SLS Rocket + Orion + Apollo LEM

RobertDyck · 2015-03-06 19:36:19

GW Johnson: I assert that the only way Orion can be used to go to the Moon, or cis-lunar space, is with a new service module. But I have a question. Which is better?

Apollo style: large service module, capable of lunar orbit insertion the entire stack into lunar orbit, plus enough propellant to return the capsule + service module alone to Trans-Earth trajectory. And 2 stage lunar module: descent stage used for lunar de-orbit plus landing, and assent stage to return crew to lunar orbit.

Soviet L3 style: small service module only capable of returning the capsule + service module to Trans-Earth trajectory. Separate expendable stage for insertion into lunar orbit. That separate stage is also used to de-orbit the lunar module. Only a single propulsion stage for the lunar module, used for both landing and ascent back to lunar orbit. To save weight, the landing gear is jettisoned during ascent.

Constellation plan: small service module. Lunar module with extra large descent stage used for 3 purposes: inserting the entire stack into lunar orbit, de-orbit lunar module, and landing. And separate ascent stage used to return crew to lunar orbit.

Or some other configuration?

kbd512 · 2015-03-07 07:12:45

If the premise is to attempt a sustainable exploration program, then I'd go for the "some other configuration" option for lunar missions. The Apollo, L3, and Altair landers were designed for single use.

Use ISS as a propellant depot and repair facility for SEP tugs and reusable landers.

The SEP tug would transfer the lander from ISS to L1 ahead of the crew. After the lander arrives at L1, the crew would then go to L1 in Dragon to transfer to the lander. The single stage lander then descends to the lunar surface from L1 for the surface mission. After the surface mission has been completed, the lander ascends to L1, the crew transfers back to Dragon, and then Dragon returns to Earth. The SEP tug then transfers the lander back to ISS for refueling, consumables resupply, and refurbishment.

This would give Boeing the opportunity to test the technologies required to transfer sizable payloads to Mars and reduce the recurring costs of a lunar exploration campaign. We can also test active radiation shielding and experiment with recovering oxygen from lunar regolith.

If ISS is upgraded with a repair facility module and payloads are sent to ISS before transfer to their ultimate destination, then humans who could actually correct problems can perform final checkout on the payloads. If something is forgotten or broken, it can be added or fixed. It's not a guarantee that a payload will reach its destination or that nothing can subsequently cause a problem that results in loss of the payload, just an additional opportunity to problem solve with greater flexibility.

I would think that the experienced garnered from exercising the capability to fix spacecraft and satellites in space have utility for a sustainable space exploration program, but that's just me. So long as episodes of space road truckers aren't inflicted on the rest of humanity, that is. (edit: I guess a more appropriate analogy would be Spacecraft Overhaulin. If some clown puts a pair of fuzzy dice on Orion or installs a chrome instrument panel, we're pulling the plug.)

Last edited by kbd512 (2015-03-07 07:25:13)

Void · 2015-03-07 10:53:57

If you will pardon a continued intrusion...
Argon, Radon on the Moon. I will continue with Argon.
http://www.lunarpedia.org/index.php?title=Argon
http://sservi.nasa.gov/articles/ladee-p … st-update/

The third lunar noble gas is argon, specifically, argon-40. This isotope comes from the decay of naturally occurring radioactive potassium-40, found in the rocks of all the terrestrial planets as a leftover from formation. As potassium-40 in the moon decays, the argon-40 product is able to diffuse and percolate up to the lunar surface, where it becomes part of the tenuous atmosphere. Lunar argon behaves differently from helium and neon; it condenses on the moon’s cold nightside where temperatures drop below -280 degrees Fahrenheit (-173 Celsius). As the moon slowly rotates, and the condensed argon sees sunrise, temperatures rise and the atoms jump off the surface into the exosphere again. Some of these jumping argon atoms leap back into the cold nightside, and are re-trapped on the cold surface until sunrise occurs for that patch of real estate. But the moon’s argon exhibits other interesting behavior. LADEE discovered that argon-40 creates a local bulge above an unusual part of the moon’s surface, the region containing Mare Imbrium and Oceanus Procellarum. This happens to be the place where potassium-40 is most abundant on the surface, and there may be a connection between the atmospheric argon, the surface potassium and deep interior sources.

