NASA Announcement for the Moon

[Yggdrasill]

If NASA is going to pay for full R&D, SpaceX can propose something entirely different that is compatible with NASA’s requirements. No reason for it to be anything like Starship.

SpaceX shouldn't focus on anything that would be a distraction from Starlink, Starship and regular launch services.

But maybe SpaceX could do something like adapt a Falcon 9 second stage to act as the decent vehicle. They might have some applicable data from their thoughts om landing their second stage, and they are already quite good at propulsive landings.

Maybe they could even do something crazy like putting a satellite into GTO, using the second stage as usual, and then have enough fuel left over to send the second stage to LOP-G to act as decent vehicle. If it's a light satellite and they use a Falcon Heavy, there could be sufficient fuel left over.

The decent vehicles/landers aren't going to be reusable anyway, judging by NASAs proposal, so this would be a way for SpaceX to reuse the second stages, if only once. And Falcon 9 including second stage is already going to be human rated, which might simplify things.

 

[Model 3]

How absurdly complicated.

I agree that this sound like an overkill for a moon mission. Bur would it make more sense on a Mars mission? If so, could this be just to test out the architecture before an Mars mission?

 

[Yggdrasill]

I agree that this sound like an overkill for a moon mission. Bur would it make more sense on a Mars mission? If so, could this be just to test out the architecture before an Mars mission?

I don't think very much, if anything, is transferrable to a Mars mission. The architecture seems quite tailored to getting to moon surface. But you could of course use the LOP-G as a base for assembling a vehicle for going to Mars. I assume they would have a larger transit vehicle with a smaller separate lander, similar to the moon landings. And no ISRU.

 

[ecarfan]

If NASA is going to pay for full R&D, SpaceX can propose something entirely different that is compatible with NASA’s requirements. No reason for it to be anything like Starship.

That is a gigantic “If”.

And even if that happened if would be a huge distraction from Elon’s Mars goal. So I don’t believe he would do that.

Eric Berger: “Bridenstine and NASA's chief of human spaceflight, Bill Gerstenmaier, both said the agency would welcome new ideas but that vehicles that did not fit this specific architecture would not be eligible for the current funding opportunity”.

The “would welcome new ideas” is just meaningless noise.

 

[bxr140]

I agree that this sound like an overkill for a moon mission.

Certainly there's a knee-jerk bias to dismiss anything that's not Elon, but its actually a pretty elegant concept from a point-design perspective. There's definitely some mass efficiencies over a single shot, and the mission risk becomes much more distributed as well--with more but less detrimental points of failure.

The real issue is that it is a state run project that [if you're cynical like me, anyway] will suffer the inevitably bloated, delayed, watered down, and congressionally appropriated fate, and not that the multi-element concept itself is flawed. Ironically, for a government-led project it actually checks a lot of boxes...but we can wax sociopolitical another time I suppose.

 

[e-FTW]

Certainly there's a knee-jerk bias to dismiss anything that's not Elon, but its actually a pretty elegant concept from a point-design perspective. There's definitely some mass efficiencies over a single shot, and the mission risk becomes much more distributed as well--with more but less detrimental points of failure.

Scott Manley sees a few distinct issues with the design (and the chosen orbit):

And that SpaceX does not have the needed engine for a lunar descent vehicle. Even Super Draco is too powerful.

 

[ggr]

See NASA emphasizing “speed” in its return to the Moon

Here is Eric Berger’s description of what NASA is soliciting bids for: “...the agency has released a broad agency announcement outlining its "architecture" for how this will be done. This will entail a transfer vehicle to go between the Lunar Gateway, in a high halo orbit around the Moon, and low lunar orbit. From there, the agency will use a descent vehicle to go down to the lunar surface, while an ascent vehicle would carry crew back to low lunar orbit.”

How absurdly complicated.

And, quote: “Most of the industry is likely to go along with this, but SpaceX has its own plans for developing a rocket (Super Heavy) and spacecraft (Starship) that could go directly to the lunar surface, without stopping at the Gateway. Bridenstine and NASA's chief of human spaceflight, Bill Gerstenmaier, both said the agency would welcome new ideas but that vehicles that did not fit this specific architecture would not be eligible for the current funding opportunity”.

Which is why I am so surprised that SpaceX has stated it is going to make a bid. I don’t see how Starship fits into that “specific architecture”.

They can dock to wave and say "Hi" on the way there and back. Sort of like when I visit my in-laws on the way to DC.

 

[e-FTW]

Also, the complexity of this solution seems driven by lift capability of rockets. No one can chuck 45-50 tons to the moon yet.
So they chopped it into three 15-ton pieces.

 

[RDoc]

I don't think very much, if anything, is transferrable to a Mars mission. The architecture seems quite tailored to getting to moon surface. But you could of course use the LOP-G as a base for assembling a vehicle for going to Mars. I assume they would have a larger transit vehicle with a smaller separate lander, similar to the moon landings. And no ISRU.

What would be the point to assembling such a vehicle in Lunar orbit? It's not like you're any closer to Mars or anything. If you want to assemble something in orbit, I'd think that doing it as close to Earth as possible would make the most sense.

IMHO LOP-G is the updated version of the ISS. The Shuttle needed someplace to go and the ISS needed the Shuttle for construction and maintenance, Just substitute LOP-G for ISS and SLS for Shuttle. Oh, and one more thing: the pork.

 

[Yggdrasill]

What would be the point to assembling such a vehicle in Lunar orbit? It's not like you're any closer to Mars or anything. If you want to assemble something in orbit, I'd think that doing it as close to Earth as possible would make the most sense.

The delta-V requirements to go from the LOP-G to Mars transfer is something like half that of going from LEO to Mars transfer. This means that you could build a vessel at LOP-G, suitable for months in transit and which could be reusable for travel to/from Mars, and never go to deep into the gravity wells. And then the crew could embark/disembark at LOP-G using Orion, and have a smaller, dedicated lander for Mars, leaving the transit vessel in high mars orbit (or a highly elliptic orbit, after aerocapturing).

This solution has some advantages. But I would tend to prefer the brute force approach of Starship. It may not be fully optimized for mass efficiency, but it should be less complicated and cheaper.

 

[RDoc]

The delta-V requirements to go from the LOP-G to Mars transfer is something like half that of going from LEO to Mars transfer. This means that you could build a vessel at LOP-G, suitable for months in transit and which could be reusable for travel to/from Mars, and never go to deep into the gravity wells. And then the crew could embark/disembark at LOP-G using Orion, and have a smaller, dedicated lander for Mars, leaving the transit vessel in high mars orbit (or a highly elliptic orbit, after aerocapturing).

This solution has some advantages. But I would tend to prefer the brute force approach of Starship. It may not be fully optimized for mass efficiency, but it should be less complicated and cheaper.

Well, that assumes that you already have all your assembly components and fuel in lunar orbit. How are you proposing they get there without expending delta V?

In the real world all that comes from the surface of the Earth, so you'd need to expend the delta V to slow it down to get it into Lunar orbit, then, after assembly, boost it back out and on it's way to Mars. Assembly in low Earth orbit doesn't require that, so it saves about 1.6 km/s.

 

[Bipo]

Well, that assumes that you already have all your assembly components and fuel in lunar orbit. How are you proposing they get there without expending delta V?

In the real world all that comes from the surface of the Earth, so you'd need to expend the delta V to slow it down to get it into Lunar orbit, then, after assembly, boost it back out and on it's way to Mars. Assembly in low Earth orbit doesn't require that, so it saves about 1.6 km/s.

But you can use the 1 km/s orbital speed of the moon as an orbital slingssli. And BTW if you manage to generate CH4&LOX from moon's surface you would be able to refill your spaceship at a less delta-V cost

 

[RDoc]

But you can use the 1 km/s orbital speed of the moon as an orbital slingssli. And BTW if you manage to generate CH4&LOX from moon's surface you would be able to refill your spaceship at a less delta-V cost

If you want to do a Lunar slingshot maneuver, just do it. Slowing down to let the moon capture you into orbit is just a waste of delta-V. You don't have to slow down to speed up.

And yes, if you happen to discover natural gas wells on the Moon, you're way ahead. If you discover abandoned alien artifacts that will instantly transport you to another galaxy, even better.

 

[Yggdrasill]

Well, that assumes that you already have all your assembly components and fuel in lunar orbit. How are you proposing they get there without expending delta V?

