Starship Artemis Contract & Lunar Starship

[TomH]

I know all the renderings show a full size Starship on the lunar surface, but does it really make sense to carry the TLI tankage and engines to and from the surface? Does anyone else here think SpaceX might break this into two separate stages and discard the TLI stage?

Definitely not.   

SX's approach is to build starships that can leave Earth and perform the rest of the journey (after refueling) using the same engines.      This advantage to this approach is that it minimizes the number and type of engines and structures that need to be developed, built and tested.   Done well, this will save huge amounts of money.

Contrast this with the NASA approach, which has been, so far, to design and build an almost entirely unique spacecraft and landing vehicle for each mission (with a few minor exceptions).

Musk's objective is to get to Mars. If you study the archives of this site, you will discover a huge number of members who thought Elon would never consider taking BFR/MCT/SS to Luna, as that would be a distraction and detour from his real goal. A number even proffered guarantees that SpaceX would never get involved in manned lunar flights. Quite a few were surprised that Elon bid on the HLS, but others thought he did it because it would provide more funding from outside SpaceX, offer more opportunity for development, flight experience, and opportunity to R&D in-space re-propping. There is a consensus that Musk decided to bid on HLS with the least degree of deviation from the eventual Mars system as possible. The lunar ship will differ from the Mars ship, but only in ways that are absolutely necessary. Any potential change to the Mars design that is not completely required for the HLS system simply is not going to happen. Is this the ideal lunar landing system? In many ways, it is not; if none of the stakeholders had a Mars objective, the HLS lander would be very different. In some other ways, however, SS is an outstanding choice because it already is in development, and it will offer the greatest amount of payload to the lunar surface and at the lowest cost per mass unit. In the end, it also helps SS eventually get to Mars.

[TomH]

One thing to keep in mind is that most of the dust isn't actually blown upward, but is blown radially away (this is apparent on the Apollo landing footage). The reason is that the flow of dust directly follows the flow of exhaust gas, there being no atmosphere to otherwise affect it.  With a descending engine, the area of lowest pressure is always away from the lander. Yes, you might get some larger fragments kicked up with enough momentum to temporarily overcome the downward exhaust pressure, but generally those will be rare. Most of the forces are acting to push material away from the lander.

Fluid dynamics are nowhere near as simplistic as you describe. They are one of the most complex and unpredictable forms of mathematical application that exists. Even considering the lack of an in situ atmosphere with which to interact, there still remains opportunity for many swirling and interacting eddy currents to throw debris into those engines.

[Barley]

but others thought that [Elon bid on the HLS] because it would provide more funding from outside SpaceX, offer more opportunity for development, flight experience, and opportunity to R&D in-space re-propping. There is a consensus that Musk decided to bid on HLS with the least degree of deviation from the eventual Mars system as possible. The lunar ship will differ from the Mars ship, but only in ways that are absolutely necessary. Any potential change to the Mars design that is not completely required for the HLS system simply is not going to happen.

I think I agree, if "absolutely necessary" means absolutely necessary to get money from NASA, to get flight experience etc. and not simply physically required to land on the moon.

There's probably some level of NASA intransigence where SpaceX would decline to continue, but there is also a fairly large space where NASA's money gets changes.

[DanClemmensen]

but others thought that [Elon bid on the HLS] because it would provide more funding from outside SpaceX, offer more opportunity for development, flight experience, and opportunity to R&D in-space re-propping. There is a consensus that Musk decided to bid on HLS with the least degree of deviation from the eventual Mars system as possible. The lunar ship will differ from the Mars ship, but only in ways that are absolutely necessary. Any potential change to the Mars design that is not completely required for the HLS system simply is not going to happen.

I think I agree, if "absolutely necessary" means absolutely necessary to get money from NASA, to get flight experience etc. and not simply physically required to land on the moon.

There's probably some level of NASA intransigence where SpaceX would decline to continue, but there is also a fairly large space where NASA's money gets changes.

