Space Stuff and Launch Info

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The mystery winner of the Inspiration4 raffle (who gave his seat to Chris Sembroski) has spoken with the press. He exceeded the maximal weight for Dragon passengers and losing the difference fast enough would have been problematic.

SpaceX prepares another triple launch using each launch pad. A radar satellite for Italy 28 January 23:11, a Starlink launch 29 January 20:00, and a military US satellite 2 February in the afternoon UTC, exact time still classified.

"Wow, what a boring 9 hour wait just sitting there before takeoff. At least they had a couple hours of weightlessness...".

And 8 hours in the seat after landing!
I have seen 25:00 used for 01:00 of the next day if the association to the previous day should be clearer, but in my post above it's video timestamps.

 

[sophiecentaur]

pinnacle of human achievement

Certainly a critical factor in the whole exercise. Just imagine; in the future there could be 're-entry stages' which would rendezvous with an incoming craft and deliver it safely to the ground, exactly where it's needed and in pristine condition.

But "pinnacle" is a very subjective term and assumes a certain set of values. I still have massive reservations about manned space flight and value for money. JWSS should deliver much more worthwhile evidence than a manned landing on Mars. But I understand we need to have a public which is ok with their taxes being spent on space so PR is a relevant factor.

 

[hutchphd]

I was in a far darker place here. It is not at all clear to me that civilization as we know it will persist long enough to get to the next zenith. Maybe after a few centuries and a new Renaissance.
I am very fond of Gene Cernan's assertion that Apollo was a piece of the 21st century grafted onto the 20th century by fiat. I fervently hope that the 21st century lives up to the previews, but the trend is not promising IMHO. Disabuse me of this assessment...please!

 

[mfb]

We are launching more to space than ever before, cheaper than ever before, by more countries and companies than ever before, with more users than ever before. The 21st century is seeing the longest continuous human presence in space (since Oct 2000).
We are not flying to the Moon at the moment (NASA and its partners are working on that), but in every other aspect spaceflight is so much bigger now.

 

[hutchphd]

Following Elon Musk in action is a little like watching a great high wire artist with your heart pounding the whole time. So far he has had the same vision and drive as Korolev and von Braun and fewer impediments (Gulags, wars, genocides). He is impressive and those damned F9 landings still look miraculous every time.
Although Nasa seems vaguely moribund let us not forget Cassini-Huyghens, Hubble (and the fixit crew) and perhaps (fingers crossed) Webb. I want another deep field image.

 

[mfb]

SpaceX prepares another triple launch using each launch pad. A radar satellite for Italy 28 January 23:11, a Starlink launch 29 January 20:00, and a military US satellite 2 February in the afternoon UTC, exact time still classified.

First delayed by weather, then delayed by a ship entering the keep-out zone. Now the launches are planned for 31 Jan 23:11, 1 Feb 18:57 and 2 Feb 20:18, i.e. three launches in 48 hours. A record for SpaceX and maybe an overall record for any launch provider.
Another Starlink launch is planned for February 15.

SpaceX wants to launch up to 52 times this year, or once per week on average. While these plans are always too optimistic: So far they are on track - six launches in five weeks once these three missions are done.

Weather delays will play an important role with such a high launch rate. They are caused by a design decision over 15 years ago: SpaceX wanted the rocket to be powerful enough to carry a crew capsule, and thin enough to be transported by road. That leads to a long thin rocket. Here is one driving through a village. Reusing the booster lowers the performance, so SpaceX made the boosters even longer to compensate. Making them wider would have been a major change to everything. Now they have an extremely skinny rocket, which means it's very sensitive to wind, leading to more weather delays than most other rockets.

 

[anorlunda]

Tonight's SpaceX launch was especially spectacular in the sky. That is because the launch time was at almost exactly sunset. That means than we on the ground were in partial darkness, while the rocket and exhaust gasses were in sunlight.

At first, the smoke trail was a beautiful flamingo pink (as were the few clouds around). A few seconds later the smoke trail was pure white as it was lit by direct sunlight not filtered in the atmosphere. By then, the pink portion below was in almost total darkness and it seemed to glow in the dark.

After stage separation, we could see two rockets, side by side. We could also see white "smoke rings" from the 1st stage as the first stage cold gas thrusters pulsed. Then after some minutes, the brilliant orange flame as the first stage engines fired. Be sure to watch until the landing back at Cape Canaveral. (This landing was on land, not on the barge.) It too was spectacular.

The video captured much of what I described. Watch starting at 1:10:45

 

[Dullard]

"Now they have an extremely skinny rocket, which means it's very sensitive to wind, leading to more weather delays than most other rockets."

I'm not necessarily disagreeing, but you've lumped a lot of things into one statement.

'Weather' and 'WInd' are actually 2 different things (for purposes of a rocket launch). 'Weather' is thunderstorms, turbulence, visibility, etc., and aren't really vehicle-specific. 'Wind' is examined for at least 2 different purposes: Loads on the structure and control authority. The wind profile (magnitude and direction at altitude) is examined to make sure that the proper thrust vector can be achieved and that the result won't create excessive loads on the structure.

A 'longer' rocket aggravates both of the 'Wind' factors. Many 'other rockets' achieve maximum capacity by adding 'strap-on' boosters. These are typically not 'steerable' and (as a result) the thrust vector becomes less 'steerable.' The heaviest configuration of the Delta-II rocket (for example) suffered massively from this issue.

 

[mfb]

I see wind as part of weather.

The SpaceX livestream had awesome shots from the ground. Shortly before main engine cutoff. You can see the main engines cut off, the stages separating, the second stage starting up, the booster rotating and starting its boostback burn. Not as diffuse blobs of variable brightness, but actually as resolved objects. Even the fairing deployment - well in space and traveling almost 2 km/s at that point - was still visible from the ground.

 

[hutchphd]

When there is no real schedule, there is, I guess, no real schedule.

https://blogs.nasa.gov/artemis/2022...s Home-,Artemis I Update,-The mobile launcher

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[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