SLS Lander?

[Caleb Cattuzzo]

I was wondering if NASA has said anything about a lunar lander for any EM missions?I know the SLS can carry cargo and the orion for the DSG station but i was wondering if they were going to put a lander in the SLS for a mission or missions?Plus after the presidents recent speech wanting america to return to the moon will NASA start one if they haven't yet?

[whitelancer64]

A lunar lander is not in any NASA plans or proposals, nor is there any budget for one.

[Caleb Cattuzzo]

A lunar lander is not in any NASA plans or proposals, nor is there any budget for one.

Is it possible with SLS though?

[whitelancer64]

A lunar lander is not in any NASA plans or proposals, nor is there any budget for one.

Is it possible with SLS though?

Not without funding.

[RonM]

Of course it's possible, just like the Altair concept for Ares V, but there are no plans and no funding for a lunar lander.

https://en.wikipedia.org/wiki/Altair_(spacecraft)

[Rocket Science]

No, it's still a rocket to nowhere...

[Hog]

"Build it, they will come."

I wish the focus wasn't being directed back to Luna, but if we're to plant flags and footprints on the Moon again, so be it.

Orion with some landing legs and an OMS engine should work.

NASA just released an RFI for a Shuttle'like OMS engine
Article by Chris Gebhardt
https://www.nasaspaceflight.com/2018/02/nasa-releases-rfi-new-orion-service-module-engine/


Here's Endeavours edit:LEFT side OMS pod.  .

[Toast]

Blue Origin (among others) has a proposal for a lander capable of flying on SLS, but it wouldn't carry crew. But like everybody else has been saying, it won't happen without funding. And Congress likes to talk about going back to the moon (and about going to Mars) but doesn't like ponying up the money to actually do so.

[whitelancer64]

"Build it, they will come."

I wish the focus wasn't being directed back to Luna, but if we're to plant flags and footprints on the Moon again, so be it.

Orion with some landing legs and an OMS engine should work.

NASA just released an RFI for a Shuttle'like OMS engine
Article by Chris Gebhardt
https://www.nasaspaceflight.com/2018/02/nasa-releases-rfi-new-orion-service-module-engine/


Here's Endeavours edit:LEFT side OMS pod.  .

Orion's already using an OMS for its service module. It would need about 20X more fuel to land on the Moon, though, and more to lift off again and break lunar orbit.

A dedicated lander is a much more efficient option.

[ncb1397]

"Build it, they will come."

I wish the focus wasn't being directed back to Luna, but if we're to plant flags and footprints on the Moon again, so be it.

Orion with some landing legs and an OMS engine should work.

NASA just released an RFI for a Shuttle'like OMS engine
Article by Chris Gebhardt
https://www.nasaspaceflight.com/2018/02/nasa-releases-rfi-new-orion-service-module-engine/


Here's Endeavours edit:LEFT side OMS pod.  .

Orion's already using an OMS for its service module. It would need about 20X more fuel to land on the Moon, though, and more to lift off again and break lunar orbit.

Actually, if you take the 4700 kg LEM ascent module and plop it on the ESM, it would have ~1800 m/s. Pretty much exactly what you would need to land on the moon with no margin from LLO. Main problem is main propulsion thrust. ESM has about 30 kN, while LEM had ~50% more than that I believe while the whole stack would be heavier because of the heavier ESM. IMO the Orion program just needs to build an american propulsion/power service module that just happens to do double duty as a descent module.

A lunar lander is not in any NASA plans or proposals, nor is there any budget for one.

Well, the new budget request has $100 million+ for lunar landing tech(starting with <200 kg landers, expanding to 5000-6000 kg eventually) and $200 million+ for lunar surface missions under the science division.

[A_M_Swallow]

{snip}

A lunar lander is not in any NASA plans or proposals, nor is there any budget for one.

Well, the new budget request has $100 million+ for lunar landing tech(starting with <200 kg landers, expanding to 5000-6000 kg eventually) and $200 million+ for lunar surface missions under the science division.

The landers are being developed under Lunar CATALYST, they will need payloads. Habitats are being ground prototyped under NextSTEP.

The 5000-6000 kg lander is probably the XEUS from ULA and Masten Space Systems. They are milestoned to release information within the next couple of months. It will need a cabin. I predict that people will dismount from that Centaur.

[Joseph Peterson]

I'm having trouble visualizing a Lunar lander lander that works in conjunction with SLS/Orion/DSG.  From the Lunar orbits and their potential uses topic[1] it appears we need roughly 700 m/s to go from a Lunar/L2 orbit Orion can reach to LLO.  LLO to the surface adds another ~1800 m/s.

Is it better to build a ~5 km/s reusable lander that can go directly to the surface or break the trip into stages?

If staging makes sense does it make more sense to build a DST that can reach all potential LLO staging orbits, an ACES-esque tug, a SEP tug, disposable options, or something I haven't considered?

Is a ~3.6 km/s fully reusable lander preferable to disposable or partially disposable options?

Obviously there needs to be funding to pay for whatever option is chosen.  I'm more interested in the possible hows for now.  As far as I can tell, we just don't know enough about where or how often we might want to land to actually start designs, but doesn't mean we can't speculate, right?

[1] https://forum.nasaspaceflight.com/index.php?topic=41784.0

[Steven Pietrobon]

Is it better to build a ~5 km/s reusable lander that can go directly to the surface or break the trip into stages?

An expendable system gets you to the Moon faster and with less hardware, since you don't need to build a gateway and the lander can be smaller, since it only needs to do 4 km/s from LLO instead of 5 km/s from NRO. You also don't need to worry about maintaining the lander and transferring propellants and cargo to the lander. The disadvantage is that you  need a new lander for every mission, but if you are only going every six months or so, that might not be so bad.

[Joseph Peterson]

Is it better to build a ~5 km/s reusable lander that can go directly to the surface or break the trip into stages?

An expendable system gets you to the Moon faster and with less hardware, since you don't need to build a gateway and the lander can be smaller, since it only needs to do 4 km/s from LLO instead of 5 km/s from NRO. You also don't need to worry about maintaining the lander and transferring propellants and cargo to the lander. The disadvantage is that you  need a new lander for every mission, but if you are only going every six months or so, that might not be so bad.

I am trying to figure out how a Lunar surface exploration program could work with SLS/Orion/DSG.  Obviously not having to design build permanent infrastructure should speed up the process.  That is not the path we are currently on.

[A_M_Swallow]

I am trying to figure out how a Lunar surface exploration program could work with SLS/Orion/DSG.  Obviously not having to design build permanent infrastructure should speed up the process.  That is not the path we are currently on.

The DSG's Power and Propulsion Element (PPE) is a solar powered space tug. A second one can be used to push consumables like food, water and power from LEO to a spacestation orbiting the Moon. Heavy items like habitat building and lunar rovers can also be transferred.

Since payload, propellent and lander can arrive separately heavier items can be landed on the Moon from a spacestation than in a single launch.

The ideal orbit for the DSG during construction of a Moon Base is probably very different from the orbit of the ship yard for the Mars Transfer Vehicle. Fortunately the DSG's orbit can be changed or a second one built.

People could go on direct SLS/Orion flights to the DSG. Most cargo could be launched to LEO on commercial launch vehicles.

[Lar]

Good analysis. For extra credit, cost the same set of operations using FH launches and Dragon spacecraft instead. Don't worry, Congress won't, so SLS/Orion is safe, but it's an interesting exercise.

[Joseph Peterson]

The DSG's Power and Propulsion Element (PPE) is a solar powered space tug. A second one can be used to push consumables like food, water and power from LEO to a spacestation orbiting the Moon. Heavy items like habitat building and lunar rovers can also be transferred.

Since payload, propellent and lander can arrive separately heavier items can be landed on the Moon from a spacestation than in a single launch.

The ideal orbit for the DSG during construction of a Moon Base is probably very different from the orbit of the ship yard for the Mars Transfer Vehicle. Fortunately the DSG's orbit can be changed or a second one built.

People could go on direct SLS/Orion flights to the DSG. Most cargo could be launched to LEO on commercial launch vehicles.

So your saying we should operate two stations then?

Here is what I am envisioning for crewed missions with two stations.

- SLS launches Orion to DSG located at a halo orbit around EML1/2.
- Orion arrives at DSG 5(EML1)-8(EML2) days later.  Crew transfers to DSG.
- Crew departs DSG on (DST???) for LLO station 0-7 days later depending on station orbital positions.
- Crew arrives at LLO station 59+ hours later using 680 m/s+ using chemical propulsion.  The + depends on which LLO orbit is used.  Current SEP will increase travel time by an amount I haven't yet learned to calculate.
- Crew departs LLO station for Lunar surface.
- Lunar surface operations are conducted.
- Crew returns using above steps in reverse.

Good analysis. For extra credit, cost the same set of operations using FH launches and Dragon spacecraft instead. Don't worry, Congress won't, so SLS/Orion is safe, but it's an interesting exercise.

Assuming a few minor modifications, a man-rated FH with a disposable center core at $95M launching Dragon II is capable transporting a crew of two to NRHO with Dv to spare.  I would expect a single crew transfer mission would cost on the order of $200M.  To equal SLS/Orion's crew of four we'd be looking at ~$400M.  Replacing SLS/Orion single piece cargo capability would require a another FH launch, meaning FH/Dragon should more than completely replace SLS/Orion's capability for somewhere near $500M.  Since the rest of the architecture is fuzzy I'll stop the comparison with the $1.5-2.5B estimate to launch SLS/Orion.