So maybe a capture method employed at first daylight when the Argon is becoming mobile, but perhaps not as excited. Or wells at locations such as Mare imbrium or Ocianus Procellarum. Or, I have to wonder, if Argon condenses on the Lunar night side, then why would it not condense into the cold traps at the poles.

Of course I am thinking of Argon for your SEP notions.

Then there is a new item, "BuckyBombs", apparently a nano-scale energy storage method.
http://phys.org/news/2015-03-buckybomb- … sives.html
The Moon has Carbon Monoxide in the cold traps, and so Carbon.
But there are Silicon Buckyballs also. I don't know if they could be modified to make Silicon BuckyBombs or not. But there is plenty of that materials around on the Moon, and it is somewhat similar to Carbon.

How BuckyBombs could be used in a propulsion device, leads to vague speculation for me at this point. My first thought was a downsized Orion propulsion method, with a pusher plate. Apparently the energy release is very quick when they decompose. Then again maybe something else.
It is not as good I think as engines using Hydrogen and Oxygen, but it is something different to consider.

One other thought I had about it would be to have a cord on a spool which has segments of this isolated by non-explosive segments, it would be unreeled into a engine bell/pusher plate, and a segment ignited. Of course, should the spool have any ignition source, the whole thing would blow up.

It is notable that this method might be suited to other dry worlds where you don't want to consume Hydrogen. However it would need more than Carbon or Silicon, so then where does that come from?

I am more interested in the Argon.

Last edited by Void (2015-03-07 11:08:24)

GW Johnson · 2015-03-07 11:09:39

Trying to answer RobertDyck in #76 above: I don't know enough about SLS/Orion and its configurations and capabilities to say. But it makes no sense at all if it cannot reach lunar orbit and return home, without a lander. (It originally had a bigger service module when they were talking about taking an Altair lander to the moon.)

I'd hazard the guess they intend to get the LEO departure burn and the lunar orbit capture burn out of the booster upper stage. Then the service module can do the departure burn for the fall back to Earth. If it can do that, then it can reach L1 or anywhere else near the moon where they end up parking that redirected tiny asteroid fragment.

Sure is a lot of bother and cost to reprise nothing more capable than Apollo 8 using shuttle-era hardware. But I guess it helps keep the likes of ULA alive.

GW

Last edited by GW Johnson (2015-03-07 11:10:44)

GW Johnson · 2015-03-07 11:12:51

Responding to KBD512 in #77 above: Why not leave the landers at L1, and shoot the supplies straight there? Why drag the inert mass of the landers back-and-forth from LEO to L1? Otherwise, I love your idea!

GW

GW Johnson · 2015-03-07 11:22:34

Responding to Void in #78: The original group doing nuclear explosion propulsion at General Atomics San Diego in the 1950's actually flew a subscale model, even though they weren't supposed to. It flew fine on pulses of ordinary high explosives (presumably dynamite). 1-meter long model. So, yes, chemical explosion propulsion is possible, at least in an atmosphere where there are blast wave effects.

In space, no. There is not enough thermal radiation released by chemistry to push anything. It takes nukes to do that. There are no blast waves in space.

The old 1959 Orion explosion-drive design used fractional-kiloton devices for surface launch where there were shock waves, and multi-kiloton devices in space, where the nuke shaped-charge effects caused a thermal radiation spike through a reaction mass (incorporated into the device) which was converted to extreme high-speed plasma. That plasma blob plus the thermal radiation spike are what put the "push" on the pusher plate in space.

That being said, how about putting your "bucky bombs" into a liquid as a dense slurry, and using that as a monopropellant?

