New Mars Forums

GCNRevenger

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Registered: 2003-10-14

Posts: 6,056

Re: A new HLLV essay

"But if we only use expendable landers then we are no closer to a substantial and sustained presence. "

Really? Then what do you call serving Mir with Soyuz-TMA and Progress vehicles? Seems to have been pretty sustained to me...

The amount of money saved with a reuseable lander is simply not going to be all that signifigant until you need a large number of flights, such as if you were building a self-sufficent (grow their own food, big enough to not need crew rotations) or if you were mining something useful (PGMs, He3).

Until such a time, it makes more sense to build an expendable lander to save on mass and mission complexity. It is quite possible to operate a Luanr base with expendable vehicles.

What I am envisioning is an initial phase of manned flights, up to three, perhaps four or so yearly. This would make for efficent exploration of various sites of interest and be able to provide transportation for four-month crew rotations at a perminant base, starting with four crew + stuff then moving to six in CEV.

And why the dumping on EELVs Bill? SDV will be launching payloads with their own TLI/3rd stage. EELV will just be launching the payload and the TLI stage seperatly. Two EELVs can do the same job as a single SDV can, and do it for aproximatly half the cost per-flight. There is nothing "flimsy" or "whimpy" about them, they can send payloads about as big as SDV can.

The SRB-launcher option is out of the running due to its low maximum capacity (20MT) and Proton is out for the same reason and for politics.

It is very likly that SDV will be unable to do this for radically lower cost then EELV can without seriously compromising its performance to minimize cost... and then there is the matter of firing the Shuttle Army too.

Oh and the flexibility issue... if you don't want to send a massive payload to the Moon, but you want to send one bigger then the measly few tonnes that SRB-launcher could, then you would be out of luck. The military and future space telescope/probe people would love to have an intermediate 40MT capacity booster too.

Making LOX on the Moon won't be that easy I don't think... the furnace would need to be large and pretty heavy, and it would only work during a short segment of the "day" when the sun is at the right angle... and not at all in the dark. A nuclear powerd system should be preferred. Oh, and there is basically no Methane anywhere on the Moon, so your only option is Hydrogen, which requires quite a bit of energy to liquify and store, also requiring nuclear energy.

And the space station... There is infact a way to access the Lunar surface even more efficently: launch suborbital hoppers from the Lunar surface base. No need to burn enough fuel to enter orbit nor brake from it, straight up and straight back down. There is just no good reason to put people up at L1.

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[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

publiusr

Banned

From: Alabama

Registered: 2005-02-24

Posts: 682

Re: A new HLLV essay

Some good news for our Friend:
http://www.space.com/spacenews/business … 40412.html

"Michael Griffin, NASA’s associate administrator for exploration from 1991-1993, says the most logical approach, all things considered, is to spend the $3 billion or $4 billion it would cost to build a shuttle-derived heavy lifter and forget about EELV-driven approaches."

“No matter what lunar or Mars architecture is chosen, a lot of mass will have to be moved through LEO, or through some other staging point,” Griffin told Space News. “I would argue that 100 [metric tons] represents a reasonable place to start, and that shuttle-derived systems can get us to that point more cheaply than other systems. No one would favor a clean-sheet approach more than would I, but unless more money is made available for it than I think likely, we won’t get it. I dislike giving up something we have in favor of something we might get.”

"Griffin also said...that...he takes a “dim view” of approaches that would rely on orbital staging and assembly operations..."

He has O'Keefe's job now:

http://www.badastronomy.com/phpBB/viewt … 690#432690

Check out how this thread begins:

http://www.badastronomy.com/phpBB/viewt … 5&start=50

The Committee has spoken:

http://www.badastronomy.com/phpBB/viewt … 688#432688

BWhite

Member

From: Chicago, Illinois

Registered: 2004-06-16

Posts: 2,635

Re: A new HLLV essay

More breaking news about http://www.space.com/news/griffin_nasa_ … ml]Griffin

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Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]

GCNRevenger

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From: Earth

Registered: 2003-10-14

Posts: 6,056

Re: A new HLLV essay

Doesn't mean that he's right, Dan Goldin was in many ways a blithering idiot. If Griffin is really pushing for SDV because it will save the jobs of Shuttle buddies, then we are doomed.

