Post central for information on CEV - iformation station for the spacecraft

GCNRevenger · 2004-08-03 14:54:01

Obviously, but its looking like it will be a very minimal setup for only the crew (3-4 tops) and a box of rocks. For that, the acent vehicle would mass only a few tons, or perhaps even in the kilogram range for a open-cockpit "sled."

comstar03 · 2004-08-03 18:25:59

Spacenut,

You are right about using nitrogen, but it can be used in plasma propulsion as well, also nitrogen can be developed on any plant growing environment as well as approx 78% of earth's atomsphere is made up of it. Even Mars atomsphere has it.

Also the best place to build large scale spacecrafts is the moon, using materials from the moon. It also provides a main reason to build and expand the moon as a dockyard to start with and a low gravity launch pad. ( compared with earth or low earth orbit )

These facilities used on moon will require a larger permanent presence on the moon and transfers between moon and earth for personnel will become more frequent. Testing on more advance drive systems could happen on the moon, and launch from that doesn't effect earth ecology.

The essence of CEV today is to develop a long term strategy for crew deployments in earth-orbit , moon transfer and landing, mars voyages or beyond. Its not there to come up with one design and then change to another different design, then another and then another, but to progress in a series of designs and improve in crew systems, propulsion, navigation, and communications for the first permanent space generation.

:bars3:

RobertDyck · 2004-08-03 19:34:42

So why not design a reusable lunar transfer vehicle that traverses from low Earth orbit to lunar surface using lunar fuel. Develop a reusable spaceplane to ferry astronauts from Earth surface to LEO and back, using Earth fuel. Develop a reusable ship to travel from low Earth orbit to Mars orbit and back, using fuel extracted from Mars moons Deimos and Phobos. Develop a reusable shuttle to go from Mars surface to Mars orbit using Mars derived fuel. Develop robotic spacecraft to mine a dead comet in near Earth space and transport fuel to Earth orbit. The Earth orbit fuel depot can refuel the Mars ship for the Earth-to-Mars leg.

The Earth-to-Mars ship can be used for human flights to other planets or asteroids. The lunar transfer vehicle could be used to visit a comet mine, although the confined space would definitely be a hardship for a multi-month journey. The complete lack of artificial gravity or zero-G exercise equipment would leave the space mine worker significantly weakened on return.

You know, if all these vehicles are reusable they don't require a single standardized design. Let's not make the mistake of Shuttle designers who developed a single vehicle that tries to be everything for everyone, but doesn't do anything well. Crew transport from Earth surface to Earth orbit can be accomplished by a single vehicle for all missions and all destinations, but don't try to take it to the Moon. Don't try to carry heavy cargo to orbit on a crew taxi.

Did you know that Skylab was designed to be a self-launching space station? The reason its decks were an open grid of metal was to permit propellant to flow through. It was a modified Saturn IVB stage, the second stage of Saturn IB or third stage of Saturn V. It was going to be launched on a Saturn IB, but a later decision changed it to launch as payload on a Saturn V. After launch complex 34 was decommissioned, the Mobile Launcher built for Saturn V required a pedestal to launch Saturn IB from complex 39. One reason a Saturn V launched Skylab was the 3 remaining Saturn Vs after the Apollo moon program was cancelled. That left no lunar capability. Decommissioning complex 34 left no affordable way to launch Saturn IB and its medium cargo. Launching from complex 39 required the same operation expense as Saturn V. These successive down-selects left no usable capability. Let's not make the same mistake again.

comstar03 · 2004-08-03 21:50:24

RobertDyck,

Yes, Yes, and the mining of the asteroids and comets, could use the ship design that would fly humans to Mars but it could test the engines, flight systems , living environments and communications at the same time mine the bodies with extended robotic facilities. If you want to make a extreme frugal budget control then use the robotic drone ship to also drop off probes, landers and satellites ( just using as a frieght handler ) for mars onroute to the asteroid field for mining and exploration program.

The series of designs for CEV could be based on two distinct groups - Atomspheric crafts and Non-atomspheric crafts. But the structure internally could have many of the same components. There cutting costs, repair issues, and training issues for crews.

What is required is thinking reusability and frugal budget restraint for the overall management of the Earth Space Exploration Program - side issue we need a new Logo for the space exploration program that doesn't have any country single logo or flag or agency or organization. If we are going to do this right then from day one - it will require a global position.

GCNRevenger · 2004-08-03 23:06:03

So why not design a reusable lunar transfer vehicle that traverses from low Earth orbit to lunar surface using lunar fuel. Develop a reusable spaceplane to ferry astronauts from Earth surface to LEO and back, using Earth fuel.

The big reason is money... to put it simply, there aren't going to be enough flights to the Moon and back for the forseeable future which could make such a highly reuseable scheme and the trouble to make it reliable enough save much money. Down the road, if we decide to do more than Apollo 2.0 on the Moon or mess around with asteroids.. and in the long term perminant Mars bases.. then such an arrangement makes sense, but at the moment the cost of developing the hardware is all-important as NASA doesn't have that much money to spend. NASA needs tangible, marketable, "CNN wants to send a camera" Lunar landings in the near term.

