totm dec 2023 Artemis Discussion Thread

[Barzon]

59 minutes ago, tater said:

Apparently during the actual announcement (with people talking), they said first flight was 2030, test flight a year before that.

for Blue Moon Mk2 the test flight is NET 2027, with it being available for a crewed landing in 2028, but the 2024 & 2025 pathfinder flights are Blue Moon Mk1, which is expendable. We've already seen flight hardware for the '24 flight in public, and there's even more behind the scenes.

And everything I know from my own contacts puts New Glenn well on track for 2024, after all, ESCAPADE is scheduled for August, and it won't be the maiden flight.

Edited May 19, 2023 by Barzon

[tater]

1 hour ago, Barzon said:

for Blue Moon Mk2 the test flight is NET 2027, with it being available for a crewed landing in 2028, but the 2024 & 2025 pathfinder flights are Blue Moon Mk1, which is expendable. We've already seen flight hardware for the '24 flight in public, and there's even more behind the scenes.

What hardware? The Be-7?

Cause that mockup Bezos stood in front of literally had inflatable prop tanks. Like beach balls inflatable.

1 hour ago, Barzon said:

And everything I know from my own contacts puts New Glenn well on track for 2024, after all, ESCAPADE is scheduled for August, and it won't be the maiden flight.

I thought they had said Q4.

 

Edited May 19, 2023 by tater

[tater]

Trying to guess actual crew volume. Floor area is ~300 sqft (28m²). height is hard to be exact about. Almost room for 2 decks depending on how high they want ceilings.

Definitely room for 1 deck, then they could loft 4 bunks.

[RCgothic]

I've seen speculation that the living area is a torus with the BE-7s and downcomers in the middle, which I think seems plausible.

[tater]

5 hours ago, RCgothic said:

I've seen speculation that the living area is a torus with the BE-7s and downcomers in the middle, which I think seems plausible.

Huh.

[tater]

Makes sense, but reduces the cargo utility.

Was hoping for the ability to leave a monolithic cargo (a ~6m dia cargo).

 

[RCgothic]

So... Both of these commercial landers are committing serious personal funds to the development of these landers. The only way this makes sense commercially is if the investment can be recouped on operational flights.

But now those operational flights, already glacial in pace thanks to the gatekeeper of lunar space, now have to be split between two providers.

Either one or both of these providers is going to fail hard, or they're going to have to develop an alternative way of getting commercial crews into lunar space. 

I wonder if the oldspace lobbyists protesting sole sourcing a lander realised they were going to end up slaying SLS/Orion?

[darthgently]

My guess is that SpaceX sees any stuff developed for the moon to have some crossover, if only manufacturing and testing experience, for Mars. 

Yes, there are many aspects of the lunar lander that have nothing to do with Mars, but many problems will be integrated (life support, refueling, crew stuff) that will pave the way for better thinking about Mars problems.  That is my take on it anyway. 

I like the moon effort as well as the Mars push myself, but i don't think SpaceX would see their moon efforts as a full fail if their lander was orphaned as learning would have occurred

[Barzon]

On 5/19/2023 at 9:06 PM, tater said:

What hardware? The Be-7?

They've shown off BE-7 hardware & RCS thrusters. There's more than that behind the curtain.

On 5/19/2023 at 9:06 PM, tater said:

I thought they had said Q4.

The last NET publicly given was Q4 2023.

On 5/20/2023 at 9:37 AM, RCgothic said:

I've seen speculation that the living area is a torus with the BE-7s and downcomers in the middle, which I think seems plausible.

Yep. You can kinda see it in the pictures in this tweet:

 

23 hours ago, tater said:

Makes sense, but reduces the cargo utility.

Was hoping for the ability to leave a monolithic cargo (a ~6m dia cargo).

It's definitely confusing but NASA seem happy with whatever solution they've come up for HDL, considering they said in the SSS that it exceeded both the mass and volume requirements.  My guess is something like this, either with the same total height kept and just a flat deck above the engine, or stretching the entire vehicle.

Edited May 21, 2023 by Barzon

[tater]

5 hours ago, RCgothic said:

So... Both of these commercial landers are committing serious personal funds to the development of these landers. The only way this makes sense commercially is if the investment can be recouped on operational flights.

Alternately, the only thing they care about is having some of the dev cost offset, and it's not about commercial success in the normal understanding.

I think this is the actual answer.

