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#151 2005-07-03 03:09:10

Rxke
Member
From: Belgium
Registered: 2003-11-03
Posts: 3,658

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0]Man, this feels weird, enthousiastically agreeing with GCNRevenger on all point, for once!
tongue  :;):

Seriously: Thiokol's big glossy makes for interesting reading.
One reason to believe their safety-claims is that exactly because of the breaches occuring in the past, they did a LOT of work to prevent stuff like that happening again. This is a quite mature piece of hardware.[/color:post_uid0]


ExoMars' launcher's 2nd stage is probably en route to Mars. Unsterilised... yikes

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#152 2005-07-03 06:05:56

jabe
Member
From: toronto Canada
Registered: 2003-10-02
Posts: 24

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0]I'm curious on how bumpy a ride "The stick" will be.  Be interesting how this will play out in the political arena[/color:post_uid0]

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#153 2005-07-03 08:17:41

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0]Now, this is not to say that I have [i:post_uid0]abandoned[/i:post_uid0] the EELV option, I think it is possible to build an upgraded "Atlas-V Mark-II" that could probobly lift just as much payload and be aproximatly as safe, or in a pinch take the Delta-IV HLV and add crossfeed fuel lines (for partial engine-out capability)... but I think that these options are probobly going to be harder to meet man-rated levels of safety and reliability versus The Stick

If Bush lets Griffin twist in the wind and Congress [i:post_uid0][u:post_uid0]orders[/u:post_uid0][/i:post_uid0] him to maintain the status quo, or just decides to because he is a weak Shuttle-hugger in disguise (no cutting ISS science, forbid drawing down Shuttle Army for SDV, continue Hubble maintenance without funding, etc) then I maintain that the Shuttle-derived route isn't an option... and something more drastic would have to be done to save NASA from a slow death in LEO (turn KSC into a museum for starters).

EELV has more then enough performance to execute the cargo carrying role for a Lunar program, and with the lower cost of operations (automation, economies of scale) the cost per-kilo of payload will probobly be about the same as SDV-HLLV (if it performs on-cost). That said though, the maximum payload will be about half the size, and it really won't be very useful for a Mars program. Modifying EELV cores and making big clusters of them to reach HLLV performance really isn't very practical, and developing a brand new clean-sheet HLLV would definatly delay mid/long term VSE plans.[/color:post_uid0]


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

The glass is at 50% of capacity

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#154 2005-07-03 22:58:18

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,898
Website

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0]GCNRevenger, who are you anyway? This obsession with killing everything that doesn't fit [i:post_uid0]your[/i:post_uid0] agenda sounds like a certain person you like to criticize. Reality is there is science to be done on ISS, and the longer we delay before starting the more it will cost. Testing/demonstrating long duration life support is an obvious start, but that's engineering, there are science issues. Remember I said there are scientists with Ph.D. and research labs working for universities who do bed rest and centrifuge experiments to attempt to extrapolate zero-G effects on the human body and remediation. The best place to do that is on a space station, not playing with toys on the ground. Apollo was in the 1960s, Skylab was launched May 14, 1973. We're well past playing with toys; it's time to get serious. As for Hubble, the James Webb Space Telescope isn't schedule for launch until August, 2011; we need Hubble so astronomers can do their work. NASA is about a lot more than manned missions. Critics of manned space exploration view robotic exploration as "real" science, and humans as just boys playing with toys. We know that's not true, in fact real geological and astrobiology research on Mars requires qualified field scientists on the ground studying rock strata. The only way we know to build an interferometry telescope to image planets around other stars is on the Moon; that requires a human construction crew. But calling for slashing science to fund your pet project does not gain credibility.