Furthermore, we are going to need an improved EELV anyway, since putting people on top of SDV is a pretty lousy option safety wise. It will also give us more mass to work with if the crew capsule and TEI stage flies seperatly.

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[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

Ad Astra

Member

Registered: 2003-02-02

Posts: 584

Re: A new HLLV essay

Here is the most relevant part of the space.com article:

Worden, who replaced Griffin as the technology deputy at the Strategic Defense Initiative Organization in the late 1980s, said he does not think Griffin would let his stated preferences for a shuttle-derived heavy-lifter interfere with NASA’s effort to reach an honest conclusion about the best way to go.

“I think he is going to be very open to whatever the best solution is,” Worden said. “He is a superb engineer and he listens to people.”

Let the engineers decide whether SDV or EELV or some combination of both (CEV on EELV, EDS & LSAM on SDV) is the best, most cost-effective solution.  Michael Griffin seems like an incredibly able choice for NASA administrator, and I expect him to review all his options when choosing the architecture for VSE.

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Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

Austin Stanley

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From: Texarkana, TX

Registered: 2002-03-18

Posts: 519

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Re: A new HLLV essay

I wouldn't be so quick to dismiss mirrors as a heat source for various oxygen production operations.   Remember that the Lunar day is nearly a month long, and the Moon recives about the same amount of sunlight we do, without an atmosphere to dilute it.  A relativly small mirror could easily generate the the 1000*C temperatures necessary for most mineral reduction operations.  The mirriors would have to be re-aligned perodicly, but given the length of the lunar day, this would only have to be every day or so.  And while the system couldn't be used during the night and some fraction of the lunar day, liquid oxygen isn't THAT difficult to store and when we aren't launching rockets we wouldn't realy be using that much of it.  So it would be realitivly easy to build up a stockpile when you do need it.  In any case, a solar power source is bound to be MUCH less masive then a nuclear system and cheaper and safer to boot.

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He who refuses to do arithmetic is doomed to talk nonsense.

Grypd

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From: Scotland, Europe

Registered: 2004-06-07

Posts: 1,879

Re: A new HLLV essay

And if we go to one of the lunar poles we already know of areas which remain in permanent shadow and Hills which have a lot shorter lunar nights.

The darker craters would be perfect for storing LOX without needing too much of a permanent power supply and the light that falls on the peaks can be used for power and to be redirected to LOX etc production by mirrors.

Still if we dont want a permanent human prescence we can use Telerobotic assets to actually "man" and work the base especially as the LOX production method proposed here lends itself to automation and telerobotic mining.

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Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

GCNRevenger

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Posts: 6,056

Re: A new HLLV essay

Sure you can generate high enough temperatures for oxide cracking, the trouble is raising a large enough amount of material to that temperature. Its all about the wattage, not the temperature, the sunlight is only going to be a few kilowatts per square meter, and you will lose a good portion of that to mirror absortion, reflection off the furnace, and heat lost to the furnace instead of the oxide dust.

And though it is never dark in a very few number of places on the Moon, the Sun does move across the sky, requiring a complex and heavy rig of rotating mirrors... no nice simple fixed anything.

And considering how the system would only be able to operate for days, not weeks (Lunar day is ~2 weeks, and the sun only overhead for days) in most places, a small nuclear reactor would actually produce more LOX over time. You will need a reactor to run the storage condenser anyway.

But most of all, if you needed oxgygen, you could have it, any time of the Lunar day.

Safety wise, you'll need a nuclear reactor to keep alive during the long night, so you are going to have to trust in one any which way.

Edit, calculations:

You can recieve about 1,400W/m^2 from direct sunlight. Say that you can collect & convert this on average with 80% efficency when the sun is directly overhead. Lets also say that you can use about half the Lunar day (1 week) when the Sun is shining at a practical angle. Photovolic cells would be used to operate the electrical needs of the solar furnace, and for the sake of argument the LOX storage system is basically "free."

A small ~10MT JIMO-class nuclear reactor will produce about 300,000W of heat continuously at full power, of which 33% of that is converted to electricity and 50% of the waste heat energy is useful for preheating the furnace at 90% efficency. Lets also say that 1/4th of the reactors' electrical output must be used to operate the fuel condenser and mechanical needs of the furnace. This adds up to about 200,000W of useful energy to heat the furnace, 24/7, 365.25 days of the Solar year.

