

 

[mfb]

Starship update is here. Not that much news, and a launch is probably a couple months away.

Jared Isaacman, who bought the Inspiration 4 mission, wants to return to space. He booked three additional flights - two with Dragon and one with Starship.

The Polaris Program seeks to demonstrate important operational capabilities that will serve as building blocks to help further human exploration to the Moon, Mars, and beyond.

The first Dragon mission "Polaris Dawn" is planned to feature the first civilian spacewalk in late 2022. That would be another big step for SpaceX and for space tourism. It needs different suits, and it's probably a step towards full SpaceX space suits which could be used on the Moon and Mars in the future. Apart from the spacewalk they have a research program focused on humans in space. They want to fly higher than previous Earth orbit missions, which means they'll be exposed to larger radiation dose rates.

No chance to get a seat this time. For both Dragon flights Isaacman will fly with Scott Poteet, an employee of his company, and Sarah Gillis and Anna Menon, two SpaceX employees ("Lead Space Operations Engineers", both were heavily involved in previous crewed missions), they are all introduced on the website of the mission.

The Starship mission is planned to be the first crew on Starship.

 

[sophiecentaur]

That would be another big step for SpaceX and for space tourism

I have a particular dislike of space tourism. It has to be either a waste of money or an unreasonable risk for the rich passengers. No one needs to go up there 'just because they can afford it'. There are much more deserving causes for space launch capacity and the idea that it delivers a real profit is questionable.

 

[hutchphd]

I have a particular dislike of space tourism.

Its hard to know.
Back in the day of unlimited resource, civilan flying was largely the province of the rich and we now have flying buses. Thereby have I seen the world.
It does also seem to me a frivolous squandering of value (resources) to orbit fat cats but what is our larger purpose on this finite planet? The technology will improve, perhaps dramatically.

 

[Oldman too]

No matter how it goes, this is going to be very cool.
https://phys.org/news/2022-02-musk-confident-starship-orbital-year.html

The "Pitch"


Catch & Release or Release & Catch?

 

[sophiecentaur]

Thereby have I seen the world.

So have many of us and we have enjoyed it. But ecotourism has not been good for 'eco', has it?

The technology will improve, perhaps dramatically.

Yes - we only have to look at the achievement with JWST. Whatever images we get back, the project has delivered in spades. But perhaps we should ask ourselves how that was all achieved. The fact is that no one was in too much of a hurry - softly softly catchee monkey. Also, what we will get back from the exercise will be beautifully 'blue skies' and not likely to help the military nor the tourist industry. That's my kind of mission.

 

[hutchphd]

I applaud your vision. In particular the Cassini/Huyghens mission to Saturn seems to me another perfectly appropriately timed effort. But we seem, as a sociological species, to have very great difficulty modulating such efforts. The JWST was vastly more expensive than it "should" have been and was nearly shelved (twice I think). The liesurely manned return to the moon by NASA continues to similarly squander inordinate capital, human and otherwise, in a slow motion farce with few side benefits . There is a vitality and inventiveness to single-minded pursuit: the gorilla might otherwise simply not get caught.
I particularly believe in the space program as a repository for defense-related technology which can largely supplant a large military idustrial complex. It cannot do this usefully in a liesurely manner: there are real gains from aggressively pushing the technologies.
Personally I prefer the Ivory Tower. But it makes no sense to me in the here and now. I'll take more space tourists over more F35's in a heartbeat.

 

[Oldman too]

Interestingly enough, NASA seems to have anticipated the public remembering the "bumpy" development of JWST and prepared a response. https://ntrs.nasa.gov/citations/20180003966

 

[hutchphd]

Interestingly enough, NASA seems to have anticipated the public remembering the "bumpy" development of JWST and prepared a response. https://ntrs.nasa.gov/citations/20180003966

Wow that is a very interesting document. Pretty damned direct ! I applaud the authors for their candor: hopefully Webb performs well there will be no crowds with torches.

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[anorlunda]

Yes candid language. But the lessons learned are not unique to JWST. Indeed, they are nearly universal for large scale technology projects.

Missing from the list of lessons learned is, "Put experienced project managers in charge of the project." It could take experienced and tough project managers to tell the science committee, "Yes you can have A, but no you cannot have B."

 

[Astronuc]

A nice tutorial on modern (and past) rocket motors.

00:00 - Intro
02:55 - Basic physics of rocket engines
06:10 - Rocket engine cycles
20:30 - Rocket fuel comparison
30:40 - Raptor vs other rocket engines
44:05 - Summary

 

[Oldman too]

About eight years in the making but it looks like China will be next in line to reach the Moon.
https://www.virtualtelescope.eu/202...lcon-9-is-going-to-hit-the-moon-next-4-march/

 

[mfb]

For more deliberate (and hopefully softer) landings, Nova-C should be the next one, with a launch in March or soon after, followed by OMOTENASHI in April or whenever Artemis 1 will actually fly. The latter has a wild landing maneuver: Enter an "orbit" that intersects with the surface at a shallow angle. Just ~10 seconds before an impact, at an altitude of maybe 2 kilometers and still at orbital velocity, fire the solid fuel retrorocket. Its burn should end ~100 meters above the surface with almost no speed. Drop the rocket motor, deploy an airbag and hope for the best while falling towards the surface. The lander has a mass of less than a kilogram so it can't have complex landing systems.