Let me give you another perspective. The Canadian Space Agency has focused almost exclusively on practical matters because so many taxpayers don't want to see anything else. That means Canada has an advanced SAR satellite (RADARSAT-1) to image arctic ice and relay that to ships at sea within an hour of the observation. This permits icebreakers to navigate through thin ice and avoid hitting land. RADARSAT-2 is being built now. CloudSat will study clouds to improve weather forecasts. SCISAT measures chemistry in the upper atmosphere at various altitudes to determine exactly how CFCs affect the ozone layer. The OSIRIS instrument on the Swedish satellite Odin measures aerosols and nitrogen dioxide to study ozone depletion. This may appear redundant, but Canada had an ozone hole over Montreal for a few weeks that caused dangerous levels of UV. Hyperspectral remote sensing provides "timely and accurate information on poisonous blue-green algae blooms, on contamination by industrial effluents and on the damage and extent of areas affected by mine tailings … there are many others in forestry, agriculture, fisheries, mineral exploration, environmental change, and more." The MOPITT instrument on NASA's Terra satellite measures carbon monoxide in the troposphere. The WINDII instrument aboard the American UARS satellite measures wind in the upper atmosphere. The Ultraviolet Imager on Sweden's Viking satellite measures aurora to study magnetic storms. Quebec Hydro was hit with a magnetic storm a few years ago that blew out the entire provincial power grid; don't want that to happen again. Notice everything has a practical purpose. This is where a large chunk of CSA funds go. The CSA president's attempt to convince Parliament to increase their budget for Mars exploration has failed, their budget remains the same every year.

NASA now has a mandate to conduct manned exploration of space, but science will have to be part of NASA's budget. The NASA administrator has to manage all of NASA, not just the Exploration Systems Mission Directorate.[/color:post_uid0]

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#155 2005-07-04 00:56:43

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0][i:post_uid0]"Reality is there is science to be done on ISS"[/i:post_uid0]

Sure there is. Just nothing worth the [i:post_uid0][b:post_uid0][u:post_uid0]tens of BILLIONS of dollars[/u:post_uid0][/b:post_uid0][/i:post_uid0] that it will cost to construct and operate for the next ten years. [i:post_uid0]Nothing[/i:post_uid0]. The science ISS can do is [u:post_uid0]insanely[/u:post_uid0], absolutely [i:post_uid0]mind-boggling-ly[/i:post_uid0], even farsically overpriced. There just isn't anything worth doing up there for that kind of money.

You want to see if astronauts survive for six months in zero gravity on the way to Mars? You want to test out the life support and other critical systems? Listen to [b:post_uid0]THIS[/b:post_uid0] Robert: for the same price as pulling the plug on ISS early (say, 2012 rather then 2017, saving $2.5Bn/year aprox) adds up to $12.5 [i:post_uid0]billion dollars[/i:post_uid0]... Which is probobly most of the money you need to build a DRM-III HAB prototype, which you would then put on Magnum into LEO, and have a CEV crew dock with it for six months. So you get to test the [i:post_uid0]whole ship[/i:post_uid0] in its actual assembled form, in the comfort and safety of Earth orbit... And if prototype LSS systems are too buggy? Power systems too gremlin filled? Since you won't be carrying a lander, there is plenty of room for backup open-loop LSS supplies and spare solar pannels. Using the ISS as a testing ground for Mars crews and hardware is unjustifiable versus simply building the HAB and testing it in LEO.

Or for the Moon? $12.5Bn would probobly buy you a nice big LOX factory and pay a good chunk to improve Boeing's (or others) lander into a reuseable LEO-to-Luna and back cargo tug system, so that CEV crews or payloads would only need to bring a modest supply of Hydrogen to orbit. That way, you could be sending up payloads for a fraction of the price of having to lug all that fuel from Earth, which is kinda great for setting up a Lunar industrial "beach head" that doesn't require $500M of rockets to get there, and which payloads don't cost much more to get to Luna then to LEO. A nice entry-level place for a AltSpace payload market, or crew ferries (if the Reality Fairy visits T/Space maybe) since they don't need TLI/TEI stages or landers anymore. Lunar tourist trips?