This adds up to 1.753Bn watt-hours of heat per year. For a solar furnace to match this output, it would therefore need to produce 1,000,000W during operation (considering efficency losses), which would require a mirror farm of 714m^2, which I hardly consider trivial given how it must be focused. A mirror the size of a 10 story building (square) roughly.

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[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

Grypd

Member

From: Scotland, Europe

Registered: 2004-06-07

Posts: 1,879

Re: A new HLLV essay

Still a nuclear power plant would require constant vigilance and heavy equipment from Earth where as the power for solar can be created using lunar materials. And we can increase power capacity just by adding mirrors.

Still a nuclear power plant is a likely necessity for a first base as it will provide power until we can create a solar power system. And though we can send a "solar" power station from Earth it will be just to add to the power grid that a nuclear option could give us.

And GCN you have forgotten that in all likehood we will be going to the poles first as the high possibility of hydrogen type ice there combined with the peaks which are almost completely in sunlight provide a prime first base site. And the ESA smart probe could well provide the best site.

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Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

BWhite

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From: Chicago, Illinois

Registered: 2004-06-16

Posts: 2,635

Re: A new HLLV essay

Would a nuclear reactor be nice to have? Of course!

Should we refrain from exploration until we have a reactor? No!

There are millions of reasons why exploration should be postponed for another 50, 75, 100 years. What we need to do is start and then explain a persuasive "why"

By the way, buying a Russian reactor (or a US design made in Russia) would allow a private company to simply by-pass all the anti-nuclear US hysteria.

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Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]

GCNRevenger

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Posts: 6,056

Re: A new HLLV essay

"Still a nuclear power plant would require constant vigilance and heavy equipment from Earth where as the power for solar can be created using lunar materials."

Untrue! A liquid-metal cooled reactor can actually be operated with no moving parts whatsoever (SP-100), and a simple reactor like JIMO's you would only have to worry about the turbine, and that you could build in redundancy. There is no reason at all why a reactor would have to be "carefully watched" or any nonsense.

And building large solar mirrors (>1 meter on a side) is a pretty distant future project, considering that they will have to be articulated to follow the Sun, especially at the Peak of Eternal Sunlight that you describe.

"...buying a Russian reactor (or a US design made in Russia) would allow a private company to simply by-pass all the anti-nuclear US hysteria."

Except one little tiny problem Bill... all of the Russian reactors are tiny pitiful toys, capable of a measly handfull of kilowatts. The little Topaz reactors used to power the Russian SBR satelites only generated 5-6kWe. No better then a cluster of RTGs... JIMO's little reactor would have been an order of magnetude more powerful, and a big Lunar base reactor should be a megawatt (thermal) class.

The lack of nuclear energy is the big reason why all the initial exploration missions will be limited to two-week stays.

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[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

Austin Stanley

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From: Texarkana, TX

Registered: 2002-03-18

Posts: 519

Website

Re: A new HLLV essay

Again, I disagree.  The moons low gravity and lack of atmosphere make some truely large mirrors relativly easy to build/import and deploy.  Currently optical spacetelescope quality mirrors are at about the 15kg/m^2 mark and decreasing rapidly with mirrors weighing as little as 1kg/m^2 on the horizon.  No doubt the lower quality mirrors required for our purpouses could be built even lighter.  However even at 15kg/m^2 the 700m^2 mirror you claim is necessary would mass about the same as the nuclear reactor, 10MT.  While it would not produce electricity, it would probably be cheaper and certianly less hazerdous.  If we could make our mirrors lighter (which is likely) they would have a clear advantage.  So thermaly mirrors are at least even and probably superior to nuclear power on the moon.

Likewise thermal dynamic systems also look promissing on the moon.  For our application (only in use during the day) advanced systems could possibly reach 40W/kg which is competative with nuclear reactors and superior to the one you specify (30W/kg).       And again are safer and probably cheaper. 

Now, I'm not against nuclear power by any means.  I think a small nuclear reactor powering the needed systems during the long night is probably a necessity.  But for power requirments that aren't necesarily need during the night such as oxygen production solar can be a real competitor on the moon.  If you just look at plane thermal aqusition during the day, they are pretty much unbeatable, some 90W/kg with the heavy 15kg mirrors assumed!  And if the base is located at the poles as some seem to think is likely constant daylight makes it even better.