Building an expendable crew capsule is relativly easy; it is safe, proven, and inexpensive while the HL-20 baby spaceplane still leaves many question about how much it will really cost. I think that $3Bn is pretty optimistic... The same for a Lunar fuel factory, be it a ice cracking arrangement or an Al/LOX slurry maker that will be big and expensive, that you simply don't have to develop, don't have to rely on, and don't have to risk not landing near if you bring the fuel from Earth. The cost of simply using a larger launch vehicle or an additional launch will certainly be cheaper.

The only thing you need to bring BACK from the Moon's surface is the astronauts and a box of rocks, where it makes more sense to simply use the Earth-to-LEO vehicle as the LEO-to-LO and use the smallest practical Moon-to-LO acender possible, so a minimum of mass is lifted from the Moon. The acender jetisoned, the Earth-to-LO vehicle is the only thing that must be pushed back to Earth. Then, the most efficent form of return from LO is a direct entry capsule where a spaceplane is not an option.

The requirement of reuseability itself will add substantial cost to the development of the system(s) involved, because they must be built to survive multiple uses, which is really not nessesarry if you only want to mount one or two short-duration missions a year plus a cargo sortie or two.

RobertDyck · 2004-08-04 02:13:34

The point of going back to space is to stay. We don't need another flags-and-footprints multi-billion dollar mission. Sceptics ask why go to space at all, so we need to accomplish more than a stunt. We need real telescopes that accomplish real science, and ideally image an extra solar planet. We need to make profit. We need to establish a permanent foothold. Most importantly we need to stop wasting billions of dollars on throw-away craft.

Mike Duke pointed out that we could use Atlas launch vehicles to deploy robotic lunar ISPP plants. His model used the Mercury version of Atlas. With space derived propellant a manned mission to the Moon could be mounted with an Atlas launch vehicle. It's not about increasing cost, it's about reducing it.

By the way, the budget for X-38 was $1.2 billion from concept to flight hardware, including construction of 2 flight vehicles.

SpaceNut · 2004-08-04 05:41:43

Andy a projectconstellation space explorer wrote an excellent response to the Hercules Exploration System (SDV) which would use the Ariane 5 derivative for a CEV launch vehicle.

But much like the fact of not being able to pay for the seats on a Rusian soyuz can we purchase said equipment from the Europeans.

My other thought is of launch sites both here and over seas that are capable of launching rockets in that how many are there that would be favorable for use if launch activity were to step up.

Also Robert that would also put the other cancelled projects of the OSP, SLI, the x-38 and other series as viable options for use with the Ariane launcher for the CEV as a Near term solution.
Especially any fully assemble units is a plus.

For andy's response:
Part Two of a three part series on CEV design & launch concepts:
Written by Kevin Waldroup expands on the ideas for Shuttle-C and discusses the possibilities of variants and space station applications using the external tank and other components of the existing shuttle infrastructure.
Kevin's article can be found on this same page also.
http://www.projectconstellation.us/news...._system

comstar03 · 2004-08-04 06:20:33

GCNRevenger,

Well If you plan for a large volume of space movement between the earth and moon then you can create it. Firstly the movement of NASA personnel, construction personnel, mining personnel, scientific personnel, and business activities including space tourism could be created to reduce the overall costs to ferry personnel from the earth to the moon that would provide a lower cost base.

Secondly, we could build large radio telescope array on the farside of the moon and it would limit the earth background radiation thus another reason for expansion of the lunar facilities. The development of earth-moon corridor is a long term process, it might start with one vehicle that a second vehicle and then third vehicle and then a fourth vehicle and then the fifth vehicle might be built on the moon reducing the costs from earth built vehicles, but the same design is still used.

Then earth resources are developing the first interplanetary voyage for humanity. This is also at the same time space tourism is growing through the use of spaceplanes and the expansion of the ISS with a tourism with a separate commercial module for space tourism keeping the non-operational personnel away from critical systems. These things will happen of the next 20 years or so , this is building on the early developments with the ISS and other space stations.

But the CEV must be able to handle the changing environment of human space program for the next fifty years. So don't think inside the box, relating to the use of vehicles but I think of the possibility of not having enough vehicle to do the jobs required.

Also I think when we talk about the CEV it denotes exploration and most of this work that outlined isn't explore - it should be called LTV ( Lunar Transfer Vehicle for the moon and other non-atomspheric satellite bodies) and for Planet fall the vehicle should be called Planetary Transfer Vehicle (PTV and atomspheric satellite bodies) and the Crew Exploration Vehicle should be the larger vehicle moving the PTVs to planets for exploration.

The CEV could be constructed on the moon and also the LTVs and PTVs assigned for that mission. The crew training could be handled from the lunar base at the sametime the crew could oversee the construction of their mothership for the exploration mission.

