What Kind of Manned Program Should We Push For? - A Time to choose

GCNRevenger · 2004-12-06 13:06:06

Multiple 250MT class launches and you could start thinking about a manned mission to Jupiter, or sending a "colony dome" in one piece from Earth to Mars... or the ultimatly needed Martian DC-I RLV... or a colony ship.

With not one new piece of major hardware or new facility for the launch vehicle.

Upon more reflection: If we do go the small-as-possible route, then what? Then it becomes Martian Apollo, and when the mission ends... so does the space program. When the science mission ends with a multi-Ares class or NOVA class missions end, you will already have the launcher for the next phase in hand, which may well save money in the long run too.

Are you willing to risk the future by pawning off the present to save a buck and shave a few years off the trip? How quickly people got bored of Apollo, not even televising Apollo 13 live... Going to Mars for a reason other then beating Communists or hunting bacteria is the only innoculation against this, and that will simply require somthing big. Real big. Available on or soon following the bug-hunt phase...

There is also the sheer "propoganda value"... What do people think about when they think Apollo? The little cramped capsule? No, they think the Saturn rockets... and when people look at the Mars mission, what will they see? America being forced to hang its head low and beg Russia for their powerful Energia, or the "headless Shuttle," which is merely a match for Saturn... or somthing more.

The public has to SEE with their own eyes the reality that colonization is within only one more step... What better way then to have a truely awe-inspiring rocket that can start in-hand? At the very least, the dual-Ares arcitecture, and show the assembled vehicle on the ground to the media.

One more thing, the cost... estimates place the development for Shuttle-C at around $5-10Bn and Shuttle-Z/Ares/comperable clean-sheet around $10-15Bn. I think that this vehicle could be built for an investment in the $20-25Bn range, and may be very worthwhile. Of the $90-100Bn or so that NASA could amass over a decade, that leaves more then enough money left over for a $60Bn NASA DRM style mission.

ftlwright · 2004-12-06 14:53:37

I actually did work on the HL-20 and some of its iterations, I assure you that very little work has been done on it. The total cost of developing the vehicle will more than likely be under the 4B dollar mark; most likely cost around 3B dollars if institutional, university and industry resources are pooled together efficiently. There are several advantages to a winged design under the right conditions, but there are several rules I feel should be followed if going with a winged design:

a) If your going to design a winged/lifting body vehicle, it should land under its own devices. If your going to use parachutes, you might as well go with a capsule.

b) Keep the vehicle as small as possible. The larger the heat shield, the more succeptible it will be to flaws.

c) but as few mounting points/landing gear doors on the heat shield as possible. READ: composite are fragile, why would you put holes it the darn thing?!?

If these conditions cannot be met, just go w/ a capsule.

My background is in advanced propulsion systems, so I prefer those methods that shorten the astronauts trip time and provides them w/ the most versatility. Further, these options would lend moreso to the exploration of the outer solar system. Plus, it will insure I have a job for the forseeable future . In all seriousness, we need to give the first folks heading out as many options as possible to return safely to Earth. By it's nature, there are way too many single points of failure for this type of mission and every effort should be taken to aleviate those failure modes.

GCNRevenger · 2004-12-06 15:06:41

Impressive Mr Wright... overall your rule schema for basic crew transport probobly is about right, though I think if you can make a much more capable, robust vehicle that is marginally bigger and heavier, then it is worthwhile. For instance, six seats instead of four or five.

I do think that your price tag is a little bit optimistic, and the whole vehicle with abort system, booster adapter, etc. would cost $5-6Bn minimum.

"Further, these options would lend moreso to the exploration of the outer solar system."

This is one item I take issue with, that a winged vehicle will not nessesarrily do this because no winged vehicle can survive direct reentry from transfer orbit velocities. If you are coming back from anywhere but LEO without a breaking maneuver, a capsule is required.

ftlwright · 2004-12-06 16:15:53

GCNR,
Sorry, I meant plasma based propulsion systems for exploration of the outer solar system. Winged vehicles only make sense if you are making an entry from Earth orbit. One possibility I've been thinking about are "desposable" heat shields that could be mounted on a winged vehicle and jettisoned once the vehicle is subsonic. I haven't done any work on this, so please take it with a gigantic grain of salt.