The other  consideration is that SpaceX was learning how flexible the Starship architecture really is. By comparison to building from scratch or even building from a less powerful base, The incremental effort for a "custom" variant of Starship is small. This changed the cost-benefit equation and allowed SpaceX to bid a profitable Starship HLS with very attractive capabilities at a very attractive price. The HLS bid is for three Starship variants (depot, tanker, HLS) and only one of them is custom. Of course, it has not flown yet: we'll see.

My guess: SpaceX would not have bid for HLS if they had to start from the F9/Dragon base. It's the huge mass budget of Starship that allows for  a relatively simple and inexpensive design and implementation.

[rakaydos]

I know all the renderings show a full size Starship on the lunar surface, but does it really make sense to carry the TLI tankage and engines to and from the surface? Does anyone else here think SpaceX might break this into two separate stages and discard the TLI stage?

Definitely not.   

SX's approach is to build starships that can leave Earth and perform the rest of the journey (after refueling) using the same engines.      This advantage to this approach is that it minimizes the number and type of engines and structures that need to be developed, built and tested.   Done well, this will save huge amounts of money.

Contrast this with the NASA approach, which has been, so far, to design and build an almost entirely unique spacecraft and landing vehicle for each mission (with a few minor exceptions).

Musk's objective is to get to Mars. If you study the archives of this site, you will discover a huge number of members who thought Elon would never consider taking BFR/MCT/SS to Luna, as that would be a distraction and detour from his real goal. A number even proffered guarantees that SpaceX would never get involved in manned lunar flights. Quite a few were surprised that Elon bid on the HLS, but others thought he did it because it would provide more funding from outside SpaceX, offer more opportunity for development, flight experience, and opportunity to R&D in-space re-propping. There is a consensus that Musk decided to bid on HLS with the least degree of deviation from the eventual Mars system as possible. The lunar ship will differ from the Mars ship, but only in ways that are absolutely necessary. Any potential change to the Mars design that is not completely required for the HLS system simply is not going to happen. Is this the ideal lunar landing system? In many ways, it is not; if none of the stakeholders had a Mars objective, the HLS lander would be very different. In some other ways, however, SS is an outstanding choice because it already is in development, and it will offer the greatest amount of payload to the lunar surface and at the lowest cost per mass unit. In the end, it also helps SS eventually get to Mars.

That was in the days before NASA not only selected, but sole sourced, a Starship variant as the Artemis program lunar lander.

In those days, the prevailing view was that Congress (via NASA) would never accept Starship. Without NASA backing, I dont think anyone doubled they would do private missions like DearMoon, but only if they supported the mars program.

[Paul451]

If you study the archives of this site, you will discover a huge number of members who thought Elon would never consider taking BFR/MCT/SS to Luna, as that would be a distraction and detour from his real goal. A number even proffered guarantees that SpaceX would never get involved in manned lunar flights.

I think you might be overreading some of those comments. In the first Starship presentation after switching to stainless steel (many design changes ago), Musk showed BFS/SS landed on the moon. And the first mission announced was DearMoon.

Perhaps you are misreading/misremembering people saying that SpaceX won't self-fund lunar missions? Which is a different thing entirely.

[FutureSpaceTourist]

twitter.com/jeff_foust/status/1586030141842620424

Rene Ortega, NASA’s HLS chief engineer, is clearly impressed with access to data SpaceX has provided during Starship tests and its hardware-rich approach during a conference panel. “It’s a big deal.” #VonBraun2022

https://twitter.com/jeff_foust/status/1586030737425211393

But a lack of technical details or Starship HLS development updates from NASA and SpaceX in a too-short panel (<20 minutes) with no audience questions.

[jpo234]

Musk's objective is to get to Mars. If you study the archives of this site, you will discover a huge number of members who thought Elon would never consider taking BFR/MCT/SS to Luna, as that would be a distraction and detour from his real goal.