But I really mentioned the "no cutting ISS science = bad" thing in reference to M. Griffin's statement to Congress, which I will paraphrase to basically: "if its a choice between seeing how bacteria grow in space versus NASA not having a future beyond the status quo, then screw the bugs!"

[i:post_uid0]"...we need Hubble so astronomers can do their work."[/i:post_uid0]

[b:post_uid0]NO,[/b:post_uid0] no we don't... [i:post_uid0]the astronomers will live[/i:post_uid0] without Hubble! There is nothing special or unique about THEIR science (beyond PR value of pretty pictures) that exempts them from objective cost/bennefit allocation of [i:post_uid0]very limited[/i:post_uid0] funds. A delay of a few years until the next big thing is not worth the [i:post_uid0]VERY[/i:post_uid0] bad proposition of trying to fix Hubble.

[i:post_uid0]"but science will have to be part of NASA's budget"[/i:post_uid0]

Yes it will be, but now rather then being NASA's [i:post_uid0]primary[/i:post_uid0] stated goal, it is now only an equal goal to exploration. That science should not be special or exempt from cost/bennefit analysis anymore.

Edit, futher thoughts...: [i:post_uid0]"We're well past playing with toys; it's time to get serious"[/i:post_uid0]

Oh, then you mean you want to get rid of the ISS too?

Now don't go accusing me of being anti-science... actually, what is being anti-science is to make it exempt from cost/bennefit analysis. Scientific projects, particularly of the billion dollar or more kind, must justifiable on Earth and so it should be with space science. Throwing piles of that nasty green paper at ISS experiments or other bad investments (Hubble) that really don't have much payoff is what NASA has been wanting to do since the 1970's in one incarnation or another, and this has to be stopped.

PS: Hmmm... I wonder... with the TEI stage fully fueled, could CEV make it to GEO and deorbit from there? That would be a trick that Shuttle could never do, make emergency trips to satelites.[/color:post_uid0]


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

The glass is at 50% of capacity

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#156 2005-07-04 12:14:19

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,898
Website

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0]

[i:post_uid0]"We're well past playing with toys; it's time to get serious"[/i:post_uid0]

Oh, then you mean you want to get rid of the ISS too?[/quote:post_uid0]
No, I mean it's time to stop playing with toys on the ground in a university lab. It's time that zero-G studies are done in zero-G. Yes, the ISS has cost too much money but I want it completed quickly rather than throwing it away.

Since we won't agree on this point, let me change the subject. I did some calculations of a lunar vehicle. Remember I said the vehicle can be reusable. You do have a point that the lunar vehicle should have an abort mode in case aerocapture has a problem. Instead of an Apollo LM with ascent module and descent module, design it with a capsule and service module. The capsule would be designed like the descent module of Soyuz, while the service module would look very much like the descent stage of the Apollo LM. For those who like to tout of American stuff, the Apollo D-2 proposal from General Electric was very similar to Soyuz. The current Northrop Grumman proposal for CEV is also very similar. The partnership between Northrop Grumman and Boeing states the Northrop Grumman CEV would be used for LEO operation such as a space taxi to ISS, but the Boeing design that looks like an Apollo capsule would be used for the Moon. That already means two separate vehicles: one for LEO and another for a lunar mission. I would suggest taking the descent module from Northrop Grumman's CEV and using it for a lunar transit vehicle. Give it just enough life support for Earth atmospheric entry and landing, put mission life support in the service module. Design it as a single stage vehicle that can land on the Moon and return to Earth, and as I said use Nextel 440 fabric as a heat shield to aerocapture into Earth orbit. Fuel the LTV with LOX and liquid methane. If you store those propellants for return to Earth, then you can use the same propellant for manoeuvring thrusters. That provides higher Isp than MMH/N2O4. However, my calculations show far too much propellant is required for transit from LEO to the lunar surface for the entire spacecraft to be a single reusable stage. Instead use an expendable TLI stage. Boeing wants to use a Delta IV upper stage for TLI, but their plan requires 2 for a lunar orbit mission, several for lunar landing. The vehicle I'm describing could be injected into trans-lunar trajectory using a single Delta 4-2 stage. That's the upper stage of Delta IV Medium, which can be lifted by a single Delta IV Heavy. For the second and subsequent missions, LOX/LCH4 fuel for the LTV as well as food and supplies can be delivered by a single cargo vehicle lifted by Delta IV Heavy. That means 2 launches of Delta IV Heavy plus a crew taxi for astronauts. The cargo version of "The Stick" could be used instead of Delta IV Heavy.[/color:post_uid0]