GW

SpaceNut · 2015-03-07 11:28:52

The shipyard overhaul dock would need a door large enough to bring the lander within, in order to work on it without space suits. One could park outside the door and grapple the lander with the arm and bring it into the dock; then tether it in place in a cradle, to allow for a stable place to do the work. That said the dock would need to be made with space walks as we have not the capability to lauch anything that large for diameter or for depth of what we would need to be able to do for the overhaul, refurbishment before reuse.

GW Johnson · 2015-03-07 11:39:17

Responding to Spacenut in #82:

Want a small "shipyard" we could build almost right now? Take a look at what I posted in the article "On-Orbit Repair and Assembly Facility" dated 2-11-14, located at my blog http://exrocketman.blogspot.com. This includes an unpressurized but thermally-stabilized and well-lit work bay, and very supple MCP suits to eable the necessary dexterity. I intended it for LEO, but it would work for this L1 refurbishment application. You only man it and use it when you need it. In point of fact, I would now put one on any Mars mission orbit-to-orbit transport design, as a part of avoiding the costs of a dead crew.

GW

Last edited by GW Johnson (2015-03-07 11:40:07)

RobertDyck · 2015-03-07 12:28:47

GW Johnson wrote:

Trying to answer RobertDyck in #76 above: I don't know enough about SLS/Orion and its configurations and capabilities to say. But it makes no sense at all if it cannot reach lunar orbit and return home, without a lander. (It originally had a bigger service module when they were talking about taking an Altair lander to the moon.)
I'd hazard the guess they intend to get the LEO departure burn and the lunar orbit capture burn out of the booster upper stage. Then the service module can do the departure burn for the fall back to Earth.

As I posted in #34, here is a diagram of the Constellation trajectory. (click image for larger view)

It shows they intended to launch the Altair lunar module on Ares V, and Orion capsule with service module on Ares I (The Stick). Rendezvous and dock in LEO. The upper stage of Ares V would be used for TLI, just as the third stage of Saturn V did for Apollo. Earth Departure Stage is jettisoned en-route to the Moon. But then the descent stage for the Altair lunar module would be used for LOI burn; that's Lunar Orbit Insertion. Apollo used the Service Module for that, but Constellation was going to use the Lunar Module.

GW Johnson wrote:

If it can do that, then it can reach L1 or anywhere else near the moon where they end up parking that redirected tiny asteroid fragment.
Sure is a lot of bother and cost to reprise nothing more capable than Apollo 8 using shuttle-era hardware. But I guess it helps keep the likes of ULA alive.

The chart is for Constellation, not ARM. I'm not sure how the ARM plan expected to enter lunar orbit, and still have enough propellant to return home. Was the Orion 606 service module supposed to have enough propellant to do the entire Apollo mission? That is LOI and TEI? When I look at propellant to mass ratio, it doesn't look like it. To me, it looks like TEI only. If they wanted to stop at L1, that requires propellant. Return from L1 also requires propellant, but not as much as TEI. Not sure how to calculate that. But not sure how ARM was going to launch.

This discussion started with Tom's suggestion to use Orion and an Apollo LM to land humans on the Moon. I'm trying to stick to that.

Last edited by RobertDyck (2016-05-24 18:59:01)

Void · 2015-03-07 15:15:43

OK, I will try to stick to the original notion and it's mirror (Why not to), and look for a mixture of the two to extend potentials.

The LEM was to get them down and to house them. If it could be supposed that housing is already established, then the LEM can be slimmed down, but you would want an abort method, abort back to orbit in that case. Abort being done if you could not land safely or could not land where the habitat was.

With that notion, then I would think of a spacesuit as the life support capsule, and the lander being a booster for that, and also of course the means to land and still be alive. At first I thought that you would want a two person lander, since if one person became unable to operate the controls, then the co-pilot could. But with the age of computers being so much more advanced than it was for Apollo, then a one person lander can have three robotic pilots to help out if not able to do the deed.