At the end of the day, We first develop a large goal then a detailed plan then create a budget forecast around the plan then we get approve and then start implementation. In the Budget forecast it would also should how to reduce the costs by bring additional income through revenue measures include alliances and corporation sponsorships and partnerships.

I just think that you need guts to implement the greatest journey for humanity and I don't think that any of the existing organizations ( including NASA they bow to Congress pressure ) have the backbone to do the task on hand.

:bars3:

SpaceNut · 2004-08-04 07:47:10

Well If you plan for a large volume of space movement between the earth and moon then you can create it. Firstly the movement of NASA personnel, construction personnel, mining personnel, scientific personnel, and business activities including space tourism could be created to reduce the overall costs to ferry personnel from the earth to the moon that would provide a lower cost base.

So under the catagory elite you have specialists from NASA personel, scientist and the rich Space tourist.

From the working class you have mining and construction.

Until we can get more from this second group of more common people into space nothing will change.

GCNRevenger · 2004-08-04 12:50:18

Again with the references to the X-38... Do you know just how bare-boned the X-38 really was? It was an escape pod and nothing more: No windows. No cockpit (just a small screen with a "go here" button, minimal radio, and parachute tension knobs). No landing gear. No restartable/variable OMS engine (just a solid rocket). No radar/lidar. No docking allignment hardware. Only 9hrs of oxygen and battery power. Little if any cabin thermal control. No mass or volume margin for drinking water or food. Questionable if you could seat six wearing space suits. No reuseable TPS. Almost no guidence at all. Little or no provision for water landing. No launch escape system... You get the idea. Escape pod, not crew taxi. Being that it would cost a cool $1.2-1.5Bn to develop, it makes the $3Bn figure for a baby HL-20 seem pretty low, i'd think it would cost $4-5Bn plus EELV modifications.

Going back to space for keeps is the eventual goal, but right now I don't think there is enough political motivation or money to justify the extra expense, much less fund even a minimal expendable mission arcitecture. Lunar mining for minerals/He3 or any sort of orbital tourism are still pipe dreams, and you simply don't need a Lunar base to set up a telescope. In fact, small telescopes spread far apart make more sense for interferrometry telescope farms. A larger Lunar lander, bigger than the LEM, could carry the prepackaged RTG powerd telescope module and the acender, the crew of 2 astronauts spends a few days setting it up, then back to the orbiting CEV for direct Earth return.

Unfortunatly "inside the box" is what we have to do... we need to accomplish real science on the Moon on the cheap. NASA isn't going to get a huge budget increase, so the money will probobly come from Shuttle after the ISS is core complete plus a little extra saved up or donated from Congress. If we keep the ISS funding of around $3Bn a year going, plus a little more for 2-3 CEV flights a year, that leaves about $4Bn a year. The project really has to made results in under a decade, and with a little extra lets say, leaves NASA with about $50Bn for the Moon. New capsule, new lander, new TLI stage, new acent vehicle, new surface HAB, modified EELV or SDV development, radio/optical telescopes, rovers, drilling rigs, and actually buying the launch vehicles and hardware - everything for about $50Bn including all mission payloads. The ultra-simple mega bareboned Mars Direct would cost nearly that much.

There is no money for a large plan, it will be a stretch to even think about a perminant manned presence, and then you want a little money left over to start thinking about a Mars trip right?... The cost of development is all important, the cost of adding a Lunar fuel factory to the arcitecture isn't happening, there is no way it could be built and sent for less than billions of dollars, then you have to trust the astronauts' lives that the thing works, and then you have to land close to it which you won't be doing since you'll be setting up telescope modules or doing geology all over the surface.

In the context of a small number of missions to different sites on the Moon, Michael Duke's plan will increase the total cost substantialy, which I believe will simply price the whole thing out of reach. Saving a booster launch here and there doesn't make up for the cost of developing multiple highly reliable reuseable spacecraft and a Lunar fuel factory... it simply does not. Two EELV+ or one SDV shot can deliver large masses to the Moon with an expendable lander for well under a $1Bn, or modest masses in only one EELV shot with the help of an ion tug to Lunar orbit. Since you'll have to use a booster anyway to put the payload or crew into LEO, it doesn't make sense to bother with Lunar refueling, especially considering the danger and mission constraints it adds... A $2Bn fuel factory would buy you quite a few Delta-V/Atlas-VI shots, twenty Zenit-II's, four or five SDVs, or a whole gaggle of Falcon-VBs... How much more can be accomlished on the Moon if the reuseability notion is abandoned.

A few billion for the factory, a billion for the reactor, another billion or so to send them, another billion or three for "HL-54" versus capsule CEV, a billion for a Lunar orbit fuel depot, a billion or two more making the tranfer vehicle reuseable versus a throw-away Lunar lander... it all adds up terribly quickly.

RobS · 2004-08-04 13:23:53

Summary of "The Next Steps in Exploring Deep Space" a report for the International Academy of Astronautics (IAA) by Wesley T, Huntress and ten others, July 9, 2004, pdf, 117 pages.