My 3-4B dollar figure comes from the fact that NASA is already seeding millions of dollars to many universities and institutions across the country for the design on a new spaceflight architecture. If NASA can properly manage these energies (a.k.a. don't let the researchers squander the money on pipe-dream or misc. side projects) then it could possibly be done. If the aerospace industry is to pull off a mission of this scale, it really needs to display the ability to tighten the purse strings when required. I'm just not seeing the contributing factors that would inflate the cost to the 5-6B dollar range; prototyping, simulation, live-testing seem as though they would be the same whether you go with a winged vehicle or capsule. The only place where cost will be distinguishable is at the production stage where a winged vehicle would probably have a higher intial cost, but will deminish due to it's reusability. Definitely a topic that needs more discussion.

The size of the crew is going to depend more on psychology rather than mission requirements. For instance, you probably going to want an even numbered crew for an interplanetary mission. When people are placed in confined spaces for long periods of time, you don't want critical mission decisions to come down to one person/vote. There is similar support as to why you would want a 6 person crew as oppose to a 4 person crew (isolation of the minority view), which is certainly relevant for long duration missions.

John Creighton · 2004-12-06 16:29:51

As far as landings from LEO go what are the advantage of a winged vehicle? Are they weight, speed, accuracy and reliability?

GCNRevenger · 2004-12-06 16:31:10

Thats putting alot of faith in universities I think... Ultimatly I think that the vehicle will cost more because it is not as easy to build such a robust vehicle as anticipated, there will be various non-vehicle items to build, and the testing involved to verify safe operation.

"The size of the crew is going to depend more on psychology rather than mission requirements."

I disagree completly. The crew size absolutely is part of the mission requirements, that the amount of work on Mars is better accomplished with marginally higher costs associated with the bigger crew. Its worth the extra money.

GCNRevenger · 2004-12-06 16:33:42

Winged vehicles generally offer a little more volume per mass, lower reentry G-forces/stresses, lower reentry heating due to nonballistic trajectory, longer cross-range (gliding), the ability to land at an airport on a runway for easy handling, and would be inherintly reuseable.

The trouble is, they can't survive the ultrahigh speed reentry from the Moon or Mars as a return vehicle, they would have to slow down first somehow.

ftlwright · 2004-12-06 17:00:10

Its worth the extra money.

No doubt about it. I'm simply trying to debunk the idea of crew sizes smaller than 6, however, I think psychology is going to be one of the biggest factors in determining crew size. Work distribution, team/social dynamics, authority and crew health and safety are critical elements that will factor into crew size. How much work can reasonable be accomplished by a crew of 6 that's cut off from the rest of humanity other than the occasional email? How much space will each individual need to keep from going at the throats of their crewmates? What about intimate contact?

With respect to university/institutional/industry cooperation, ESA has managed to do a much better job of this than we have. They have been able to utilize the synergies between the three and build upon the work at each level. We have managed to do this decently in the area of electric propulsion; where universities are doing a lot of the theoretical/conceptual work, NASA and the Air Force do most of the qualification/scaling investigations, and industry focuses on the production/deployment side. Certainly there is a lot of inertia behind the current manned spaceflight paradigm, but that something we have to overcome if we plan on going to Mars.

RobertDyck · 2004-12-06 21:43:55

I don't think that Congress would tollerate permitting Russia to hold veto power over our space program again, nor would they tollerate large sums of money leaving the country for space hardware under any circumstance.

I don't think NASA has much more patience than I for that sort of nationalistic crap. They are currently working with international partners on the International Space Station. That is not US space station Freedom. America wouldn't have any station at all if it wasn't for its partners. NASA has always led the way to international friendship and cooperation.