 

[Oldman too]

This came to mind.
https://www.space.com/russia-ukraine-invasion-us-space-partnership-impacts

 

[mfb]

NASA official says U.S.-Russian partnership continues on space station

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We finally have overall cost estimates for the Artemis program, and they are as bad as expected or even worse. Tweet chain and article.

$4.1 billion per Artemis launch - only rocket, capsule and ground systems for that launch, no development or other infrastructure.
$93 billion total spending from 2012 to 2025. For a program that was claimed to be cheap because it would largely reuse Space Shuttle hardware.

"Part of it goes to the efficiencies of the underlying contractors, like Boeing," Martin said. "One of the problems we saw in development of the SLS and Orion—it's a challenging development of course—but we did notice very poor contractor performance on Boeing's part, poor planning, and poor execution."
[...]
"We saw that the cost-plus contracts that NASA had been using to develop that combined SLS-Orion system worked to the contractors' rather than NASA's advantage," Martin said.

Compare that to the $2.7 billion SpaceX gets for developing Starship HLS and landing on the Moon and returning to orbit twice, once with astronauts. A system that does all the hard parts of the program. The other $90 billion, 30 times as much money, are spent launching astronauts to space and returning them back from Moon orbit to Earth.

 

[sophiecentaur]

We finally have overall cost estimates for the Artemis program, and they are as bad as expected or even worse.

This sort of thing happens with governments of all persuasions. So much money disappears into black holes that there just has to be corruption involved. Boeing is a bad boy but not the only one. Once a company starts to have a cosy relationship with a government, standards drop, costs go up and they maintain their privileged position by paying those in power to ignore the problem.

It's such a shame but I guess it's just human nature.

 

[hutchphd]

It's such a shame but I guess it's just human nature.

Its good that the present leader of NASA boondoggled his way on to a Shuttle flight when he was a US Congressman. At least he understands the system.

[A sentence has been redacted from this post by the Mentors]
Rephrase: At least he understands the system and in a way that Christa McAuliffe likely did not.

 

[anorlunda]

But there's some good news here. A significant segment of NASA, the unmanned space program seems to have escaped from the death spiral that the manned space segment suffers from. How they escaped, I don't know.

For our manned space future, watch SpaceX. Not NASA. Not ESA.

 

[hutchphd]

And NASA did produce Cassini/Huyghens among other unmanned success..!

 

[Oldman too]

Bureaucracies aside, there are worse things that delay missions.
https://www.nature.com/articles/d41586-022-00608-3

 

[gleem]

Compare that to the $2.7 billion SpaceX gets for developing Starship HLS and landing on the Moon and returning to orbit twice, once with astronauts. A system that does all the hard parts of the program. The other $90 billion, 30 times as much money, are spent launching astronauts to space and returning them back from Moon orbit to Earth.

When a project's concept and execution is led by the originator then things get done ASAP. Boeing is not in the business of launching people into space it is building airplanes.

 

[hutchphd]

Boeing is not in the business of launching people into space it is building airplanes.

Boeing was the prime contractor for the S-1C for the Saturn V back when they did engineering and I believe they did a good job. Elon musk also makes cars. I don't see your point.

 

[gleem]

Boeing was the prime contractor for the S-1C for the Saturn V back when they did engineering and I believe they did a good job.

When they did engineering so they don't now? The S-1C used the veteran F-1 engine by Rocketdyne so nothing needed to be done there.

I don't see your point.

Boeing's priorities are divided. Musk is CTO of SpaceX and in charge of development, (priorities are focused) his rocket fits the needs of NASA and will cost less. Do you think Boeing could compete in the cost of development of an SLS comparable to Starship?

 

[hutchphd]

When they did engineering so they don't now? The S-1C used the veteran F-1 engine by Rocketdyne so nothing needed to be done there.

The engineering comment was a derogatory comment on the new management style.
The F-1 engine had never been previously flown but was indeed developed by Rocketdyne. It flew only on the S-1C.

.

 

[sophiecentaur]

How they escaped, I don't know.

The decision makers may share my thoughts about this - that unmanned is far better value than manned. IMO, manned expeditions are basically useful for getting votes when finances allow. Stopping all space work would be throwing the unmanned baby out with the manned bathwater and the cost of the baby is much lower than the cost of the bathwater, in this case. So keep the baby.

 

[Oldman too]

https://www.nature.com/articles/d41586-022-00727-x

Collateral fallout?