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#157 2005-07-04 14:55:15

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0][i:post_uid0]"but I want it completed quickly rather than throwing it away"[/i:post_uid0]

You can't complete it quickly, there is no possible way of signifigantly accelerating construction for any practical sum. And even if it is finished, it will cost billions of dollars every year to operate... money that COULD have been going to build the prototype DRM HAB and fulfill the same function, except it would do it better and not go to waste like the dang ISS. The ISS is [i:post_uid0]already[/i:post_uid0] a dismal failure, nothing will substansively change that, its time to cut our losses and pull the plug.

[i:post_uid0]"Design it as a single stage vehicle that can land on the Moon and return to Earth"[/i:post_uid0]

[i:post_uid0]"The vehicle I'm describing could be injected into trans-lunar trajectory using a single Delta 4-2 stage"[/i:post_uid0]

No no, direct return is much too inefficent for early missions. We must absolutely have maximum payload [i:post_uid0]with the crew[/i:post_uid0] for exploration. Dinky kilogram-scale capacities like the Apollo landings aren't good enough, and too much fuel would be needed for hauling the TEI fuel back to Lunar orbit. I also think that you are [u:post_uid0]very[/u:post_uid0] likly underestimating how much the whole vehicle weighs, I find it a little hard to believe that you have somehow managed to cut the entire 4-6 seat system mass aproximatly [b:post_uid0]in half[/b:post_uid0] versus other plans even after sacrificing the non-crew payload, particularly with the added aerobrake shield mass.

The Boeing plan wisely avoids direct return, and the Lunar lander doubles as the "mission module," which frees up enough mass from the CEV so that it can be built with large margins while still bringing every last drop of TEI/abort fuel (modified RL-10 burning LOX/Methane) with it in a single launch. The big ~120MT SDV would then launch the Lunar lander and TLI stage in a single shot, mate in LEO, and off to the Moon. The lander could be powerd by Hydrogen, which being one of the bigger Delta-V expenses, increases payload signifigantly.

Later on, in the future when we are established and LOX is plentiful on the Moon, then the Hydrogen powerd lander could serve as both a LEO-L1 and L1-Luna vehicle, with each CEV only bringing a Hydrogen tank behind it to supply the fuel. Oh and the LEO-L1 tug would not have to carry Luna landing propellant, which should help keep the TLI/TEI budget down. Extra Hydrogen could be provided to make up any differences from a variety of sources (direct HLLV occasionally, Solar/Electric tug w/ condenser, AltSpace launch systems, perhaps Lunar "snow" mining).

[i:post_uid0]"That already means two separate vehicles"[/i:post_uid0]

Nonsense, I doubt that will happen... Griffin will put his foot down and demand only one vehicle or the other, I have faith in him for that. I imagine they are just having their bases coverd, so if NASA wants Soyuz or Apollo style capsules, then the Northrop/Boeing cooperative will at least have the appearence of having either option closer at hand.[/color:post_uid0]