In the real world all that comes from the surface of the Earth, so you'd need to expend the delta V to slow it down to get it into Lunar orbit, then, after assembly, boost it back out and on it's way to Mars. Assembly in low Earth orbit doesn't require that, so it saves about 1.6 km/s.

I thought the delta-V hit was less than that. But there can still be arguments for doing it this way. Assuming commercial launchers can *juust* reach LOP-G with worthwhile modules for a mars transit vehicle, and you need a human presence for assembly, it can be more practical to build it at LOP-G, even with the delta-V hit.

 

[Yggdrasill]

But you can use the 1 km/s orbital speed of the moon as an orbital slingssli. And BTW if you manage to generate CH4&LOX from moon's surface you would be able to refill your spaceship at a less delta-V cost

Basically no carbon on the moon. But it is possible to produce hydrogen and oxygen from water on the moon, at least.

 

[ecarfan]

Assuming commercial launchers can *juust* reach LOP-G with worthwhile modules for a mars transit vehicle, and you need a human presence for assembly, it can be more practical to build it at LOP-G, even with the delta-V hit.

The idea that it is advantageous to assemble a Mars “transit” vehicle in space, even if that involves “only” connecting several modules, strikes me as lunacy. It took decades to build the ISS, a structure that only had to stay in LEO and provide life support for a handful of people.

Working in space is incredibly difficult and the pace of work is extremely slow. In contrast, building the SpaceX FSH/Starship on Earth, launching it to LEO, then refueling the Starship while in LEO and proceeding directly to Mars, while a formidable task, seems far easier.

Launching fully reusable vehicles to fuel a Starship in LEO is relatively cheap, compared to building the LOP-G, manning it for extended periods and then assembling a Mars transit vehicle in deep space (a vehicle that you cannot test before building it!). That will be incredibly hard and the cost will be gigantic. It will make the cost of an FSH/Starship look like pocket change.

 

[RDoc]

The idea that it is advantageous to assemble a Mars “transit” vehicle in space, even if that involves “only” connecting several modules, strikes me as lunacy. It took decades to build the ISS, a structure that only had to stay in LEO and provide life support for a handful of people.

Working in space is incredibly difficult and the pace of work is extremely slow. In contrast, building the SpaceX FSH/Starship on Earth, launching it to LEO, then refueling the Starship while in LEO and proceeding directly to Mars, while a formidable task, seems far easier.

Launching fully reusable vehicles to fuel a Starship in LEO is relatively cheap, compared to building the LOP-G, manning it for extended periods and then assembling a Mars transit vehicle in deep space (a vehicle that you cannot test before building it!). That will be incredibly hard and the cost will be gigantic. It will make the cost of an FSH/Starship look like pocket change.

Totally agree. However, I'm afraid we're not talking about a Space Program, we're talking about a Pork Program. Remember the Muppets' episodes of Pigs in Space? Same thing, but they're in Congress.

If LOP-G isn't built and maintained, there will be nothing newsworthy for the SLS to do. Then people might start wondering why we've spent billions on it, and who was it that kept supporting it. Not a good place to go.

 

[RDoc]

I thought the delta-V hit was less than that. But there can still be arguments for doing it this way. Assuming commercial launchers can *juust* reach LOP-G with worthwhile modules for a mars transit vehicle, and you need a human presence for assembly, it can be more practical to build it at LOP-G, even with the delta-V hit.

Um, sorry? You're saying that even though it's much harder, there are clear disadvantages, it's undoubtedly much more expensive and likely dangerous (radiation, difficulty of emergency return, etc.), and building it there is overall harder to launch to Mars, it still is better?

 

[ecarfan]

I'm afraid we're not talking about a Space Program, we're talking about a Pork Program.

Yep. After nearly $50 billion, NASA’s deep-space plans remain grounded

 

[Bobfitz1]

Yep. After nearly $50 billion, NASA’s deep-space plans remain grounded

"As far as I'm concerned, SLS and Orion are doing their jobs of providing work for NASA centers and contractors and giving the US a sense of national pride to have a major goal to work toward," Forczyk said. "They are not meant to be quick, cost efficient, or sustainable. They are symbolic grand acts of a grand nation."

Linda Forczyk sounds like a real winner. What is grand about an act (or nation) spending $50 billion on space hardware programs which will rarely or never fly, and accomplish anything?