I don't understand why we would bother with the same set of operations using FH/Dragon.  Instead, I'd replace Dragon's trunk with enough Dv for LLO insertion and the TEI burn.  This allows surface exploration to commence with only one station, no interstation transport required, while allowing for a sub 4 km/s lander.  Then again, my assumption is early Lunar exploration will focus on the poles, tourists will accept 48-72 hour trips to Apollo 11 Lunar park, and other locations are explored using robots with sample returns run through the LLO station.  86° covers all of these options sooner.  Transfer times are 3-5 days to LLO versus the 8-20 via L1/2 halos.

While this is an interesting thought exercise, I don't see how it gets us closer to the specifications a Lunar lander designed to work with SLS/Orion requires.

[ncb1397]

While this is an interesting thought exercise, I don't see how it gets us closer to the specifications a Lunar lander designed to work with SLS/Orion requires.

The solution is an upgraded Orion service module made in the United States. Bump the solar power capability to 20 kw from 11 kw to match NeMO, add Next-C or AEPS engines. Acting as a lunar lander, It could self ferry itself ahead of crew to whatever orbit Orion can reach(might even be considered LLO) with the upgraded service module utilizing the extra lift capability of the Block 1B. The descent modules get re-used on the surface for power, consumable storage, fuel storage. Once you get some sort of fuel production going on the surface, you could look at fueling them and sending them back up to orbit. Orion would just use ESMs until this is available, freeing up Europe to focus on other stuff (like a European lunar hab equivalent to their contribution to ISS).

Either that or base the lander at DSG like what seems to be the plan. The difference between 4.5 km/s and 5.5 km/s for a lander isn't exactly a deal breaker.

[Joseph Peterson]

While this is an interesting thought exercise, I don't see how it gets us closer to the specifications a Lunar lander designed to work with SLS/Orion requires.

The solution is an upgraded Orion service module made in the United States. Bump the solar power capability to 20 kw from 11 kw to match NeMO, add Next-C or AEPS engines. Acting as a lunar lander, It could self ferry itself ahead of crew to whatever orbit Orion can reach(might even be considered LLO) with the upgraded service module utilizing the extra lift capability of the Block 1B. The descent modules get re-used on the surface for power, consumable storage, fuel storage. Once you get some sort of fuel production going on the surface, you could look at fueling them and sending them back up to orbit. Orion would just use ESMs until this is available, freeing up Europe to focus on other stuff (like a European lunar hab equivalent to their contribution to ISS).

Either that or base the lander at DSG like what seems to be the plan. The difference between 4.5 km/s and 5.5 km/s for a lander isn't exactly a deal breaker.

That isn't the current plan though.  NASA's RFI requested drop-in replacements for Shuttle OMS engines.  I guess the SM tanks could be stretched but that will cut into payload capacity.  How long would it take and how much would it cost before an upgraded Orion would be available?  How many more SLS launches are needed to send cargo?

https://www.nasaspaceflight.com/2018/02/nasa-releases-rfi-new-orion-service-module-engine/

Why are you adding a ~20% margin for LLO to surface and back compared to a minimum margin of ~9% for L2 halo orbits?

LLO to Lunar surface with no plane changes is ~1.87 km/s.  L2 to Lunar surface with no plane changes is ~2.52 km/s.  The NRHO version with the same margins as a 4.5 km/s LLO lander needs ~6 km/s.  Plane changes would be required for robotic sample return or <72 hour crewed access to the entire surface from halo orbits so we only have a partial equivalency.

I should probably make it clear that I am not arguing against the use of L1/2 stations in the future.  Once Lunar sourced propellant is available in sufficient quantity, they make perfect sense.  I'm not trying to plan an inner solar system transportation network using existing Lunar propellant production capacity though.  What I am trying to understand is how DSG actually helps locating, then building, Lunar production capacity.  It would seem to me that it is hard to compete with LLO when SEP can replace ~25% of cargo lander chemical Dv using LLO.

[A_M_Swallow]

The DSG's Power and Propulsion Element (PPE) is a solar powered space tug. A second one can be used to push consumables like food, water and power from LEO to a spacestation orbiting the Moon. Heavy items like habitat building and lunar rovers can also be transferred.

Since payload, propellent and lander can arrive separately heavier items can be landed on the Moon from a spacestation than in a single launch.

The ideal orbit for the DSG during construction of a Moon Base is probably very different from the orbit of the ship yard for the Mars Transfer Vehicle. Fortunately the DSG's orbit can be changed or a second one built.

People could go on direct SLS/Orion flights to the DSG. Most cargo could be launched to LEO on commercial launch vehicles.

So your saying we should operate two stations then?

{snip}

More like 3 spacestations.
LEO gateway spacestation to load SEP and chemical tugs.
LLO spacestation to garage lunar lander.
EML-1/2 spacestation for loading and repair of Mars transfer vehicles.

I think the manned Mars trip is 20-30 years away.