Artemis I Launch Attempt Scrubbed
blogs.nasa.gov
blogs.nasa.gov
- "Hearing a rollback to the VAB of the SLS rocket is likely, but I don't have confirmation. If that happens, it is very likely that Artemis I does not launch before October 17, at the earliest."
- "I'm told that Space Launch System program officials will recommend a rollback to the VAB to investigate the hydrogen leak. The Artemis I mission management team will consider this recommendation at their afternoon meeting, and publicly announce a decision at 4pm ET."
Meanwhile, starship will see its first orbital flight (likely not before a few RUDs) while SLS just grows mould.
That said, the whole purpose of SLS was to provide jobs and to retain technical expertise in the US, which it has achieved - actually launching the thing is almost besides the point.
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.
If they launched today they’d be 4 years late
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.
I think you're confusing Virgin Galactic with SpaceX here.
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.
Note: neither Booster 7, nor Booster 8, or Ship 20 and 24 for that matter, are even close to being anything that could be considered "Starship" by even the most generous observer.
Even if B7/S24 do launch in a test flight they are so far removed from anything that could potentially be in the far future an operational and usable spacecraft that they resemble "starship" the same way a wooden mockup of an airplane resembles an actual airplane.
An object being the same general shape and dimensions of something doesn't make that object the "something".
At least SLS exists and has problems that can be, perhaps, probably at tremendous expense, fixed.
Since it's members joined forces to form ULA 15 years ago, I've watched them launch the same machines they've been using since 2002.
I have a lot more faith that SpaceX will launch something new than that ULA will get anything done.
Artemis 1 doesn't have the configuration of a fully operational vehicle either. Artemis 1's Orion doesn't have a fully functioning life support system, launch abort system, or docking system – and probably is missing other components too.
To compare apples to apples – SLS (without Orion), to just the components of Starship/SuperHeavy which form part of launch vehicle proper (as opposed to payload) – what is Starship/SuperHeavy actually missing?
I'm sure we've all experienced situations where we realize that the work we're being paid to do is futile and will never reach achieve it's intended purpose. It's really demoralizing but the thing to remember in that situation is that you're still getting paid.
Would you rather be an aeronautical engineer who gets paid and doesn't launch of a rocket, or an aeronautical engineer who doesn't get paid and doesn't launch a rocket?
That's the spirit.
https://arstechnica.com/science/2019/06/new-report-finds-nas...
Cost overruns would have put NASA 33% over budget a few years ago, but they committed accounting fraud to cover it up.
The SLS is nothing more than a welfare check to Georgia and Florida.
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.
Still the sink cost fallacy though.
One of the arguments for doing so was that the engines were "proven."
checks news story
Oh hey, it's the engines that are causing these delays.
NASA has been so over-budget on the project, they had to commit accounting fraud to try and cover it up.
??? Last scrub was because of a problem with providing bleed cooling to cold soak everything.
This scrub appears to be a problem with a quick disconnect used in fueling operations or the piping just inside it.
Neither are the "engines".
I'm skeptical of Artemis, but come on.
"Multiple troubleshooting efforts to address the area of the leak by reseating a seal in the quick disconnect where liquid hydrogen is fed into the rocket did not fix the issue"
The joints connecting each piece of Space Launch System’s five-segment rocket motors are certified for one year once booster stacking begins, a clock that began ticking Jan. 7 with the hoisting of the SLS’s left-hand aft center booster segment on top of the booster’s lowermost piece.
But the 12-month certification limit, a holdover from the space shuttle program, could be extended with an engineering review, according to John Honeycutt, NASA’s Space Launch System program manager at the Marshall Space Flight Center in Alabama.
Honeycutt said in January engineers planned to make measurements and collect data as ground teams stacked each segment of the Artemis 1 boosters inside the Vehicle Assembly Building. The data could help NASA and Northrop Grumman extend the certification of the rocket motor joints beyond 12 months.
“That gives us the best opportunity to do some sort of a life extension on the booster stacking in the event that we need that,” Honeycutt said.