As for the lack of ability for the Orion, the vehicle, it seems to me that it would be a relatively simple matter to hire SpaceX to send a augmentation booster into LEO, to couple with the device and extend it's abilities.

As for Orion, the pulsed propulsion device, I would think it might be smart to cut it's teeth on chemical explosives first to demonstrate method, and to wait until nuclear methods were available. It is likely that nuclear materials from Earth will not be available since it is wanted for use in power plants, and of course there are balance of power issues involved. I am not sure when nuclear weapons in orbit might be tolerated. Not now I think.

And so if you are going to do a chemical Orion, then it becomes silly to bring the explosives up from Earth, when rockets are developed with great power.

So, to expand the implementation of a chemical Orion, it will be necessary to loose the restrictions on thought. Can't get chemical explosive materials from the Moon, unless you first have the Chicken or the Egg.

Last edited by Void (2015-03-07 16:16:50)

Void · 2015-03-07 15:53:29

GW, I made a reference to one of your posts here. (#83)

Index
» Life support systems
» Emulation of Earth life form methods to achieve value added purposes.

Suit yourself.

Last edited by Void (2015-03-07 15:54:20)

RobertDyck · 2015-03-07 18:58:48

Another interesting point: the chart for Constellation said the lunar polar outpost would have life support for 7 months. To do that would require life support similar to ISS. Apollo style life support can't do that. Interesting. Another reason why Altair is so heavy.

If you want to make the lunar craft reusable, I would argue for single stage to orbit. I tried doing a calculation a couple years ago; couldn't make it work with chemical. Features included aerocapture into Earth orbit using ADAPT, rendezvous and dock with ISS until the next lunar mission. Park the tug in lunar orbit, rendezvous and dock with landing legs in lunar orbit. The crew cabin would be common for transit between Earth and Moon, and for landing/ascent. A separate lunar outpost. But even with all that, chemical wasn't enough. The problem is no CO2 or ice for ISPP on the Moon. Yes, I said no ice. At least not enough for return propellant. To carry propellant from Earth to lunar orbit and back, you need advanced propulsion of some sort. Nuclear thermal with Americium-242m might do it.

And there's another issue if you use a common cabin. Aerocapture is risky. Using aerocapture for Earth requires a capsule capable of direct entry. The most mass efficient we have is Dragon. That's heavier than the Apollo LM cabin. Do you use a completely separate craft for lunar orbit to Earth orbit and back? Then a lunar shuttle: surface to lunar orbit and back? That works if your transit craft isn't going to receive propellant from the Moon. If you use lunar propellant, then the craft should land on the Moon. Efficiency of propellant transfer.

But what could you use from the Moon? Lunar soil is oxides: silicon oxide, aluminum oxide, iron oxides, magnesium oxides, titanium oxides. But not simple oxides, they're complex minerals; mostly alumino-silicates. Titanium is ilmenite: iron-titanium-oxide. You could smelt, producing oxygen as a byproduct. Use oxygen as propellant. Not the greatest specific impulse, but available.

kbd512 · 2015-03-07 20:03:00

GW Johnson wrote:

Responding to KBD512 in #77 above: Why not leave the landers at L1, and shoot the supplies straight there? Why drag the inert mass of the landers back-and-forth from LEO to L1? Otherwise, I love your idea!
GW

This is all theoretical and would never be done in real life because it accomplishes too many stated space exploration objectives, tests too many technologies required for interplanetary travel, and isn't complex enough to satisfy the complexity cravings that NASA has.

We build three SEP tugs and four landers. The fourth lander is a contingency spare kept at L1 along with a smaller SEP tug for station keeping (the same design that we'll use to return satellites to ISS for repair/refurbishment/refueling/repurposing).

