Moon mission today - Dragon & Mars hab

RobertDyck · 2016-05-24 22:42:02

If we were to do a Moon mission today, what exactly would it look like. We've discussed something similar, but let's get the details. First delta-V ...

Apollo 12 parked in fairly high orbit, reducing delta-V for TL. (additional reference)

 	   ft/s    km/s
TLI 	10,515.   3.20497
MCC 	    61.8  0.0188
LOI 	 2,889.5  0.88072
deorbit	   191.3  0.0583
TEI 	 3,042.0  0.92720

Next mission architecture. I'm doing this, so I want to use my Mars mission architecture. I've discussed that many times, it's a modification of Mars Direct. First brief review for Mars:

Mars surface habitat based on Mars Direct. This means upper deck usable, but lower deck has just an airlock, garage for Mars rover, life support equipment, landing rockets, and RCS thrusters. Surface science equipment and inflatable greenhouse packed around rover in garage. I've considered making the surface hab all soft plus a capsule for crew during landing, but lets make it a hard wall hab.
Deep Space Habitat for transit both ways: Earth-Mars and Mars-Earth. Reusable fabric heat shield for aerocapture. Tether for artificial gravity.
Dragon capsule for emergency escape pod in case aerocapture fails.
LH2/LOX chemical stage for TMI, and that stage used as counterweight for artificial-G.[*/]
pre-land Mars Ascent Vehicle, ISPP. Non-pressurized capsule, astronauts ride in spacesuits. MAV has additional propellant, it is TEI stage.
first mission only, pre-land all soft lab with pressurized rover and backup life support. Soft lab can be moved to the surface hab and connected.

Now Moon architecture.

Mars surface hab used as Moon base. No fabric heat shield or parachutes, all propulsive landing because the Moon has no atmosphere. Land without crew.
no MAV, no DSH, no lab
Dragon used as Apollo CSM. Requires a service module with propellant TEI.
Separate stage for LOI with LM attached, and to de-orbit LM. This is the approach used by the Soviets in 1960s, and current approach for Orion.
LM based on Soviet LK, enlarge to 4 crew. No rover, no surface science equipment, and only enough life support for lunar landing and ascent. Taxi only, surface hab will have everything else.

Soviet LK landing sequence...

Mass numbers, Apollo Grumman LM vs Soviet Yangel LK:
LM used by Apollo 9...14: 15,200kg
LM used by Apollo 15...17: 16,400kg
LK: 5,560kg

Assume our new LK uses modern electronics, and composite propellant tanks. Use MMH/N2O4 since that's safe, currently available, and doesn't boil off when parked for days/weeks/months. Apollo demonstrated it doesn't require nesting rockets. Side hatch for surface egress, and top hatch to dock with Dragon. Astronaut in LK stood like the Apollo LM, they will in this one too. The reverse curve section allowed a window that looked down; the pilot stood at that window. This LM will do the same, but more windows. The pressure hull is a sphere, same diameter as the cylinder pressure hull of the Apollo LM. One pilot will stand in front looking through the window, one astronaut each side on the front/back centre line, and one in the back behind the pilot. Additional windows I mentioned will be in the spherical hull: one to allow the pilot to look forward to the horizon, and one for each side astronaut. The guy in back has to look over everyone else's shoulder. To reduce weight, windows made of polycarbonate like a spacesuit helmet visor. For simplicity, assume mass of this new LM is the same as the Soviet LK.

For context, side cutaway of Soviet LK, showing pilot standing at window:

Next, mass of Dragon. Dry mass of the Dragon capsule is 4,200kg, propellant 1,290kg, but that's without astronauts or life support or seats/controls. The trunk has radiators for cooling, as well as solar arrays. So the service module would start as the Dragon trunk, then add propellant, tanks, engines. Calculate propellant mass for delta-V of 0.92720 km/s for TEI.

Next calculate stage required for 0.88072 km/s delta-V for LOI with Dragon, SM, and LM attached. Plus 0.0583 km/s de-orbit with just LM.

Once you have Dragon, SM, LM, stage, then calculate launch vehicle required.

Last edited by RobertDyck (2016-09-08 02:38:45)

Tom Kalbfus · 2016-05-25 07:56:16

Excuse me, but why land the Mars Hab on the Moon first? On Mars the Earth Return Vehicle gets landed first, and it lands only after they Earth Return Vehicle is ready and on the surface to go. I think the Apollo Lunar Module is an Earth return Vehicle, well its a surface to orbit vehicle. We just have to make it a little larger to accommodate four astronauts. The Russian LK never landed on the Moon after all, and I thought it was awkward to have a space walk just to go from the Russian Soyuz to the LK, but beside that the LEM got to the Moon and delivered the astronauts back to Orbit.

Now we use a Dragon Heavy or two, or an SLS to launch a command module plus LEM to Lunar Orbit, this pair is unmanned, the Command module could be a Dragon or it could be an Orion, they arrive at Lunar Orbit with supplies to get the astronauts back to Earth. The LEM seperates and lands on the Moon without astronauts on board and then it waits and sends a signal to Mission Control that all systems are ready.

esas.report.4.67.jpg

Then another Dragon Heavy or SLS launches from Cape Kennedy, this one carrying the HAB with astronauts onboard. The Hab lands on the Surface of the Moon, where the LEM is parked, the astronauts roll out the rover and do some exploring for a month of so, maybe six months, then when their supplies are used up, the get into the LEM and ascend to Orbit, dock with the waiting Command Module, undock with the LEM upper stage, and then fire their rockets for the return to Earth, they reenter the Earth's atmosphere Apollo style with parachutes and a splashdown, to be recovered by a Navy ship. Mission Complete!