In some ways the report fleshes out the space exploration initiative announced by President George Bush in January 2004, but the work on the report started months earlier than the announcement and thus does not address the President's initative in detail. It offers four principles for deriving the mission architecture for a space exploration plan:

1. The plan must be goal-driven. The report offers a series of scientific goals for space exploration, but notes that exploration also has political and cultural imperatives.

2. Cargo and passengers must be separated whenever possible to maximize efficiency and crew safety.

3. Each major new destination requires develoment of one new piece of equipment only, and an evolving sequence of challenges and capabilities.

4. Existing transportation tools must be used as much as possible; no new launch vehicles or propulsion systems are proposed, but use in-orbit assembly and refueling must be used as much as possible.

It proposed four major architectural steps for exploring the solar system:

1. Human flight to lunar orbit and Earth-Sun L2 (ESL2). The latter Lagrange point (1.5 million kilometers beyond the earth) is an ideal location for telescopes and for launching interplanetary missions. Alternately, Earth-Moon L1 or L2 could be a destination. The new vehicle to be developed for this step is the "Geospace Exploration Vehicle"; (GEV) a vehicle capable of supporting 3-7 human beings in space up to 50 days. A trip to ESL2 would take 2 weeks, the return to Earth would take 2 weeks, and astronauts would need to stay there 2 weeks to do telescope assembly. The GEV would be reusable.

1A. Lunar surface. The report does NOT require a lunar landing; in fact it says repeatedly that it is unclear whether further nearterm exploration of the moon requires the presence of humans. But obviously if a lunar landing is to be carried out, there would need to be a step, and it would require the development of a lunar landing vehicle.

2. Near-Earth Objects (Asteroids). The report recommends the second step in exploration be a human mission to an NEO. This would require development of the "Interplanetary Transfer Vehicle" (ITV) for 3-7 persons, about twice the size of the Geospace Exploration Vehicle, with much more robust and efficient life support systems able to support a crew up to three years. The ITV would later be used to send a crew to Mars orbit. The report gives the example of a mission to 1999 AO10, which would depart from ESL2 on Feb. 20, 2025, use a delta-v of 5.3 km/sec (when performing a close flyby of the Earth), rendezvous with the asteroid November 14, 2025, leave it January 14, 2026, and return to Earth on Feb. 20, 2026, exactly a year after departure. The ITV would be reusable and would normally be stationed at ESL2. It would be resupplied robotically; the crew would fly to it in a GEV and meet it a few days before it reached flyby. The ITV would need a delta-v of only 300 meters per second to travel to Earth, and could use lunar gravity-assist flybys to enter any orbit it needs. After a return to Earth orbit, lunar gravity assists and a small burn would take the ITV back to ESL2.

3. On to Mars orbit. A mission to Phobos and Deimos would be flown and a cargo transport vehicle (CTV) would be developed and flown ahead of the crew. The CTV would leave low earth orbit and fly to Mars using solar or nuclear ion propulsion (they favor nuclear because they say solar-ion engines can't be made larger than 50 kw; I'm not sure why, I've seen a proposal for a 450-500 kilowatt solar ion tug on the web). The crew would arrive after the cargo vehicle was already in Mars orbit with scientific equipment and other necessities, including surface rovers they would operate from orbit. The report adds that possibly this step would not be needed (though the CTV would be).

4. Down to Mars. This would require development of a Mars descent/ascent vehicle (MDAV) which would be fueled using in-situ propellant production powered by a nuclear reactor. The MDAV could be quite simple; the life support would only need to be for a few days. The MDAV would be sent to Mars using an ion tug.

They also propose the use of aerobraking but NOT aerocapture (in other words, orbital injection will be done with engines, but vehicles can move from high to low orbits slowly using aerobraking, unless aerocapture is developed further).

In addition to these vehicles, surface vehicles and a Mars habitat will be needed. A crew return capsule would be used to fly crew to low earth orbit and return them to the Earth's surface. Thus at the end of a Mars mission, the crew would leave the ITV before it reaches Earth and would fly straight into the Earth's atmosphere and land. The ITV would slow with its engines into a high elliptical orbit around the Earth, then would fly back to ESL2 using lunar gravity assists and engines. The GEV would always be based in low Earth orbit. The crew return capsule can be thought of as the crew exploration vehicle, block 1; the GEV as block 2; and the ITV as block 3.

Rather than "core complete" the report recommends retiring the shuttle after ISS is "US core complete" and launching the European and Japanese modules using EELVs or other means. This would speed up shuttle retirement.

-- RobS

RobertDyck · 2004-08-04 13:59:50

Ah, first you agreed to $2.0 billion for an OSP, then said $3 billion, now $4-5 billion plus EELV modifications. This sounds like the “ratchetting up” that caused the OSP program to be cancelled. Do you work for Boeing or Lockheed Martin? You keep emphasizing the Delta IV as apposed to Atlas V, so my guess is you work for Boeing. When you increased the price from $2 billion to $3 billion, I reduced it from $2 billion to $1.2 billion. The more you increase it, the more I decrease it. Congress demonstrated they won't tolerate “ratchetting up”, either keep the cost down or the project won't happen.