We're going to design the tugs to be capable of transferring payloads to Mars from the outset rather than wasting time and money screwing around with a bunch of intermediate designs requiring subsequent testing. Every functional part will be designed such that it is on-orbit replaceable without tools, if possible. As new tech comes out of our labs, the tugs are upgraded. Think of it as propulsion legos for astronauts to play with.

The SEP tugs enable LEO/L1/LEO transfers of heavy payloads between refuelings, but you have to be willing to wait a few months for the transfers. This is not a major problem because we can only maintain a relatively low launch cadence for crewed launches. The heavy landers only use chemical propulsion to get to the lunar surface from L1 and then back to L1. This maximizes useable propellant mass for our tugs and landers, as additional propulsion hardware and propellant would be required to supply the depot in any orbit other than LEO. After the initial support infrastructure is in place at ISS, subsequent launches provide consumables and replacement parts only.

If we're willing to launch the landers and SEP tugs with minimal propellant mass and use subsequent launches for fueling, it's possible to make this work with F9H only. When F9 and F9H become reusable, we can purchase ten or more F9H flights for the price of a SLS flight. F9/F9H are the American equivalents of Soyuz and Proton. If the upper stages are also reusable, the crew can launch to ISS aboard a F9, instead of the more expensive F9H.

I was thinking methalox for the landers because it makes the stack shorter since the tankage is smaller and it doesn't have the storage issues associated with LH2. The propellants are moderately cryogenic, but cooling requirements are within the capabilities of existing active cooling systems that NASA's contractors have already expended considerable effort to develop. The attitude control thrusters should also use methalox.

The general idea is to test the propulsion systems and landers through years of actual operations in space in the actual configuration required for a Mars mission, less components unique to atmospheric operations like inflatable heat shields.

Dragon is mass efficient enough that a F9H and RL-10 powered upper stage (or something similar to it that doesn't cost so much) can transfer it between LEO and L1, but more importantly, back to LEO without refueling. Active cooling is required, but we're supposed to be testing that tech because NASA says it's required for mid term space exploration objectives.

If we're doing space exploration on the cheap, we might as well have a concept of operations that makes that possible.

kbd512 · 2015-03-07 20:29:28

GW Johnson wrote:

Responding to KBD512 in #77 above: Why not leave the landers at L1, and shoot the supplies straight there? Why drag the inert mass of the landers back-and-forth from LEO to L1? Otherwise, I love your idea!
GW

I realize that I wasn't clear about the design of the lander and its propulsion hardware, so I'll be more specific. The lander is a wheeled or preferably tracked methalox/electric hybrid vehicle. The propulsion module is a separate piece of hardware that attaches to the top of it.

The propulsion module rests on hydraulic jacks/posts to enable the surface exploration vehicle to attach/detach from it for mobile surface exploration. The propulsion module also provides refueling capability for the surface exploration vehicle. This makes servicing the propulsion module and surface exploration vehicle easier and permits a wider variety of payloads to be carried.

kbd512 · 2015-03-07 20:39:32

GW Johnson wrote:

Responding to KBD512 in #77 above: Why not leave the landers at L1, and shoot the supplies straight there? Why drag the inert mass of the landers back-and-forth from LEO to L1? Otherwise, I love your idea!
GW

Gee whiz, GW. My brain isn't working today. I finally realized what you were asking. The surface exploration vehicles could stay at L1 with the station keeping tug if they didn't require significant repair or refurbishment, but the chemical propulsion modules have to be ferried back to ISS for refueling and refurbishment.

GW Johnson · 2015-03-08 10:13:19

I would think if you built the engines on those propulsion sections to be long-life reusable (whatever that might actually mean), there would be little need for refurbishment after every use, until that operating life runs out. Thus you could just do in-space refueling and supply-loading at the L1 point. Returning the stage to LEO for refurbishment should only be occasional. You get to send more propellants and supplies most of the time, if you're not ferrying inert stage weights around.