[1] https://spaceflightnow.com/2021/03/09/stacking-complete-for-...
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 this context it all looks like a total sham, it would literally be cheaper and easier to send them up in another reusable Starship.
What other purpose does Artemis have except building the most expensive trip to orbit existing so NASA can say „hey, we did something about this moon mission too!“?
Making Senators happy.
There is absolutely no need to fly any hardware in the process.
They want to go to the moon.
Artemis 3 isn‘t just depending on one, but two super heavy launchers that haven‘t even left the ground yet.
And if you put Starship in the critical path, why would you spend billions to introduce another bottleneck that‘s literally just duplicating Starship‘s ground to orbit capability?
If NASA agenda really only was getting the USA to the moon, the only rational choice would be doubling down on Starship all the way.
Their site is a good start: https://www.nasa.gov/specials/artemis/
And I've just skimmed this, but looks like a decent comparison of SLS vs Starship:
To put an uncharitable spin on it: to full federal space spending into the same places where its been since the 70s, to not rock the boat.
I think one of the reason some people are so cynical about it is that it appears to have succeeded at the second goal while being ineffective at the first.
Those tiny molecules want nothing more from life than to sneak through the smallest of openings. Well, possibly second to mating violently with oxygen.
Bomb: To explode, of course.
In fact, it was his student film.
Looks like he was going for a 2001 A Space Odyssey feel.
I thought he was communicating just how _boring_ and time consuming space exploration will be, being such vast emptiness.
It's specific impulse ('fuel efficiency') is unbeatable. That buys you a lot more cargo capacity for the same sized rocket. And since this program is putting large items into lunar orbit, you need that badly.
But as you said, it's... complex to work with.
Hey it worked for the space shuttle.
Liquid hydrogen is very low density, and requires extremely low temperatures.
This means that you need a much bigger tank for a given weight of fuel, and that tank needs to be insulated bc liquid hydrogen must be kept below 33 kelvin.
Both of these downsides can come close to negating the upside of increased ISP.
But the upside for SLS is that they already had engines that can run on hydrogen. Like you said, trade offs all around
I think you mean the same mass rocket, because hydrogen is not dense, which factors into the tradeoffs (more structural mass to contain it).
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.
Etc. etc.
A lot of other launch vehicles use RP-1, which is basically just kerosene. Lower specific impulse so lower payload capacity but it doesn’t need to be cryogenically stored and cooled with everything that entails.
That’s a fine choice for single use rockets but when you get into reusable rockets you now have a new problem: RP-1 burns and leaves a lot of carbon behind. This is costly and slow to clean.
For this reason SpaceX’s next rocket uses methane. Like hydrogen or must be cooled but not as much. Still it’s more complex engineering.
Artemis to me seems too expensive but it will be the most powerful launch vehicle ever created with the highest payload capacity.
So how is it wrong?
(We need to finally replace SRBs with something cleaner too.)
What does it turn into when burnt? Would there be much unburnt methane leaking into the environment from these rockets and the infrastructure to support these rockets?
One molecule of methane combines with two molecules of oxygen to form one molecule of carbon dioxide along with two molecules of water. Releasing good amounts of energy when this reaction (oxidation of hydrocarbons by simply burning them) is taking place.
CH4 + 2 O2 = CO2 + 2 H2O
Hydrogen is the simplest flammable gas. H2, in molecular form.
2 H2 + O2 = 2 H2O
Two molecules of hydrogen combine with one molecule of oxygen to form two molecules of water with no other byproducts. Lots of energy comes out too when hydrogen burns but it is a completely clean gas unlike any other. If hydrogen can be manufactured using only green energy, it is completely benign to the environment when burned. Also harmless when released unburnt as long as it doesn't cause any fires or asphyxiation or something.
OTOH when the methane burns it turns into an equal number of carbon molecules in the atmosphere in the form of CO2. Fortunately the CO2 has a lesser greenhouse effect than if the unburnt methane were directly released (or leaked) into the environment.