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

The glass is at 50% of capacity

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#158 2005-07-04 17:02:49

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,898
Website

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0]Oh, the tired old dogma of throwing away multimillion dollar spacecraft with every mission. Lift mass isn't the only concern, do you know what the cost of a Soyuz launch vehicle is vs the Soyuz spacecraft? Last we discussed this they were about equal. I can't give you American numbers right now since America only flies the Shuttle. Do you really think an American CEV will cost less than Soyuz? It would be better to use a reusable mini-HL-20 space taxi to get up to LEO, then a reusable lunar vehicle to get to the Moon. Since the spacecraft is as expensive as a whole launch vehicle, how much do you think it would cost per mission for Delta 4-2 stage as an expendable TLI stage? How much for a LOX/LCH4 tank with manoeuvring thrusters to rendezvous with the LTV? Keep the expensive manned spacecraft.

Here's another perspective. You want to use Magnum to go to the Moon. That involves 2 SRBs, at least 3 SSMEs, and a modified ET. A pair of cargo Sticks would each have one SRB and one SSME, and a smaller tank for the upper stage. The mini-HL-20 would expend an ET but everything else is recovered. The absolute maximum launch cost is the same, possibly less for the reusable system, but the spacecraft is entirely reused so there is no spacecraft cost for the second and subsequent flights. That cuts mission cost for the second flight in half.

You're ignoring my plan to use Shuttle-C/Orbiter combination flights to complete ISS construction. It would work.

L1 is an unstable point; it's not like L4 or L5. Anything at L1 falls away from it as soon as it drifts just the tiniest bit from absolute centre. At L4 or L5 gravity would pull a drifting space station back.

As for a mission module: remember separation of cargo from crew? That applies to the Moon as well. Send a one-way cargo lander that doesn't return and doesn't have all the human safety gear. Send the Mars surface habitat on an unmanned cargo lander; this will be the lunar base. Prove Mars hardware on the Moon. Following the Mars Direct architecture, the LTV serves as the ERV and the one-way surface hab is sent with very minimal modification. The Moon has micrometeoroids and more radiation so the envelope must be sturdier.[/color:post_uid0]

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#159 2005-07-04 18:53:25

dicktice
Member
From: Nova Scotia, Canada
Registered: 2002-11-01
Posts: 1,764

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0]The last two posts are very thought provoking, and just to blunt the hardware rants a bit--since you both are "going to the Moon first, and not to Mars, how including where on the Moon: one of the poles, the back side, or...?  I really go for the idea of landing Mars-intended hardware on the Moon, first, by the way.[/color:post_uid0]

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#160 2005-07-04 23:01:58

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0]Blah blah, "dogma" indeed... and how much extra is that super Lunar tug, the one thats reliable enough for multiple flights going to cost to develop? One billion? Two billion? Three?

A Lunar lander is not that big or complex a piece of machinery, using about $10-15M worth of engines, another few million for the avionics... A one-use lander won't be all that expensive. Neither will an expendable TLI stage as you point out. And a service module won't be that bad if its just solar pannels, LSS tankage, and thrusters (the capsule having a too-cold equilibrium temp like Apollo), probobly ten or twenty million worth of parts. Oh, and we [b:post_uid0]DO[/b:post_uid0] get the capsule back, you know... This nonsense about LEO taxi is not going to happen, so I don't see the point of discussing it any further.

If we're "saving" up to $100M of rocket hardware with each shot sounds nice, but if we're launching one or two expeditions per year, then you have to wait 5-10 years to save a single penny with your reuseable scheme. And the whole dry mass, ullage, and unit cost of that Methane tug goes completly to waste. Say, that Methane tug with refueling hardware isn't a whole lot less complex then the CEV service module (thrusters, avionics, fuel cells, docking guidence, fuel transfer gear...) but you aren't going to reuse it.

So you save the lander and the service module, at the expense of a Methane tug, higher development costs, and much lower surface payloads. Doesn't sound like much of a deal to me for a half-crippled spaceship. Now what were you saying about throwing things away?