These slides are from Elon Musk’s presentation at the 68th International Astronautical Congress on September 28, 2017 in Adelaide, Australia.

And this is what he said according to the transcript:

Based on our calculations, we can actually do lunar surface missions with no propellant production on the surface of the Moon. If we do a high elliptic parking orbit for the ship and retank in high elliptic orbit, we can go all the way to the Moon and back with no local propellant production on the Moon. I think that would enable the creation of Moon Base Alpha or some sort of lunar base. It is 2017. We should have a lunar base by now.

[InterestedEngineer]

Musk's objective is to get to Mars. If you study the archives of this site, you will discover a huge number of members who thought Elon would never consider taking BFR/MCT/SS to Luna, as that would be a distraction and detour from his real goal.

These slides are from Elon Musk’s presentation at the 68th International Astronautical Congress on September 28, 2017 in Adelaide, Australia.

And this is what he said according to the transcript:

Based on our calculations, we can actually do lunar surface missions with no propellant production on the surface of the Moon. If we do a high elliptic parking orbit for the ship and retank in high elliptic orbit, we can go all the way to the Moon and back with no local propellant production on the Moon. I think that would enable the creation of Moon Base Alpha or some sort of lunar base. It is 2017. We should have a lunar base by now.

I wasn't even aware of this preso when some of us independently came up with the HEEO refuel idea on the extra-solar probe thread.

cool!

[FutureSpaceTourist]

twitter.com/jeff_foust/status/1587093904331083776

A recap of ongoing work on the Starship lunar lander for HLS. NASA’s Mark Kirasich says SpaceX has a “lot of test flights” planned between now and the HLS missions (uncrewed and crewed demos) including a variety of tests for cryo fluid management and transfer.

https://twitter.com/jeff_foust/status/1587095043449536516

Kirasich says current schedules call for a first Starship/Super Heavy launch in December, but notes that schedule has slipped by several months. [Also dependent on testing and receipt of an FAA launch license.]

twitter.com/jeff_foust/status/1587097144468676612

Kirasich says that while Starship crews will use an elevator to get from the crew cabin to the surface, there will be “some sort of independent backup system” in addition.

https://twitter.com/jeff_foust/status/1587098687716597762

Kirasich: no plans to reuse the Starship for the Artemis 3 landing. Will dispose of it by putting it on heliocentric orbit.

[FutureSpaceTourist]

https://twitter.com/free_space/status/1587094320359870469

First test of cryo fluid transfer in orbit planned during second @spacex Starship orbital flight, @NASA's Mark Kirasich tells NAC HEO. First orbital flight targeted for December

[InterestedEngineer]

https://twitter.com/free_space/status/1587094320359870469

First test of cryo fluid transfer in orbit planned during second @spacex Starship orbital flight, @NASA's Mark Kirasich tells NAC HEO. First orbital flight targeted for December

wouldn't this require 2nd and 3rd flights to be near simultaneous?

[DanClemmensen]

First test of cryo fluid transfer in orbit planned during second @spacex Starship orbital flight, @NASA's Mark Kirasich tells NAC HEO. First orbital flight targeted for December

wouldn't this require 2nd and 3rd flights to be near simultaneous?

Apparently a lot of cryo fluid transfer testing can be done with equipment in a single spacecraft.

[oldAtlas_Eguy]

First test of cryo fluid transfer in orbit planned during second @spacex Starship orbital flight, @NASA's Mark Kirasich tells NAC HEO. First orbital flight targeted for December

wouldn't this require 2nd and 3rd flights to be near simultaneous?

Apparently a lot of cryo fluid transfer testing can be done with equipment in a single spacecraft.

Actually read the details explaining about the missions/flights that NASA will be following. And that there are 4 of them. Each is a significant milestone event. Not the list of actual total Starship launches which there will be a lot more between each of these milestones occurrence.