[tater]

I posted this in the BO thread, but it has broader utility than just their lander.

I was always a fan of the real STS. The last S, System, being the critical bit. Multiple vehicles working cooperatively to achieve a mission goal.

In the above diagram, the diameters of cargo and tug are the same, because it was envisioned that a shuttle likely delivered them to LEO. In the case of the tug, in pieces assembled in orbit.

One problem with Starship is that the cargo has to fit through whatever door up above the tanks, and then be craned down to the surface. This is not impossible, but challenging. More importantly, loading cargo for a second trip is substantially harder. The first cargoes will be loaded before launch, but how do you reload a lander with cargo where the cargo is held inside the crew compartment? Or even an unpressurized deck that the airlocks open to? Fly it up with another Starship then EVA it if it is large? Dock and move it though a tiny  docking port then stow it by hand?

What if BO comes up with a solution like the image above? SpaceX could easily add the same sort of rail system to LSS, and mass is basically unconcerning if the cargoes are designed to be lander neutral. They might max out at ~15t for BM, and LSS could take as many as they can have a rail/deploy system for.

Cargo would be loaded on Earth. Getting the mass distribution just so, making sure everything is tied down, etc. Pods brought to LEO in whatever vehicle supports 6m dia cargo (spreading the launches among commercial partners—smaller diameters might be possible as long as they use the same rail system, so other partners (ESA/JAXA) can fly their own. Gateway becomes a little more useful as the place where cargoes are marshaled.

[magnemoe]

6 hours ago, tater said:

Alternately, the only thing they care about is having some of the dev cost offset, and it's not about commercial success in the normal understanding.

I think this is the actual answer.

Agree, SpaceX had done a lot of smart business moves, 
But the core idea of colonizing Mars don't make any economical sense, best case it would take centuries and I don't see they bee able to keep it. 
Blue origin is a bit more realistic but still far off. 
But I say its nice that you have billionaires passionate about space rather than inflate the cost of sport teams. 

[Gargamel]

Apparently NASA released the engineering footage after a FOI request.    Apologies if this has been discussed already.   Some pretty epic shots here.  
 

 

[Exoscientist]

Artemis 2 will use lasers to beam high-definition footage from the moon (video)

By Josh Dinner published 19 days ago

https://www.space.com/nasa-artemis-2-laser-communications-video

 Interesting idea. I always wanted to know if it were possible to get continuous imaging of Mars.  What I mean is, if you look at the high resolution images presented of Mars it’s always spotty. Why can’t you image swaths of the Martian surface during each path at high resolution  so you can look at any point you want at high resolution?

 Perhaps this high bandwidth laser communication method can allow this to happen?

  Bob Clark

[tater]

On 5/26/2023 at 7:42 AM, Exoscientist said:

Artemis 2 will use lasers to beam high-definition footage from the moon (video)

By Josh Dinner published 19 days ago

https://www.space.com/nasa-artemis-2-laser-communications-video

 Interesting idea. I always wanted to know if it were possible to get continuous imaging of Mars.  What I mean is, if you look at the high resolution images presented of Mars it’s always spotty. Why can’t you image swaths of the Martian surface during each path at high resolution  so you can look at any point you want at high resolution?

 Perhaps this high bandwidth laser communication method can allow this to happen?

I still think they would buffer the images vs streaming, so it might simply be a storage issue. My friend at JSC is actually working on the laser comms for Artemis as I recall.

 

Was hiking this morning with a friend, and we were talking about Artemis. I love the fact that these 2 landers completely obviate SLS/Orion. Their mere existence should either work.

The min dv for Gateway—>lunar surface—>Gateway (~5.5 km/s) is substantially larger than the propulsive dv required for Gateway—>LEO (3.65 km/s).

BTW, the docs say that the BO lander is ">45t" wet. I think it launches on NG at ~45t, then tanked up it must be at least 56-57t wet (needs to be to do the stated mission). Call it 60t wet for slop (max props)

So any BO tanker must deliver 40-41t of props to NRHO. Returning to LEO from NRHO, only takes 20t of props, however.

Assume the crew cabin is ~10t. Then the other dry mass is only 6t. A tanker version of the BO lander can load up with 60t of props, and deliver 23t to NRHO. It gives 15t to the lunar lander, and keeps 8. Tanker can return to LEO with the 8t it has.

Make another trip, and the lander can fly to LEO. Total props expended would be 120t.