Last edited by Tom Kalbfus (2016-05-25 08:03:35)

RobertDyck · 2016-05-25 13:37:53

Tom Kalbfus wrote:

Excuse me, but why land the Mars Hab on the Moon first? On Mars the Earth Return Vehicle gets landed first, and it lands only after they Earth Return Vehicle is ready and on the surface to go.

That's Mars Direct. And that is a problem. In the early 1960s, NASA considered Direct Launch and Earth Orbit Rendezvous. The latter meant assemble the vehicle in Earth orbit, using medium lift launch vehicles such as Saturn 1B. That was considered to slow and cumbersome. Direct Launch would land the Apollo CSM on the Moon, it would return directly to Earth, no LM. The problem with Direct Launch is Saturn V was not big enough, it would have required Nova. If Apollo is too big to land on the Moon and return, what makes you think you can do it now with Orion? The Apollo Command Module was half the mass of the Orion capsule, even if you built a capsule as small as Apollo, you still couldn't do it with SLS block 2 or 2B.

The only reason it work for Mars, is the ERV is landed with propellant tanks empty. But you can't do ISPP on the Moon because it has no atmosphere.

Tom Kalbfus wrote:

I think the Apollo Lunar Module is an Earth return Vehicle, well its a surface to orbit vehicle. We just have to make it a little larger to accommodate four astronauts. The Russian LK never landed on the Moon after all, and I thought it was awkward to have a space walk just to go from the Russian Soyuz to the LK, but beside that the LEM got to the Moon and delivered the astronauts back to Orbit.

Yea yea. America good, Russia bad. Could we get past the Cold War propaganda bullshit? I posted mass of the LM and LK above. The LM had the advantage that it could carry a rover, and a lot more surface science equipment. But this time the surface hab will have all that, all you need the LM to do is taxi astronauts to/from the surface. And the surface hab can be left as a permanent lunar base, the LM can taxi replacement crew.

And could you please finish reading what I posted before tearing it down. I said this new LM would be based on LK, but would dock the same way the Apollo LM did. Using the modern docking hatch used by crew Dragon, Orion, and CST-100 Starliner. The 1960s vintage Soviet LK could carry just 1 cosmonaut plus some surface science instruments. Not nearly as many or as much mass of science as the Apollo LM, and the later LM had a rover. The LK had an option to carry 2 cosmonauts, but that would have required removing all science instruments. I'm saying use of modern composites and alloys should allow expanding to 4 astronauts, but still no science or rover. Again, that stuff will be on the surface hab.

The image you posted of the Altair lunar lander is even bigger than the one I've seen. The one I saw had exposed propellant tanks. Remember, Constellation required 2 launches of SLS just to deliver one mission to the Moon. Apollo just used one Saturn V.

Notice what I'm trying to do. Can Dragon plus SM, plus LM, plus that stage fit on a single Falcon Heavy? If not then SLS block 1. Not 1B, I said block 1. Ideal is Falcon Heavy, let's work out the numbers. The surface hab will require 1 SLS block 2 or 2B.

Your image of a surface habitat includes 3 stories: 2 pressurized stories for crew, plus a third for landing rockets, propellant tanks, and air lock. The Mars Direct habitat had one story plus a second for rockets, tanks, airlock. The problem is FMARS and MDRS have made complete use of both decks. A real Mars hab would not have all that space, the lower deck would be just airlock plus garage plus solid equipment. The garage would be packed with the rover, surface science instruments, and inflatable greenhouse. Once on Mars (or Moon) all that would be unpacked leaving an empty space the size of a single car garage. That garage plus airlock is all you get for the lower deck. Still, as I've said many times, the upper floor alone has as much floor area as a 60-foot class A motorhome with slide-outs, plus the lower floor has airlock plus single car garage. Every drawing or painting of Mars Direct has shown the inflatable greenhouse the same width as a double car garage, and twice the length. That's plenty! Talk to a real Apollo astronaut who walked on the Moon. Compared to the Apollo LM, this is luxurious! No need to expand that to more stories.

Part of the point of this is to demonstrate the Mars surface hab on the Moon. That proves it works, so we can proceed on to Mars. That was part of Robert Zubrin's pitch to NASA in June 1990. I'm just trying to address weaknesses, and update equipment.

Tom Kalbfus · 2016-05-26 10:24:51

RobertDyck wrote:

Tom Kalbfus wrote:
Excuse me, but why land the Mars Hab on the Moon first? On Mars the Earth Return Vehicle gets landed first, and it lands only after they Earth Return Vehicle is ready and on the surface to go.
That's Mars Direct. And that is a problem. In the early 1960s, NASA considered Direct Launch and Earth Orbit Rendezvous. The latter meant assemble the vehicle in Earth orbit, using medium lift launch vehicles such as Saturn 1B. That was considered to slow and cumbersome. Direct Launch would land the Apollo CSM on the Moon, it would return directly to Earth, no LM. The problem with Direct Launch is Saturn V was not big enough, it would have required Nova. If Apollo is too big to land on the Moon and return, what makes you think you can do it now with Orion? The Apollo Command Module was half the mass of the Orion capsule, even if you built a capsule as small as Apollo, you still couldn't do it with SLS block 2 or 2B.
The only reason it work for Mars, is the ERV is landed with propellant tanks empty. But you can't do ISPP on the Moon because it has no atmosphere.