[FutureSpaceTourist]

https://arstechnica.com/science/2022/11/spacex-is-now-building-a-raptor-engine-a-day-nasa-says/

SpaceX is now building a Raptor engine a day, NASA says
"This, by the way, is very high on their top risk list."

ERIC BERGER - 11/2/2022, 2:11 PM

A senior NASA official said this week that SpaceX has done "very well" in working toward the development of a vehicle to land humans on the surface of the Moon, taking steps to address two of the space agency's biggest concerns.

[…]

Two of NASA's biggest technological development concerns were the new Raptor rocket engine and the transfer and storage of liquid oxygen and methane propellant in orbit […]

[FutureSpaceTourist]

https://twitter.com/tsr/status/1590880740912566272

In Texas, SpaceX is getting closer to the first orbital launch attempt of Starship, a milestone in its plans to develop an Artemis lunar lander for NASA. Neither NASA nor SpaceX will share many details about those efforts, though. buff.ly/3UKp3H5

https://www.thespacereview.com/article/4478/1

In the shadows of lunar landers

by Jeff Foust
Monday, November 7, 2022

[oldAtlas_Eguy]

https://twitter.com/tsr/status/1590880740912566272

In Texas, SpaceX is getting closer to the first orbital launch attempt of Starship, a milestone in its plans to develop an Artemis lunar lander for NASA. Neither NASA nor SpaceX will share many details about those efforts, though. buff.ly/3UKp3H5

https://www.thespacereview.com/article/4478/1

In the shadows of lunar landers

by Jeff Foust
Monday, November 7, 2022

To do an official Media release of a launch date and other details is still dependent on a unknown: the FAA launch license. I suggest The Space Review ought to do a deep dive as to what the FAA is up to as well as all SpaceX efforts to get the license. That would be a more interesting set of info than an article that laments no official statements on the launch from SpaceX or NASA.

[Robotbeat]

I suspect the FAA doesn’t know either as they’re waiting for the vehicle to get to a flight certifiable state, ie a successful full static fire or something.

[DanClemmensen]

I suspect the FAA doesn’t know either as they’re waiting for the vehicle to get to a flight certifiable state, ie a successful full static fire or something.

FAA employees have plenty of non-SpaceX work to do.They have no reason to try to work on this in advance of a request from SpaceX for a launch license. When they get the request, I suspect the license grant will be routine unless there is a weirdness in the request.

[su27k]

The launch license discussion would be better held at the FAA thread.

To be fair to Jeff Foust, I do think SpaceX is keeping a lot of details about Lunar Starship under wraps, examples include how many refueling launches are needed, what is the interior looks like, what is the redundancy for the elevator, etc. But this is no different from the other providers (for example I'd like to see what LM is planning with NTP), and this is also no different from Commercial Crew where after the 2014 unveil there's not much detail provided about Crew Dragon until it started launching.

I don't know SpaceX's rationale behind this, I think oldAtlas_Eguy provided one reason in another thread which is they're still iterating the designs, so anything released at this point is very preliminary and will be changed in the future, so there's not much point to publicize it. I have some additional guesses:

1. Keep it a secret from competitors: SpaceX was only awarded a demo mission or two, eventually Lunar Starship will compete against the 2nd lander for the recurring lunar transportation service, so they have a legitimate need to keep the details a secret for competitiveness reasons just as the other HLS providers.

2. Keep it a secret from China: Should be obvious China is copying Starship as fast as they can, no need to make their job easier.

3. Minimize media attack surfaces: Despite the fact that Blue Origin's attack against HLS Starship has been strike down multiple times a year ago, there're still people using the nonsense Blue created to attack HLS Starship. And I'm not talking about the usual Musk detractors, I'm talking about people in the space industry still to this day refuse to believe Starship is the future and that NASA has bet the entire Artemis program on it. They could do some damage in today's media environment given their credential, so no need to make their job easier either. By keep the details light, it makes it difficult for them to create concern trolling narratives.