X-38 was originally designed to be a 4-person escape pod, not 7-person. Some political type tried to claim Russian Soyuz is not reliable so they would have to evacuate all ISS personnel in an American vehicle. Bullshit, Soyuz is reliable. With 7 crew on ISS and the Soyuz that carried 3 of them still there, the American escape pod only needs to carry 4. X-38 was also designed to use the metal heat shield. That decision was changed to the same REUSABLE heat shield material as Shuttle. A metal heat shield requires a shallow atmospheric entry angle, changing the heat shield changed the entry profile. After CRV was cancelled, ESA entertained the idea of using X-38 instead of Hermes, which required conversion from CRV to OSP. All these changes increased the price from $1.2 billion to $2.0 billion.

Any CRV or OSP only requires a couple hours of life support, no need for water or food. I believe you have argued that rendezvous takes days on-orbit. I disagree. Proper navigation means a couple hours.

I also disagree regarding size and cost of the fuel factory. It should cost thousands for a brass-board technology demonstrator, and millions to develop flight hardware. I'll let you argue whether that's 10's or 100's of dollar units. Michael Duke has been arguing this point for many years, give him a contract for a brass-board technology demonstrator.

Launch vehicles: you do make sense there. SDV could go a long way to simplifying either a lunar or Mars mission. However, considering how much everything costs, how much would development cost for Shuttle-C or any other SDV?

SpaceNut · 2004-08-04 14:33:11

Shuttle C cargo only, could be done very cheaply from a design stand point but from a continous launch of multiple units very costly. Cargo pod plus engines, External tank are expendable only the srb's would be recovered.

SDV manned version would mean the expense of design for the CEV capsule and to orbit stage engines. The capsule could be placed at the top of the external tank with orbit stage and main engines could be a pod on the side of the tank or directly beneath the tank.

Capsule could be some what reusable depending on design or just the inside electronics could be place into a new shell each time for re-use.

GCNRevenger · 2004-08-04 15:03:45

At first the pricetag for the original HL-20 was $2Bn or a little more as quoted from the original designers in 1990's money. Making it around $3Bn in 2004 dollars. I think this estimate is low, so it would cost at the least around $4-5Bn, perhaps a bit more... thus, only one real "adjustment." The idea that the little $1.2Bn (closer to $1.7Bn in today's dollars) X-38 CRV could be converted into a vehicle of tripple the complexity into OSP without at least doubling the cost is not credible, and thats pushing it.

And yes, it does have to be able to last on orbit for several days, preferably a week. Its a simple matter of orbital mechanics, that the vehicle cannot be sent directly to rendevous with the ISS from Florida or French Guinea; the persuit orbit takes several days to rendevous with ISS in order to aproach it slowly. Another day or two to come back down over the preferred landing site... a week for safety margins. Its not about "proper navigation."

I think you are being extremely optimistic about the trouble of making a Lunar fuel factory. You've got to make a nuclear power plant able to operate for years in the hard vacuum: the Prometheous reactor will do the job, but since there is little money for that ATM you've got to pay the billion(s) for it "out of pocket." You've got to send a large regolith-hauler rover, preferably fuel cell or direct nuclear powerd because of the long Lunar night... given its size and mission compared to the $0.6-0.7Bn solar/battery golf cart MER development, I can't see it costing under $1Bn any which way and would probobly mass in the region of a ton. Then you have to worry about fuel boiloff once you do crack the stuff, which will require even more energy to re-condense the stuff continously. Now you can think about the fuel factory proper, which even if it is half the complexity of Bob Zubrin's one on MD, is going to cost a cool billion too and also mass tons.

Several billions of dollars and another billion or two to deliver/setup the componets is the smallest credible ballpark range... If Michael Duke says that it can be done for only millions, then you have either forgotton about the other costs for the operation or Mr. Duke is an idiot.

And then, even with the factory, you still have to entrust that it will work and that you can land nearby it reliably or somebody is going to die. Plus, since the station is relativly stationary given the large requisit size of the reactor radiators, you can't land long distances apart to set up interferometers or different geology sites... Or you can just send a bigger rocket.

As far as the SDV, thats hard to say... for a simple 70MT "shuttle sans wings & people" i've heard of figures as low as $1-2Bn. For a big refit with new boosters and verticle upper stage mount, anywhere from $5Bn to $10Bn.

Edit: Plus the Lunar fuel isn't worth that much if you simply abandon the notion of launching anything but people and boxes of rocks from the surface. The amount of fuel needed to launch a little 2-4MT acent vehicle is pretty small and isn't a big deal to haul from Earth, so it makes even less sense to make it on the Moon. Since thats alot of the fuel needed for a round-trip from the Moon, I really don't think the factory is a good investment, particularly if you have to make another investment for a LO fuel depot and its condenser.