Maybe such engines exist and maybe they don't yet. Spacex at least thinks they have one in the Merlin 1D's. We'll see. At small thrust sizes, maybe XCOR has one in their piston-pumped Lynx engine. That's because the highest risk of failure in rocket engines has to do with turbopump machinery. They at least think they can scale up to larger sizes, too. That extends to methane and hydrogen, not just kerosene and LOX.

One or the other of those approaches, or maybe something else, will give us the long-life, low-maintenance liquid rocket engines we need to make this transportation happen efficiently. And I think it's not very far off. Both companies I mentioned are making good progress.

My suggestion does imply that we develop in-space refueling well enough to make it both safe and reliable with mild cryogenics. Most folks are talking LOX and methane these days. The Russian refueling is with simple storables, NTO and one of the hydrazines, if memory serves. NASA has never learned how to do any of this for itself, though. It's this issue, probably more than long-life engines, that limits our ability to do replenishment at L1 instead of coming back every time to LEO.

We'd have to start with exactly your suggestion, but we'd have to work on long-life engines and in-space cryo-refueling to make it more efficient, which is my suggestion.

Given what I have been saying about NASA declining elsewhere, I think I'd look to the private companies to actually get this done. If one of them sees value going to the moon, something like what we are discussing is the better way to do it. It'll happen then, and not before.

GW

kbd512 · 2015-03-08 16:28:04

GW Johnson wrote:

I would think if you built the engines on those propulsion sections to be long-life reusable (whatever that might actually mean), there would be little need for refurbishment after every use, until that operating life runs out. Thus you could just do in-space refueling and supply-loading at the L1 point. Returning the stage to LEO for refurbishment should only be occasional. You get to send more propellants and supplies most of the time, if you're not ferrying inert stage weights around.

I'm going to presume relatively small and simple regeneratively cooled pressure fed or expander cycle engines since the methane is moderately cryogenic. The major parts would be 3D printed, so they could be produced at ISS. The engines would be arranged in four banks of two.

GW Johnson wrote:

Maybe such engines exist and maybe they don't yet. Spacex at least thinks they have one in the Merlin 1D's. We'll see. At small thrust sizes, maybe XCOR has one in their piston-pumped Lynx engine. That's because the highest risk of failure in rocket engines has to do with turbopump machinery. They at least think they can scale up to larger sizes, too. That extends to methane and hydrogen, not just kerosene and LOX.

Something like the XCOR 5M12 (descent/ascent) and XR-3M9 (rcs) are what I had in mind for the propulsion module. A bit more performance or more banks of engines would be required for Mars missions, but we need to concern ourselves with development of the propulsion module first.

GW Johnson wrote:

One or the other of those approaches, or maybe something else, will give us the long-life, low-maintenance liquid rocket engines we need to make this transportation happen efficiently. And I think it's not very far off. Both companies I mentioned are making good progress.

I think in about three to five years or so, we'll have LOX/LCH4 engines that are suitable for manned spacecraft. NASA moves slowly, so there's plenty of time to design the module while we're developing the engines.

GW Johnson wrote:

My suggestion does imply that we develop in-space refueling well enough to make it both safe and reliable with mild cryogenics. Most folks are talking LOX and methane these days. The Russian refueling is with simple storables, NTO and one of the hydrazines, if memory serves. NASA has never learned how to do any of this for itself, though. It's this issue, probably more than long-life engines, that limits our ability to do replenishment at L1 instead of coming back every time to LEO.

Yes, on-orbit refueling, purging, and refurbishment of the propulsion module are what make this architecture possible. Transferring the propulsion modules back to LEO for refueling is about efficiency and availability of repair facilities. The SEP tugs can transfer the propulsion modules to L1 with far less propellant mass consumed than with chemical propulsion. There's no advantage to a L1/L2 propellant depot if you're not making the propellant on the moon because you have to expend propellant to get to L1/L2 and you have to have something to store the propellant in. All of this infrastructure also has to get to LEO to begin with. The propulsion module stores the propellant because it's using the propellant. The propulsion module has to be inspected after each use and only ISS will have the facilities to repair or replace damaged parts and crews trained for that task.