To put it another way, how much longer will Congress tolerate contractors gouging the American taxpayer? The Shuttle cost $10.1 billion including development of a 104.3 tonne orbiter, the world's first reusable rocket engines, the first reusable solid rocket boosters, conversion of Saturn V launch facilities, conversion of the factory at Michoud from Saturn V 1st stage to Shuttle external tank, the first reusable heat shield, and construction of the first 3 orbiters. The orbital space plane would have been a comparatively tiny spacecraft plunked on top of an expendable rocket. The EELV program paid for development of the rockets, construction of their factories and launch facilities. OSP should be a small fraction of Shuttle's cost. The $2.0 billion cost for X-38 included expansion from 4 to 7 astronauts, conversion from metallic heat shield to Shuttle style, and conversion to an OSP. The vehicles that were built were more than just full-size mock-ups, they flew and tested its flight handling, operation on the parafoil, and automated landing. Congress cancelled the OSP program because they knew the $11-13 billion price was way too high.

So far excused have been found for cancelling every alternative to the Shuttle: X-30, DC-X/DC-XA, X-33/VentureStar, and roughly a month after I told a salesman at Orbital Sciences that Energia launch facilities were in perfect operating condition the roof collapsed. It is time for Congress to consider drastic alternatives, and Russia is one such alternative. Unless something is done to dramatically reduce launch cost, America will be out of the space business. That would have severe negative consequences on American society. It already suffers from an inadequate education system, and national focus on war and conquest rather than peace and liberty. One engineer I work with in Canada is an immigrant from Ukraine, and was trained in aerospace engineering in Russia. He pointed out America is running out of resources. He's right; if America doesn't open new resources in new lands it can only go to war with the rest of the planet in an effort to steal theirs. I was shocked at the level of security in Washington, DC; America is becoming a police state, if it isn't already. Failure to open new resources in space means reliance on foreign resources, and the military conquest necessary to secure those resources mean the end of freedom and liberty in America. Failure to get launch cost under control means failure to harvest space resources profitably. I don't think you understand what's at stake here.

This is sounding like a rather passionate space advocate we all know. Perhaps I need to tone it down a notch; after all I live in Canada where there are plenty of resources. But I want to work for NASA, so I have a vested interest. (Sigh)

RobertDyck · 2004-12-06 21:50:21

I actually did work on the HL-20 and some of its iterations
...
My background is in advanced propulsion systems

Welcome ftlwright! Does that name imply you will be the Wright brother for Faster Than Light propulsion? Gotta love that goal.

Here's a technical question. How close is the Glenn Research Center to developing carbon/silicon carbide for rocket engine turbines and exhaust bell cones? How much work would it take to develop a reusable tri-propellant engine similar to RD-701 using carbon/silicon carbide?

SpaceNut · 2004-12-06 22:14:43

Yes thanks for joining NewMars ftlwright, It is good to here from some one that actually works for the very agency that most of us can only dream of doing.

Now back to the cost of the Rocket specifications from the previous page.

For dimensions of a vehicle with roughly twice the volume of Shuttle's main tank, a 10m wide first stage would be called for in order to not exceed the height of the VAB. Such a tank would have a length of around 66m, which would leave about 60m for for the upper stage and the vehicle.

So this tank will be in the 70million plus cost ball park.

The first stage would have attach points for up to six of the big five-segment Thiokol SRBs, with option for using only 2, 3, or 4 for smaller missions (like JIMO launch).

That make options cost approximately 60million, 90 or 120million for the 4 segment units. While the 5 segment must be at least 45million each. Also for the lighter lift requirements why not make a 3 segment unit also for use.

The first stage would have five RS-68R engines like Saturn, so that engine out would not be fatal. The optional upper stage would also be about double the size of Energia's and use a single RS-68R engine, and would be either 10m by 12m or 9m by 18m, either option leaving you about 50m of available height for payload farings.
This vehicle would require no new construction facilities as Michoud can produce 10m tankage, and no engines as Boeing already makes the RD-68 today for a very reasonable price ($15M each) and the Thiokol SRB is in production right now. It is simply a matter of upgrades and putting them together in a monsterous vehicle.

All for trying to save where ever possible. 6 engine total at 15million each.

So let total up the figures
engines 90m
solids 60 to 120 million
fuel tank 1 70 plus
fuel tank 2 less than the 40 million on a normal shuttle tank.