Throw in a large ion tug w/ fuel condenser and a single EELV+ could deliver 20MT range masses with built-in lander to anywhere on the Lunar surface for around $400-500M. Since it would cost $200M to launch that payload on either EELV to a reuseable LO-to-Luna vehicle powerd by Lunar fuel, its going to take alooot of flights to make up the billions needed to pay for such a scheme.

RobertDyck · 2004-08-04 15:37:22

Thanks Rob Stockman, that report makes a lot of our arguements moot. There isn't going to be an OSP, as much as I would like one. There also isn't going to be an SDV. Reusable GEV and ITV sound great! No aerocapture...uhhh...we really need to work on that. No human return to the Moon: I'm surprised since George W. Bush made such a big deal of it.

clark · 2004-08-04 15:49:42

That report is moot.

It was designed prior to the VSE, outside of those who had, and who have input on VSE. It has elements that may be incorporated into the current VSE proposal, but it is not endorsed by anyone associated with the VSE or NASA.

In some ways the report fleshes out the space exploration initiative announced by President George Bush in January 2004, but the work on the report started months earlier than the announcement and thus does not address the President's initative in detail.

It does not address the reality as proposed by VSE, therefore it has no value unless the elements directly relate to actual goals as outlined by the VSE.

comstar03 · 2004-08-04 17:10:27

Well If you plan for a large volume of space movement between the earth and moon then you can create it. Firstly the movement of NASA personnel, construction personnel, mining personnel, scientific personnel, and business activities including space tourism could be created to reduce the overall costs to ferry personnel from the earth to the moon that would provide a lower cost base.

So under the catagory elite you have specialists from NASA personel, scientist and the rich Space tourist.
From the working class you have mining and construction.
Until we can get more from this second group of more common people into space nothing will change.

No, I mean that because of the lower costs associated with the increasing frequency of journeys to the moon will reduce the cost on movement of people.

Secondly, I named current organizations including mining and construction personnel required for expansion of space in the earth - moon zone.

Also SpaceNut, ( space socialist ) for the near term space will be the domain of space organizations and wealth individuals because we haven't got the star trek transporter that costs to move people at zero, But as our population outside the earth grows so does the normal (common ) / non-wealth people grow and thus can have holidays to the moon or space station or even mars in the future at a lower cost than the earth people can pay for, Also we could develop faster and more fuel efficient designed vehicles again the costs come down and get lower for everyone.

RobS · 2004-08-04 20:26:02

Regarding the conversion of lunar water into LOX/LH2, in Duke's "A Lunar Reference Strategy" at http://www.marsinstitute.info/rd/facult … /mm22.html he says that the plant could be operated by a 1-tonne nuclear OR SOLAR power system. If solar, presumably one would have to land the plant on or near a peak and deploy the panels in a place where there is near-perpetual sunlight. Vehicles would have to drive from there into the cold areas under remote control, presumably using fuel cells refueled with hydrolyzed lunar water .

Costs: he said the entire plan would cost $2.6 billion, $900 for three shuttle launches, $500 million to develop the reactor, $500 million to develop the solar-ion tug. The remaining $700 million is not specified in David Portree's summary, but that would presumably cover the development of the lunar fuel plant, the inflatable surface hab, and other essential equipment for the human crew. But it probably is mostly the fuel making plant because he said the lunar fuel making plant was to be intermittently human tended; it would not be located at a permanent human station.

Note that Duke was an employee of the Johnson Spaceflight Center at the time and would have access to reasonably good information about costs and masses. I am under the impression that the presentation was made at Johnson Spaceflight Center as well.

The lunar fuel making plant, including its power source, was to mass 8 tonnes and was to make 32 tonnes of LOX-LH2 per year. In a private email Duke told me in Jan. 2003 that the plant should be able to make more fuel than that per year.

Regarding liquification of oxygen and hydrogen, how difficult is that? Yes, it takes energy, but one has access to both energy and cold in the lunar poles. Radiators should work fairly well if they are shielded from sunlight. The plant will function in an environment with gravity, so it can be designed on the Earth. If one wants to refrigerate 50 tonnes of LOX/LH2 per year, that's only half a kilo--one pound--per hour. Keeping the fuel cryogenic is facilitated by the fact that the regolith never gets very warm near the poles and thus doesn't radiate as much infrared heat as it does near the equator. If the old 1% boiloff of LH2 per month rule works, 50 tonnes of fuel (7 tonnes LH2) would experience 70 kilograms of LH2 boiloff per month, requiring only a modest augmentation of the cryogenic refrigerator.

As for landing near the fuel making plant, Apollo technology was adequate for that; Apollo 12 landed near Surveyor, and Surveyor didn't broadcast a landing beacon. If a lander misses the landing site because of engine problems, a crash is likely to follow. Modest rescue capacity could be created by landing a pressurized rover that could be driven by remote control to a lander that missed its target (presumably by just a few kilometers).