GW Johnson wrote:

We'd have to start with exactly your suggestion, but we'd have to work on long-life engines and in-space cryo-refueling to make it more efficient, which is my suggestion.

Agreed.

GW Johnson wrote:

Given what I have been saying about NASA declining elsewhere, I think I'd look to the private companies to actually get this done. If one of them sees value going to the moon, something like what we are discussing is the better way to do it. It'll happen then, and not before.
GW

I'm not holding my breath on NASA going anywhere in my lifetime. I believe that the vast majority of our political establishment is completely uninterested in space exploration of any kind and can't or won't provide clear, consistent, and achievable objectives for NASA to accomplish. Leadership has to start at the top and we don't have any.

RobertDyck · 2015-03-08 16:57:09

GW Johnson wrote:

The Russian refueling is with simple storables, NTO and one of the hydrazines, if memory serves.

Yes. Russia uses N2O4 (di-nitrogen tetra-oxide, aka nitrogen-tetra-oxide) as oxidizer, and UDMH as fuel. That's the same propellant mix as the Apollo CM and SM.

RobertDyck · 2015-03-08 17:07:21

GW Johnson wrote:

maybe XCOR has one in their piston-pumped Lynx engine

Did you say piston-pumped rocket engine?

GW Johnson · 2015-03-09 09:17:03

Yep. XCOR has been flying piston-pumped engines in two rocket airplanes starting several years ago. These rocket engines end up with a maintenance lifetime resembling ordinary piston aircraft engines, or even better, approaching turbine.

They started with ordinary storables, went to LOX-kerosene piston pumped (that's Lynx), have done LOX-methane, and even LOX-LH2, all piston pumped. Sizes are still fairly small, I think the Lynx engines are each about 2700 lb thrust. But the technology is definitely scaleable, since they are turning the pump at a tiny fraction of its rated speed.

What's the significance of the photo of the pretty old Ryan? Is somebody learning tailwheel?

GW

RobertDyck · 2015-03-09 10:31:47

It's a prop plane with a piston engine. Implied a piston rocket engine is equivalent to a piston plane. This specific plane because Thursday actor Harrison Ford crashed one at a golf course. He played Han Solo in Star Wars, who flew the Millennium Falcon. SpaceX Falcon9 is named for the Millennium Falcon.

Last edited by RobertDyck (2015-03-09 10:44:09)

RobertDyck · 2015-08-04 22:46:31

This discussion thread is about an Apollo style mission to the Moon, using an Apollo LEM (LM) taken out of a museum. We already came to the conclusion that it would require a new service module. Either the Orion 606 service module for TEI, plus another stage for LOI, or a new larger service module with enough propellant to do both. Apollo Service Module (SM) did both.

Here's a wild idea. What if we use the CST-100 capsule with a new service module? That spacecraft uses its service module for launch abort, so the new service module would have to do the same. But this proposal would use LCH4/LOX, with enough delta-V for both TEI and LOI. And LOI with an Apollo LM attached. Composite propellant tanks for reduced mass. Could this be launched with SLS block 1B? The chart posted by SpaceNut shows SLS block 1B with Exploration Upper Stage (EUS) with 4 RL-10 engines and 105 metric tonne propellant could throw 40.6 metric tonnes to TLI. Saturn V could throw 47 metric tonnes to TLI. Using LCH4/LOX instead of UDMH/N2O4 would reduce propellant mass by 3.7 metric tonnes. Block 2B with liquid boosters could throw 52.3 tonnes to TLI, so big enough for Orion. But could block 1B throw CST-100 with a new service module and Apollo LM to TLI?

SpaceNut · 2015-08-05 18:22:14

102 mT to LEO which is the capsule,sm,eus gives a total dry mass plus the remaining fuel 105 mT after the orbital burn is one way to read the table, since once the tli burn is done and the stage is jetisonned it leaves the 40 mT going to the moon..

RobertDyck · 2015-08-06 01:24:01

According to the chart you posted in Space Policy, SLS block 1B can throw 40.6 mT to TLI. The question is can we reduce the capsule + SM + LM to that total?

In post #20 of this discussion thread, I calculated how heavy Orion would be...

Orion capsule 8,913kg + ATV-based service module 12,337kg + launch abort system 7,250kg + fairings 3 * 450 kg. Total 29,850kg.

But there's a problem: the ATV-based service module doesn't have enough propellant to return to Earth from Lunar orbit. You would need the American built service module. Post #8...

With the Orion 606 Service Module:
Capsule 8,913kg + SM 3,700kg + fuel 8,300kg + LAS 7,250kg = 28,163kg

That Service Module would require fairings as well, so add 3 * 450kg for a total of 29,513kg.
Apollo LM mass was 16,400kg for Apollo 15-17. And the Orion 606 SM does not have propellant for LOI.

I found a reference here that states Delta-V for Apollo 12 LOI was 2,889.5 ft/s. That converts to 880.9 m/s. So what could we use as an LOI stage? Rocket stage Ariane 5-2 is manufactured in Germany for the European Space Agency. It uses N2O4/MMH propellant, Isp=324s, gross mass 12,500kg, unfuelled mass 2,700kg. A delta-V calculator states this stage connected to Orion capsule + Orion 606 SM + Apollo LM would give delta-V of 696.07 m/s. Not quite good enough.

Delta III upper stage has gross mass 19,300kg, empty mass 2,480kg, Isp=462s. It uses LOX/LH2. Ignoring the problem of LH2 boil-off, that would give delta-V of 2454.51 m/s. That's more than enough. What a difference Isp makes.

Total launch mass including fairings would be 65,213kg. The Apollo LM and Delta III upper stage would not fit within the payload adapter for SLS EUS, so a larger payload adapter would be needed. That will add more mass. All this would fit not within SLS block 2, much less 2B or 1B.

So could we use CST-100 capsule instead of Orion? And a custom service module with LOX/LCH4 and composite propellant tanks. Should we design the SM to do the same job as Apollo SM? Or a smaller SM, with Ariane 5-2 stage for LOI? Either way, would that fit on SLS block 1B?

RobertDyck · 2015-08-06 01:59:42

Another interesting option:
Launch a Mars Direct habitat to the Moon. Develop a new lunar module, as spartan as the Apollo LM but designed for 4 astronauts. CST-100 capsule and new SM. Launch the Mars Direct habitat without heat shield or parachute, because the Moon doesn't have gravity. Launch the Hab on SLS block 2B, and CST-100 with the new LM on another SLS block 2B. That would make the Hab a permanent lunar base. Future missions could use the new LM / CST-100 to return crew to this base.

Of course this means demonstrating Mars hardware on the Moon.

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#76 2015-03-06 19:36:19

Re: SLS Rocket + Orion + Apollo LEM

#77 2015-03-07 07:12:45

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#78 2015-03-07 10:53:57

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Re: SLS Rocket + Orion + Apollo LEM

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#83 2015-03-07 11:39:17

Re: SLS Rocket + Orion + Apollo LEM

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#85 2015-03-07 15:15:43

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#86 2015-03-07 15:53:29

Re: SLS Rocket + Orion + Apollo LEM

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Re: SLS Rocket + Orion + Apollo LEM

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Re: SLS Rocket + Orion + Apollo LEM

#90 2015-03-07 20:39:32

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#91 2015-03-08 10:13:19

Re: SLS Rocket + Orion + Apollo LEM

#92 2015-03-08 16:28:04

Re: SLS Rocket + Orion + Apollo LEM

#93 2015-03-08 16:57:09

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#95 2015-03-09 09:17:03

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#96 2015-03-09 10:31:47

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#97 2015-08-04 22:46:31

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