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Artemis I Launch Attempt Scrubbed

blogs.nasa.gov

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Re: Artemis I Launch Attempt Scrubbed

#101

Post by dsl »

Teever wrote: post #51
imtringued wrote: post #47

Earlier quoted context omitted.

Musk said he was going to Mars by 2018.

SpaceX could absolutely launch a mars mission with their existing rocket platforms and launch infrastructure. It would be tedious launching little pieces of a larger ship and assembling them in orbit but it could absolutely be done. Instead of doing that they're choosing to build better, bigger rockets, and more infrastructure to make the eventual launches to mars more cost-effective and substantial.

> SpaceX could absolutely launch a mars mission with their existing rocket platforms and launch infrastructure.

Which highlights the major difference between public and private sector exploration. SpaceX killing everyone on their first attempt is a tragedy and they quickly move on, NASA doing it is a 10 year halt to any further work until a full public investigation takes place.

Re: Artemis I Launch Attempt Scrubbed

#102

Post by imglorp »

ceejayoz wrote: post #76
endymi0n wrote: post #73

Does anyone get the point with Artemis? Because I really don‘t. To my untrained eye the current outlook on the program looks like that rocket is right now only supposed to make two roundtrips along the moon — and then in that third „Starship HLS“ mission Artemis’ only job is to take up the astronauts to orbit: while Starship (notably designed to be human rated) will be doing all the heavy lifting of the mission. In t…

> Does anyone get the point with Artemis? Making Senators happy.

Right, the Senate Launch System maximizes transfer of cash from taxpayers to defense contractors.

There is absolutely no need to fly any hardware in the process.

Re: Artemis I Launch Attempt Scrubbed

#103

Post by awillen »

adastra22 wrote: post #63
yarpnird wrote: post #43

Earlier quoted context omitted.

Think about all the work done by people that you are discounting...

Since the rocket gets thrown in the ocean at the end of this, this is literally the sunk cost fallacy at play.

It's not entirely sunk cost - there's reputational effects for a lot of people involved. Politicians who supported it look much worse if all this work (and money) has gone into it, only to have it not launch. How bad they will look is proportional to how much money was spent/work was done, so the work put in does matter to the outcome, at least for them.

That probably shouldn't be the case, but when it comes to politics, perception is very much reality in that people's perceptions translate directly to votes.

Re: Artemis I Launch Attempt Scrubbed

#104

Post by theteapot »

wumpus wrote: post #92
theteapot wrote: post #87

Earlier quoted context omitted.

Worked pretty well for 135 shuttle missions.

Let's see: killed a ton of people, was extremely expensive, ...

What? Hydrogen fuel nor the RS-25 had anything to do with either Shuttle loss. In fact RS-25 has an almost flawless history. Yeah it was expensive - nothing like all those other space planes that were way cheaper hey.

Re: Artemis I Launch Attempt Scrubbed

#105

Post by bastawhiz »

adastra22 wrote: post #69
bastawhiz wrote: post #8

Earlier quoted context omitted.

It's not, actually. They're not running anything. In fact, they're doing the literal opposite of what your comment suggests.

It’s an accurate description of todays launch attempt. They decided to repeat assuming the sensor problem that scrubbed the last launch was a sensor issue only. It was not.

Admitting you don't have enough information to make an informed decision for an investment to implement a fix but also not enough information to be sure the problem isn't transient doesn't seem like that at all.

Re: Artemis I Launch Attempt Scrubbed

#106

Post by thematrixturtle »

dsl wrote: post #101
Teever wrote: post #51

Earlier quoted context omitted.

SpaceX could absolutely launch a mars mission with their existing rocket platforms and launch infrastructure. It would be tedious launching little pieces of a larger ship and assembling them in orbit but it could absolutely be done. Instead of doing that they're choosing to build better, bigger rockets, and more infrastructure to make the eventual launches to mars more cost-effective and substantial.

> SpaceX could absolutely launch a mars mission with their existing rocket platforms and launch infrastructure. Which highlights the major difference between public and private sector exploration. SpaceX killing everyone on their first attempt is a tragedy and they quickly move on, NASA doing it is a 10 year halt to any further work until a full public investigation takes place.

> SpaceX killing everyone on their first attempt is a tragedy and they quickly move on

I think you're confusing Virgin Galactic with SpaceX here.

Re: Artemis I Launch Attempt Scrubbed

#108

Post by adastra22 »

mabbo wrote: post #88
adastra22 wrote: post #65

Earlier quoted context omitted.

> That buys you a lot more cargo capacity for the same sized rocket. I think you mean the same mass rocket, because hydrogen is not dense, which factors into the tradeoffs (more structural mass to contain it).

An excellent point. Fortunately bigger tanks get better and better the bigger they are. The mass of the tanks is mostly a function of it's surface area, growing with n^2, while the fuel stored grows by n^3. And the SLS tank is pretty darned big indeed, with a very large diameter.

That is only a first order approximation. Second order effects scale badly. Larger tanks for the same amount of propellant have more weight, which means they need to be built sturdier, which means even more weight, etc. LH2 can’t have a common bulkhead with LOX like Falcon 9 has, so that’s more weight, and sitting on top of the tank so the tank needs to be studier still. And LH2 is way lower temperature so you need foam insulation, which adds weight. And you don’t want that foam peeling off and hitting the SRB on the way up, so you need a layer of sealant, which (all together now!) adds weight.

Etc. etc.

Re: Artemis I Launch Attempt Scrubbed

#109

Post by adastra22 »

awillen wrote: post #103
adastra22 wrote: post #63

Earlier quoted context omitted.

Since the rocket gets thrown in the ocean at the end of this, this is literally the sunk cost fallacy at play.

It's not entirely sunk cost - there's reputational effects for a lot of people involved. Politicians who supported it look much worse if all this work (and money) has gone into it, only to have it not launch. How bad they will look is proportional to how much money was spent/work was done, so the work put in does matter to the outcome, at least for them. That probably shouldn't be the case, but when it comes to polit…

Those politicians are retiring, or already retired (except the one that is currently running NASA).

Still the sink cost fallacy though.

Re: Artemis I Launch Attempt Scrubbed

#110

Post by skissane »

imtringued wrote: post #47
hfgbvhevrt wrote: post #34

Earlier quoted context omitted.

When is that first starship orbital launch again?

Musk said he was going to Mars by 2018.

Back in 2016, Musk was talking about landing a Crew Dragon capsule on Mars, albeit with no crew on it.

His original 2018 timeline was likely over ambitious, but SpaceX probably could have achieved it by now – if they'd stuck with their plan to do it. By all accounts, it was abandoned, not because of any technical or financial obstacles, but simply because they decided to redirect their resources towards a far more ambitious alternative (Starship).

I think landing an uncrewed Starship on Mars has a fair likelihood of actually happening, before this decade is over.

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