Starship Artemis Contract & Lunar Starship

[yg1968]

Interest image in the NASA video of two Starships at Gateway. The one that is departing is HLS. The other ones seems to be a regular Starship.

May I repeat?

As you can see from top right corner, it's NOT an official render (although interesting that NASA use one)

Please no misinformation (tbf the ability of David Willis to research before posting is questionable anyway)

I think that it is artistic license more than anything. But yes, maybe NASA should have used a better clip. As somebody else pointed out, Gateway doesn't look like that either.

[r8ix]

Take a look at the booster in the first 3-4 seconds, and maybe that will help you judge the accuracy of the video...

[Robotbeat]

They must have asked for permission. I found the twitter account of Deep Space Courier:
https://twitter.com/ds_courier?lang=en

Doesn’t look like a usual rendering contractor. Agreed, then, that it’s not official unless we know NASA commissioned that YouTube channel.

[Robotbeat]

How many refueling flights would be needed if Starship tankers were to fly reusable, partly reusable, or expendable?

Musk said 8 flights to fill up the 1200t tanks since 1200t/150t=8.

Then he said maybe half-filled is enough, so 4 flights.

If a partially reusable Starship (first stage recovered, upper stage intentionally expended) gets to 200t, that’s 3-6 launches.

But Starship’s payload if expendable is about 250t, that knocks the number of fueling launches down to 2 to 5.


If the marginal cost of a reusable launch is $10M, then tanker flights cost $40-80M.

Partly reusable may add $25 million for the expended upper stage (which can be simpler, no flaps, possibly no header tank, reduced engines, no TPS) for a cost of $35*(3 to 6) = $105-210M, or $65-130M more to refill a mission than fully reusable.

Fully expendable, we’ll put at $150M per launch (Elon argued even lower than Falcon 9 would be possible or about $75M, but let’s ignore that), or about $300M-750M to refuel, $260 to $670M more than fully reusable.

They have to do all that twice. But even in the worst case, it’s still only a total of $1.5B out of an almost $3B contract. I think the middle case is fairly likely. 6, partially expended tanker launches for a total cost of about $400M out of the $2.9B. Not bad.

Possibly they’ll attempt reuse on every Starship tanker flight. That puts the cost at $600M or so, assuming they fail to recover each tanker. I suspect they’ll start succeeding.

[Timber Micka]

https://twitter.com/SpaceX/status/1506732905829056513

https://www.nasa.gov/press-release/nasa-provides-update-to-astronaut-moon-lander-plans-under-artemis

In April 2021, NASA selected SpaceX as its partner to land the next American astronauts on the lunar surface. That demonstration mission is targeted for no earlier than April 2025. Exercising an option under the original award, NASA now is asking SpaceX to transform the company’s proposed human landing system into a spacecraft that meets the agency’s requirements for recurring services for a second demonstration mission. Pursuing more development work under the original contract maximizes NASA’s investment and partnership with SpaceX.

[plank]

So many questions... is SpaceX still a participant in LETS, or does this modification to their Option A contract effectively separate them from the other participants to pursue 'sustainable lander' on their own?

From what I understand under option b, they will have to use SLS to launch a new lander, correct?

[dglow]

So many questions... is SpaceX still a participant in LETS, or does this modification to their Option A contract effectively separate them from the other participants to pursue 'sustainable lander' on their own?

From what I understand under option b, they will have to use SLS to launch a new lander, correct?

I don't think so. Also, I didn’t think there was an 'Option B' - LETS is referred to as 'Option Appendix N' IIRC.

[yg1968]

So many questions... is SpaceX still a participant in LETS, or does this modification to their Option A contract effectively separate them from the other participants to pursue 'sustainable lander' on their own?

From what I understand under option b, they will have to use SLS to launch a new lander, correct?

I don't think so. Also, I don't think there is an 'Option B' - LETS is referred to as 'Option N' IIRC.

No there is two contracts. One is for Option B (of Appendix H) for SpaceX. Option B was described in the original BAA: it's a sustainable crewed demo mission. Only companies that won Option A (SpaceX) are eligible for Option B. So SpaceX will win that option by default. 

A new Appendix P is being provided for the second lander. This new Appendix P is likely to be similar to Option A & B with one uncrewed and one crewed sustainable demos. LETS is dead.

[dglow]

^ Thanks! This is the lesser thread – am reading here now, and listening to the media conference.

