NASA Moon Plans After LRO

[halman]

gsuschrist,<br /><br />Hopefully, we are not going to be seeing landings at completely different points on the Moon's surface every time we send a crew there. Picking a spot to focus our efforts upon means that only one crew will be landing in 'unknown' territory, because that crew should establish a landing zone to be used by all the following crews. Setting up a beacon, photographing the area from the surface, and marking hazards should be a top priority.<br /><br />I cannot imagine sending our initial exploration crew to the Moon in a vehicle with such a narrow margin of maneuverability that having to shift the landing site for a few hundred meters is impossible. I have seen enough photos of the Moon's surface taken from the surface to know that there are many areas flat enough and clear enough for a safe landing. Picking such a site for our initial base is, to me, the most important criteria.<br /><br />To me, this situation is analogous to someone learning to fly. To chose to learn how to land an airplane, should they use an airport in the daytime, or an aircraft carrier at night? After we have mastered the process of getting back and forth to the Moon, we can begin branching out into landng in the highlands, or in uncharted territory. We know enough about the Moon to be able to pick a site that is easy to land at, I believe. Establishing our presence there is the most important thing, which means regular flights to a proven landing zone.<br /><br />Sending a lander to the site that we choose for our initial base would certainly make sense, I think, so that we can get a view from the surface of the area we intend to land. Beyond that, I can see no gain in further robotic landings, given that money is going to be tight. Once we have established a base, robotic survey missions would make sense, but they would be for naught if we can't afford to build our first base. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[nacnud]

<font color="yellow">It would be foolhardy to try to establish the first lunar base at either of the lunar poles.<br /><br /><font color="white">Why? OK the delta-v requirements are more but the CLV and CaLV seem to be growing more than large enough to cope with that. Beyond that what are the problems?</font></font>

 

[scottb50]

What is needed is a central base and satellite bases. If you use a vehicle that lands and takes off might as well use the same one to move between bases as you use to rendevous in orbit with a Cycler Ship. Another plus is the same concept and essentially the same vehicle could be used at Mars or on asteroids and Comets.<br /><br />Basically hop around the moon and Mars or jump up to orbit. At Mars the atmosphere would present a challenge, but could be handled with a Re- Entry Vehicle. The vehicle descends from orbit through the high speed and temperature phase, releases the Lander and returns to orbit. <br /><br />You could do the same thing for return to Earth from LEO. A slightly modified Lear Jet would even work. Mount it to an REV and release it at a safe altitude. The REV then returns to orbit for re-use. <div class="Discussion_UserSignature"> </div>

 

[halman]

JO5H,<br /><br />I consider myself to be very daring to dream of the Moon being developed by humans for profit and knowledge, but I am put to shame by those who dream of manned missions to Mars in the near future. Certainly the technology exists to send small payloads to either destination, but beyond that, everything is dependent upon building new vehicles, learning new methods of working in orbit, and securing financing for projects which will be very expensive without any hope of return for at least a decade. But the Moon is no where near as challenging as Mars, for the simple fact that we have never attempted to keep humans alive in space for the periods of time required for any possible mission to Mars.<br /><br />And very little is said about one of the most daunting of the problems: building a ship large enough to allow a group of people to maintain their sanity on missions which will last for over a year. Spending months at a time in a cabin little larger than a minivan is very likely to lead to problems, especially when one cannot even go out on deck, or take a walk, or do anything to get away from the other members of the crew. Nuclear submarines which stay submerged for two or three months at a time have many diversions, as well as enough space to allow one to get off by one's self for a little while. Initially, the cruise durations were much longer, but it was discovered that crew efficiancy fell off considerably, and pyschological problems developed which could not be addressed within the confines of the subs. These vessels were easily capable of staying at sea submerged for six months or more, but the crews were not, in spite of movie libraries, juke boxes, and lavishly equiped recreation rooms.<br /><br />If hydroponic techniques are not used to provide plants which can clean the air, and supply food, the amount of expendables required per person on such missions is measured in tons. To talk of sending a mission to Mars using a vehicle based on the c <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[halman]

nacnud,<br /><br />Please explain to me why it would be worth the additional expense, danger, and delay to site the first lunar base at one of the poles. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[halman]