The Moon does have volatiles at the poles, you land the hab at one of the poles and you don't worry about the long length of the lunar day or night. The polar regions are the most sought after lunar real estate anyway.. At the poles you set up solar collectors, you don't need a nuclear reactor, you scoop up some regolith and you bake the gases out, you liquefy them and turn them into rocket fuel, and you can do this remotely from Earth. I don't think it makes much difference whether you land at the poles or the equator, the Moon doesn't rotate much anyway. the circumference of the moon is 6,783 miles. The moon is rotating at 9.42 miles per hour about one sixth the average cruising speed of your car on the highway! You think that's going to make a tremendous difference to a spaceship trying to land?

Tom Kalbfus wrote:
I think the Apollo Lunar Module is an Earth return Vehicle, well its a surface to orbit vehicle. We just have to make it a little larger to accommodate four astronauts. The Russian LK never landed on the Moon after all, and I thought it was awkward to have a space walk just to go from the Russian Soyuz to the LK, but beside that the LEM got to the Moon and delivered the astronauts back to Orbit.
Yea yea. America good, Russia bad. Could we get past the Cold War propaganda bullshit?

If you were standing on the deck of that US destroyer when the Russian Mig buzzed it, would you still call it "bullshit" or is it only "bullshit" when other sailors are subjected to this danger. They didn't ask for a "flying circus" from their Russian comrades after all, and you think we should go in space with these people?

I posted mass of the LM and LK above. The LM had the advantage that it could carry a rover, and a lot more surface science equipment. But this time the surface hab will have all that, all you need the LM to do is taxi astronauts to/from the surface.

The LEM can carry additional supplies, thus extending the stay for those in the Hab.

And the surface hab can be left as a permanent lunar base, the LM can taxi replacement crew.
http://www.amazing-animations.com/anima … keys11.gif

And since the Moon has only two poles, their are only two regions they would be interested in, both provide 24-hour access to sunlight just like free space.

And could you please finish reading what I posted before tearing it down. I said this new LM would be based on LK, but would dock the same way the Apollo LM did. Using the modern docking hatch used by crew Dragon, Orion, and CST-100 Starliner. The 1960s vintage Soviet LK could carry just 1 cosmonaut plus some surface science instruments. Not nearly as many or as much mass of science as the Apollo LM, and the later LM had a rover. The LK had an option to carry 2 cosmonauts, but that would have required removing all science instruments. I'm saying use of modern composites and alloys should allow expanding to 4 astronauts, but still no science or rover. Again, that stuff will be on the surface hab.

The question is why would you want to start with an inferior model that didn't even go to the Moon, and then try to improve on that. The Altair also didn't go to the Moon, just like the LK, and its bigger! If you are going to stay on the Moon for half a year, you need to land big things on its surface, the LK was designed for a flags and footprints mission, it was designed to get their Soviets there first, and still it did not succeed at that! The Soviets weren't interested in science, they were interested in propaganda, that has been the main purpose of their space program all along and why they build those space stations in the absence of Skylab, to rub our noses in it!

The image you posted of the Altair lunar lander is even bigger than the one I've seen. The one I saw had exposed propellant tanks. Remember, Constellation required 2 launches of SLS just to deliver one mission to the Moon. Apollo just used one Saturn V.

Mars Direct requires two launches for every mission, first you send the Earth Return vehicle, then you send the hab. For a Moon mission the Earth Return vehicle has two parts, the part that stays in orbit is the Command Module, the part that lands on the Moon's surface is the lander. Now because the lander needs to carry its ascent fuel down with it to the surface, its not very roomy, so you land a separate hab on the Moons surface with no ascent engines or fuel, so the astronauts can stay there for long periods of time. I would suggest up to a year since Moon missions are going to be infrequent due to cost, you would want to keep humans there until you can send up their replacements with another hab, and each additional hab further expands the Moon base.

Notice what I'm trying to do. Can Dragon plus SM, plus LM, plus that stage fit on a single Falcon Heavy? If not then SLS block 1. Not 1B, I said block 1. Ideal is Falcon Heavy, let's work out the numbers. The surface hab will require 1 SLS block 2 or 2B.
Your image of a surface habitat includes 3 stories: 2 pressurized stories for crew, plus a third for landing rockets, propellant tanks, and air lock. The Mars Direct habitat had one story plus a second for rockets, tanks, airlock. The problem is FMARS and MDRS have made complete use of both decks. A real Mars hab would not have all that space, the lower deck would be just airlock plus garage plus solid equipment. The garage would be packed with the rover, surface science instruments, and inflatable greenhouse. Once on Mars (or Moon) all that would be unpacked leaving an empty space the size of a single car garage. That garage plus airlock is all you get for the lower deck. Still, as I've said many times, the upper floor alone has as much floor area as a 60-foot class A motorhome with slide-outs, plus the lower floor has airlock plus single car garage. Every drawing or painting of Mars Direct has shown the inflatable greenhouse the same width as a double car garage, and twice the length. That's plenty! Talk to a real Apollo astronaut who walked on the Moon. Compared to the Apollo LM, this is luxurious! No need to expand that to more stories.
Part of the point of this is to demonstrate the Mars surface hab on the Moon. That proves it works, so we can proceed on to Mars. That was part of Robert Zubrin's pitch to NASA in June 1990. I'm just trying to address weaknesses, and update equipment.

Last edited by Tom Kalbfus (2016-05-26 10:29:08)

RobertDyck · 2016-05-26 11:55:28

I found one web forum, August 2014, that quoted a paper (The Golden Spike) that estimated total mass for Dragon v2 would be 8,853kg. Official statement from a representative of SpaceX said it would be the same mass as the cargo version, but the crew version has to add Draco thrusters for launch abort or propulsive landing, tanks and propellant for that system, landing legs, life support, seats, control console, and astronaut body weight and spacesuits. I was hoping for lower mass, but 8.8 metric tonnes is credible.

