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Grizlas
RE: Starship orbital launch attempt

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Posted on 11-12-2023 20:38
Well, complexity should be avoided where possible, but some things just are complex. If all you care about is touchdown on the moon, then Starship makes little sense (as lander or transporter) - you should just use some SLS configuration and repeat the Apollo missions. If, on the other hand, you are going back to the moon to maintain a permanent presence there, then you are going to need a lot of additional complexity. But as it was with Falcon 9 during its development, it was unclear what its final capabilities were going to be. (Reuse of second stage was intended and later scrapped. The Dragon capsule was going to land propulsively, also scrapped). Starship too will inevitably end up different than whatever plans Spacex currently has mapped out, because there are so many unknowns. Heat shield might require changing the rocket and so might orbital refueling. The ability to be able to reuse the booster and/or ship might also require radical design changes.

With so many unproven technologies, Starship really should not feature in any realistic return of humans to the moon, before these technologies have been developed and tested. But the push to return to the moon is political, so NASA needs to make it happen ( within a reasonable budget). Enter the Artemis program - a political, financial, technical 50 state program clusterfuck compromise that 100% relies on Starship - a rocket in its infancy. Falcon 9 went through 6 versions before the design was locked in. Starship, a much more complex rocket, is on version 1.

Artemis program might become a reality some day. But I doubt whatever plan is on the table today will look much like what the final plan will be.
On the positive side, we probably will move quickly from Starship 1 to starship version 10 during the next couple of years and by that time NASA can adjust their Artemis program according to the end result and go to the moon. But 2 years? more like 4-6 years.


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Edited by Grizlas on 11-12-2023 20:41
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Norlander
RE: Starship orbital launch attempt

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Posted on 12-12-2023 00:09
A key point of his talk (22 minutes in) was about the near-rectilinear halo orbit (NRHO), which is an inane orbit chosen for reasons, with the real reason being that SLS and Orion are not able to actually use low lunar orbit (LLO). It doesn't have enough Δ v to actually use the most useful lunar orbit.

It's not just Starship that is causing this clusterfuck, SLS is causing plenty of these issues by itself and cannot replicate the Apollo missions even if they wanted to keep Starship out of the program. SLS cannot do it alone, SLS + 15 Starship launches is absurdly complex.


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Grizlas
RE: Starship orbital launch attempt

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Posted on 21-12-2023 18:29
I don't know if I've posted this video before - I think not. It is a really inspiring talk for anyone even a little bit interested in spaceflight. This laid back Spacex dude explains why he is passionate about Spacex and why what they are doing is such a big deal:



For a more informative, but less entertaining talk, here is Kathy Leuders, a former NASA associate administrator that now works as the general manager of Starbase (Spacex Boca Chica facility). She talks about why Spacex thinks their second flight of Starship was a success:
https://youtu.be/fQwpPIOfyPk?si=OtpOfm-8kGJBtCN-&t=1769


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Edited by Grizlas on 21-12-2023 18:47
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Grizlas
RE: Starship orbital launch attempt

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Posted on 30-12-2023 13:07
Spacex completes full duration static fire of booster 10.
33 raptor engines firing at 2x power of Saturn 5 - the rocket that took astronauts to the moon.

Just wow.




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Grizlas
RE: Starship orbital launch attempt

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Posted on 31-12-2023 13:21
Norlander wrote:
A key point of his talk (22 minutes in) was about the near-rectilinear halo orbit (NRHO), which is an inane orbit chosen for reasons, with the real reason being that SLS and Orion are not able to actually use low lunar orbit (LLO). It doesn't have enough Δ v to actually use the most useful lunar orbit.

It's not just Starship that is causing this clusterfuck, SLS is causing plenty of these issues by itself and cannot replicate the Apollo missions even if they wanted to keep Starship out of the program. SLS cannot do it alone


Yeah, the whole thing is pointless and rushed.

SLS + 15 Starship launches is absurdly complex.


Not that absurd, really. It is only absurd if viewed with Old Space glasses. I cannot put it better than this guy did:

In fairness, from an old-space perspective where launches must be booked years in advance and every drop of fuel accounted for during mission planning, saying "We can add more tankers on demand during the launch campaign, so there is no need to worry about it now," is like telling survivors of the Oregon Trail that we can stop at Walmart on the way if we need anything. It's an entirely alien concept to them. That their jobs depend on not understanding it due to political shenanigans doesn't help, either.


I mean, Falcon 9 completed 96 launches this year. Starship, which is built to be reusable, will (if everything pans out) be able to fly 10 times more than that, easily. That is at least 1000 launches a year. If orbital refueling works out, 15 launches will take a couple of weeks to get done at most.

It's all the ifs that are the real problem. If orbital refueling or rapid reuse turn out to be insurmountable obstacles, then Artemis is doomed. So lets clear these things up before we begin creating silly pointless missions.