To fill the lander for reuse in NRHO (assume 60t props for easy math) is 4 trips times 60t. 240t of props.

Filled in LEO (40t props), the lander arrives at NRHO with ~10t of residuals. It then needs 3 tanker flights to be ready for a surface sortie. So to total expense in props of 220t. But we need to add the 120t it took to bring it home to LEO. So 340t.

Only 40t more to refill in LEO for return That's 1 NG launch.

A small cost delta to eliminate a >$4B SLS launch.

(eliminated since the crew could board in LEO).

Edited June 1, 2023 by tater

[tater]

CONOPS for Gateway in this case would be that NG would deliver props to a depot in LEO on some schedule to keep it full. Crew board full lander, fly to Gateway. At the same time a tanker follows them, refilling en route after TLI, so they are OTW to Gateway with 23t of props—which is contingency for them to simply head home if there is an emergency (astronaut has a medical issue or whatever, they can simply head home). If they put a depot at Gateway, there's already a depot tanker parked there with at least 40t in it. 20t to top off for the sortie to the surface, and 20t so when the lander returns it can immediately fly home if required.

Edited June 1, 2023 by tater

[AtomicTech]

8 hours ago, Exoscientist said:

Perhaps this high bandwidth laser communication method can allow this to happen?

It's definitely possible!

I just thought it was amazing that they managed to pull this off!

https://www.nasa.gov/directorates/heo/scan/opticalcommunications/overview/#:~:text=Optical spectrum uses light as,secure%2C lighter and more flexible.

[darthgently]

2 hours ago, AtomicTech said:

It's definitely possible!

I just thought it was amazing that they managed to pull this off!

https://www.nasa.gov/directorates/heo/scan/opticalcommunications/overview/#:~:text=Optical spectrum uses light as,secure%2C lighter and more flexible.

Earth - Mars distances will lower bandwidth at minimum as more decoherence of the laser will occur the further it travels.  But given enough laser "channels" in parallel high bandwidth comms between Earth and Mars seems doable.  Still going to have monster lag and latency though

 

Edit:  also, if distance makes decoherence overwhelming then relays in solar orbits could be used to hop signals

Edited May 27, 2023 by darthgently

[Exoscientist]

13 hours ago, tater said:

I still think they would buffer the images vs streaming, so it might simply be a storage issue. My friend at JSC is actually working on the laser comms for Artemis as I recall.

 

 Perhaps you could ask him this question. Take a look at the images available browsing on the HIRISE imaging page on the MRO spacecraft orbiting Mars:

 The image browser works by selecting an area on Mars you want to look at then it will present the high resolution images available in that area. You see the coverage by high resolution imaging is tiny.

 Why can’t it as the camera sweeps over Mars image the entire area underneath it at high resolution?

 

 Bob Clark

 

[Exoscientist]

On 5/26/2023 at 11:57 AM, tater said:

I still think they would buffer the images vs streaming, so it might simply be a storage issue. My friend at JSC is actually working on the laser comms for Artemis as I recall.

 

Was hiking this morning with a friend, and we were talking about Artemis. I love the fact that these 2 landers completely obviate SLS/Orion. Their mere existence should either work.

The min dv for Gateway—>lunar surface—>Gateway (~5.5 km/s) is substantially larger than the propulsive dv required for Gateway—>LEO (3.65 km/s).

BTW, the docs say that the BO lander is ">45t" wet. I think it launches on NG at ~45t, then tanked up it must be at least 56-57t wet (needs to be to do the stated mission). Call it 60t wet for slop (max props)

So any BO tanker must deliver 40-41t of props to NRHO. Returning to LEO from NRHO, only takes 20t of props, however.

Assume the crew cabin is ~10t. Then the other dry mass is only 6t. A tanker version of the BO lander can load up with 60t of props, and deliver 20t to NRHO. It gives 10t to the lunar lander, and keeps 10. Tanker can return to LEO with the 10t it has.

Make another trip, and the lander can fly to LEO. Total props expended would be 120t.

To fill the lander for reuse in NRHO (assume 60t props for easy math) is 4 trips times 60t. 240t of props.

Filled in LEO (40t props), the lander arrives at NRHO with ~10t of residuals. It then needs 3 tanker flights to be ready for a surface sortie. So to total expense in props of 220t. But we need to add the 120t it took to bring it home to LEO. So 340t.