Dragon v2: 8,853kg
Orion: 10,387kg capsule + 15,461kg service module + 9,276kg service module propellant = 35,124kg

Now how much do we add for Dragon propellant and tanks for TEI? Using a delta-V calculator, for delta-V 927.20 m/s, assuming Isp=312s, and empty mass of 8,853kg, result is gross mass 11,987kg. That assumes no mass for tanks or engines. But the mass of Dragon v2 is just a guess anyway. If we assume the fairing cap on the capsule is discarded (Dragon v2 doesn't), could I assume SpaceX will find mass saving to keep gross mass down to that?

I notice Dragon v1 has solar array wings that track the sun. Dragon v2 has solar cells covering the trunk. That means at least half the solar cells will not generate power, requiring more solar cells. Furthermore, Dragon v2 trunk has fins, presumably for stability during abort. Couldn't an electronic control system use propulsion from the 8 SuperDraco thrusters to keep the capsule balanced during abort? Could we base the service module on the trunk from Dragon v1 instead of v2? Yes, folding wings require a small fairing, but that's discarded so not mass brought to Lunar orbit. And space rated solar arrays are expensive, so this should keep vehicle cost down. My excuse to use to not add mass for SM tanks or engines.

So payload mass entering Lunar orbit will be 11,987kg for Dragon plus 5,560kg for LM. The stage has to enter that into Lunar orbit, with enough propellant left to de-orbit the LM. Looking through actively manufactured upper stages, Fregat-MT is the right size. Delta Cryogenic Second Stage and Centaur are too big. Fregat-MT would provide our stack with 1056.65 m/s delta-V, so 880.72 m/s for LOI with reserve to de-orbit the LM. Fregat-MT uses UDMH/N2O4, empty mass 1,050kg plus propellant 7,100kg, Isp=333.2s.

Total mass to TLI = 11,987kg for Dragon + 5,560kg for LM + 8,150kg for Fregat-MT = 25,697kg.
Falcon Heavy is rated for 54,400kg to LEO, 13,600kg to TMI, or 22,200kg to GTO. So not quite enough. Damn!
SLS Block 1 is rated for 25,000kg to TLI, so maybe.

RobertDyck · 2016-05-26 12:09:23

Tom, you responded with politics and propaganda. Politics does not belong here. Post that in the politics thread, I promise I will not respond and will not even read it.

RobertDyck · 2016-05-26 13:30:21

Tom Kalbfus wrote:

The Moon does have volatiles at the poles

Seriously? Lunar water? So you want to commit human lives to producing rocket fuel from Lunar soil? Lunar Prospector used orbital instruments to identify the most concentrated water anywhere on the Moon. LCROSS then impacted exactly there. From a document released by NASA...

            Water Mass (kg)   Dust Mass (kg) Total water%
Time (sec)   Gas       Ice
   0-23    82.4±25   58.5±8.2  3148±787        4.5±1.4
  23-30    24.5±8.1 131±8.3    2434±609        6.4±1.7
 123-180   52.5±2.6  15.8±2.2   942.5±236      7.2±1.9
 Average   53±15     68±10     2175±544        5.6±2.9

Again that was the most concentrated water on the Moon. It isn't concentrated anymore, now it's dispersed by LCROSS. What you can expect is something less than 5.6% water. Do you really think you can produce return propellant form that?

Tom Kalbfus wrote:

The question is why would you want to start with an inferior model that didn't even go to the Moon, and then try to improve on that. The Altair also didn't go to the Moon, just like the LK, and its bigger!

Big = bad. Small and light = good. Big = expense, and expense will not get funded. Light = affordable enough to happen.
The model I just described would land a Mars Direct habitat as a Lunar base. I've said it many times, but obviously have to repeat: the upper story has an 8.4 metre outside diameter, giving the upper story alone as much floor area as a 60-foot class-A motorhome with slide-outs. The lower story has an airlock, plus garage to store a rover to carry all 4 astronauts, plus surface science equipment and an inflatable greenhouse. Once crew arrive, all that stuff is taken outside. That gives the lower deck a workshop or lab the size of a single car garage. The rest of the lower deck is solid equipment: landing rockets, propellant tanks, RCS thrusters, life support equipment, batteries. Once the greenhouse is setup, that will be the width of a double car garage and twice the length. That's lots of space. And plenty of room for science equipment.

Tom Kalbfus wrote:

Mars Direct requires two launches for every mission, first you send the Earth Return vehicle, then you send the hab. For a Moon mission the Earth Return vehicle has two parts, the part that stays in orbit is the Command Module, the part that lands on the Moon's surface is the lander. Now because the lander needs to carry its ascent fuel down with it to the surface, its not very roomy, so you land a separate hab on the Moons surface with no ascent engines or fuel, so the astronauts can stay there for long periods of time. I would suggest up to a year since Moon missions are going to be infrequent due to cost, you would want to keep humans there until you can send up their replacements with another hab, and each additional hab further expands the Moon base.

Robert Zubrin's presentation to NASA, I think this is from 1990. This shows the hab with one story, plus a landing stage. It didn't even have an enclosed garage for the rover. This version had the airlock on the one pressurized story, the rover was not shown but described in text. I assume the rover was hung by cables and a winch from the under side, between propellant tanks for landing. Lunar version is the same as the Mars version, except no heat shield, and the Earth Return Vehicle has one ascent stage instead of two. A common landing stage for both the habitat and ERV.

Mars Direct ERV is a simple capsule. It isn't spacious. In 1961 NASA attempted to design Direct Ascent for the Moon, it looked like this...