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Edited by Grizlas on 31-12-2023 13:30
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Grizlas
RE: Starship orbital launch attempt

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Posted on 10-01-2024 18:03
In a recent briefing, NASA officially delayed Artemis 2 to September 2025. There are a bunch of issues to work through, they say, and that further delays can be expected. No shit.
Also, Starship seems to actually be on track for a February launch!




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Grizlas
RE: Starship orbital launch attempt

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Posted on 15-03-2024 09:09
We didn't get a February launch as it turned out, but a March launch!
Overall the launch was another success. This time stage separation went flawlessly and Starship reached orbit.
The main new problem that has emerged seems to be related to the attitude control of Starship.
Next Flight in 2-3 months!





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Grizlas
RE: Starship orbital launch attempt

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Posted on 27-05-2024 20:32
Its getting to be that time again. Spacex is targeting NET June 5th for their 4th flight. Last time they lost both booster and ship to valve clogging of various kinds. They have tried to fix that and added redundancy thrusters on Starship. This time the full focus is on demonstrating reuse, by showing that the heat tiles work for reentry, that they can control both vehicles through their decent and ending in a landing on a virtual tower in the ocean.

I think Spacex have been more than a little bit lucky with the Starship launches so far - especially the first one, which could have gone a lot worse. So, I think they're due for some sort of mishap. Still I'm hoping their luck holds smiley

Here's a bit of in depth rocket news from NasaSpaceFlight:






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RE: Starship orbital launch attempt

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Posted on 31-05-2024 17:07



The conventional view serves to protect us from the painful job of thinking.
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Grizlas
RE: Starship orbital launch attempt

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Posted on 01-06-2024 09:06
Good concise video from The Everyday Astronaut, as usual.
Unfortunately, it seems he wont be going to the moon but Elon tweeted this yesterday:

This is a matter of execution, rather than ideas. Unless we make the heat shield relatively heavy, as is the case with our Dragon capsule, where reliability is paramount, we will only discover the weak points by flying.

Right now, we are not resilient to loss of a single tile in most places, as the secondary containment material will probably not survive.

I will explain the problem in more depth with @Erdayastronaut next week. This is a thorny issue indeed, given that vast resources have been applied to solve it, thus far to no avail.


So we will likely be treated to another in depth one on one interview while they are walking around Starbase. Can hardly wait.


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Edited by Grizlas on 01-06-2024 09:07
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Grizlas
RE: Starship orbital launch attempt

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Posted on 06-06-2024 14:53
I've just finished watching IFT-4 and here's my hot take.
Liftoff went smoothly, despite losing a single of the outer engines. One engine out is a loss of 3% thrust, which they compensate for easily by throttling up the other engines. On to stage separation which also went off without a hitch. The booster actually managed to relight 12 of the intended 13 engines for the landing burn, which was enough for what looked to be a perfect soft landing in the ocean. Seems the thirteenth raptor decided to explode instead of relighting, but the other engines managed to compensate.

The Starship went on to reach close to orbital velocity. No ice or whatever it was clogging up the attitude thrusters this time, allowing the ship to re-enter the atmosphere at the correct attitude.
We were treated to a historical first live view of reentry (almost no loss of signal) thanks to Starlink antennas on the ship. The plasma was eating at the ship more and more as it got deeper and deeper into the atmosphere until the plasma basically started chewing through the flap, melting the steel. But somehow the flap kept actuating and the ship somehow made it far enough to execute the flip maneuver and the landing burn. It is hard to tell, but it looks like it made a soft water landing!

Here's the flap getting punished:
https://x.com/MarcusHouse/status/1798720558441562460

I can't believe it actually held up.

Spacex certainly has some work to do on the heat shield still but all in all this launch is another HUGE success. More info to come I'm sure


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Edited by Grizlas on 07-06-2024 22:41
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Norlander
RE: Starship orbital launch attempt

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Posted on 07-06-2024 20:20
Grizlas wrote:
Spacex certainly has some work to do on the heat shield still but all in all this launch is another HUGE success. More info to come I'm sure


It was amazing, that flap that refused to fail even as everything was being pummeled with plasma. Have very high expectations for the next one! And Starlink, to be able to send those images live in that ionized environment is unreal.

Think Scott Manley did the best summary I've seen so far:



Funny thing was that Boeing finally got their demo flight of Starliner to the ISS at the same time, with a breakdown 200 m from ISS. 6 years after SpaceX began sending Crew Dragon to ISS on a reusable rocket, which Boeing still hasn't been able to figure out - still single use rockets, still a capsule that is barely an upgrade from Soyuz. They are literally a decade+ behind now smiley


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Grizlas
RE: Starship orbital launch attempt

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Posted on 08-06-2024 18:11
Funny thing was that Boeing finally got their demo flight of Starliner to the ISS at the same time, with a breakdown 200 m from ISS. 6 years after SpaceX began sending Crew Dragon to ISS on a reusable rocket, which Boeing still hasn't been able to figure out - still single use rockets, still a capsule that is barely an upgrade from Soyuz. They are literally a decade+ behind now smiley


Yeah not sure what to make of Boeing/ULA at this point. They are incredibly far behind Spacex, that is a fact. They will need to develop a more reusable rocket to stay in the game, and will need to iron out any final issues with Starliner to keep their Nasa contracts going. But at least they finally got Starliner launched and it finally managed to deliver crew, so they are still in it, even if they are eons behind. In the end I think it is beneficial for spaceflight having them around - the more launch providers the better. I hope they can get their act together in the coming years/decades.