This figures are rough but this is just to lobe cargo to orbit.
minimum figure 250million plus all the way to the super duper model 310million as best guess cost.

So now how much would be the development fees and for how many launches that could be used to spread the costs over to give us an average cost for each rocket in full production mode.

GCNRevenger · 2004-12-06 22:38:51

Nationalistic crap? On the contrary, I don't think NASA nor Congress has any patience left with our so-called "partners," Russia has now on more then one occasion stabbed us in the back to squeeze more money out of us... In any event, NASA has plenty of money, more then enough in fact for a Mars mission twice as expensive as the DRM, the problem is that its all going to the worthless ISS and the "Worlds' Most Sucessful Make-Work Program," the Shuttle. Without signifigant increase in budget, NASA could undertake an $80-90, perhaps even a $100 billion dollar decade-long Mars program. All that is needed is to force the realization that the ISS is untennable and abandon it... treaties or no. "International cooperation" has kept us trapped in LEO for as long as I have lived.

As far as using Russian hardware, I think you might have to be an American to completly understand why that is simply not an option. The only reason that NASA gets so much money is that the vast majority of it stays right here in America... Congressmen can tollerate an extra billion dollars going to Florida every year, but would never swallow $100M going to Baikanour. You also ignore the simple fact that if we were to employ Energia, that a large portion of the US space program would simply have to be moved to Russia.

Think about that for a minute... let it sink in... Payloads would have to be assembled in Russia. Integrated in Russia. Tested in Russia. Cargo loaded in Russia. Controlled after launch from Russia. Crew leaving from Russia perhaps... You would outsource about half of NASA's spaceflight program. Think about that... Thats why it will never happen, because it wouldn't BE an American program anymore.

And then there is the politics... Americans will see that their Mars mission has been outsourced to the Russians, and they will be MAD reguardless of the low price. I would be mad if we outsourced to Russia for Energia... Americans are, after all, a fairly prideful people by and large.

Also, Russia would see that they hold not only a multibillion dollar American investment in the palm of their hands, but a major investment of political capital of American lawmakers in the grip... And the Russians will be quite happy to ruthlessly cut their own engineers and space ambitions loose to play that card on their whim... To think otherwise is naieve.

"America is becoming a police state, if it isn't already. Failure to open new resources in space means reliance on foreign resources, and the military conquest necessary to secure those resources mean the end of freedom and liberty in America."

Please, thats really nonsense, and a little bit insulting...

I am sure that if you had botherd to remember that Washington has been the site of the world's first bioterror attack (Anthrax), an attempt to destroy the seat of government in the world's most deadly suicide bombing (9/11) plus the fact that the people in our government (particularly Bush-II) are the most hated people on Earth by thousands of insane murders with a little less value for human life then your typical Nazi... that you would understand the security precautions. Visit other parts of the country, DC is the exception to the rule.

We have plenty of reasources here in America just fine if we use them properly. Breeder-fed fission reactors to split water for Hydrogen to run fuel cells, diesel oil, jet fuel, and bulk biopolymers from corn, no shortage of coal for the next two centuries, massive untapped agricultural capacities, enough bulk metals to last for a long time with careful mining and recycling... I don't know how this idea of "running out" got into your Ukrainian friends' head, but he is quite mistaken. There is no need for America to invade anyones' state for natural reasources, to say otherwise is to speak from a position of ignorance.

GCNRevenger · 2004-12-06 22:59:17

SpaceNut: On rough calculations, I am assuming that the Superheavy version will cost about $500M for the hardware, so I think it within reason to think that it could be flown for under $1Bn a flight... not bad for that kind of power, under $2,000/lbs.

I am also growing quite tired of your "evil money grubbing corperations, why not just use socialism!" critique of the big aerospace firms. Two billion dollars is simply not that much money to build a delicate spacecraft with high reliability no matter what size it is. I also think that the Shuttle $10Bn figure is too low and is in error, and it has actually cost quite a bit more than this. If you would account for inflation, you would see that the Shuttle cost $22Bn in 1990 dollars, when the HL-20 concept was seriously studied.

The OSP would require everything that Shuttle does except the main engines and in a smaller version. Plus, the EELVs are not so easy to use with lift body shapes, they will require serious structural modifications, especially on the pressure-stabilized Atlas rockets. There will also be aerodynamic requalifications, and testing of the tricky rear seperation motors, among other things that a capsule would not need.

I don't think that either the HL-20 figure nor the X-38 figure is or was credible, the extreme delta in cost from the big aerospace companies to what you propose is so large as to defy all resistance to smirking... I see no reason at all that such a vehicle that has to have so much stuff packed into such a small package, and operate under extreme conditions with near perfect reliability repeatedly, would possibly cost less then even half what the $8-10Bn proposed.

X-30, DC-X/DC-XA, X-33/VentureStar were all canceld because they were too technically ambitious or were simply unessesarry. Perfectly sound reasoning in axing them, my only complaint is they weren't terminated fast enough.

RobertDyck · 2004-12-06 23:25:58

Think about that for a minute... let it sink in... Payloads would have to be assembled in Russia. Integrated in Russia. Tested in Russia. Cargo loaded in Russia. Controlled after launch from Russia. Crew leaving from Russia perhaps... You would outsource about half of NASA's spaceflight program. Think about that... Thats why it will never happen, because it wouldn't BE an American program anymore.

Payloads are now. Do you know how many DirectTV satellites were launched on Proton rockets?

Americans are, after all, a fairly prideful people by and large.

No shit.

Also, Russia would see that they hold not only a multibillion dollar American investment in the palm of their hands, but a major investment of political capital of American lawmakers in the grip... And the Russians will be quite happy to ruthlessly cut their own engineers and space ambitions loose to play that card on their whim... To think otherwise is naieve.

I have news for you, the cold war is over. Russia was an ally in the war in Afghanistan; it could be an even greater ally if you just treat it with respect. Russia won't tolerate being dictated to, but if you treat them as an equal they'll respond honourably. Iran is an example; George W. said not to sell a nuclear reactor to Iran and Russia wouldn't let Washington dictate who they can sell to. They invited UN inspectors to ensure no nuclear weapons would be developed. Now Bush wants to go to war against Iran to take the reactor away; he knows damn well there aren't any nuclear weapons. Threatening war against Russia's customer to take away what Russia sold to them is no way to build a partnership.

But I suggested using the Energia launch vehicle for cargo and MAV. I didn't say anything about moving mission control away from Houston. I also talked about crew leaving on a reusable space taxi from the US, not Russia. And vehicles designed and built and tested in America, only launched from Kazakhstan on a vehicle with boosters built in Ukraine. I also suggested the possibility of building core module tanks in America. What's actually Russian, the main engines?

We have plenty of reasources here in America just fine if we use them properly. Breeder-fed fission reactors to split water for Hydrogen to run fuel cells, diesel oil, jet fuel, and bulk biopolymers from corn, no shortage of coal for the next two centuries, massive untapped agricultural capacities, enough bulk metals to last for a long time with careful mining and recycling...

Yup, that's true, but how many businesses actually use resources properly. How much recycling is actually happening? Is there a single commercial breeder fission reactor in America today? Is there any nuclear waste reprocessing for the purpose of reducing radioactive waste, never mind responsible use of a non-renewable resource? There's plenty if used properly, but it isn't being used properly. The disposable mindset is so entrenched in business psychology as a means to generate recurring business that it would be easier to harvest metals and energy from space than to get them to produce durable goods. A mechanic at a small auto-manufacturer pointed out the ball joints of tie-rods now use nylon inserts. They may provide smooth movement from a tight joint, but they will wear out after a predictable number of miles; designed to fail. High quality joints don't support the weight of the car on a nylon bushing.

RobertDyck · 2004-12-06 23:37:52

X-30, DC-X/DC-XA, X-33/VentureStar were all canceld because they were too technically ambitious or were simply unessesarry. Perfectly sound reasoning in axing them, my only complaint is they weren't terminated fast enough.