[i:post_uid0]"...remember separation of cargo from crew? That applies to the Moon as well. Send a one-way cargo lander that doesn't return and doesn't have all the human safety gear."[/i:post_uid0]

And I think that there is some kind of disconnect here about exactly what we will be doing on the Moon, and what payload configuration we need... Each flight will most likly be prospecting, hardware testing, and base/scope/comm tower site work. These things take time, no one-day Apollo flights here, and so the most efficent thing to do is make it big enough to hold four men for two weeks or so. This is going to be pretty big, particularly without zero-G, and not any of this dinky Soyuz orbital module sized stuff!

Now, for prospecting you will need a little gear, preferably a pretty big drill, a Lunar rover or two, and siesmometers for explosive subsurface mapping, etc... Under ten tonnes, but more then Apollo LM could carry. Same with testing out a Lunar LOX pilot plant or Snow extractor. Setting up telescopes? A nice RTG-powerd 1-2m scope' shouldn't weigh but 5-10MT. Or perhaps a communications relay antenna set. Or a new bulldozer for a base. Or a nice roomy TransHAB module to put in the hole it makes...

...Anyway, the point is, that early expeditions probobly won't be to the same site, and that the payload they need to do worthwhile things is not heavy enough to justify a whole seperate cargo flight, which will itself cause severe duplicity of hardware. This is why seperating crew from [i:post_uid0]LIGHT[/i:post_uid0] cargo for Lunar landers is infact a [b:post_uid0]BAD[/b:post_uid0] thing, and is why the ultralight crew taxi is out of the question.

The plan is pretty simple... the big 120MT class SDV launches both the Lunar lander and TLI stage in one go into LEO, and The Stick launches the capsule CEV with its TEI/service module, mate together, and its off to the Moon... [b:post_uid0]with up to 150MT of ship[/b:post_uid0]. None of that "two Delta-IV HLV!" 75MT nonsense.

[i:post_uid0]"You're ignoring my plan to use Shuttle-C/Orbiter combination flights to complete ISS construction. It would work."[/i:post_uid0]

Thats because you plan is so idealistic and unrealistic in its scheduling as to be completly naieve, so of course I don't take it seriously. Probobly just about as bad as the mass of your Lunar taxi.

L1 isn't entirely stable, but if you can park a ship there for a few months with minimal automated stationkeeping, that shouldn't be too bad, and it has advantages over lower Lunar orbits for anywhere-access to the surface... perhaps some advantages for cargo coming in from Earth via low-energy trajectories.[/color:post_uid0]


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

The glass is at 50% of capacity

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#161 2005-07-04 23:08:41

Michael Bloxham
Member
From: Auckland, New Zealand
Registered: 2002-03-31
Posts: 426

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0]

The last two posts are very thought provoking, and just to blunt the hardware rants a bit--since you both are "going to the Moon first, and not to Mars, how including where on the Moon: one of the poles, the back side, or...?  I really go for the idea of landing Mars-intended hardware on the Moon, first, by the way. [/quote:post_uid0]
Atleast with heavy lift we will have that choice. If we really screw up the apollo redux, we can re-focus on Mars efforts without too much extra fuss. But the real question is, what else can we do with a 120MT+ to LEO launch stack when its not required for lunar missions? I mean, the promise about the 40 per year launch rate never held up for the Shuttle, but a cargo-only SDV is a different story altogether. Thats potentially 4800+ tonnes per year! I reckon Griffins got the right idea, making the shuttle system more efficient, not scrapping it altogether.[/color:post_uid0]