Scottb50,<br /><br />I think that we all have good ideas for ways to handle lunar exploration, and even exploration on Mars. But we have got to take things one step at a time, and getting a base established on the Moon as quickly as possible for the smallest expense is the first step, unless my concept of exploration is completely off the wall. I have always envisioned an Earth-orbit to lunar-surface shuttle as being the first goal in setting up a lunar base, but I guess that I was wrong, from what I have been reading.<br /><br />Actually, I have serious doubts if the United States is going to return to the Moon at all, so I consider discussions such as this to be primarily for entertainment. Our window of feasibility has just about closed, due to the national debt and the state of our launch capability. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[qso1]

halman:<br />And very little is said about one of the most daunting of the problems: building a ship large enough to allow...<br /><br />Me:<br />Actually, a lot has been said at least in terms of most practical designs. The Von Braun study in 1969 had two manned vehicles, six persons each going to Mars in 1982. Living conditions aboard any practical designed craft will be spartan and crews going to Mars will understand this. Space Station Mir was a good rough analogy to the habitable volume one might expect from a manned mars craft. Robert Zubrin in his book, "The Case For Mars" wrote very detailed proposals on how to accomplish going to Mars in his scenario called "Mars Direct". NASA adapted this scenario in 1994, calling it mars semi-direct which was a bit more realistic but not without its spartan elements.<br /><br />And I adapted this scenario for my graphic novel acount of man (And women) going to Mars. I generated my own designs which are still based largely on NASA concepts but my own vehicular interpretations where the Mars craft are concerned. Using a 3D program to make them as realistic as necessary for a book that follows the real science of space travel as possible.<br /><br />I developed a 7 story mother ship 25 feet in diameter and came up with as many novel ways as I could internally to maximize crew comforts. The craft is nuclear electric powered which means roughly three month transit times to Mars which means artificial gravity is not required so long as a crew is selected based in part on their demonstrated excercise discipline.<br /><br />The mother vehicle is much larger internally than a minivan. <br /><br />halman:<br />To talk of sending a mission to Mars using a vehicle based on the current concept of the Crew Exploration Vehicle is ludicrous, in my opinion...<br /><br />Me:<br />And your quite right. But bear in mind, Mars was only defined as a goal more or less to be achieved after 2020. In other words, Mars will probably not happen under the current CE <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[j05h]

> I consider myself to be very daring to dream of the Moon being developed by humans for profit and knowledge, but I am put to shame by those who dream of manned missions to Mars in the near future.<br /><br />Mars, and especially Phobos have industrial potential far in advance of the Luna, simply due to available material. If a group/company/facility is established early and permanently, they will have a huge leverage on future development. I do think that water-mining on Phobos is closer to reality than water-mining on Luna. We already have a surprising amount fo technical development done, waiting for people with the money. Check out the other thread for details:<br /><br />http://uplink.space.com/showflat.php?Cat=&Board=businesstech&Number=503952&page=0&view=collapsed&sb=5&o=0&fpart=<br /><br />I'm not in any way talking about NASA going to Mars, I'm talking about a private consortia building up a large enough customer base to do it. CEV and other viewgraph spaceships need not apply. The craft specced would involve descendants of Soviet/Russian FGB and similar (search MarsPost). While not explicitly built yet, it at least follows a 30 year hardware heritage. Energia has said they are ready to build a Mars vehicle, my plan calls for several of them along with at least an equal number of Bigelow inflatables on Phobos. Building more, productionline-style, will produce economies of scale, and I'm interested in more people, not less going Out There.<br /><br />There would be plenty of room outbound and at destination, nearly a full module per person (4MarsPosts, 4-6 standard FGBs, a couple of Ascent craft, 6-12 Bigelow Habs for estimated 25 crew initially). The equipment would fly "flotilla" style or on one huge truss. Sick of your crewmates? Go hang with the Miners for a while, <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[scottb50]

I agree an established base on the moon as well as on Mars is the first priority. Where I disagree is using an Earth-orbit to lunar surface shuttle.<br /><br />It would be much more efficient to use an Earth-LEO vehicle, a LEO-LMO Cycler and an Ascent/Descent- surface transport vehicle based on the moon or Mars.<br /><br />I also don't see why it has to be governments that do it. With all the tax cuts the richest Americans have been given you could build a commercial system. Why not invest the blood money instead of buuying another yacht or SUV so you can get even more tax breaks? <div class="Discussion_UserSignature"> </div>

 

[chriscdc]

What extra delay or danger would there be in giving a rocket a little more dV in order to get to the poles and what delays are you talking about? It also has several advantages including a more constant temperature, eg you could be in a constantly shaded crater, with a large mylar dish on the crator directing a constant amount of light onto it. You can also build massive super cooled telescopes in polar craters.