-- edit --

A good sight about some of this stuff. http://www.belmont.k12.ca.us/ralston/pr … es.html]Is here.

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He who refuses to do arithmetic is doomed to talk nonsense.

GCNRevenger

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Posts: 6,056

Re: A new HLLV essay

Again I state, that one of the big achillies' heels of the solar option is that there will be mass penalties other then the mirrors themselves. You must nessesarrily have some kind of articulated physical support structure to aim the mirrors at the furnace as the sun moves accross the sky. Being that we will be in no position to build scaffholding or electric motors or wiring for a while out of Lunar material, then these structures would have to be imported.

Speaking of which, everybody keeps singing the praises of this mountain that is bathed in sun most of the time. Just one little problem, that the Sun would stay low in the sky, and circle the horizon every month. How do you reflect its sunlight onto a fixed furnace if it percesses 360deg around the sky?

"it would probably be cheaper and certianly less hazerdous"

Not if the furnace was more of an add-on to the reactor. Being that it is a relativly simple thing (basically a kiln with air-tight doors and high-temp gas pump), and it would weigh alot less since it could produce LOX all month, so it would only have to be a fraction as big as the one-week solar/thermal one.

If you use the heat coming off the reactor to provide the majority of the thermal cracking energy, then it is clear that a reactor scales far better thermally then solar scales at all. Look into the old SP-100 project, you would note that the whole reactor would weigh about 5-6MT, with 4MT as a target flight mass. This reactor would have made two megawatts of thermal energy. It also would have had no moving parts at all other then the external controls.

The little JIMO-class reactor uses a much more efficent conversion system and produces the same amount of electricity, but produces 300kWt. The only reason NASA is going this direction I can figure is that this type of reactor with dynamic conversion scales better to MWe applications.

Moral of the story, if you use the thermal energy from a reactor, it scales extremely well since much of the reactor cores' mass isn't the Uranium fuel.

And the safety issue? Why on or above the Earth would a reactor be unsafe? As long as you put it in a crater or build a dirt berm around it, it would be perfectly safe. The link you cite even mentions that Brayton turbines have been simulated to operate for five years solid.

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[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

BWhite

Member

From: Chicago, Illinois

Registered: 2004-06-16

Posts: 2,635

Re: A new HLLV essay

This is really a silly argument.   

David Poston has done some terrific work on small reactors in his spare time! Give him some real money and we could have space-rated power generation reactors within 10 years.

But, if we agree that a lack of reactors are a "show stopper" for exploration then the anti-space folks need only de-fund reactor research to stop us cold. The current VSE does not include funding for these "house" reactors (house = running the habs and smelters and O2 generators rather than for propulsion). It appears MIke Griffin agrees we need house reactors. Let's see what he says about the current lack of funding in this area. 

My main point is that  =IF=  we accept the idea that reactors are essential to space exploration, we set ourselves up for another decade or two of delay when 2018 rolls around. But  =IF= we make plans to go forward whether or not we have reactors (less desirable, but feasible) then I predict reactors will be developed somewhere along the line.

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Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]

GCNRevenger

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Posts: 6,056

Re: A new HLLV essay

Project Prometheus' effort is actually centerd on making portable space power reactors, and last I knew they were still being at least half funded despite the JIMO probe being canceld (one wonders if JIMO was just an excuse for Promethus...).

Depends on what you consider "exploration"

Basically, it is not practical to mount any sortie to the Lunar surface longer then two weeks or so without a nuclear power source except near the Lunar poles. I would argue that solar pannels and mirrors won't produce enough raw energy for a Lunar base either on their own, no matter where the base is located.

It goes without saying that a reactor would be standard equipment for a Mars expedition, given their superior power at that distance from the Sun, lots of useful waste heat, and no power storage concerns.

Can we set foot back on the Moon and explore its surface without reactor? Sure we can. We just can't do anything more then visit.

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[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

BWhite

Member

From: Chicago, Illinois

Registered: 2004-06-16

Posts: 2,635

Re: A new HLLV essay

It goes without saying that a reactor would be standard equipment for a Mars expedition, given their superior power at that distance from the Sun, lots of useful waste heat, and no power storage concerns.