As it is now, any methane likely to be used as rocket fuel would alternatively just be turned into atmospheric CO2 by some other terrestrial user of natural gas anyway. Without launching any spacecraft.
Methane fuel still puts CO2 into the atmosphere at the push of a button, which would require a herculean effort to remove later, and that removal would not be justifiable until the situation is much more dire, as we have seen.
Still, methane really can be considered the cleanest burning hydrocarbon, but nowhere near the zero-CO2 exhaust from a hydrogen flame.
Both of these gaseous fuels are so light they do not like to be physically liquified at all, not even when highly pressurized, and that would require very heavy-walled storage cylinders in that case. But they still need to be stored as a liquid in order to carry orders of magnitude more fuel than the same size tank would hold in gaseous form. So they use extreme low-temperature cryogenics to liquefy these fuels and the storage & handling is accomplished at temperatures so far below zero that the product remains liquid without needing to be kept under very much pressure. Instead, it's handled very cold at all times with lots of insulation & refrigeration. If it warms up too much the pressure rise is certainly expected to exceed the design maxiumum of the storage tank, so all safety relief devices must be highly reliable under these conditions.
There's this thing about cryogenics.
Everything can't be expected to work right the first time, and success may not be had until all possible failures have already been witnessed to occur, and further design experience has been gained developing the workarounds.
Yes, it has the highest practical specific impulse. No, that is not the most important metric for a lower stage. Take a look at how many new launchers are using hydrogen in their lower stages. Hint: it’s a big, round sort of a number.
I believe a part of reasons why launch attempts are called "attempts" is because of extreme scrub and failure rate of launch vehicle launches, and I think the fact that scrubs are now considered abnormal can be attributable to SpaceX and Elon Musk. I was old enough to remember watching last few of Space Shuttle launch attempts, and from my experience watching launch streams, scrubs and recycling due to hydrogen leaks, erratic sensor readings, upper atmosphere weather, and private boats and planes violating keepout areas were entirely normal events, with a global sole exception of the Soyuz launch vehicle flying from Baikonur Cosmodrome, which delayed or failed up to once in a decade or so.
Apparently it pisses off people in power, sometimes might have caused off-season human resource reallocations, but rocketeers basically never cared. That was until Falcon 9 started launching on first tries of each attempts.
It’s about mature vs immature vehicles, mostly. Much as I loathe the entire SLS program and design of the rocket, it is not because they’re having some trouble with scrubs. That’s going to happen with a unique, complex, and new system.
I guess we have to ask TLC…
And this case is particularly spectacular because while it's ostensibly just a test, they are literally using the exact same engines that the Space Shuttle used. Not as in the exact model, but literally refurbished RS-25 engines that already completed successful flights on the Space Shuttle.
8-inch quick disconnect hoses have to be really gnarly to do anything with.
https://www.nasa.gov/image-feature/launch-abort-motor-for-or...
Give what you said all of the military is a jobs program also.
…which is why it’s often a good idea to not use a new launch vehicle on the critical path for your crewed spaceflight program. (Could have used LEO rendezvous of various types to go to the Moon.)
https://spacecraft.ssl.umd.edu/akins_laws.html
> 39. The three keys to keeping a new human space program affordable and on schedule: 1) No new launch vehicles. 2) No new launch vehicles. 3) Whatever you do, don't develop any new launch vehicles.
The same is now true of the Starship, which is again being entirely privately funded. The cost is certainly going to be much more than $100 million, but also nowhere near the absurd extremes of cost that Boeing imposes on the taxpayer. At this point "we" have spent tens of billions of dollars on this catastrophe. And the icing on the cake is that if this monstrosity is ever deemed flight worthy, it will likely already be obsolete.
It's quite difficult to understand why giving a company billions of dollars a year, unless they succeed, does not seem to be leading to great outcomes. Maybe we should just give them more money. That'll fix everything.
And just to put things in perspective: SLS (not Orion, just SLS) is projected to cost a total of $30 Billion
The shuttle cost $1.5BN/launch and SLS, forty years later? Over $2BN/launch.
Absolute insanity.
People on here sure are fickle.