Notice this is the same as the "Return Vehicle" depicted as "Lunar Vehicles" in the Mars Direct slide. NASA found a Saturn V is not large enough to launch that; not when you have to land fully fuelled. It only works on Mars because the ERV lands empty, makes fuel on Mars via ISPP.

What I'm proposing is the Mars Direct hab, but replace the return vehicle with Apollo style equipment. Instead of the Apollo CSM, use Dragon. Instead of the Apollo LM that carried 2 astronauts plus surface science equipment and rover, use a simple lander for 4 astronauts and nothing else. Surface science equipment and rover will be on the hab.

Last edited by RobertDyck (2016-05-26 14:30:26)

kbd512 · 2016-05-26 14:06:45

Can we give it a rest with the political posts and limit our responses in this section of the forum to technical arguments about the merits of one approach or solution in comparison to another?

I can't speak for anyone else, but I find the technical arguments and data a lot more interesting to read than the US vs The World arguments.

Back on topic:

I think my two seat MDV/MAV capsule concept and LPR concept is ideal for the lunar environment, too.

It's the same basic design as the MDV/MAV except that only one capsule is required per crew per mission and EDL hardware for atmospheric reentry will be removed. The propellant storage requirements for the LDV/LAV are lessened, the mass constraints for the LPR are considerably lessened so MMOD and radiation shielding can be incorporated into the inflatable. Since lunar surface gravity is considerably less, the same electric motors that power the Mars LPR would provide a marginal performance improvement for this application.

Most other aspects of the solution would work in a very similar manner:

* Same basic mission - look for evidence of past life and determine optimal locations for colonies based on resource discovery
* Shorter 250 day nominal surface stay with extra life support consumables carried instead of extra food
* 4 vehicle convoy (two manned, two robotically operated like-kind spares or alternatively, everyone operates their own LPR)
* Daily EVA's for exploration and rover maintenance (need to determine how much atmosphere is lost in the decompression cycles- NASA created a doc with this info in it, in which they also put forth their own LPR concept for lunar exploration; need to find the doc to determine the feasibility of longer surface stays from a consumables standpoint)
* Smaller flexible solar panels for recharging the rover batteries
* Extraction of oxygen from lunar regolith using a small solar powered furnace
* Perhaps initial operations will be conducted near the poles to take advantage of ice deposits there and to explore those regions of the lunar surface

Tom Kalbfus · 2016-05-26 23:24:13

RobertDyck wrote:

Tom, you responded with politics and propaganda. Politics does not belong here. Post that in the politics thread, I promise I will not respond and will not even read it.

Well if you did not read it, you don't know there was politics in it. I stated a fact, made no campaign speeches, endorsed no one for president, and only a tiny portion of that post had anything to do with Russia. The fact is, the LK never went to the Moon, I would not trust a vehicle that was never tested. In fact the only nation that ever sent anyone to the Moon was the United States, the only vehicle that ever landed men on the Moon's surface was the Apollo Lunar Excursion Module (LEM).

Here is another lunar lander that never flew, why not use this one? The LK was a tiny thing compared to this!

RobertDyck · 2016-05-26 23:42:11

There you go again: America good, Russia bad. I have no patience for that. This is about engineering, not politics. And would you care to explain how you launch that on a single SLS block 1 or Falcon Heavy?

Tom Kalbfus · 2016-05-26 23:45:57

RobertDyck wrote:

Tom Kalbfus wrote:
The Moon does have volatiles at the poles
Seriously? Lunar water? So you want to commit human lives to producing rocket fuel from Lunar soil? Lunar Prospector used orbital instruments to identify the most concentrated water anywhere on the Moon. LCROSS then impacted exactly there. From a document released by NASA...
            Water Mass (kg)   Dust Mass (kg) Total water%
Time (sec)   Gas       Ice
   0-23    82.4±25   58.5±8.2  3148±787        4.5±1.4
  23-30    24.5±8.1 131±8.3    2434±609        6.4±1.7
 123-180   52.5±2.6  15.8±2.2   942.5±236      7.2±1.9
 Average   53±15     68±10     2175±544        5.6±2.9
Again that was the most concentrated water on the Moon. It isn't concentrated anymore, now it's dispersed by LCROSS. What you can expect is something less than 5.6% water. Do you really think you can produce return propellant form that?

You can't seriously believe that LCROSS dispersed all the Moon's water in that spot? The Moon may be only a quarter the size of the Earth, but it is bigger than your backyard!

Tom Kalbfus wrote:
The question is why would you want to start with an inferior model that didn't even go to the Moon, and then try to improve on that. The Altair also didn't go to the Moon, just like the LK, and its bigger!
Big = bad. Small and light = good. Big = expense, and expense will not get funded.

The LK does not look like it can bring much up besides the astronauts, it is a very spare vehicle.
1) I think whoever is funding it, might want some Lunar rock samples brought back to Earth.
2) Big rockets are expensive, because of that, expect one Lunar mission per year, and expect each astronaut party to stay there a year. I think my plan would involve three big rocket launches per year, one to carry the Orion Spacecraft, One to carry the Altair Lunar Lander, and one to carry the Lunar Hab with astronauts onboard. the hab contains enough supplies to last a year on the Moon. Without the Hab, the Altair and Orion can be used for short term missions, but then you would not have the continuous presence on the Moon you'd get if you used the Hab, and each new mission to the Moon adds another hab to the Lunar Base and more supplies to last another year. I think the old habs could be used as greenhouses to grow food on the Moon, and once we have enough habs on the Moon, the Lunar crew can grow their own food, and no longer need to import it from Earth, in which case other things can be shipped with the next hab.