I agree with this entirely. No nukes? No Mars.

If you are right about Luna, I sure hope Griffin gets those small nukes funded. Otherwise, the VSE would be just for show.  ???

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Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]

Austin Stanley

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From: Texarkana, TX

Registered: 2002-03-18

Posts: 519

Website

Re: A new HLLV essay

Again I state, that one of the big achillies' heels of the solar option is that there will be mass penalties other then the mirrors themselves. You must nessesarrily have some kind of articulated physical support structure to aim the mirrors at the furnace as the sun moves accross the sky. Being that we will be in no position to build scaffholding or electric motors or wiring for a while out of Lunar material, then these structures would have to be imported.

I don't think you are properly taking the moons low gravity into account.  Since it's gravity is only .16 G that 10MT mirror would only weigh about 1.6MT on the Moon, so the structure to support could be fairly lightweight.  While it mass remains the same, which is important when you consider rotating moving/rotating it, this movment will occur very slowly, so the necessary motors would not have to be very power/large.  In fact, haveing someone go out every 8 hours or so and manualy adjust the grid might be plausible.  And of course, as the mirror mass decreases so will the mass of the necessary support equipment.  All you are realy looking at is a hinge and a perhaps a small motor anyways, the mirrors are strong enough to support themselves in Earth gravity.

Speaking of which, everybody keeps singing the praises of this mountain that is bathed in sun most of the time. Just one little problem, that the Sun would stay low in the sky, and circle the horizon every month. How do you reflect its sunlight onto a fixed furnace if it percesses 360deg around the sky?

As for the problem of tracking the sun 360* around the sky, this is actualy a fairly simple problem.  If for some reason it's not practical to have the primary track the sun and focus on your furnace (and I don't see why this would have to be the case, the geometry is certianly possible), you would just utilise a secoundary mirror to reflect the concentrated light onto the furnace.  Such an arangment may be used in any case to alow the light to be concentrated more easily.

And the safety issue? Why on or above the Earth would a reactor be unsafe? As long as you put it in a crater or build a dirt berm around it, it would be perfectly safe. The link you cite even mentions that Brayton turbines have been simulated to operate for five years solid.

Now I do not think that nuclear reactors are OVERLY hazerdous, just that they are much more so than a solar dynamic system.  One would not want to approach one of these space reactors to closely or linger nearby for to long as the will likely not have enough shielding.  This creates a delima however as the furnace has to be fairly close for efficent heat transfer AND you are going to want to visit the processor to get your oxygen out of it.  This has made me worry a little bit about Mar ISPP as well.

Not if the furnace was more of an add-on to the reactor. Being that it is a relativly simple thing (basically a kiln with air-tight doors and high-temp gas pump), and it would weigh alot less since it could produce LOX all month, so it would only have to be a fraction as big as the one-week solar/thermal one.

I'm unclear on this argument.  The furnace as you say will be realtivly cheap and simple.  The nuclear reactor however is neither.  It's hard for me to imagine a situation where the reactor would be cheaper per thermal watt than a mirror would be.  While the solar furnace would certianly have to be bigger, it is likely only to be a fraction of the weight of any generation system in anycase.

This brings in another point.  The solar system could be utilised practicly forever with proper maintence.  The nuclear system is going to have a definet shelf life, after which it would be useless.  The system would have to be abandond or disassembled as the old reactor would remain a danger for years to come, with disposal in place being the most practical retirment option.

Moral of the story, if you use the thermal energy from a reactor, it scales extremely well since much of the reactor cores' mass isn't the Uranium fuel.

Not necessarily so.  The SP-100 would get about 400W/kg of thermal energy.  The 1kg/m^2 mirrors would get 1400W/kg of thermal juice, MUCH better.  And as you scale up the amount of thermal (basicly total) energy produced with a nuclear reactor you also scale up the radiation dangers and possible scale back its effective lifetime.

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He who refuses to do arithmetic is doomed to talk nonsense.

BWhite

Member

From: Chicago, Illinois

Registered: 2004-06-16

Posts: 2,635

Re: A new HLLV essay

Without atmosphere and with 1/6 gravity tracking motors to move an inflatable mirror array could be quite tiny, right?