The recent report from the Colorado School that Duke coauthored (he's now at the School of Mines) about selling lunar water showed that water could be delivered to low earth orbit and converted to LOX/LH2 for less than about $10,000 per kilogram. It also indicated that such fuel costs about $90,000 per kilogram delivered to the lunar surface from Earth via chemical rockets. I don't remember the cost delivered to L1, but it should be at least $20,000 per kilogram from Earth even with an ion tug. From the lunar surface it would be much cheaper than that; cheaper than delivery from the moon to low earth orbit, since no aerobraking would be needed. So if Duke's economics are correct, lunar water DOES have a role to play, especially if we can deliver large masses to Earth-Moon L1 or L2 by ion tug and use lunar LOX/LH2 to send them quickly in their way to Mars.

But the question of whether the scale is large enough remains to be determined. If the lunar fuel making system costs $3 billion to develop and deploy--more than Duke says, but let's try that number for a moment--it would have to produce 1,500 tonnes at $20,000 per kilogram or 600 tonnes at $50,000 per kilogram (if that were the cost of delivery from earth to L1) to pay for itself. If the lunar fuel making system cost $1 billion the numbers would be 500 tonnes at $20,000 per kilogram and 200 tonnes at $50,000. It would take a long time to use up 1,500 tonnes of fuel on the moon or at L1.

-- RobS

RobS · 2004-08-04 20:46:37

Regarding "The Next Steps in Exploring Deep Space", the report's authors had made efforts to adjust their ideas to the Bush space initiative. The latest version is July 2004, which I read and summarized, but the preliminary draft had been presented at a conference in October 2003. I was surprised they were as cool on lunar surface exploration as they were. One of the people involved, Jim Head (an old graduate student advisor of mine, and a doctoral advisor to Paul Spudis) had worked on the Apollo mission as a geologist. But it would be easy enough to convert step 1A (which I added parenthetically) into a step 2 and renumber the others. The report seemed to have been written partially with that in mind.

I very much liked their idea of visiting near Earth asteroids as a vital step to Mars. NEAs are becoming more and more important; the possibility one will collide with Earth is raising their priority.

I was fascinated that they were proposing a geospace exploration vehicle and an interplanetary transfer vehicle. This is very much like what Robert Dyck was advocating about two years ago, which I incorporated into my "Mars-24" proposal. And while I favored a large reusable Mars shuttle, the MDAV of the report is closer to Robert Dyck's idea of a small vehicle to carry the crew quickly back to the ITV (though they are assuming in situ propellant production on Mars would only have to make enough fuel for the MDAV, not to push the ITV back to Earth as well, which had also Robert suggested and I used in Mars-24). And of course, I'm happy (I guess) that they proposed ion tugs and using existing launchers, not a new, large SDV. On the other hand, Huntress is also the chief author of the other report I summarized the other day, and that one DOES call for a SDV. I think that shows how unclear the economics of the choices is.

-- RobS

SpaceNut · 2004-08-05 09:09:00

When one looks at cost of an Item it will always boil down to Material versus labor. Labor is almost always the higher of the two.

So to drive cost down first you must lessen the amount of labor required to construct the rocket. Then it comes down to automation of build and changes to use cheaper material.

GCNRevenger · 2004-08-05 09:26:59

Thought I would bounce a few numbers around...

Isp for modern Cryogenic engines: 460sec
Delta-V for TLI burn: 3900m/sec
Delta-V for LLO-Surface landing: 2500m/sec

Say a LEO-LLO nuclear ion tug would cost a billion to develop, using a medium (300kWe) Prometheous reactor. Said tug would come standard with a cryogenic condenser, be periodicly refueled by dedicated Xenon launches from Earth, and the RL-60 powerd Lunar lander cost around $50M each. Each lander weighing in at around 3MT dry, would give you about 10MT directly to the Lunar surface for around $250M launched on a Delta-IV HLV. That would be pretty hard to beat I think... $25,000 per kilo for a billion in development sans Lander.

Say you wanted to scale it up... spend a billion to develop a man-rated "Atlas-VI" that is 5M wide top to bottom, uses the new RL-60 upper stage, and 6X SRMs to boost 40MT to LEO for $300M. With a 3MT lander (same as the other w/ extended tankage) you can place 20MT directly to the Lunar surface for $350M. Thats only $17,500 per kilo for about $2Bn in development.

You'd have to sell 400-500 metric tons of Lunar fuel at $10,000/kg just to make the fuel factory scheme pay for itself versus the Ion Tug + Atlas-VI scheme and save a single penny. Now for direct flights...

Delta-IV HLV system with two launches, one for TLI rocket + LOX and one for the Lander + LH2 gives you about 9MT directly to the Lunar surface, which isn't bad and would be plenty for a manned Acent vehicle that seats 2-3 plus have a few tons left over for telescope modules or drill rigs. The same setup with the CEV from LEO to LLO gives you about 21MT to play with, which ought to be enough give or take. Each lander sortie ought to cost $500M or $600M-700M for CEV if its construction can be kept cheap enough... $60,000 per kilo with no development at all other than the lander and Centaur-derived TLI rocket.