Light = affordable enough to happen.
The model I just described would land a Mars Direct habitat as a Lunar base. I've said it many times, but obviously have to repeat: the upper story has an 8.4 metre outside diameter, giving the upper story alone as much floor area as a 60-foot class-A motorhome with slide-outs. The lower story has an airlock, plus garage to store a rover to carry all 4 astronauts, plus surface science equipment and an inflatable greenhouse. Once crew arrive, all that stuff is taken outside. That gives the lower deck a workshop or lab the size of a single car garage. The rest of the lower deck is solid equipment: landing rockets, propellant tanks, RCS thrusters, life support equipment, batteries. Once the greenhouse is setup, that will be the width of a double car garage and twice the length. That's lots of space. And plenty of room for science equipment.
Tom Kalbfus wrote:
Mars Direct requires two launches for every mission, first you send the Earth Return vehicle, then you send the hab. For a Moon mission the Earth Return vehicle has two parts, the part that stays in orbit is the Command Module, the part that lands on the Moon's surface is the lander. Now because the lander needs to carry its ascent fuel down with it to the surface, its not very roomy, so you land a separate hab on the Moons surface with no ascent engines or fuel, so the astronauts can stay there for long periods of time. I would suggest up to a year since Moon missions are going to be infrequent due to cost, you would want to keep humans there until you can send up their replacements with another hab, and each additional hab further expands the Moon base.
Robert Zubrin's presentation to NASA, I think this is from 1990. This shows the hab with one story, plus a landing stage. It didn't even have an enclosed garage for the rover. This version had the airlock on the one pressurized story, the rover was not shown but described in text. I assume the rover was hung by cables and a winch from the under side, between propellant tanks for landing. Lunar version is the same as the Mars version, except no heat shield, and the Earth Return Vehicle has one ascent stage instead of two. A common landing stage for both the habitat and ERV.
http://canada.marssociety.org/winnipeg/ … irect8.jpg
Mars Direct ERV is a simple capsule. It isn't spacious. In 1961 NASA attempted to design Direct Ascent for the Moon, it looked like this...
https://upload.wikimedia.org/wikipedia/ … Ascent.png
Notice this is the same as the "Return Vehicle" depicted as "Lunar Vehicles" in the Mars Direct slide. NASA found a Saturn V is not large enough to launch that; not when you have to land fully fuelled. It only works on Mars because the ERV lands empty, makes fuel on Mars via ISPP.
What I'm proposing is the Mars Direct hab, but replace the return vehicle with Apollo style equipment. Instead of the Apollo CSM, use Dragon. Instead of the Apollo LM that carried 2 astronauts plus surface science equipment and rover, use a simple lander for 4 astronauts and nothing else. Surface science equipment and rover will be on the hab.

Well if you land the humans in the lander instead of the Hab, they can abort, I'll give you that. if you land in the Hab, your committed, there is no going back in the Hab, if you land in the wrong spot, your in trouble, the hab has supplies for one year however, the second mission will have to be sacrificed to rescue the first. Well maybe not, you just have to land another lander next to the Hab, the next mission can simply land their Hab next to the first lander where the first mission was supposed to have gone, but did not, because of the lousy piloting skills of one of the crew!

Tom Kalbfus · 2016-05-26 23:50:33

RobertDyck wrote:

There you go again: America good, Russia bad. I have no patience for that. This is about engineering, not politics. And would you care to explain how you launch that on a single SLS block 1 or Falcon Heavy?

Chesley+Bonestell+Ships+orbiting+Mars+%25281956%2529.png
Probably with something like this. What I stated was a fact, no ones been to the Moon since the United States landed men on the Moon, and its been 47 years, not the Russians, not the Chinese, not anyone! Now its a bit embarrassing that we haven't been back to the Moon since 1972, but the Russians, and Chinese have yet to go, and when they do go, they will only be repeating the accomplishments of the United States last century. We did it, its our accomplishment, we should be proud of that fact, and if it spurs others to want to go to the Moon, Good!

Last edited by Tom Kalbfus (2016-05-26 23:56:09)

RobertDyck · 2016-05-27 12:53:27

Apollo was a wonderful and amazing technology for the 1960s, but this is the second decade of the 21st century. We can do better now. The descent stage had additional structure that we can do without. We have time to design it better. Look at all the vertical pieces of sheet metal. We can reduce mass by eliminating them.

Perhaps I shouldn't pander to you at all, but also notice the LM proposed uses the same tunnel as the Apollo LM, a separate de-orbit stage like LK, separate LOI stage like Constellation, stage tank like any launch vehicle, "basket" with legs like LK, window material like NASA spacesuit helmet visors. And propellant would be MMH/N2O4 used by Orion & Altair, not either Apollo LM nor Soviet LK. Call it a hybrid.

Tom Kalbfus · 2016-05-27 21:34:26

One project we might work on is a lunar based solar powered laser rocket. Say for instance we build a laser into the side of a mountain near the north pole, we cover the sides of the mountain with solar panels, and for any given part of the month, there will always be some solar panels receiving sunlight, the electricity flows into the laser, and we fire the laser toward Earth to power a laser hydrogen rocket to get better ISP than is possible from any chemical rocket, and boot strap our way into orbit.

By the way, I'll bet there are some parts of the Moon that look like this, not any of the places that Apollo missions have visited. The giant lunar lander looks like something that can someday be built. They sure thought big in the 1950s didn't they!

Last edited by Tom Kalbfus (2016-05-27 21:38:29)

RobertDyck · 2016-05-27 21:53:02

Tom, you appear determined to ensure nothing gets done. By posting stupid ideas like a laser on the Moon aimed at Earth, and giant rockets too expensive to get funding from Congress, you ensure nothing gets done. Since you like images of big things, let me post this...

That is SLS block 1. The rocket that Congress has actually funded. Notice that I propose an Apollo style mission with CSM & LM that can be launched with just one of these. Dragon already exists, Dragon v2 will fly soon. Frigat also already exists, and several American companies could build a comparable stage to do the same thing. The LM that I propose is a lot more practical than Altair, and Altair has not received any funding. At all. Period. Constellation is cancelled, this could happen. And this together with a Mars Direct habitat is a major step towards Mars.

Last edited by RobertDyck (2016-05-28 02:56:24)

Terraformer · 2016-05-28 05:15:58

Tom,

Are you an aspiring supervillain? Seriously, a laser on the moon powerful enough power a laser thermal rocket on Earth? Or in other words, a moon based laser that can destroy targets on the surface of Terra.

Tom Kalbfus · 2016-05-28 07:26:22

You ever hear of Peter Glaser's idea of Solar Power Satellites? https://en.wikipedia.org/wiki/Peter_Glaser
This is just a version of that, except we build it on the Moon and transmit the power via laser to Earth. Now since the Moon orbits the Earth and does not hold a fixed position relative to Earth surface features, this is not going to be so useful in powering a city for instance. However the Moon does stay up in the sky over any given position on Earth long enough to launch a satellite into space. Here I just skip the step Gerard O'Neill proposed to launch Moon material into orbit and build Solar Power Satellites out of it. We instead build the Solar collectors out of Moon material on site, where the Moon material is to be found, and we build it on a mountain side at the North or South Poles of the Moon. The North Pole is more useful, since there are more continents in the Northern Hemisphere of the Earth. The Earth holds a relatively fixed position in the Lunar sky, so the laser need only swivel a little bit to keep track. The North Polar region is also the place to find all the other elements the Moon otherwise lacks. We may have all the stuff we need to build the giant laser we need to build right in that location. As for destroying stuff on the surface of the Earth, we already know how to do that, we don't need to go as far as the Moon to destroy something on Earth. The almost 3 second delay makes it kind of difficult to destroy moving targets, such as a terrorist who we might otherwise kill with a drone. We can compensate for that by making the laser beam wider. For instance lets say a terrorist leader is reviewing his troops, he can move three steps in about 3 seconds, the laser targeting him would therefore need to be 6 meters wide to stand a good chance of hitting him no matter which direction he moves in the next three seconds, the explosive effect would be that of a small bomb, quite localized in its destructive effect. Everything caught within the beam's radius burns. As a person who lived in the New York Tri-State area at the time of the 9-11 attack, I have little sympathy for such people!

Oh by the way, most real world "super villains" don't have the resources to build a laser on the Moon, they are simply terrorists that strap bombs onto human beings and tell them to go blow someone up.

Last edited by Tom Kalbfus (2016-05-28 07:29:18)

RobertDyck · 2016-05-28 10:01:25

kbd512 · 2016-05-28 10:26:07

NASA is thinking about putting a laser on ISS to remove space debris from the station's orbit, but the power level required for that is far lower than one used for propulsion. So, how much power are we talking about for Glaser's lunar laser?

I would think we'd need a fusion reactor to provide the kind of power required to deliver useful payloads. The idea has merit from an efficiency standpoint, but only if we have an incredibly energy dense power source. I don't think current technology solar panels come close to qualifying.

GW Johnson · 2016-05-28 15:43:22

It depends upon how continuously you need beam power from the laser.

For a short-pulse shot, you can get into the gigawatt/terawatt range with EM-stopped flywheel technology. Spend minutes to hours spinning the multi-ton thing up, and then stop it in a split millisecond with EM braking, dumping the kinetic energy as electricity straight to the laser.

Also works for particle beam weapons.

GW

RobertDyck · 2016-05-28 17:25:45

Solar power is more efficiently generated here on Earth. There's practically no power loss when a cable directly provides the power. Solar power doesn't work at night, and reduced power on cloudy days, but that's less than the power loss from microwave beam. Now you want to do it with a laser? All the way to the ground? What about clouds over the target site? And if it's significant power, misalignment would cause the beam to become a powerful weapon.

Ps. Click the image above for the YouTube video.

Tom Kalbfus · 2016-05-28 20:35:12

RobertDyck wrote:

Solar power is more efficiently generated here on Earth. There's practically no power loss when a cable directly provides the power. Solar power doesn't work at night, and reduced power on cloudy days, but that's less than the power loss from microwave beam. Now you want to do it with a laser? All the way to the ground? What about clouds over the target site? And if it's significant power, misalignment would cause the beam to become a powerful weapon.
Ps. Click the image above for the YouTube video.

Well for a cable that provides power to a laser on the Moon, there is no power loss either. You can use the power collected on the Moon on the Moon to do useful things on Earth. The poles of the Moon are wonderful places to collect solar energy, the poles of the Earth not so much. On Earth, the slanted rays of the Sun are filtered through the atmosphere, on the Moon, there is no atmosphere. Also the Earth has an axial tilt plunging the poles into darkness every winter for 24-hours a day, while the Moon has almost no tilt and no seasons. There are mountains and crater rims that receive continuous sunlight, so he Moon is an excellent place to lay down Solar Panels for 24-hour year round access to sunlight, no battery storage devices required.

Also when compared to an Earth based laser, a Moon based laser can track a laser rocket for far longer, as the Earth's horizon and thick atmosphere does not block it!

kbd512 · 2016-05-28 21:29:12

I actually think Tom is onto something here, but only for getting humans into orbit from the surface of the moon or Mars.

~100MW is required to propel a 1t payload into LEO from Earth at SL. So, on a planetary body with 1/6 to 2/5 the gravity of Earth and little to no atmosphere, is this doable with a small fusion reactor like the one Lockheed-Martin is working on?

How much power are we talking about to get a one or two person craft and perhaps 50kg worth of samples back into orbit from the surface of the moon or Mars? Let's say it's just an unpressurized capsule with thermal control for two suited astronauts and their rock collection.

How big will the frickin layzur be? If the laser is not feasible, what about HPM?

Once a capsule is in LLO or LMO, I figure our astronauts would transfer back to Earth using conventional chemical rockets. It sure would be nice to only have to carry the propellant required to land on the moon or Mars. If you use the system two or three times, it's already paid for itself in terms of the propellant for the ascent vehicle that you don't have deliver.

I haven't really thought this through. I'm just brainstorming here.

Tom Kalbfus · 2016-05-29 07:38:57

You got to have a product before you can sell it. The only fusion we got right now is the Sun and nuclear bombs. My idea is to treat the Moon as a giant space station.

Kind of like this, but much bigger!

The most important parts of the Moon are the places where we get 24 hours a day, 30 days a month sunlight that way we don't have to worry about the slow rotation of the Moon. The portion of the Moon that is in its polar region is relatively small compared to the rest of the Moon, but large enough for our needs. We just cover every mountain side and crater rim with solar panels, We could do the same on the rest of the Moon, but at the poles, these solar panels can be much closer together, For instance on a polar mountain, one side is in shadow while the other side is illuminated, as the Moon slowly rotates, the part that is in shadow is illuminated, while the part that was illuminated falls under shadow, in the polar regions we can get all the sunlight we need just by covering this mountain with solar panels. Closer to the equator, we need to distribute these panels over different part of the Moon, and we'd need long distance transmission lines to connect them in order to have a constant power source, but at the poles, we don't need to do this, just one mountain will do. This will be as good as any nuclear reactor, fission or fusion, as the Sun is quite a reliable power source, so long as you have constant access to it, and at the poles we do. Solar panels are easier to maintain at the moon than a nuclear reactor is. Solar panels have no moving parts, they just produce electricity. We need to be able to manufacture solar panels out of lunar material right on site. No moving tons of material off moon required, this should be very simple. Now the question is what can we do with this power?

On possibility, beam microwaves to Earth, and use the power to pump water up hill into a reservoir, then an hydroelectric dam will extract energy from it when the Moon is not beaming power to it.

Another application is a desalinization plant, such a plant does not need to operate 24 hours a day, it only needs to produce enough fresh water for the day's needs, we can generate the power to do this on the moon and beam it over to Earth.

What other application, a synthetic fuel plant. We can use energy beamed from the Moon to crack water into hydrogen and oxygen, combine the hydrogen with carbon dioxide to make methane or some more complex hydrocarbon that we can burn in our cars. We don't need an uninterrupted power supply to do this.

RobertDyck · 2016-05-29 09:09:42

Getting back on topic. A low-mass achitecture to go to the Moon.

Robert Zubrin and his partner David Baker pitched Mars Direct to NASA at a symposium in June 1990. That pitch included testing Mars hardware on the Moon. NASA got excited, but there were a couple problems with the plan. For Mars, using the Hab with artificial gravity for transit to Mars is a brilliant idea. However, return meant 6 months in a capsule and zero-G. This wasn't seen as a big deal at the time, because NASA's plans for Mars from 1965, 1968, and 1970 were a modified Apollo CSM. That modified CSM included a PICA heat shield instead of AVCOAT, and one additional seat: 4 instead of 3. That meant the Apollo CSM would not have enough room for food or spare lithium hydroxide canisters, so it required a Deep Space Habitat of some sort. But this is where Mars Direct got it's number of astronauts: 4. However, in 1990 NASA saw returning crew from Mars in a capsule with no DSH as a problem.

My mission architecture addresses this issue. I include a dedicated DSH for interplanetary transit only. The DSH is reused. Astronauts ride in the DSH from Earth to Mars, it remains parked in Mars orbit, then astronauts return to Earth in it. The DSH then parks at ISS, waiting for the next mission.

For the Moon, Mars Direct would use Mars equipment, just without heat shield or parachute. The issue is the ERV was designed to land with empty propellant tanks, use ISPP to fill those tanks before astronauts leave Earth. But the Moon doesn't have a CO2 atmosphere, so that doesn't work. In 1961 NASA found an Apollo CSM with service module(s) large enough to land on the Moon and return was so big that Saturn V was not large enough. Landing a Mars Direct ERV with full propellant tanks would have the same problem.

My solution is to replace the ERV with Apollo style CSM & LM. The Mars Direct hab would remain, becoming a Moon base.

A couple principles here. If you design for the Moon, the vehicle cannot be used on Mars or an asteroid. At all. You end up with Orion. It's big, heavy, no artificial gravity, no room for zero-G exercise equipment. It's too small for Mars or a multi-month mission to an asteroid, and too big to be used with a DSH. If you design for Mars then the vehicle can be easily adapted for the Moon. The reason is simple: Mars is hard. If you design for the difficult destination, it can be used for the easy one. If you design for the easy one, it cannot be used anywhere else. Calling the Moon "easy" is an over-simplification, but Mars is much more difficult than the Moon.

Congress currently favours Orion. But Orion is too heavy to launch with a Lunar Module on a single SLS.
Orion: capsule + SM + propellant = 35,124kg. For launch you have to add Launch Abort System, blast shield for the capsule (to protect from LAS exhaust), and fairing around the SM.
Dragon v2: 8,853kg (estimated) + propellant for TEI = 11,987kg. LAS included, no blast shield, no fairing.

Last edited by RobertDyck (2016-05-29 12:17:47)

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