[yg1968]

Actually, I created a new thread for these new contracts:
https://forum.nasaspaceflight.com/index.php?topic=56067.0

[Roy_H]

From what I read here, there is no advantage to sending a tanker to re-fuel HLS at Lunar orbit vs bringing the HLS back to LEO and refuel. There is more than sufficient capacity in the tanks and by refueling in LEO there is the advantage that supplies can be loaded into HLS while in LEO for the next moon landing mission.

[M.E.T.]

From what I read here, there is no advantage to sending a tanker to re-fuel HLS at Lunar orbit vs bringing the HLS back to LEO and refuel. There is more than sufficient capacity in the tanks and by refueling in LEO there is the advantage that supplies can be loaded into HLS while in LEO for the next moon landing mission.

Might have missed a section of the discussion (forgive me, if so), but how do you get the HLS back to LEO? I thought it doesn’t have enough fuel for the trip back - and certainly not for propulsive deceleration into LEO.

[DanClemmensen]

From what I read here, there is no advantage to sending a tanker to re-fuel HLS at Lunar orbit vs bringing the HLS back to LEO and refuel. There is more than sufficient capacity in the tanks and by refueling in LEO there is the advantage that supplies can be loaded into HLS while in LEO for the next moon landing mission.

Might have missed a section of the discussion (forgive me, if so), but how do you get the HLS back to LEO? I thought it doesn’t have enough fuel for the trip back - and certainly not for propulsive deceleration into LEO.

You do need to refill somewhere between the lunar surface and LEO. There are several possible mission profiles for this. Since the HLS is assumed to not be carrying much mass on the way back, you don't need that much fuel. I saw one analysis that used a single tanker, itself fully refilled in LEO, to go to an intermediate orbit (GTO was used in the example) to meet HLS and provide it enough fuel to get into LEO while the tanker still has enough fuel to also get back to LEO. That particular analysis was for missions using HLS to take crew from LEO to the lunar surface and back without SLS/Orion/Gateway, and of course used a depot and multiple tankers to get from LEO to the lunar surface on the way out.

[su27k]

https://twitter.com/jeff_foust/status/1519790614073774081

SpaceX’s Aarti Matthews says at AIAA ASCENDx that the Starship lunar lander is “taking away one of your biggest constraints” in designing payloads: far greater mass (100 metric tons to lunar surface) and volume and an order of magnitude lower cost.

https://twitter.com/SciGuySpace/status/1519786392200564736

Aarti Matthews of SpaceX says the company's investment in Starship is "significantly greater than 50 percent of the cost of the vehicle" compared to government. Point being, the $2.9 billion NASA is putting in for the Human Landing System is a small fraction of the overall cost.


NASA engineer asks what they should do to help industry. Matthews: Plan for capabilities of Starship; 100 metric tons, essentially infinite volume for payload, an order of magnitude of lower costs. "What does your system look like when you have no mass or volume constraints?"


More from Matthews: That's four firetrucks. It's 100 Moon rovers. It's the mass of 11 elephants. "NASA specified a high level need, but industry is taking away one of your biggest constraints, mass. I think that we all need to be thinking bigger and better."

[warp99]

From what I read here, there is no advantage to sending a tanker to re-fuel HLS at Lunar orbit vs bringing the HLS back to LEO and refuel. There is more than sufficient capacity in the tanks and by refueling in LEO there is the advantage that supplies can be loaded into HLS while in LEO for the next moon landing mission.

Might have missed a section of the discussion (forgive me, if so), but how do you get the HLS back to LEO? I thought it doesn’t have enough fuel for the trip back - and certainly not for propulsive deceleration into LEO.

You cannot get HLS back to LEO without refueling in NRHO and it makes very little sense to do so.  Propulsive braking is a waste of propellant that has been boosted to NRHO at huge expense and effort when non-HLS Starships can use aerodynamic braking instead.

The NASA mission profile is to discard the HLS from Artemis 3 into a heliocentric disposal orbit.  For Artemis 5 the HLS will be parked in NRHO after the mission and for Artemis 6 it is likely that that a tanker will be sent up from LEO to provide a bit over 50% of a full propellant load which is enough to get to the Lunar surface and back. 

Payloads can be brought up from Earth co-manifested with Orion on SLS 1b or with a modified tanker with a small payload bay.  Large payloads would be delivered to the Lunar surface separately from crew on a one way cargo flight. 

If SLS gets retired then a Crew Starship with TPS would deliver crew and cargo to NRHO and then the HLS Starship would take them down to the Lunar surface.  So Gateway would effectively act as a lifeboat and waystation in case of launch holdups or equipment failure that prevented an immediate return to Earth.

[Robotbeat]

Again, aerobraking doesn't require a full TPS. Mars orbiters do it all the time with their solar panels. Just pick an altitude to aerobrake at that has a low enough aeroheating flux (i.e., comparable to, or a small multiple of, sunshine). Dipping down to 140km or so would put peak aeroheating approximately the same as sunshine. Some of that heat ends up in the air, so maybe you can go slightly lower.

(Granted, this can take a long time...)

[DanClemmensen]

From what I read here, there is no advantage to sending a tanker to re-fuel HLS at Lunar orbit vs bringing the HLS back to LEO and refuel. There is more than sufficient capacity in the tanks and by refueling in LEO there is the advantage that supplies can be loaded into HLS while in LEO for the next moon landing mission.

Might have missed a section of the discussion (forgive me, if so), but how do you get the HLS back to LEO? I thought it doesn’t have enough fuel for the trip back - and certainly not for propulsive deceleration into LEO.

You cannot get HLS back to LEO without refueling in NRHO and it makes very little sense to do so.  Propulsive braking is a waste of propellant that has been boosted to NRHO at huge expense and effort when non-HLS Starships can use aerodynamic braking instead.

The NASA mission profile is to discard the HLS from Artemis 3 into a heliocentric disposal orbit.  For Artemis 5 the HLS will be parked in NRHO after the mission and for Artemis 6 it is likely that that a tanker will be sent up from LEO to provide a bit over 50% of a full propellant load which is enough to get to the Lunar surface and back. 

Payloads can be brought up from Earth co-manifested with Orion on SLS 1b or with a modified tanker with a small payload bay.  Large payloads would be delivered to the Lunar surface separately from crew on a one way cargo flight. 

If SLS gets retired then a Crew Starship with TPS would deliver crew and cargo to NRHO and then the HLS Starship would take them down to the Lunar surface.  So Gateway would effectively act as a lifeboat and waystation in case of launch holdups or equipment failure that prevented an immediate return to Earth.

It appears that everyone agrees you need a Starship HLS optimized for lunar landing and takeoff, and a different Starship optimized for Earth landing (i.e., with a TPS and flight control surfaces).  The problem then becomes: where should these two rendezvous? Choices mentioned here include NRHO and LEO, but the depot EO (apparently not an LEO) is another choice. All choices must include quite a bit of refill (tanker flights) and probably one or more depots. Given these elements, it is fairly easy (for professionals, not for me) to construct various mission profiles to optimize various parameters. The "best" choice will depend on how you weigh the parameters. If you optimize for minimized mission costs for ongoing missions, you get a different answer than minimum cost for the first mission, or earliest date for first mission.

In my (totally nonprofessional) opinion, the "best" early mission would use Starship HLS from LEO to the lunar surface and back, and use Crew Dragon on F9 to ferry crew Earth to LEO. This requires lots of tanker flights. Maybe eleven to tank of for the outbound trip and an additional three to put a tanker into a high EO to provide refill for the return trip. This is "best" only in the sense that it requires the minimum new hardware. (SLS/Orion/Gateway are new hardware). This proposed mission requires only the three Starship variants (HLS, tanker, depot) that are already required for the Artemis III mission that this would replace.

In the mid term, a crewed Starship would replace the Crew Dragon on F9 somehow, and rendevous might be in a higher EO to reduce fuel costs.

In the long term,  it might make sense to use lunar LOX to reduce refill cost. LOX represents 80% of the refill mass for a methalox engine. This changes the equation for the optimal rendezvous point.

[dglow]

From what I read here, there is no advantage to sending a tanker to re-fuel HLS at Lunar orbit vs bringing the HLS back to LEO and refuel. There is more than sufficient capacity in the tanks and by refueling in LEO there is the advantage that supplies can be loaded into HLS while in LEO for the next moon landing mission.

Might have missed a section of the discussion (forgive me, if so), but how do you get the HLS back to LEO? I thought it doesn’t have enough fuel for the trip back - and certainly not for propulsive deceleration into LEO.

You cannot get HLS back to LEO without refueling in NRHO and it makes very little sense to do so.  Propulsive braking is a waste of propellant that has been boosted to NRHO at huge expense and effort when non-HLS Starships can use aerodynamic braking instead.

The NASA mission profile is to discard the HLS from Artemis 3 into a heliocentric disposal orbit.  For Artemis 5 the HLS will be parked in NRHO after the mission and for Artemis 6 it is likely that that a tanker will be sent up from LEO to provide a bit over 50% of a full propellant load which is enough to get to the Lunar surface and back. 

Payloads can be brought up from Earth co-manifested with Orion on SLS 1b or with a modified tanker with a small payload bay.  Large payloads would be delivered to the Lunar surface separately from crew on a one way cargo flight. 

If SLS gets retired then a Crew Starship with TPS would deliver crew and cargo to NRHO and then the HLS Starship would take them down to the Lunar surface.  So Gateway would effectively act as a lifeboat and waystation in case of launch holdups or equipment failure that prevented an immediate return to Earth.

It appears that everyone agrees you need a Starship HLS optimized for lunar landing and takeoff, and a different Starship optimized for Earth landing (i.e., with a TPS and flight control surfaces).  The problem then becomes: where should these two rendezvous? Choices mentioned here include NRHO and LEO, but the depot EO (apparently not an LEO) is another choice. All choices must include quite a bit of refill (tanker flights) and probably one or more depots. Given these elements, it is fairly easy (for professionals, not for me) to construct various mission profiles to optimize various parameters. The "best" choice will depend on how you weigh the parameters. If you optimize for minimized mission costs for ongoing missions, you get a different answer than minimum cost for the first mission, or earliest date for first mission.

In my (totally nonprofessional) opinion, the "best" early mission would use Starship HLS from LEO to the lunar surface and back, and use Crew Dragon on F9 to ferry crew Earth to LEO. This requires lots of tanker flights. Maybe eleven to tank of for the outbound trip and an additional three to put a tanker into a high EO to provide refill for the return trip. This is "best" only in the sense that it requires the minimum new hardware. (SLS/Orion/Gateway are new hardware). This proposed mission requires only the three Starship variants (HLS, tanker, depot) that are already required for the Artemis III mission that this would replace.

In the mid term, a crewed Starship would replace the Crew Dragon on F9 somehow, and rendevous might be in a higher EO to reduce fuel costs.

In the long term,  it might make sense to use lunar LOX to reduce refill cost. LOX represents 80% of the refill mass for a methalox engine. This changes the equation for the optimal rendezvous point.

Agree on Crew Dragon in the near/short term and on lunar LOX. Dragon won’t fill LSS’s cargo hold, though, so a missed opportunity until Starship EEL (Earth entry & landing) replaces it.

If NHRO sucks as a waypoint for LSS just move Gateway to a more accessible lunar orbit. Once SLS gets its EUS doesn’t much of NHRO’s rationalization fade? Other commercial launchers delivering to Gateway can either beef up or get in on the refueling game. “Last station for 225K miles, fill-up before TLI.”

[DanClemmensen]

Agree on Crew Dragon in the near/short term and on lunar LOX. Dragon won’t fill LSS’s cargo hold, though, so a missed opportunity until Starship EEL (Earth entry & landing) replaces it.

If NHRO sucks as a waypoint for LSS just move Gateway to a more accessible lunar orbit. Once SLS gets its EUS doesn’t much of NHRO’s rationalization fade? Other commercial launchers delivering to Gateway can either beef up or get in on the refueling game. “Last station for 225K miles, fill-up before TLI.”

Crew Dragon is needed in the short term only because it will be awhile before there is a crew-certified Earth-to-LEO Starship. However, it is probably feasible to build a lunar lander with both crew and medium-large cargo capabilities, and build an Earth-to-EO cargo Starship with cargo transfer capability. An HLS mission would load cargo using the Starship and crew using Crew Dragons. Really big cargo would still use specialized one-way lunar cargo Starships.

Apparently, every young engineer in the aerospace industry is dreaming up mission profiles based on Starship variants, and I suspect almost all of them are better than mine. I'm not young, not an engineer, and not in the industry, so please give my idea all the attention it deserves. 

[Zed_Noir]

....

Agree on Crew Dragon in the near/short term and on lunar LOX. Dragon won’t fill LSS’s cargo hold, though, so a missed opportunity until Starship EEL (Earth entry & landing) replaces it.

If NHRO sucks as a waypoint for LSS just move Gateway to a more accessible lunar orbit. Once SLS gets its EUS doesn’t much of NHRO’s rationalization fade? Other commercial launchers delivering to Gateway can either beef up or get in on the refueling game. “Last station for 225K miles, fill-up before TLI.”

Crew Dragon will only carry people and small package cargo.

However after the crew is aboard the LSS. A few Cygnus with a docking port can rendezvous with the LSS to transfer as much cargo as needed in LEO. The stevedores crew is required to transfer cargo. Also there is a size limitation of the cargo that can go through the docking port.

The EUS doesn't increase the delta-V available with the current Orion European service module.