 

[nibb31]

The problem with RV with a cycler is that you need as much energy to catch up with the cycler as you would need to get onto that trajectory in the first place.<br /><br />With a moon direct return scenario, you have:<br />- Launch to LEO (accelerating)<br />- Trans Lunar Injection (accelerating)<br />- Lunar Orbit Insertion (braking)<br />- Descent (braking)<br />then:<br />- Launch to LMO (accelerating)<br />- Trans Earth Injection (accelerating)<br />- Direct Re-entry<br /><br />With a "moon ferry" or cycler scenario:<br />- Launch to LEO (accelerating) and RV with ferry<br />- Trans Lunar Injection on ferry (accelerating)<br />- Lunar Orbit Insertion (braking)<br />then<br />- Launch to LMO (accelerating) and RV with ferry<br />- Trans Earth Injection (accelerating)<br />- LEO insertion (braking) and RV with return vehicle <br />- Re-entry<br /><br />That extra LEO insertion burn will require as much energy as the original TLI burn. Therefore you need to take that much more propellant with you to the moon and back, which means more mass, and therefore yet more propellant for the TLI and LOI burns.<br /><br />This could be overcome somewhat with lunar ISRU of propellant, but that is still theory and has never been experimented. You can't wait until ISRU is developed and tested to set up a moon base. And you would still need a means of lifting that fuel up from the moon surface to the cycler/ferry.

 

[scottb50]

The Cycler would leave LEO, Brake into lunar orbit. The Lander would depart the moon base, rendevous with the Cycler in orbit then return to the Base. The same thing Apollo did, just reversed. <br /><br />In fact the main difference from the apollo is the return to Earth, instead of direct re-entry the Cycler brakes into LEO and rendevous with a LEO Station. Payloads to the surface would be transfered to re-entry/landing vehicles. The biggest difference would be all but the re-entry/landing vehicle stays in Space or on the moon. Not having to take up all the hardware for every flight would not only negate the propellant needed to brake into LEO but would increase available payload capacity. <div class="Discussion_UserSignature"> </div>

 

[brellis]

ESA's SMART-1 used ion propulsion to gradually tweak its trajectory from LEO to LMO. The fuel cost in the construction/assembly phase could be greatly reduced if the heavy stuff was sent out to the Moon or Mars in this manner. Ion propulsion can also be used to adjust the orbit of a manufacturing station for linking to new modules, etc.<br /><br />A station could be assembled in an earth-Moon Cycling orbit, used in assembling a lunar base, then with ion propulsion it could be sent into an earth/moon-Mars Cycle for construction of a Mars base. <br /><br />The SMART-1 vehicle was only the second vehicle to use ion propulsion [Deep Space 1 was the first], and even with unknown unknowns, ion technology has proven to be reliable and a whole lot cheaper than chemical propellant. It just takes a long time to get up to speed, and adjustments happen only very gradually. The non-living components of the Moon/Mars program won't mind spending years in outer space, though.<br /><br />After compopnents of a lunar cycling manufacturing station have arrived in place, have robots do the assembly, then send the humans up in a small vehicle [less fuel], and why not figure out a way to re-use the shells of rocket boosters by attaching solar panels and ion engines to them, and after blastoff, send them on a comfortable, gradual journey towards a manufacturing station, or a Recycling Cycler? <img src="/images/icons/smile.gif" /><br /><br /> How big and expensive is an ion engine? Maybe we don't have to have so much off-planet litter. <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[brellis]

JPL will be webcasting its "Apollo on Steroids" vision later in June:<br /><br />http://www.jpl.nasa.gov/events/lectures/jun06.cfm <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[scottb50]

I would rather build the Stations, Bases and Cyclers from autonomous Modules, rather than assembling structures you just snap then toget like Legos. Expansion uses additional pre-outfitted Modules delivered to LEO as needed.<br /><br />I would think the first mission would be delivery of the first lander and tele-operated robots to prepare a proper landing area as well as the site the Modules will be assembled on. The second mission would take three Modules, that would be the Station Core. By the third cycle cargo and personnel would begin going down. <div class="Discussion_UserSignature"> </div>

 

[radarredux]

> <i><font color="yellow">JPL will be webcasting its "Apollo on Steroids" vision later in June:</font>/i><br /><br />(edit my mistakes)<br /><br />Oops. Here are the dates:<br /><br />Jun. 22 & 23<br /> Topic: The NASA Space Exploration Vision Plan<br />http://www.jpl.nasa.gov/events/lectures.cfm</i>

 

[radarredux]

> <i><font color="yellow">The SMART-1 vehicle was only the second vehicle to use ion propulsion [Deep Space 1 was the first]</font>/i><br /><br />I thought I once read that some satellites use small ion engines to adjust the orbit locations, but Deep Space 1 was the first to use ion engines for primary propulsion.</i>

 

[nacnud]

Yep, lots of sats use ion engines for station keeping.

 

[halman]

chriscdc,<br /><br />In reply to:<br />"What extra delay or danger would there be in giving a rocket a little more dV in order to get to the poles and what delays are you talking about? It also has several advantages including a more constant temperature, eg you could be in a constantly shaded crater, with a large mylar dish on the crator directing a constant amount of light onto it. You can also build massive super cooled telescopes in polar craters."<br /><br />Landing in the open, flat parts of the Moon is still dangerous. Trying to land in rough country, even with an hours worth of hover time is logically going to be more dangerous. We have enough information on hand to select a site in the equatorial maria regions for our first permanent base today. We have obtained samples of the regolith in those regions, and we can infer the difficulty of surface transportation with some hope of accuracy. <br /><br />It is wonderful that there is a part of the Moon that does not experience the 14 day cycle of light and dark, but we have to learn to cope with the associated extremes if we are going to be able to develop any part of the Moon that we like. What other benefits are you referring to?<br /><br />And what has building massive super cooled telescopes got to do with establishing our first toe-hold on a new world? <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[chriscdc]

Hardly. Modern tech could put the craft down within meters. If you can't find a place on the poles of the moon that you can put down safely, what chance do you have of constructing a base anywhere on the moon (unless you want to start trucking several tens of km over the surface)? They can now target where a probe is going to land on earth to within a few km, through the atmosphere and all the difficulties that it entails. Landing on the moon is pure newtonian mechanics with not a air resistance equation in site.<br />If you somehow can't find the landing site then there's allways the abort option.<br /><br />A lunar telescope would be a huge reason for going to the moon and it would need human assistence to work.The possible ice source at the poles would help to open up the solar system. The larger impact carters at the poles would also tell you more than the dust blasted central regions. The craters will also be more likely to be filled with useful material.<br />In fact almost all of the interesting stuff, I can think of, on the moon is likely to be at the poles.<br />So do you want to drive for hours over a dull moon like maria, or do you want to go over the next crater ridge which will show you new layers through the moons surface.

 

[henryhallam]