Making electricity from an inexpensive solar furnace seems trickier than heating enclosed boxes with the objective being to extract oxygen.

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Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]

Austin Stanley

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From: Texarkana, TX

Registered: 2002-03-18

Posts: 519

Website

Re: A new HLLV essay

Without atmosphere and with 1/6 gravity tracking motors to move an inflatable mirror array could be quite tiny, right?

Exactly.  In fact they may not be necessary at all, the rate of motion for the mirrors is quite small, somebody could probably just go out there and turn them manualy, perhaps with a big lever if the array was still to heavy.

Making electricity from an inexpensive solar furnace seems trickier than heating enclosed boxes with the objective being to extract oxygen.

Somewhat.  It realy isn't that diffrent from most nuclear power plants in principle.  Focused light it used as a heat source instead of uranium but otherwise the two are identical.  Any of the power generating mechanisims used by a nuclear reactor could be used by a solar dynamic system.  The big diffrence of course is that you can't use a solar dynamic system at night.  But in locations with continual sunlight on the moon, solar dynamic systems meet and possible even beat nuclear power in w/kg and definetly in w/$$.  Mirrors can be lighter than uranium and it's necessary containment and radiation protection and defiently are cheaper.

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He who refuses to do arithmetic is doomed to talk nonsense.

SpaceNut

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From: New Hampshire

Registered: 2004-07-22

Posts: 29,433

Re: A new HLLV essay

I envision the mirrors being move by something simular to what moves the large radio telescope dishes here on Earth. Also the array of mirrors does not need to be one large or a few fairly large ones. They could be a group of mediums sized mirrors on a common frame all able to track and to redirect the light to the furnace individually.

Also here is a solution to the night time use of solar energy.
creat a system of conductors that circum around the moon as a power grid tapping point. The grid then has multiple beam down light capturing furnace power plants along it. With multiple mirrors reflecting light to each and only those on the dark side not active we could assume full power is then those station getting light to which are on the grid at one time.

dicktice

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From: Nova Scotia, Canada

Registered: 2002-11-01

Posts: 1,764

Re: A new HLLV essay

The circumlunar power grid, fed by solar mirror power stations situated at intervals along the way, is brilliant. Breakage would be catastrophic unless redundancy were added and/or burying the insulated cable(s) in the regolith. Along with autonomously self-steered Sun-seeking mirrors, and high-voltage three-phase ac electricity, it  should work a treat!

BWhite

Member

From: Chicago, Illinois

Registered: 2004-06-16

Posts: 2,635

Re: A new HLLV essay

Without atmosphere and with 1/6 gravity tracking motors to move an inflatable mirror array could be quite tiny, right?

Exactly.  In fact they may not be necessary at all, the rate of motion for the mirrors is quite small, somebody could probably just go out there and turn them manualy, perhaps with a big lever if the array was still to heavy.

For humanity's very first lunar LOX pyrolysis unit, laboratory efficiency would seem irrelevant. Inflate some parabolic mylar balloons, point them at a box filled with regolith (filled with a rudimentary Bobcat)

Sit back and let the thing bake off O2.

Suppose "efficiency" were 50% of a fancy robotic system. Instead of building the fancy systemn spend a few milllion on mylar balloons and the lift needed for another 100 or 200 pounds of mass and build TWO solar furnaces.

Waay cheaper than the fancy system.

If the objective is LOX for ISPP (bring your methane like Zubirn says) make LOX in the sunshine and fly away in the dark. Load up the system as night approaches and "hop" to the sunlight.

= = =

Pump the O2 out of your passive box, compress and store the LOX tanks in the shade. If in 100% shade, wiht the tank pre-chilled before it is left, how long would a tank of LOX survive without boil off?

Make 125% (for example) of what the tanks will hold, deploy the tanks in 100% shade (no sunlight at all, even reflected) chill the tanks with surplus LOX then fill.

How long would the LOX tank remain usefully filled?

Edited By BWhite on 1110986308

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Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]

publiusr

Banned

From: Alabama

Registered: 2005-02-24

Posts: 682

Re: A new HLLV essay

http://www.britishtitanium.co.uk
Nice site. (down now) Nice SDV pic. That at least saves you 12 RS-68s on 4-5 Delta IVs.

Those are your real costs.

