totm dec 2023 Artemis Discussion Thread

[tater]

This video is a good take, and mirrors many things discussed in this forum over the last several years.

1. That NG could be a lift vehicle for Orion. With a third stage, achieving SLS mission capability for Orion at a small fraction of the cost.

2. He suggests a Centaur upper stage for NG. Good idea.

3. FH to launch SLS. Discussed here in some detail as well.

The most interesting have also been discussed. Using SH as the booster for SLS either with an alternate upper stage, or an expendable SS-derived upper stage.

 

 

[Beccab]

 

[sevenperforce]

On 9/16/2022 at 5:24 PM, tater said:

This video is a good take, and mirrors many things discussed in this forum over the last several years.

1. That NG could be a lift vehicle for Orion. With a third stage, achieving SLS mission capability for Orion at a small fraction of the cost.

2. He suggests a Centaur upper stage for NG. Good idea.

3. FH to launch SLS. Discussed here in some detail as well.

The most interesting have also been discussed. Using SH as the booster for SLS either with an alternate upper stage, or an expendable SS-derived upper stage.

The trouble is that SH+SS is just so capable that any reasonable analysis ends up reducing to "just use Starship".

Comanifesting is fun and all, but part of the point of the whole way Artemis is envisioned is that comanifesting isn't really the point since you're sending other stuff separately, because neither Orion nor SLS have the capability.

If political considerations were nonexistent and you were willing to field a lego rocket that is truly accursed, I wonder what capability you'd get if you slapped two Falcon Heavy side boosters onto a New Glenn core topped with a Centaur V upper stage.

But Orion's SM is ultimately the problem.

[tater]

28 minutes ago, sevenperforce said:

The trouble is that SH+SS is just so capable that any reasonable analysis ends up reducing to "just use Starship".

Yeah, but the all-SpaceX version gets no juicy government bucks. No bucks, no Buck Rogers.

So some Frankenrocket with a Lockmart capsule, ESA SM (maybe a decent one, since mass is not an object), and perhaps a ULA upper stage ticks all the boxes except solid rocket jobs. But there are missiles for that itch.

 

 

[sevenperforce]

1 hour ago, tater said:

Yeah, but the all-SpaceX version gets no juicy government bucks. No bucks, no Buck Rogers.

So some Frankenrocket with a Lockmart capsule, ESA SM (maybe a decent one, since mass is not an object), and perhaps a ULA upper stage ticks all the boxes except solid rocket jobs. But there are missiles for that itch.

We must always and forever lament that Orion Lite wasn't flying ISS missions this whole time. If it had been, we'd be accustomed to Orion reuse and adaptable Orion service modules. Things like upgrading the heat shield and doing an extended service module for cislunar missions would be natural evolutions rather than clean-slate challenges.

But, alas, it was not to be.

Orion is a little bloated for a capsule, but given its additional capabilities and carrying capacity, the bloat over the Apollo CM isn't THAT bad. It really just needs a meaningful service module. Lunar Gateway makes no sense absent Orion's current SM, but let's suppose we give Orion's new service module a total of ~2.1 km/s of dV. That's enough to shuttle between TLI and LLO with one stopover in NRHO (but not 2). Current injected lunar mass is 26.5 tonnes with 8.6 tonnes of propellant, giving it the measly 1,216 m/s it has right now. Multiplying the propellant mass by 2.3 (and adding on another ~2 tonnes for tank mass growth and associated margin) gives it 2,150 m/s and gives an injected TLI mass of just under 40 tonnes.

Is there any commercial upper stage big enough to push 40 tonnes to TLI? You've got to have some reasonable T/W ratio at staging, after all. Here's what existing and near-future upper stages would do for a 40-tonne evolved Orion (note, some values estimated):

Stage	Stage m0	Stage mf	Total thrust & Isp	T/W ratio w/OrionX	dV w/OrionX
Centaur III DEC	23.3 mt	2.5 mt	198 kN, 451 s	0.32	1,762 m/s
Centaur V	57.2 mt	5.2 mt	214 kN, 453.8 s	0.22	3,407 m/s
New Glenn US	190 mt	15 mt	1,420 kN, 449 s	0.63	6,300 m/s
Starship Lite	1240 mt	40 mt	7,825 kN, 378 s	0.62	10,160 m/s
ICPS	34.2 mt	3.5 mt	110 kN, 465.5 s	0.15	2,438 m/s
Ariane 6 ULPM	34.6 mt	3.6 mt	180 kN, 457 s	0.24	2,407 m/s
Falcon 9/H US	111 mt	4.5 mt	934 kN, 348 s	0.63	4,170 m/s

Any upper stage for an evolved Orion would need to do the same job as the S-IVB: completing orbital insertion and then providing the TLI burn. The requirement for TLI is 3.2 km/s, so that alone eliminates everything but Centaur V, New Glenn US, F9/H US, and of course Starship Lite. However, I'm skeptical that a staging T/W ratio of 0.22 will be sufficient, given the need for abort modes.

