NASA Artemis 1 going to the Moon (launched Nov 16)

[hutchphd]

I am certainly jaded. But I carefully limited my comments to the manned side NASA. The unmanned Rovers and trips to the gas Giants have been breathtaking in scope, planning, and execution. The Huygens probe for instance (although much of it was ESA I guess) was maybe as good as it gets. And even though jaded I am amazed to have shared an office with the woman who later fixed Hubble..Kathy tossing the bad solar arrays off the Canada arm to flap in the thruster wash is a picture for the ages (mine at least). One of NASA's great saves IMHO. And look at what Hubble did
But the rediculous PR about shuttle safety throughout, the Challenger debacle, the endless pork and then recycled pork for promised next steps belies ferocious mismanagement. I will be surprised if Aries actually delivers a moon landing.
But Elon keeps stickin those landings. Fingers crossed.

 

[neilparker62]

In the Apollo era they said humans would land on Mars by 1985. Still waiting...

Like nuclear fusion, it might never happen. But then again just imagine both do for if one then definitely the other!

 

[Borg]

Launch will be attempted again on Saturday.

https://www.cnbc.com/2022/08/30/nasa-artemis-1-moon-mission-update-saturday-launch-attempt.html

 

[mfb]

Saturday September 3, 2:17 pm local (18:17 UTC), again a two hour window.

NASA blog
I don't see a discussion what exactly they want to change/fix, apart from starting the engine chilldown earlier.

Last year we got this launch window planning document. It says at least 48 hours between a first and a second launch attempt, and at least 72 hours between a second and third attempt, based on the time needed to refill hydrogen and oxygen tanks on site. With the five days between attempt 1 and 2 now it's likely that a third attempt 48 hours later will be possible: September 3 as baseline, and September 5 (5:12 pm local or 22:12 UTC, 90 minute launch window) as option if needed.
If they miss both they need to roll the vehicle back to VAB and we won't get a launch before October.

 

[.Scott]

Yeah, I recall asking myself why one big single point failure during the Apollo missions (okay, I was 16 and didn't frame the thought quite this way), why not park pieces in orbit using much smaller rockets? In todays world not doing this seems really wasteful and risky. Perhaps doing it without certain CEOs is a mission goal.

Big rockets are more efficient than smaller ones.

The formative SLS decisions were made around 2011 when SpaceX was applying itself to making the Falcon 9 usable for astronauts. There was some expectation that SpaceX might progress so swiftly and that ULA might encounter so many blocks - but not enough to make SpaceX a contender.

Since then, the SpaceX option has not been enough to displace the ULA option. In fact, SpaceX has benefitted from NASA's policies that encourage at least two available launch providers.

 

[Paul Colby]

Big rockets are more efficient than smaller ones.

Sorry, I didn't follow your comment. Doesn't mean it isn't spot on or incorrect somehow. My track record even while in aerospace wasn't what I consider stellar when it came to big picture stuff. As far as big rockets are more efficient, what are the metrics? Energy, time, money, mean fatalities per launch?

 

[.Scott]

Sorry, I didn't follow your comment. Doesn't mean it isn't spot on or incorrect somehow. My track record even while in aerospace wasn't what I consider stellar when it came to big picture stuff. As far as big rockets are more efficient, what are the metrics? Energy, time, money, mean fatalities per launch?

You're post was related to getting functional mass to orbit. Elon has described the reasoning behind the mammoth size of Starship as being the proportional size of its components as the scale goes up. Basically, there's a bunch of stuff that has to be on the rocket no matter what the rocket's size, so with a semi-fixed numerator, make the denominator big.

There's also been a lot of discussion about the practicalities of routinely assembling large components in orbit. Clearly it can be done (as with ISS), but in the Apollo era, the rendezvous maneuver alone was "new". Obviously, later space stations were assembled and refueled in orbit. Orbital refueling is planned for Starship. Blue Origin ULA has criticized the practicalities of the Starship refueling as related to the lunar landing mission (with obvious partiality to their own proposed solution).

So the "efficiency" is one of economy (your "money" option) and seems to be a combination of overall engineering efficiency and that numerator issue.