Elon said in a recent interview that they will most likely try to catch the booster on the next attempt. Imagine this 100 meters long, 9 meters wide silo being caught mid air. it will be absolutely crazy to watch:



Check out the exploding raptor! Their efforts to shield raptors from each other is working way better than I would expect. Usually a rocket goes boom immediately when any part of it explodes like that.

And also, as Scott Manley pointed out, this is more than anything a demonstration of how software is changing the industry. All Spacex flights are fully autonomous. All the mission control guys are just sitting there looking at screens with minimal if any ability to affect the launch. As we see with the toasted flap and exploding raptor, the control software is able to adapt instantly to a wide range of circumstances. This is probably another area where ULA is far, far behind.


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Edited by Grizlas on 08-06-2024 18:22
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Grizlas
RE: Starship orbital launch attempt

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Posted on 08-06-2024 19:09
I want to write a little bit about stainless steel.
When starship development began, they wanted to use carbon fiber composite, which is all the rage these days. Here are some early starship test tanks:



But sometime in 2018 Musk decided that Starship would be built entirely from stainless steel. This decision went against the consensus of his rocket building team, which he himself had assembled by headhunting the smartest aerospace engineers he could find (including Tom Mueller). Still he persisted, and eventually changed their minds. Here he explains his decision to switch to stainless steel:

https://youtu.be/vLC5W53Fsyg?si=di611rZO1kZKkp9y&t=940

I understand that Elon Musk is a controversial figure that has said a lot of bullshit and dumb stuff about a great many things. But he is not an idiot. He knows at least one thing: rockets.


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Edited by Grizlas on 08-06-2024 19:49
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Norlander
RE: Starship orbital launch attempt

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Posted on 08-06-2024 19:49
Grizlas wrote:
I want to write a little bit about stainless steel.
When starship development began, they wanted to use carbon fiber composite, which is all the rage these days.


There was a good post about this as well on r/elonmusk earlier today, with excerpts from the Isaacson book.


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Grizlas
RE: Starship orbital launch attempt

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Posted on 09-06-2024 08:21
Our boy Thunderf00t apparently live streamed the launch!
Skipping through this, there are some hilarious bits when he tries to make sense of what he is seeing, showcasing his complete lack of knowledge and when he is visibly struggling to put a negative spin on something that is so obviously a success smiley




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Grizlas
RE: Starship orbital launch attempt

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Posted on 25-06-2024 16:18





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Edited by Grizlas on 25-06-2024 16:19
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Grizlas
RE: Starship orbital launch attempt

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Posted on 10-08-2024 22:15
Someone took the time to give thunderf00t "review" of his live stream:



P.S ("the dark in the fuel there" is mostly the high temperature of the plume creating reactions between the oxygen and nitrogen in the atmosphere i.e. NOx, which appears brownish/yellow)


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Edited by Grizlas on 10-08-2024 22:17
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Grizlas
RE: Starship orbital launch attempt

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Posted on 24-08-2024 16:43
RE:Boeing
But at least they finally got Starliner launched and it finally managed to deliver crew


They "delivered" crew yes.... but not without issues with Starliner control thrusters, and now it looks like NASA will decide that Starliner is unsafe to use as a return vehicle. This decision will impact the current Boieng-NASA partnership/contracts and will require Boieng to do a bunch of extra stuff. This is another huge setback for Boeing and the Starliner program which I fear might not survive for much longer.

This decision then results in two major new problems: 1. getting rid of the Starliner capsule docked to one of only two operational docking ports. Apparently, Starliner has no software onboard to pilot autonomously so that is something they will have to fix first. 2. they need to find room for the astronauts on dragon capsules, which should not be much of a problem, since it is designed to be able to carry up to 7 passengers.

EDIT: and now it is official:




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Edited by Grizlas on 24-08-2024 17:27
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Grizlas
RE: Starship orbital launch attempt

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Posted on 01-09-2024 10:16
Another absolutely ridiculously nerdy 1½ hour deep dive from CSI Starbase.

TL;DW:
Spacex uses exhaust from the raptor 2 preburners to pressurize the lox tank on the booster. This contaminates the tank with CO2 ice which sinks to the bottom and clogs up the filters causing engine failures. Raptor 3 might solve this problem entirely.



EDIT: Video turns out to be full of questionable assumptions and factual errors, take with grain of salt.


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Edited by Grizlas on 11-09-2024 16:18
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