Atlas-VI system with two launches likewise will give you 16MT to the Lunar surface or a CEV massing almost 34MT for the region of $700M for the lander and $800M-900M for the CEV flight. $44,000 per kilo to the surface.

Hypothetical SDV developed for $3Bn lets say carrying 100MT directly to the Lunar surface with built-in TLI stage and costing around $450M each gives you about 21MT for a cost of $23,800 per kilo, which is competitive to the Ion Tug + EELV aproach. It should be noted that this method delivers the payloads quickly (i.e. for manned vehicles) and has the added bennefit of being able to launch Martian ship componets or other large LEO objects.

Number of metric tons of Lunar payload needed to pay for Ion Tug ($1.5Bn) versus direct launch with Atlas-VI: 57MT or about 4 flights with a little for a Xenon launch.

Number of metric tons of payload needed to pay for Ion Tug -and- the Atlas-VI development ($2.5Bn) versus direct launch with Delta-IV HLV: surprisingly, also only about 58MT or about six flights.

Number of metric tons needed to make up for SDV development versus Delta-IV HLV direct scheme: 82MT or about four flights.

GCNRevenger · 2004-08-05 12:00:03

Side note: I probobly should have thrown in a ton or two for the TLI stage dry mass, but that shouldn't make a huge difference... Atlas-VI two-launch direct scheme with 3MT for TLI stage dry mass would be around 15MT.

Anyway, even if my numbers are a good 25% low, thats still several hundred tons of rocket fuel you'll have to sell and make a reuseable lander that will compete with a cheap expendable lander plus the fuel needed to launch the lander empty to pick up the next payload.

RobS · 2004-08-05 15:39:16

Wait a minute, let's review the numbers a bit more clearly. I have these figures:

Low Earth orbit to escape: 3200 m/sec
Lunar escape velocity: 2300 m/sec

Total, 5.5 km/sec. You have 6.4 km/sec; maybe that includes gravitational losses, accelerating to a velocity faster than escape to get to the moon faster, etc.

A specific impulse of of 460 seconds means an exhaust velocity of 4.6 km/sec, so:

6.4/4.6 = 1.39

And e to the 1.39 power = 4.01

Let's round it down to 4.0, to make the calculations simpler. That means every tonne in low earth orbit needs 3 tonnes of LOX/LH2 propellant to get it to the lunar surface.

If you are starting with some sort of augmented Atlas that can launch 60 tonnes to LEO, those 60 tonnes must include 45 tonnes of propellant and 15 tonnes payload.

The 15 tonnes of payload has to include about 4.5 tonnes of tanks and engines. The Atlas Centaur is 9% tanks and engine and 91% propellant; the Delta IV large second stage is 11.4% tanks plus engine. Assuming that this stage is 9% tanks plus engines, that's 4 tonnes.

So your 60 tonnes of mass launched into LEO can only include 11 tonnes of usable payload landed on the moon. For the Delta IV large and 27 tonnes to LEO, two of them equals 54 tonnes and the total landed on the lunar surface equals 54/4 = 13.5 - 3.5 stage = 10 tonnes on the moon.

If we use an intermediate delta v of 6 km/sec (half way between my figure of 5.5 and your 6.4) then the mass ratio is 6.0/4.6 = 1.3, e to the 1.3 = 3.7, thus 1 tonne on the moon needs 2.7 tonnes of propellant. Thus

60 / 3.7 = 16.2, 60-16.2 = 43.8 tonnes propellant = 3.9 tonnes stage, thus you can land 16.2-3.9 = 12.3 tonnes crago on the moon.

For two Delta IV heavies, 27 + 27 = 54 tonnes in LEO, 54/3.7 = 14.6 tonnes payload, 54-14.6 = 39.4 tonnes propellant, x 0.09 = 3.5 tonnes of stage, 14.6 - 3.5 = 11.1 tonnes.

Does than make sense? Can you run through your numbers a bit more slowly so we can follow them?. . .

-- RobS

GCNRevenger · 2004-08-05 16:00:44

My Delta-V figures are from a Google search, so they might be a little off. Anyways, the equation I used was

Delta-V (meters/sec) = Isp (460sec) x G (9.805m/sec^2) x Ln(Mf/Mi) (tons, mass ratio)

The figures for the TLI rocket setup are in two parts, one to deliver the payload + fueled lander to Lunar orbit of 3.9km/s, followed by the ejection of the TLI stage and whatever mass left over from the TLI burn lands with a second burn of 2.5km/s minus 3MT for the lander. Quick back-of-envelope stuff.

SpaceNut · 2004-08-06 06:01:24

You two both blow me away with the numbers but did I see only a one way trip for this rocket and lander to the moon or did I miss something about the lander.

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