 

[Paul Colby]

Yeah, I get the trade in the era of Apollo given the state of the technology. In the present if one claims larger reusable rockets are better than more smaller reusable rockets, this is also quite a reasonable trade result. What I definitely don’t get a single massive one time use rocket.

 

[Filip Larsen]

https://arstechnica.com/science/202...attempt-to-launch-the-sls-rocket-on-saturday/:

During a news conference on Tuesday evening, NASA's program manager for the SLS rocket, John Honeycutt, said his engineering team believed the engine had actually cooled down from ambient temperature to near the required level but that it was not properly measured by a faulty temperature sensor.

If true that certainly makes it more likely the next launch attempt will at least move past this step (assuming here they will have enough time to replace the sensor over the next few days - even though it is NASA).

 

[gleem]

According to this article https://www.msn.com/en-us/news/tech...launch-its-moon-rocket/ar-AA11k1Mp?li=BBnbfcL , they are not replacing the sensor. (?) Examination of the engine does not show any problem so they assume the sensor is faulty. Replacing it would mean too much of a delay. The other engines did not reach the target temperature so they are starting the chill down sooner.

 

[.Scott]

Yeah, I get the trade in the era of Apollo given the state of the technology. In the present if one claims larger reusable rockets are better than more smaller reusable rockets, this is also quite a reasonable trade result. What I definitely don’t get a single massive one time use rocket.

The expectation is that Starship will be the best of all worlds. Big and 100% (both stages) reusable.
Rocket reusability has been criticized and then adopted by Europe and China.

 

[.Scott]

According to this article https://www.msn.com/en-us/news/tech...launch-its-moon-rocket/ar-AA11k1Mp?li=BBnbfcL , they are not replacing the sensor. (?) Examination of the engine does not show any problem so they assume the sensor is faulty. Replacing it would mean too much of a delay. The other engines did not reach the target temperature so they are starting the chill down sooner.

That's not the whole plan. According to that same article, they are going to give the engine more time to cool down and the sensor more time to detect the change. That wait could be enough. If it isn't, they are where they started and the article does not say where they would go from there.

 

[mfb]

ULA has criticized the practicalities of the Starship refueling as related to the lunar landing mission (with obvious partiality to their own proposed solution).

That was Blue Origin. ULA had nothing to do with that, they didn't propose any Moon lander either.

According to this article https://www.msn.com/en-us/news/tech...launch-its-moon-rocket/ar-AA11k1Mp?li=BBnbfcL , they are not replacing the sensor. (?)

If they can't replace the sensor on the pad then there is not much else they can do at the moment.
The past months have shown how problematic that approach is: Too many things that need fixing just to find the next things that also need to be fixed, leading to months of delays. No redundancy in the temperature measurement is another issue.

SpaceX can replace Raptor engines on the launch pad within a day. Not just a temperature sensor - the whole engine.

 

[PeroK]

If there's anything that will make us old cynics "feel like kids again" , it's Elon's plan to put a man on Mars. Most likely himself!

Best place for him, if you ask me!

 

[.Scott]

Best place for him, if you ask me!

Elon does seem to rub some people the wrong way. I can't say I understand how. I've heard him called "arrogant". Is that your impression?

 

[Paul Colby]

Elon does seem to rub some people the wrong way. I can't say I understand how. I've heard him called "arrogant". Is that your impression?

Elon turned rubbing people the wrong way into an art form. At the moment this make little practical difference.

Rocket reusability has been criticized and then adopted by Europe and China.

I have a difficult time taking such criticism seriously. If I reuse a rocket 10 times I recoup 9 of those launches minus the turnaround cost. The turnaround cost appear to be a small fraction of a launch given the observed turnaround time is so small (assuming fuel cost are small).

In the days of Apollo the business models were adopted from the economy of ICBMs. Reusability was a silly question in the 1960s.

 

[PeroK]

Elon does seem to rub some people the wrong way. I can't say I understand how. I've heard him called "arrogant". Is that your impression?

He seems to me like a mad megalomaniac, who believes we're living in a computer simulation from the future. It's frightening how much wealth and power are in the hands of one man, especially one with crackpot notions.

Others, no doubt, will see him as mankind's saviour.

 

[anorlunda]

Others, no doubt, will see him as mankind's saviour.

IMO, better than someone from the public sector.

 

[.Scott]

He seems to me like a mad megalomaniac, who believes we're living in a computer simulation from the future. It's frightening how much wealth and power are in the hands of one man, especially one with crackpot notions.

Others, no doubt, will see him as mankind's saviour.

I don't see him as either a maniac or a savior. I'm not sure what you mean by "crackpot notions". He often completely misses the mark (calling the Tesla driver assistant "autopilot" and the notion of parachuting from orbit come to mind), but he seems to be able to drive engineering to find very pragmatic solutions. Anyone in engineering for more than a decade or two has seen persistent management over-optimism. It's part of the process. I don't fault him for his aspirational goals - it's what keeps his engineering efforts energetic.

In the American democracy there are several ways of gaining influence. Pleasing the electorate is one. Gaining wealth is another. Both have elements of meritocracy and each drives different decisions.

Contemporary US statesmen are compelled to address basic constituent survival issues as a priority. If followed to its logical conclusion and wars are avoided, it would result in a very large population committed to survival. In contrast, shooting for the stars measures society by challenging accomplishments and is better at creating "purpose".

 

[Janus]

In the Apollo era they said* humans would land on Mars by 1985. Still waiting...

*World Book Encyclopedia circa 1967.

It might have been a reality, if Nixon hadn't cut funding to the NERVA project. By the end of 1968 they had already had developed an engine that met the requirements for such an endeavor. It was a lack of political will more than anything else.

 

[pinball1970]

Saturn V is still taller:

View attachment 313282

This was the comparison I was talking about, @Astranut

 

[fresh_42]

This was the comparison I was talking about, @Astranut

I was searching as far as NASA's fact sheet for the SLS but haven't found a comparison of thrust.

 

[hutchphd]

It's frightening how much wealth and power are in the hands of one man, especially one with crackpot notions.

I do not see him as frightening. He has earned his wealth by repeatedly producing very high quality products and services in a variety of fields. One does not produce the extraordinary using ordinary methods. We have survived far scarier past examples
He was not handed his real estate money from daddy to build a quasicriminal enterprise.
He did not build underground factories at Dora/Nordhausen.
He did not peddle addictive substances to children
I could continue ad infinitum

 

[gleem]

And he is doing his part to defer the population stagnation.

 

[bob012345]

It might have been a reality, if Nixon hadn't cut funding to the NERVA project. By the end of 1968 they had already had developed an engine that met the requirements for such an endeavor. It was a lack of political will more than anything else.

Mars did not require a nuclear rocket. I believe after Apollo the reality was that public just did not want to spend the money.

 

[mfb]

Can you discuss Musk in a different thread please? This thread is about a NASA rocket. SpaceX rockets can be a relevant comparison, but the CEO of SpaceX is completely off-topic.

I was searching as far as NASA's fact sheet for the SLS but haven't found a comparison of thrust.

39 MN for SLS (Block 2 will have 41 MN)
35 MN for Saturn V
31 MN for the Space Shuttle
45 MN for N1.
All N1 launch attempts failed, so SLS can become the rocket with the most thrust to ever make it to orbit - and obviously the heaviest operational rocket. Falcon Heavy has 23 MN.

~11 hours to launch. Far less press coverage this time, but we should get into the more active regions of the launch countdown soon.

 

[bob012345]

Godspeed Snoopy!

 

[mfb]

They have problems with a hydrogen line, as a result the tank filling proceeded much slower than necessary. Something is mechanically in the wrong place, they warmed up the line trying to get it into the right spot twice but that didn't work. Still trouble-shooting, looks like a launch time will be towards the end of the launch window even if they can fix it.

 

[mfb]

The launch director hasn't made a final decision yet but the responsible teams propose to scrub the launch attempt. It would be surprising if the launch director overrules that (especially with the Space Shuttle failures in mind).

They can try another attempt on Monday, if that doesn't work then the vehicle will need to roll back to the VAB and there won't be a launch this month.

Edit: Scrub is official now.

 

[.Scott]

They have a launch window on Monday and Tuesday. After that, they would need to wait for at least 2 weeks.