With Five SDVs (which will not bankrupt NASA any more than shuttle--and will cost less without the orbiter) you have 500 tons in orbit for the same number of hydrogen engines.

An added market for HLLV
There's an article on potential space based weapons online at the IEEE website:

http://www.spectrum.ieee.org/WEBONLY/pu … 5star.html

http://www.aps.org/public_affairs/popa/ … /nmd03.cfm

Another reference is the RAND book, Space Weapons, Earth Wars, at:

http://www.rand.org/publications/MR/MR1 … MR/MR1209/

http://www.missilethreat.com/]http://ww … hreat.com/
http://www.highfrontier.org]http://www.highfrontier.org

New Polyus pics.

http://fpmail.friends-partners.org/pipe … ...56.html

http://www.spaceislandgroup.com]http://www.spaceislandgroup.com

On Solids...

We are going to have to make do with solids--like it or not. Chances are, the CEV--if used for exploration, could get away with a Delta IV med or Atlas Med--but will probably need solids.

If anything, the fact that the SRBs kept going after the Challenger accident (a bad seal can doom any rocket) impresses me all the more. They have been fixed, and have heavy steel construction. The smaller solids actually scare me more. Let one turn loose, and it's headed right toward the capsule. ISS could force the CEV to turn into a pig for servicing--provided it gets to ISS at all:

Which CEV?
http://www.thespacereview.com/article/3 … icle/322/1

With the abundant lift capacity of HLLV, the CEV design can be about as big as you like--no problem.

Not having SDV is what will bankrupt NASA.

As I see it, we stand to lose Shuttle architecture, the CEV will be a pig--(from a future DNC administration that abandons the Bush vision in favor of a LEO-only "Earth First" stance--and we will be stuck with capsules in LEo and be worse off than we are now. I see a big NASA hit if the DNC takes over.

Call it Hand-waving if you will--but I am of the opinion that it is now--or never--before we get into another stupid war.

Austin Stanley

Member

From: Texarkana, TX

Registered: 2002-03-18

Posts: 519

Website

Re: A new HLLV essay

Ronald Regan is dead, why oh WHY can't SDI rest with him?  It's bad enough that George Bush went ahead with the ABM defense system which, despite being in theory "operational", failed another test recently.  The last thing we need is the pentagon wasting more of our money on more brain dead space based weapon systems.

The cold war is over, it is highly unlikely that the US will ever face a serious threat from ICBM attacks again.  And even if we did, the threat of MAD kept us safe during the greatest period of this threat, and will do so in the future.  And on top of this I have little confidence that such a system will actualy work if called upon in the future.  Certianly the tests performed so far do not bode well for it.

---

He who refuses to do arithmetic is doomed to talk nonsense.

publiusr

Banned

From: Alabama

Registered: 2005-02-24

Posts: 682

Re: A new HLLV essay

Even so--chew upon this.

If missile defense money goes into useless ground-based silos that Republicans dig and Dems bury over with Caterpillers--it helps us not a jot. If the money for SDI goes to an HLLV--then if a Dem gets in office--we still have a good booster out of the deal--instead of moth-balled silos that help space-exploration and solar powersat construction not at all.

In this sense ONCE HLLV IS UNDER CONTRACT, it becomes politician-proof. It keeps the shuttle jobs in place, and institutional inertia keeps it flying as it has kept the shuttle. The only diff' is that the SDV puts up 100 tons of cargo--not a puny 20 ton load with a big orbiter people are after with a hatchet.

Both Dems and Reps should support this--in that--if a Dem gets in office--it won't be as if that HLLV money has been wasted, because it--unlike JSF and other SDI tech--has a use beyond the military. Space Based Solar Power sats are best built with HLLVs.

My goal is to ramp up throw-weight to get us out of this
THALL SHALT NOT LAUNCH OVER 20 TONS TO LEO mindset the bean counters have locked us into.

SDV is only the beginning. I will not rest until SDV HLLVs are the smallest boosters we have, with that crutch of a Delta II banned and Sea Dragon flying with 550 tons to LEO. Only then will space open up to commerce--in bulk--not in Rutan's useless toys.

My mantra is that we all should be in the one true Church of the Heavy Lift.

Thy five segment solids comfort me--and the EELV heretics shall be put to the sword  :angry: