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JimM

Member

From: England

Registered: 2004-04-11

Posts: 247

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

IMHO this is not an good idea. Laser induced fusion is still too far away to be useful.
Use the MiniMag Orion instead.

Thanks for pointing me at this.

The information is interesting and very useful. However, I'm not sure Mini MagOrion is likely to be a fully functional system ready for use on the scale required here any sooner than laser induced fusion, and fusion has a number of attractions, everything else being equal. For one thing it's characteristic Isp should be higher, and for another the exhaust should be a lot cleaner-- and easier to defocus, helping keep the treehuggers (relatively) quiet.

But these are relaively minor points. One way or the other, this is the way to colonise the Solar System, I'm sure. But you'll never do it with DH-1, delivering its baby-sized helpings to LEO.

To make the atomic spaceship a reality, you don't need a toy, you need the big dumb booster!

ANTIcarrot.

Member

From: Herts, UK

Registered: 2004-04-27

Posts: 170

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

Ugh. And they say a week is a long time in politics. Is here too apparently. And NB:IF YOU CAN DISABLE SCANDISK RUNNING AT STARTUP DO SO NOW!

I still have faith in the DH-1, mostly because I've read the book, done the math, and agree with some of the design philosophy. The stickler would be the heat-shield design, which I have no way to varify.

Though I agree that some applications do seem somewhat unjustifiably optimistic.

ANTIcarrot.

RobS

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From: South Bend, IN

Registered: 2002-01-15

Posts: 1,701

Website

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

I'm with you, Anticarrot. The heat shield design is pretty funky, but the math otherwise seems pretty good. I'd much prefer as larger vehicle; at last 8 tonnes to LEO, preferably 10.

              -- RobS

JimM

Member

From: England

Registered: 2004-04-11

Posts: 247

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

I still have faith in the DH-1 ... The stickler would be the heat-shield design...

Don't forget the other stickers:the microscopic and hence fundamentally useless payload; the pointless pilot in, and the extravagant and wasteless vertical flightpath of, Stage I; the superoptimistic cost and schedule estimates for development; the hopelessly naive sales forecasts... I could go on.

I'd much prefer as larger vehicle; at last 8 tonnes to LEO, preferably 10.

You'd need about 20 tons to be taken seriously, which is about 8 times what DH-1 can manage.

The best that DH-1 could hope for is to be is a proof-of-concept project. If it works, go back and build the serious one.

ANTIcarrot.

Member

From: Herts, UK

Registered: 2004-04-27

Posts: 170

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

For a significant part of the twentieth centuary 90% of the US Army was designed to be carried around on 2.5 ton trucks. Even today similar vehicles form the logistical backbone of many armys and similar organisations. Would you have us believe JimM that US army equipment that can be carried on 2.5ton trucks should not be taken seriously?

And you can't gind behind the "We don't do it that way so it can't be done" arguement like GCNR does. If you do you turn yourself into the elderly but respected scientist who says that a new idea is impossible, and who is often later shown to be very actually wrong.

And the DH-1 does not only deliver 2.2 tons to orbit, it delivers 2.2 tons AND ITSELF. And that can count as payload, since unlike the shuttle the DH-1 upperstage can be refueled and sent on to other locations. It's essentially a CEV with a deltaV of 8kmps with a standard load. A second DH-1 to act as booster can substantially increase that.

As for the pilot... There's an arguement that putting people in space is patently pointless. The counter-arguement to that is piloted vehicles are still very unreliable - which is one of the more important reasons freight 747-400s still have people onboard.

Vertical flight = ease of use. It's an option that's strongly recomended as a way or lowering operating costs, but it's stated nowhewre that it is essential to the DH-1. In fact the author points out a purely ballistic flight could considerably increase payload.

The sales forecasts are based on the DH-1 operating as it does in the book. If that happened then organisations would want to buy it. Given the eagerness with which american companies sell fighters and passenger planes, and the willingness of other nations to buy them...

ANTIcarrot.

Euler

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From: Corvallis, OR

Registered: 2003-02-06

Posts: 922

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

For a significant part of the twentieth centuary 90% of the US Army was designed to be carried around on 2.5 ton trucks. Even today similar vehicles form the logistical backbone of many armys and similar organisations. Would you have us believe JimM that US army equipment that can be carried on 2.5ton trucks should not be taken seriously?

If you only have 2.5 ton trucks, that means no tanks, no mechanized infantry, no heavy artillery, no helicopters, no airplanes, no radars, no SAM sites...  the army would be crushed in any conventional battle.  Also, the analogy is not real useful because the trucks don’t burn 100s of tons of fuel to deliver their payload, and space habitats weigh a lot more then tents.

RocketCo

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From: wisconsin

Registered: 2004-03-28

Posts: 4

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

What wrong with the DH-1 heatshield?  Every reentry vehicle except the shuttle uses an ablative heat shield. The ceramic blanket used by the DH-1 is based on the work of Paul Sawko of NASA Aimes for the shuttle. see US Patents 5,657,795  5,451,448. The ceramic blanket alone which can handle 2,500 F can just about handle the max DH-1 heat loads of about 2600-2800 F which are relatively low because the DH-1 has no sharp leading edges. Add something to the ceramic blanket which holds water as a hydrate as suggested in the book and you have ceramic heatshield which is light weight flexible and can take the heat and should stay well below 2,500 F.

ANTIcarrot.

Member

From: Herts, UK

Registered: 2004-04-27

Posts: 170

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

Euler: Good point about tanks and helicopters! Most of them usually carry less than 2.2 tons of cargo as well. Would you say they were useless based on that criteria alone - as you seem determined to do with the DH-1?

any conventional battle.

Oh look! There's that word again: conventional. No one is claiming the DH-1 will put ISS style modules into orbit any more than anyone would suggest the shuttle could be used to send LEMs to the Moon. The DH-1 is about doing many things in a new and different way.

space habitats weigh a lot more then tents

Not by much. Care to guess how much a MASH unit weighs?

Three Inflatable Compartments from the below link would easily fit within for the DH-1's 27m^3 cargo bay and be well within the weight limits. The remaining half ton of cargo could be used for interior supplies and fixtures.
http://www.ilcdover.com/SpaceInf/habita … ermore.htm
Two launches for 6ICs & two more for fixtures. That's a total of 8.8 tons. Since aerospace grade engineering seems to work out at ~$10,000/kg (construction cost) the station would cost $88M. So for less than a $100M you have a 347m^3 station. For the metrically challanged that's just shy of 13,000cf, which was Skylab's volume.

Transhab's wall is so thick because it's made to be all-wsinging and all dancing. If you seperate the functions of pressure vessel, secondary pressure vessel, radiation protection, thermal protection and micrometorid protection the multiple walls can be made thinner and hence can be rolled up into relatively small spaces. (~10:1 compression in the above exmple) Yes there is some assembally required once you arrive in orbit but this is a trade off for the significant weight and cost savings.

I asked this question before: Name satellite that couldn't be split into DH-1 components. The only example I can think of is something like the Viking capsule, where there are bio-contamination problems that aren't an issue for most payloads.

ANTIcarrot.
PS: Rocketco - It's not that there's a problem, it's just that much harder to varify materials than it is to varify maths.

Euler

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From: Corvallis, OR

Registered: 2003-02-06

Posts: 922

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

Actually, most combat helicopters can carry more than 2.5 tons now.  That is not really relevant though.  What is relevant is that the tanks and helicopters do not get to the war zone on their own.  They also cannot be easily broken down into 2.5 ton pieces.  That means that the must be carried by something that is a lot bigger than a 2.5 ton truck.  That is why the army needs thing like http://en.wikipedia.org/wiki/C-5_Galaxy]this.  However, even a 200 ton capacity is not enough for sustained large scale military operations.  For serious logistics, the military uses large ships with 50,000+ ton displacements.

ANTIcarrot.

Member

From: Herts, UK

Registered: 2004-04-27

Posts: 170

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

What is also relevent is that no one is talking about putting 60-ton main battle tanks into orbit. You'll also notice almost none of the large transports are left behind when the army goes into action. Carrying small loads is better for many applications, such a crew launch. One of the most useful ELVs is currently the soyuz which is not known for it's exceptional cargo capacity.

Anyway, the orrigonal point is that you and others claim that anything under 2.2 tons is useless for space applications without providing any proof or examples to back your claim up.

ANTIcarrot.

JimM

Member

From: England

Registered: 2004-04-11

Posts: 247

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

For a significant part of the twentieth centuary 90% of the US Army was designed to be carried around on 2.5 ton trucks…

…and before the truck was invented they made do with mule trains, each mule carrying what? 150lbs? 200lbs? What has this got to do with the price of fish?

And you can't gind behind the "We don't do it that way so it can't be done" arguement like GCNR does.

You’ve got this back to front. “We don’t do it that way BECAUSE it can’t be done” would be a more accurate summary of my view of your project.

And the DH-1 does not only deliver 2.2 tons to orbit, it delivers 2.2 tons AND ITSELF. And that can count as payload, since unlike the shuttle the DH-1 upperstage can be refueled and sent on to other locations. It's essentially a CEV with a deltaV of 8kmps with a standard load.

Delta-V from LEO to GEO is approx. 4km/sec. If you want to return your DH-1 to LEO after depositing a satellite at GEO, you’re going to need twice that delta-V if it’s all done by rocket burns. That’s approx. 8km/sec (all of the 8km/sec you so proudly announce here) which is about the same as was required to get DH-1 from Stage One burnout and separation to LEO in the first place. To achieve this takes about 82,000lbs of propellant, all of which would have to be brought up to the GEO-bound DH-1 from Earth by other DH-1s. Allowing for spillage, etc., that means another 20 or so earth-to-LEO launches. (We'll just ignore the fact that no-one has even attempted on-orbit refueling so far, and I'm certain it'll turn out to be a highly non-trivial excercise.) Add to that the certain need for an astronaut handling crew (Basically gas station attendants) which must mean another 2 or 3 earth-to-LEO trips at least and we’re at about 22 trips, let’s say. However GEO satellites don’t typically weight 5,000lbs but at least 20,000lbs. So we’re going to need at least 88 earth-to-LEO trips. Plus when you get all these four payloads to GEO you’re going to need another crew to assemble them all together (you can’t do this earlier) check out the joined up satellite and make sure it works. Another DH-1 to LEO, another 22 earth-to-LEO fuelling trips for the assembly crew, thanks. Plus, of course, four trips to deliver the components for the satellite and another for the assembly crew. (I'm ignoring the need for somewhere for the crew to wait around for a year or so while their ship is refuelled. I suspect being crammed into DH-1 might get rather tedious afer a while.) So what’s the total? A mere 115 trips!

At DH-1’s $200/lb to LEO, your 20,000lb GEO satellite would have cost a mere $2,875/lb to GEO which is not bad admittedly. However if the true cost to LEO for DH-1 is more likely to be $3,500/lb as I have shown earlier, the true cost to GEO would have been in excess of $50,000/lb.

One possible area for cost reduction is returning DH-1s to LEO or (more likely) earth by atmospheric braking. I guess this would reduce the delta-V requirement from 8km/sec to about 5km/sec, and so the refuelling missions (including gas station attendants) from earth to LEO to about 14 (from 22) so total trips to LEO are now a piddling 65 and the cost to GEO for the payload would be about $28,000/lb.

Whether it takes 115 or 65 trips to get that satellite to GEO, can you imagine any customer crazy enough to go along with a harebrained scheme like this? Do you really imagine you could fly as many missions as this without something going wrong, screwing up your whole schedule (at least)? Even without any failures, even with almost instant turnaround on the ground and remembering you have to launch so as to allow orbit matching, how long to do you imagine it would take to launch, rendezvous, dock, etc. 65 flights? A year? Two? And if you needed 115 flights?

Especially since in comparison with existing commercial GEO launchers DH-1 is far more pricy?

Get real!

Of course the same killer problems apply to any mission for DH-1 to the Moon, Mars, or indeed anywhere beyond LEO.

A second DH-1 to act as booster can substantially increase that.

Not until it’s had 22 refuelling visits from the ground it can’t.

As for the pilot... There's an arguement that putting people in space is patently pointless. The counter-arguement to that is piloted vehicles are still very unreliable - which is one of the more important reasons freight 747-400s still have people onboard.

Spacecraft are not aircraft. Your Stage One pilot remains effectively useless. I don’t say putting people in space is pointless, but proposals like DH-1 just make the case for manned flight that much harder to justify.

Vertical flight = ease of use. It's an option that's strongly recomended as a way or lowering operating costs, but it's stated nowhewre that it is essential to the DH-1.

It would be even easier to use if it just sat unmoving on the ground, and would be about as useful. Think balloon!

The sales forecasts are based on the DH-1 operating as it does in the book. If that happened then organisations would want to buy it. Given the eagerness with which american companies sell fighters and passenger planes, and the willingness of other nations to buy them...

There are things to do with fighters and passenger planes. Not DH-1. (See above)

ANTIcarrot.

Member

From: Herts, UK

Registered: 2004-04-27

Posts: 170

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

We don't do it that way BECAUSE it can't be done.

That's an opinion, not a reason or arguement.

(all of the 8km/sec you so proudly announce here)

No. 8kmps with 2.2 tons onboard. If you carry 2.2 tons to GEO, and then leave it there, you effectively increase the deltaV capacity of your remaining fuel, so you'd actually have more than 8kmps. Hence using aerobreaking as well you can easily carry a payload much heavier than 2.2 tons to GEO.

To achieve this takes about 82,000lbs of propellant, all of which would have to be brought up to the GEO-bound DH-1 from Earth by other DH-1s.

That's one option. A better way would be to build an ELV version of the upper stage and give it it's own inorbit cooling system and docking points. Or you could store the fuel as water ice, which doesn't boil off to nearly the same extent as cryogenic fuels. Then split it up again and store it in an entirely conventional way for only a few hours before launch.

(We'll just ignore the fact that no-one has even attempted on-orbit refueling so far, and I'm certain it'll turn out to be a highly non-trivial excercise.)

To the best of my knowledge this was demonstrated several times on Salyut 6.

However GEO satellites don't typically weight 5,000lbs but at least 20,000lbs. So we're going to need at least 88 earth-to-LEO trips.

Plus when you get all these four payloads to GEO you're going to need another crew to assemble them all together (you can't do this earlier)

Not until it's had 22 refuelling visits from the ground it can't.

I said that earlier. So you have 44 flights to put enough fuel up. Stage the two DH-1s together and suddenly you can take a whopping 30,000lb to GEO. You have read the Rocket Company, haven't you? Half the number of your launches for 50% greater payload.

The satellite could be assembled in LEO, and then attached to the structure that connects the two ships. After you get to GEO, perform a check, fix any problems, launch it and store the 'inter-stage' structure in the second DH-1's cargo bay so it can be reused later.

However if the true cost to LEO for DH-1 is more likely to be $3,500/lb as I have shown earlier

Where? When? I do not remember this argument. 'Earlier' is a little vague. Could you provide a link or cut&paste them from the earlier post?

NB: Even if true, a DH-1 launch at 5000lb cargo would only cost $17M. This is OBSENELY cheep for a manned launch vehicle and would make the DH-1 the ideal delivery truck to places like the ISS, and for a starter craft for foreign manned space programmes.

Spacecraft are not aircraft.

No, aircraft are required to actually be reliable. Hence they are required to have a pilot on board. Now you can say that placing a pilot on board does not increase reliability but the entire world-wide aircraft safety industry would disagree with you. This may change in the future as pilotless aircraft increase their reliability, but at present it's an iron hard rule. In light of that it's easier to get the first stage certified if it's manned. Once you can actually fly it you can later certify an unmanned version if it proves profitable.

Think balloon!

Think recovery problems. Think durability. Think world wide production of large balloons. Or helium. Or weather pushing you away from your release point or into the ground at your launch site. Balloons may prove practical one day, but they are not a be-all and end-all solution for this problem. And I'm not certain but I'm pretty sure they've never been demonstrated in this capacity.

There are things to do with fighters and passenger planes. Not DH-1.

How far above? Ten pages? This topic or the old one? Your post or someone else's?

If you mean the terrorism, that's over rated. You can see it coming a thousand miles off, easily shoot it down once it has re-entered, and Mach25 kinetic warheads would have to rely on inertial guidance, which has problems hitting small targets. If you have a nuke, you send it to New York in a shipping crate along with tens of thousands of others via three or four false shipping companies. You don't use a DH-1.

ANTIcarrot.

JimM

Member

From: England

Registered: 2004-04-11

Posts: 247

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

At DH-1’s $200/lb to LEO, your 20,000lb GEO satellite would have cost a mere $2,875/lb to GEO which is not bad admittedly. However if the true cost to LEO for DH-1 is more likely to be $3,500/lb as I have shown earlier, the true cost to GEO would have been in excess of $50,000/lb.

Sorry, that should have read $5,750/lb to GEO based on $200/lb to LEO. Which is not so great, of course. And at $3,500/lb to LEO, you would be looking at $100,000/lb to GEO, not $50,000/lb. Congratulations! You’ve made Shuttle look cheap!

With 65 trips, the cost would tumble to $58,000/lb. Shuttle still looks cheap.

JimM

Member

From: England

Registered: 2004-04-11

Posts: 247

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

That's an opinion, not a reason or arguement.

But apart from the fact that an opinion can be a “reason or an argument”, all I was doing here was countering your opinion that some people claim that “We don't do it that way so it can't be done.” This is a pointless discussion if you can’t comprehend that.

No. 8kmps with 2.2 tons onboard. If you carry 2.2 tons to GEO, and then leave it there, you effectively increase the deltaV capacity of your remaining fuel, so you'd actually have more than 8kmps. Hence using aerobreaking as well you can easily carry a payload much heavier than 2.2 tons to GEO.

(BTW Where did you get this mysterious 2.2 tons from? Last time I looked your payload was 5,000lbs which is 2.5 US tons. OTOH if you want to go metric, that’s fine but please tell us.)

Not so much heavier. Maybe 7,000 or 8,000lbs. Work it out. And anyway, how do you get an 8,000lbs load up to LEO in the first place? All you can lift to LEO in DH-1 is 5,000 lbs, remember? And you’re still going to need 22 refueling missions.

And, as I said before, “To achieve this takes about 82,000lbs of propellant, all of which would have to be brought up to the GEO-bound DH-1 from Earth by other DH-1s.”

That's one option. A better way would be to build an ELV version of the upper stage and give it it's own inorbit cooling system and docking points.

Now you’re kidding us. It would clearly be cheaper, simpler and more reliable to stick with existing ground-launched ELVs than this ridiculous vessel, neither fish nor fowl.

Or you could store the fuel as water ice, which doesn't boil off to nearly the same extent as cryogenic fuels. Then split it up again and store it in an entirely conventional way for only a few hours before launch.

That would work just great once you’ve got your solar power station operational. Small snag: Most SPS’s are supposed to be out at or beyond GEO. How many hundred thousand DH-1 launches (all without the benefit of an H2/O2 splitter) to get the SPS up and running, do you suppose?

Or maybe you’re planning an orbiting nuclear power station? Apart from all the tree-huggers  screaming at you, how do you propose to get the reactor up there, because as sure as God makes little green apple, it ain’t gonna be by DH-1. And I think even I might object to an operational nuclear power station in LEO.

(We'll just ignore the fact that no-one has even attempted on-orbit refueling so far, and I'm certain it'll turn out to be a highly non-trivial excercise.)
To the best of my knowledge this was demonstrated several times on Salyut 6.

To the best of my knowledge, you’re wrong.

So you have 44 flights to put enough fuel up. Attach the two DH-1s together and suddenly you can take a whopping 30,000lb to GEO. You *have* read the Rocket Company, haven't you? Half the number of your launches for 50% greater payload.

Yes, this was where The Rocket Company parted company with me. The rules of orbital mechanics are the rules, yet somehow TRC seems to imagine they don’t apply if you join two DH-1s together. A.C. Clarke once wrote a short story called “The Cold Equations”. You should fetch it out and read it. In real life, it’s ‘half the number of launches for 50% LESS payload’. Oh, and that’s not just an opinion. Sorry about that, but Newton will not be mocked.

However if the true cost to LEO for DH-1 is more likely to be $3,500/lb as I have shown earlier

Where?

It’s earlier in this thread—possibly the ‘first’ one before it ‘broke’.

NB: Even if true, a DH-1 launch at 5000lb cargo would only cost $17M. This is OBSENELY cheep for a manned launch vehicle and would make the DH-1 the ideal delivery truck to places like the ISS, and for a starter craft for foreign manned space programmes.

No, it’s more expensive than any current manned space vehicle except Shuttle. And as we know, Shuttle is hardly a paragon of cheapness. And DH-1’s tiny payload capability makes it pretty much useless, what’s more. It’s kinda like going back to Mercury. Yes, that’s it, it’s the first retro spacecraft.

Spacecraft are not aircraft.

No, aircraft are required to actually be reliable., etc., etc.

Beside the point. The WHOLE commercial argument for DH-1 is that is cheap. But, as I have shown, it is not. Having a crew just makes it more expensive.

Also, if we have learned one lesson from Shuttle surely it is that is criminally stupid and pointless to have people on board when they don’t actually have to be there. TRC does not seem to have learned this, however.

There are things to do with fighters and passenger planes. Not DH-1.

How far above? Ten pages? This topic or the old one? Your post or someone else's?

If you mean the terrorism, that's over rated….

Huh?

No, I mean running either a profitable business like airlines are sometimes(g) or useful (depending on your POV) military purposes like jet fighters, etc.

I can’t see anyone buying DH-1 and hoping to make a profit. At least, not if they’ve done their sums right. And as for military uses, if it has any significant ones, TRC won’t be allowed to sell it. As already set out here, it’s well nigh useless for GEO satellites, and beyond GEO it’s just a joke, really. Sorry, but there you are.

ANTIcarrot.

Member

From: Herts, UK

Registered: 2004-04-27

Posts: 170

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

No, it’s more expensive than any current manned space vehicle except Shuttle. And as we know, Shuttle is hardly a paragon of cheapness. And DH-1’s tiny payload capability makes it pretty much useless, what’s more. It’s kinda like going back to Mercury. Yes, that’s it, it’s the first retro spacecraft.

???

Okay, let's set aside the rest for the moment and concentrate on this one small point:

You said $3500/lb.
DH-1 carries 5,000lb
So DH-1 costs $17,000,000 per launch.
Soyuz costs $30,000,000 per launch. (http://www.spacedaily.com/news/launcher-russia-01k.html)
Shuttle (optomisticaly) costs $600,000,000 per launch.

As a people carrier, which is cheeper? Even if the worst of your doom-saying is true which is cheeper? Of course this isn't a fair comparison since the DH-1 can cary twice as many people as the soyuz but still...

ANTIcarrot.

Rxke

Member

From: Belgium

Registered: 2003-11-03

Posts: 3,669

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

in-orbit refuelling has been done, and still is, by Progress, re-stocking FGB module's altitude-maintaining thrusters...

Of course, IFAIK, it's not H2 O2 but something else (forgot what)

Bill White

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Registered: 2001-09-09

Posts: 2,114

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

No, it’s more expensive than any current manned space vehicle except Shuttle. And as we know, Shuttle is hardly a paragon of cheapness. And DH-1’s tiny payload capability makes it pretty much useless, what’s more. It’s kinda like going back to Mercury. Yes, that’s it, it’s the first retro spacecraft.

???

Okay, let's set aside the rest for the moment and concentrate on this one small point:

You said $3500/lb.
DH-1 carries 5,000lb
So DH-1 costs $17,000,000 per launch.
Soyuz costs $30,000,000 per launch. (http://www.spacedaily.com/news/launcher-russia-01k.html)
Shuttle (optomisticaly) costs $600,000,000 per launch.

As a people carrier, which is cheeper? Even if the worst of your doom-saying is true which is cheeper? Of course this isn't a fair comparison since the DH-1 can cary twice as many people as the soyuz but still...

ANTIcarrot.

Soyuz prices are far from certain.

I read one report that Dennis Tito paid much less than was reported in the media with a contrct provision that he never divulge the actual amounts paid. (Pay $12 million but you can never say you didn't pay $20 million.)

The same report suggested that this lesser amount paid more than enough to cover the incremental cost of the entire mission.

Obviously, no one knows for sure.

= = =

Even if DH-1 works, who will pay to develop it if the design cannot be patented?

If the Ukrainians or Chinese start building knock off DH-1s for less than RocketCo charges for a "real" DH-1 - - > I predict bankruptcy.

ANTIcarrot.

Member

From: Herts, UK

Registered: 2004-04-27

Posts: 170

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

"I predict bankruptcy."

I predict chinese fireworks.  :;):

ANTIcarrot.

JimM

Member

From: England

Registered: 2004-04-11

Posts: 247

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

I predict chinese fireworks.

   
Fair enough. After all, the Chinese invented fireworks in the first place.

JimM

Member

From: England

Registered: 2004-04-11

Posts: 247

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

You said $3500/lb. DH-1 carries 5,000lb. So DH-1 costs $17,000,000 per launch. Soyuz costs $30,000,000 per launch. (http://www.spacedaily.com/news/launcher-russia-01k.html)
Shuttle (optomisticaly) costs $600,000,000 per launch.

As a people carrier, which is cheeper? Even if the worst of your doom-saying is true which is cheeper? Of course this isn't a fair comparison since the DH-1 can cary twice as many people as the soyuz but still...

The payload that can be carried by Soyus varies a lot depending on which mission you look at, but it would be reasonable to say about 8,000 kg average. That's about 17,600 lbs.

At $30m/launch, that's roughly $1,700/lb to LEO, half the cost/lb of DH-1.

Soyuz can carry three people. Your people-carrying ability of DH-1 is hoplessly, laughably, over-optimistic.

Q.U.E.D.

I'm not doom-saying, I'm just realistic. You should try it some time. A lot of the problem with manned spacefight--from the very beginning--is it's been populated with people who don't like to have their dreams brought back down to reality.

For just one example, Shuttle's $60/lb to LEO promise

Euler

Member

From: Corvallis, OR

Registered: 2003-02-06

Posts: 922

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

Carrying people is the one application where the DH-1 would probably be competitive with existing launchers.  However, the demand for launching people just isn't big enough right now for the DH-1 to be successful.  DH-1 was supposed to be making 6000 launches per year.  However, the current total world launch market right now is less than 100 launches per year.  Most of those go to geostationary orbit, where the DH-1 is not at all competitive.  Most of the rest are still unmanned, so DH-1 would probably not be competitive for them either.  This year there will be a total of 2 manned orbital flights.  While there are more than 2 manned flights per year on average, there are still not enough of them to even keep one DH-1 fully employed.  Also, all of the current manned flights are done by government space agencies that would probably want to use domestic space vehicles even if they are more expensive to operate than the DH-1.  The market just isn't large enough to support the DH-1.

JimM

Member

From: England

Registered: 2004-04-11

Posts: 247

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

Euler,

I agree with all you say except your first line...

Carrying people is the one application where the DH-1 would probably be competitive with existing launchers.

... because at the flight frequency you forecast for DH-1 (which I agree about) the actual cost of flying DH-1 would be vastly greater than forecast by TRC. By the time development costs are plowed back into not hundreds of DH-1s but one or two only, the cost/lb to LEO would probably exceed Shuttle by a vast degree.

ANTIcarrot.

Member

From: Herts, UK

Registered: 2004-04-27

Posts: 170

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

JimM, look here:
http://www.spaceref.com/iss/spacecraft/ … gress.html
Exactly how many soyuz/progress modules do you think it would take to launch 1 ton of air? Or a ton of water?

The soyuz module WEIGHS 8 tons, it doesn't CARRY eight tons! Even progress only carries 1.8 MT of pressurised cargo.

Though I'm not surprised that you can't seem to tell the difference since you've claimed that staging to increase rocket performance violates newtons' laws of motion. You are of course entitled to your own opinion but forgive me if I don't share it.

Look here as well:
http://www.astronautix.com/craft/soyuzt … oyuztm.htm
The DH-1 has three times the volume of soyuz. And that's three times the total volume, not just the crew compartment. You really think it can't carry more people?

ANTIcarrot.

JimM

Member

From: England

Registered: 2004-04-11

Posts: 247

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

Though I'm not surprised that you can't seem to tell the difference since you've claimed that staging to increase rocket performance violates newtons' laws of motion.

As I feared, it is you that does not understand Newton, or the rocket equation. Staging does NOT improve the performance of a given rocket, as you and TRC seem fondly to imagine. Staging lets two (or more) rockets do more work than one rocket. But the individual rockets don't get any better, as DH-1 is supposedly going to do.

Attach the two DH-1s together and suddenly you can take a whopping 30,000lb to GEO.

... you said. Sorry, that was tosh and remains tosh. In any case, even if it were possible to take 30,000lb payload from LEO to GEO, how do you get your 30,000 lb payload up to LEO in the first place?(g)

(DH-1 x 2) payloads is 10,000lbs. That's what you can get to GEO, and it's still not enough to get any GEO business, so by the time you're finished, you'll still need 65 or so ground launches to get a serious GEO payload up there.

As I said, this is where TRC finally parted company from reality. Newton will still not be mocked.

The soyuz module WEIGHS 8 tons, it doesn't CARRY eight tons!

The Soyuz comes in a variety of weights, but the basic three-man command module (ie., the living module for a crew of up to three) masses in at about 8 tonnes. (That's almost 9 US tons, BTW)
I do not believe that DH-1 could provide a life support 'module' for three astronauts for any less mass than this.If it could be done for less mass, the Russians would have done it.

As a cross-check, the Apollo three-man Command Module weighed in at about 6 tons, from memory, but that had life support for no more than an hour or two; most of its life support came from the Service Module. Take away the CM heat shield and add life support and 8 tonnes sounds like the right ballpark.

And take a look at this:
http://www.astronautix.com/craft/apouec … ouecsm.htm
5 crew, 16,800kg.

With a DH-1 payload capacity of 5,000lbs, as I said earlier you'd be lucky to be able to keep the pilot alive, never mind passengers.

Thank you for pointing out Progress to me. You're quite right about ISS being refuelled by this. What you overlooked, however, is that it points out that by the time you install all the tankage and pumps and other controls, etc. to handle the propellant, the mass of propellant deliver is clearly going to fall from 5,000lbs per trip to LEO to something more like 2,000lbs, if that.

Thus the number of earth-to-LEO journeys has just jumped up from 65 to something more like 160 or so per GEO mission.

Euler

Member

From: Corvallis, OR

Registered: 2003-02-06

Posts: 922

Re: Low-cost-reusable vehicle design-FICTION *2* - last topic got borked

It doesn't matter if it takes 44 launches or 160, or if it delivers 30,000 lbs or 10,000.  It can't compete with conventional expendable rockets in either case.  EELVs can generally get at least 40% as much payload to geostationary orbit as they can get to LEO.  Even with the most optimistic assessment of the DH-1's capabilities, 44 launches for 30,000 lbs, it still gets less than 15% as much payload to GTO as it must get to LEO.  The added time and complexity of the whole operation is also a clear minus.  I don’t see how a system that is so inefficient even under the most optimistic assumptions can possible be practical.