- Mike,  Member of the Clean Slate Society

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#162 2005-07-05 02:55:40

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,898
Website

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0]Actually the TLI stage still costs millions of dollars so it isn't cheap, but it's not nearly as expensive as the spacecraft. As for "not that expensive", realize NASA has a lot of space centers to run. It has a $16.3-16.5 billion budget (what did the politicians decide?) but roughly $4.5 billion of that goes to the Shuttle. I don't know off-hand how much goes to ISS and I'm too tired right now to look it up, but there are a lot of things that have to be funded. Don't through around money like you have the entire NASA budget at your disposal. And don't forget that Nixon slashed the NASA budget for political reasons. John Kerry almost got in at the last election and he doesn't care about space either. Eventually America will get a president who doesn't have an interest in space and doesn't have political capital tied to it; then NASA's budget will be slashed again. If you require expensive throw-away vehicles for every mission then those vehicles will be cancelled as thoroughly as Apollo was in 1972. Keep cost down or we won't make it to Mars.

I'm sure many people in the Mars Society would like to go directly to Mars and skip the Moon, actually I would as well, but the current president said "Moon and eventually Mars". Ok, we go to the Moon and use it as a stepping stone to Mars. Let's get it done and ensure lunar hardware prepares us for Mars and builds infrastructure for Mars. That means sending a surface habitat for Mars to the Moon. Whether you want to use the Mars Direct mission architecture or NASA Design Reference Mission 3, that includes a large surface habitat that doesn't come back. The ideal for a Moon mission is to send a Mars habitat. Once it's there you don't need to send another habitat. After all, if the point is to test a habitat on the Moon then you want to examine that habitat to see how it holds up. The first manned mission to the Moon won't include a 14 month surface stay. Mars Direct does and NASA DRM3 includes a 600 day surface stay. That means going back to the same lunar habitat to see how it holds up. That's why I talk about a little Lunar Transit Vehicle with as much interior space as a Soyuz descent module. Once on the Moon astronauts will get into the full-size habitat. This habitat will form a small simple lunar base.

Oh let me guess, instead of a full-size Mars Direct habitat that stays permanently on the Moon with a lunar taxi, you want to send a full double-story 8-metre diameter surface habitat and a separate Earth return vehicle with every mission. Well I have news for you, not going to happen. Do you want to send a separate rover with every mission as well? No, we really need a big base with lots of equipment and, yes, a dinky lunar taxi to deliver crew to/from the Moon. The habitat will take one of those big in-line SDV launch vehicles. Did you know that Caterpillar got a contract from NASA to develop a lunar vehicle to scoop regolith to feed an oxygen generation system? I would like to see that lunar Cat on the Moon as well as a lunar rover, and oxygen generation, and a full-size science lab. Need a pretty big drill for your prospecting? Ok. All that stuff will take a second launch of the big SDV, separate from the habitat. That costs money, so all that stuff must be used for more than one mission. The dinky lunar taxi will carry crew to/from this lunar base.

By the way, the LTV full of fuel and with its TLI stage will fit on a single Shuttle-C. You don't need to send the CEV separately. That's why I said a mini-HL-20 crew taxi that's left parked at ISS until they come back. Two launches of Delta IV Heavy or The Stick are for subsequent missions. Another thing, Delta IV Heavy can lift 25.8 tonnes to 185 km orbit, not 75MT to ISS.

One last thing: how long do you think it'll take to do all this stuff? President George W. Bush is in his second term, he isn't allowed to run for re-election again. That means there will be a new president elected in November 2008. What's to keep him from canceling VSE in January 2009, the way Nixon cancelled Apollo? If you want manned space exploration to proceed there will have to be a lot of momentum by November 2008. If NASA doesn't have the ISS completed and a working crew vehicle by then, you seriously risk the next president canceling VSE just as Bush cancelled VentureStar. Do I have to remind you that the US has commitments with its partners so it can't abandon ISS?[/color:post_uid0]

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#163 2005-07-05 07:03:15

BWhite
Member
From: Chicago, Illinois
Registered: 2004-06-16
Posts: 2,635

Re: Shuttle derived revival - Space.com

[color=#000000:post_uid0]Locked, continue on at Shuttle Derived II[/color:post_uid0]


Give someone a sufficient why and they can endure just about any how

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