For those four stages, this is the staging velocity you'll need:

• Centaur V: 7.6 km/s
• New Glenn US: 4.7 km/s
• Starship Lite: 0.8 km/s
• Falcon 9/H US: 6.8 km/s

So, the question is whether there's a way to build a commercial frankenrocket capable of lofting any of the above configurations to those respective staging velocities. Note that Starship Lite is still just massively overpowered for this job.

It would make more sense for SpaceX to build a Starship Ultralite with shorter tanks and only a single Raptor Vacuum if they were asked to send a 40-tonne payload to TLI in a single launch.

There has already been some talk about a three-core Vulcan Heavy. It's horribly cursed, of course, but I would suspect that an expendable Vulcan core with two Falcon Heavy side boosters could surely loft the New Glenn upper stage to 4.7 km/s...possibly while preserving recovery of the FH boosters and perhaps even SMART reuse on Vulcan. The diameter change from Vulcan's 5.4 meters to New Glenn's upper stage 7 meters would be horrific, though.

Edited September 20, 2022 by sevenperforce
clarification

[sevenperforce]

14 hours ago, sevenperforce said:

There has already been some talk about a three-core Vulcan Heavy. It's horribly cursed, of course, but I would suspect that an expendable Vulcan core with two Falcon Heavy side boosters could surely loft the New Glenn upper stage to 4.7 km/s...possibly while preserving recovery of the FH boosters and perhaps even SMART reuse on Vulcan. The diameter change from Vulcan's 5.4 meters to New Glenn's upper stage 7 meters would be horrific, though.

Here's what that absolutely horrific monstrosity would look like, just in case you've got extra eye bleach you need to use:

[Barzon]

 

 

 
 

Edited September 22, 2022 by Barzon

[tater]

"Better margin"?

Their proposal had a negative margin, does this mean they made it close, or does it not work, but strands the astronauts with slightly more fuel aboard?

[RyanRising]

21 hours ago, tater said:

"Better margin"?

Their proposal had a negative margin, does this mean they made it close, or does it not work, but strands the astronauts with slightly more fuel aboard?

It means they made it work. They were able to get the design mass back within margins shortly after the HLS selection, so this isn’t really news.

Edited September 23, 2022 by RyanRising

[tater]

2 hours ago, RyanRising said:

It means they made it work. They were able to get the design mass back within margins shortly after the HLS selection, so this isn’t really news.

I had not heard that they had improved it to the point it was not a joke. Cool.

(sorry, but them even submitting a design that could not actually complete the required mission after being paid >$100M (>$200M?) was nothing short of absurd)

[sevenperforce]

1 hour ago, tater said:

I had not heard that they had improved it to the point it was not a joke. Cool.

(sorry, but them even submitting a design that could not actually complete the required mission after being paid >$100M (>$200M?) was nothing short of absurd)

I'm eternally sad that they jettisoned the drop tank plan (pun intended). It always seemed like an electric-pump-fed methalox lander with solar-rechargeable batteries and drop tanks was a really clean solution.

[SunlitZelkova]

I decided to put this here instead of the JAXA thread because it involves the US too.

Kanai Norishige was part of a NASA-JAXA team that did training with the old SEV prototypes. They drove around during the night to see what rover ops might be like in permanently shadowed craters.

With Lunar Starship still in the design phase and SLS ridden with problems, astronaut training for Artemis is the coolest aspect of the program I think. A week ago or so NASA also shared pictures of what looked like surface sample collection training at the NBL.

[SunlitZelkova]

It's a Desert RATS mission! NASA PR must be pretty sporadic at times because I didn't realize this until now.

Here's the blurb from NASA-

Quote

Desert RATS returns to the high-desert terrain of Black Point Lava Flow in October 2022 to conduct “day in the life” mission simulations for future Artemis missions at the Moon. From October 11-22, three two-person crews will live, work, and sleep inside a prototype pressurized rover, driving across the challenging terrain that stands in as a terrestrial proxy for the Moon.

Astronauts and engineers from the Japan Aerospace Exploration Agency (JAXA) will join NASA for Desert RATS 2022. The two agencies are working together on the potential opportunity for JAXA to provide the lunar pressurized rover for Artemis.

Operated like a real mission, the Desert RATS crews will carefully rove the desert, exiting the vehicle in their mock spacesuits when they come across scientifically intriguing regions to explore. At NASA’s Johnson Space Center in Houston, a Mission Control team will track crew movement and activities, help them stay on schedule, and troubleshoot for them if problems arise.

Also at JSC, a Science Evaluation Room will be staffed with scientists who can help the crews identify and investigate geographic features or areas of interest.

NASA crew:

Jessica Meir (astronaut, participated in first all female spacewalk)

Sarah Shull (systems engineering and integration manager for the EVA & Human Surface Mobility Program had to copy paste that and previously worked at MCC)

JAXA crew:

Hoshide Akihiko (astronaut, has the record for most spacewalking time among Japanese astronauts)

Kanai Norishige (astronaut, lieutenant and Diving Medical Officer in the JMSDF)

Ikeda Naofumi (systems integration and driving systems engineer for pressurized rovers also had to copy paste that, worked in the auto industry (consumer and racing related research) before joining JAXA)

Yamasaki Yusuke (engineer, is now working on the rover but previously worked with the Kibo module on the ISS, and prior to that he worked as a test engineer in a "commercial airplane development program", possibly the Mitsubishi Regional Jet)

They are taking turns and going out on different excursions in teams, the rover isn't big enough for all six.

[Beccab]

6 hours ago, SunlitZelkova said:

It's a Desert RATS mission! NASA PR must be pretty sporadic at times because I didn't realize this until now.

Here's the blurb from NASA-

NASA crew:

Jessica Meir (astronaut, participated in first all female spacewalk)

Sarah Shull (systems engineering and integration manager for the EVA & Human Surface Mobility Program had to copy paste that and previously worked at MCC)

JAXA crew:

Hoshide Akihiko (astronaut, has the record for most spacewalking time among Japanese astronauts)

Kanai Norishige (astronaut, lieutenant and Diving Medical Officer in the JMSDF)

Ikeda Naofumi (systems integration and driving systems engineer for pressurized rovers also had to copy paste that, worked in the auto industry (consumer and racing related research) before joining JAXA)

Yamasaki Yusuke (engineer, is now working on the rover but previously worked with the Kibo module on the ISS, and prior to that he worked as a test engineer in a "commercial airplane development program", possibly the Mitsubishi Regional Jet)

They are taking turns and going out on different excursions in teams, the rover isn't big enough for all six.

That's the Constellation rover right? Not the one that will fly on artemis

[SunlitZelkova]

2 hours ago, Beccab said:

That's the Constellation rover right? Not the one that will fly on artemis

Yes.

Interestingly, I recall an interview with a project member of this rover being specifically asked about how he felt now that it was decided for good that the LEV/SEV would not be going to space. He said he was disappointed considering how much time and effort went into it, but understood the international nature of Artemis compared to Constellation, and was glad to see new nations being able to participate in lunar exploration. He also noted that Japan’s experience with the auto industry would be beneficial in their development efforts.

Checking now these are actually separate statements from different people. Mark Kirasich, who at the time was the acting director of Advanced Exploration Systems, said that Japan’s auto industry was related to the decision here https://arstechnica.com/science/2020/07/nasas-first-lunar-habitat-may-be-an-rv-like-rover-built-by-toyota/ and “Senior Lunar Scientist” Clive Neal said he thought it was unfortunate the SEV wouldn’t land on the Moon, but the link to it is dead.

Mr. Kirasich also stated the decision wasn’t purely related to the ideal nature of Artemis, but also to cut American costs in the program.

[SunlitZelkova]

https://www3.nhk.or.jp/nhkworld/en/news/ataglance/2286/

Oh my god NHK-World! It’s not a “new” rover!

Ignoring that line, that link has a 1 minute video with some footage of it driving around during D-RATS 2022.

That’s Hoshide Akihiko and one of the engineers wearing their EVA suits.

[tater]

 

[StrandedonEarth]

1 hour ago, tater said:

 

Further down that thread…

[RCgothic]

Artemis IV is the not a moon landing launch, isn't it? Somebody needs to take SLS/Orion out of this programme and shoot it.

Edited October 27, 2022 by RCgothic

[Beccab]

 

 

[insert_name]

So the two of the groups that lost out on the last round because of high cost and programmatic risks are now pushing for nuclear rockets on their next bid?

[Codraroll]

1 hour ago, insert_name said:

So the two of the groups that lost out on the last round because of high cost and programmatic risks are now pushing for nuclear rockets on their next bid?

"Hey, we promise to do this really cool thing if you pick us! Of course, we would probably spend a fortune without making much progress and it'd take years to even see if we got anywhere, but consider this: Cool thing! Come on, let the pork flow to us like before! For the sake of the cool thing!"

[Beccab]

 

[tater]

 

[RCgothic]

I like how they biassed Artemis II left but centred starship as though to imply Artemis II has any chance of launching early 2024.

Edited October 31, 2022 by RCgothic