<font color="yellow">Not having to take up all the hardware for every flight would not only negate the propellant needed to brake into LEO but would increase available payload capacity.</font><br /><br />I'm not sure that's true, have you run the numbers? You have to not only carry x tonnes extra propellant to brake into LEO but also y tonnes more propellant to launch x tonnes on TEI, z tonnes to brake (x+y) into lunar orbit, w tonnes to send (x+y+z) tonnes more propellant on TLI and even more to get all that off the ground in the first place.<br /><br />You can get a very rough estimate by considering the mass of the S-IVB upper stage. While in Earth orbit but before TLI this mass was something like 95 tonnes. The CSM massed 30 tonnes and the LM was 15 tonnes.<br /><br />So a 95 tonne booster is required to send a 45 tonne payload to the moon. Since the dV for TLI is approximately the same as the dV for Earth Orbit Insertion you would need a 95 tonne booster to brake 45 tonnes back into LEO. Of course you don't need to brake all 45 tonnes because some of that will have been burned as propellant for LOI and TEI, but you are reusing all of the equipment, no staging is taking place and you might want to bring back some cargo from the moon so maybe you need to brake 30 tonnes into LEO. This means that you need an EOI stage of about (30/45)*95 ~= 63 tonnes. Considerable additional propellant will be needed to carry out LOI and TEI with those 63 tonnes attached, but you can save some mass by using the same engines for everything so let's be generous and call it a mere additional 75 tonnes that needs to be put on a translunar trajectory. Our translunar mass has suddenly increased from 45 tonnes to 120 tonnes, requiring a TLI booster of (120/45)*95 ~=250 tonnes. So total extra Earth launch mass is 250+75-95 = 220 tonnes! All that just to brake 30 tonnes of used equipment back to LEO. Remember we also made a couple of very generous assumptions.<br /><br />Now i

 

[josh_simonson]

We're not going to the moon to build a base at the safest location we've already explored. Rather we're going first and foremost to investigate the most interesting sites on the moon from a scientific perspective, and the most promising sites on the moon from a ISRU/commercial perspective. In the case of the poles there is strong reasons to visit them for both goals. <br /><br />Say we build a base on the equator, then find that we can get h20 out of polar dirt just by heating it to 100'C, meanwhile the equatorial site is producing O2 only by heating the dirt to 2000'C. That'd be a major 'Doh!' moment.<br /><br />The terrain in the south pole is somewhat rough, but the north pole is pretty flat, I don't doubt NASA's ability to land in either place though.<br /><br />There is one other location that has a fairly high value to the economics of the moon, that's the point on the moon right under LL1 - where a lunar space elevator could be located.

 

[j05h]

I think you've got to consider one other thing: while the LEO-LLO vehicle is going to be large, it won't be pushing a 45ton passenger craft - it just needs be able to do LEO-LLO-LEO safely. Fuel depots on each end would be a huge leverage in a multi-point transit system. <br /><br />From a small depot in Low Lunar Orbit, a lander would take crews to any surface facilities. Everything gets reused somehow. The problem with my variant is that it requires economics to reign, not politics. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[scottb50]

I plan to use LH2 and LOX exclusively. Sure it takes a lot of propellant, but it sure seems like the cheapest and safest way. Launch water.<br /><br />Nothing else comes close in efficiency which means it takes a lot more of anythink else to do the same thing. And while the density of Hydrogen is a problem in packaging, with solar power it could easily be kept liquid.<br /><br />As I see it we take the dwindling fossil fuels we have and disperse the Carbon in Space or we sacrifice water. Maybe not a bad idea considering global warmings effect. Go to Mars and keep New York Above Water, kind of has a ring to it. <br /><br />I'm not saying it's cheap, just trying to find the cheapest way to do it. <div class="Discussion_UserSignature"> </div>

 

[halman]

chriscdc,<br /><br />This is really amusing. There are people arguing for several landing probes to insure that the landing site is safe and well mapped, and others insisting that landing anywhere we want is no problem. I am quite sure that we are capable of having a probe land at any specific site we want, but I see no guarentees that it won't fall over upon landing because it got one gear leg hung up on a boulder. If the landing site is heavily strewn with boulders, a lander could burn up the engine before finding a safe spot to set down.<br /><br />In flat country, oblique lighting will reveal many surface irregularities, because of the shadows cast. This doesn't work so well in rough terrain, or in hill country. It can also be very difficult to determine inclines when looking straight down on them. Inclines tend to be more common in rough and hilly terrain.<br /><br />There are a multitude of reasons to go to the Moon, among them extraction of natural resources. The maria are a strange type of surface feature, unparalled in the Solar System. They may contain many materials which elsewhere would be found deep under the surface. Supposedly, the cheapest way to get materials off of the Moon using existing technology is with a lunar catapult. This device will require several kilometers of flat surface, and would benefit from an equatorial location because of the added velocity.<br /><br />But again, all of this is far down the road from where we are right now, which is trying to get back to the Moon again. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>