Only 40t more to refill in LEO for return That's 1 NG launch.

A small cost delta to eliminate a >$4B SLS launch.

(eliminated since the crew could board in LEO).

 How many refueling flights of Starship required?

   Bob Clark

[mikegarrison]

On 5/26/2023 at 10:44 PM, Exoscientist said:

the coverage by high resolution imaging is tiny.

 Why can’t it as the camera sweeps over Mars image the entire area underneath it at high resolution?

There are only so many pixels available to any camera. It can use them for wider shots where it gets more field of view and less resolution, or it can use them for more focused shots where it gets more resolution and less field of view. The same is also true for your eye looking through a telescope, or anything similar to that.

[tater]

37 minutes ago, Exoscientist said:

 How many refueling flights of Starship required?

Nominally a 90t LSS is 1200t of props. Looks like it can fly LEO to the lunar surface and back to a lunar orbit with ~800-900t of props. At 900t of props the lunar orbit it can return to is NRHO (Gateway). If tanked all the way to 1200, it can fly LEO to the lunar surface, then up to Gateway with 810 m/s remaining (22t props).

Expendable SS is now up to ~300t payload. So even without reuse, they can tank up LSS with 3 launches (5 at 100% reuse). Note that if they expend the booster to launch LSS in the first place, it arrives with ~1 of those launches worth of props already aboard. If the full tank is used, then it needs 4 expendable launches (including the LSS launch itself). If 100% reusable launches, then 7. So overall, between 3 and 7 launches.

A 100t tanker SS that holds 1600t of props can get ~445t of residuals to Gateway. It can give 245t to LSS, and have enough props remaining to fly itself back to LEO (more to LSS if allowed to aerobrake). LSS only needs ~185t of props to return to LEO, so a tanker can allow it to come back to LEO. It needs 310t to make another surface sortie round trip. The tanker is a little shy of that in 1 flight.

Filling up in LEO makes more sense to me, since they could also load crew aboard there, eliminating any need for SLS entirely.

CONOPS would be 4-7 refilling flights, 1 commercial crew flight to load crew, then visit the Moon. Even if tanking flights cost $100M each, the entire Moon mission for 4 crew landed would cost the same or less than the cost of just the Orion capsule (supposedly $900M in production using reused capsule parts from previous missions). For missions per year for the cost of a single SLS/Orion flight per year. Ideally a depot at Gateway, and any excess props outbound would be left at Gateway (vs bringing them to the Moon and back).

 

Edited May 30, 2023 by tater

[StrandedonEarth]

 

[tater]

 

[RCgothic]

5 hours ago, tater said:

Nominally a 90t LSS is 1200t of props. Looks like it can fly LEO to the lunar surface and back to a lunar orbit with ~800-900t of props. At 900t of props the lunar orbit it can return to is NRHO (Gateway). If tanked all the way to 1200, it can fly LEO to the lunar surface, then up to Gateway with 810 m/s remaining (22t props).

Expendable SS is now up to ~300t payload. So even without reuse, they can tank up LSS with 3 launches (5 at 100% reuse). Note that if they expend the booster to launch LSS in the first place, it arrives with ~1 of those launches worth of props already aboard. If the full tank is used, then it needs 4 expendable launches (including the LSS launch itself). If 100% reusable launches, then 7. So overall, between 3 and 7 launches.

A 100t tanker SS that holds 1600t of props can get ~445t of residuals to Gateway. It can give 245t to LSS, and have enough props remaining to fly itself back to LEO (more to LSS if allowed to aerobrake). LSS only needs ~185t of props to return to LEO, so a tanker can allow it to come back to LEO. It needs 310t to make another surface sortie round trip. The tanker is a little shy of that in 1 flight.

Filling up in LEO makes more sense to me, since they could also load crew aboard there, eliminating any need for SLS entirely.

CONOPS would be 4-7 refilling flights, 1 commercial crew flight to load crew, then visit the Moon. Even if tanking flights cost $100M each, the entire Moon mission for 4 crew landed would cost the same or less than the cost of just the Orion capsule (supposedly $900M in production using reused capsule parts from previous missions). For missions per year for the cost of a single SLS/Orion flight per year. Ideally a depot at Gateway, and any excess props outbound would be left at Gateway (vs bringing them to the Moon and back).

 

If we're dropping SLS/Orion, is there a better lunar rendezvous point than NRHO?