The X-30 was too technically ambitious, but the others weren't. The DC-X was converted to DC-X Advanced. Both versions worked fine until someone left a locking pin in place, preventing one of the legs from being deployed on landing. Landing on only 3 legs caused it to fall over, who would'a thunk it! Human error. The real kicker is they didn't rebuild it. The X-33 was designed to have a solid wall composite tank. A last-minute decision replaced that with a hollow wall honeycomb structure. The first test of that tank demonstrated cryogenic cold caused micro-fractures that let liquid propellant (tested with nitrogen) to get in. When it warmed the fractures sealed shut, the liquid boiled, and the pressure blew out the honeycomb cells. It literally disintegrated. Ok, the logical conclusion is to go back to the solid wall design. NASA activated the contract clause that stated the contractor had to share the cost of a set-back like that, but Lockheed-Martin refused to pay. The contract disagreement cancelled X-33, not anything technical. My paranoid side suspects they made the last-minute change in the hope of creating a failure they could bill to NASA, they deliberately set-up a cost overrun, and got upset when NASA said they had to pay for it.

GCNRevenger · 2004-12-06 23:50:15

You confuse the American national space program operated by the National Aeronautics and Space Administration with the needs of commertial communications customers. Americans have no big qualms with letting businesses buy foreign rockets as long as the sellers are not anticompetitive... but to farm out the National space program to Russia, even if they were out bestest buddies and Congress didn't care to let their states rot? I don't think you know what it is to be an American...

The sole fact that large sums of money would be going to Russia and not America for spaceflight hardware dooms the whole idea of large-scale use of Russian reasources entirely anyway... You also assume that you can assemble and test the vehicle seperate from its launcher, which is nonsense, because you are only testing a piece of it. The assembled vehicle on the pad is what must be tested. Vehicle assembly would be Russian, and control the vehicle following acent would have to be Russian, since Houston is on the wrong side of the Earth. It would also take a great deal of trouble to retool Michoud to make Energia tankage, and there is no way to get the tanks to landlocked Baikonour anyway.

Though Russia is no longer our sworn enemy bent on the destruction of the West, you are obviously very foolish if you think they do not hunger for power and influence... and having their hand on NASA's throat would be a temptation too great whenever there was a "disagreement."

"They invited UN inspectors to ensure no nuclear weapons would be developed. Now Bush wants to go to war against Iran to take the reactor away; he knows damn well there aren't any nuclear weapons..."

Hhahaahahahaahahaa! Thats FUNNY! Wow, thats a good one Rob...

And overall, I can't help but feel a bit offended that you think that America would conquer another country in the name of convienance to avoid having to "change our culture" or somthing... come on, we would not do somthing so awful.

GCNRevenger · 2004-12-06 23:55:23

The DC-I project was not excessively ambitious, it was simply unessesarry. There was no chance that it would be big enough or light enough to carry much cargo because of its SSTO nature, and with low demand for satelite launch, had no purpose.

No, the X-33/VentureStar required the honeycomb tank because it would have been too heavy otherwise, and not been able to lift things like ISS modules. Same reason as the DC-I, which by the way would have also used solid composit cryogenic tankage.

Even Hydrogen/Oxygen aerospike engines, either radial or linear, don't offer a high enough mass fraction to be a viable medium launch SSTO RLV without being truely monsterous.

GraemeSkinner · 2004-12-07 00:02:15

Winged vehicles generally offer a little more volume per mass, lower reentry G-forces/stresses, lower reentry heating due to nonballistic trajectory, longer cross-range (gliding), the ability to land at an airport on a runway for easy handling, and would be inherintly reuseable.

Trying to bring the thread back towards the subject line (I can't stand politics :;): )

Winged vehicles may be the way to go in future for manned missions to Mars, but I think to start with its not going to help much unless we can send rovers out before hand to clear away any rocks etc and compact a strip of land for the vessel to glide down onto.

Graeme

RobertDyck · 2004-12-07 01:28:49

control the vehicle following acent would have to be Russian, since Houston is on the wrong side of the Earth.

Houston is in the wrong state for a launch from KSC, but it works anyway. Telecommunications can work from anywhere on the planet, and people work what ever shift is required.

It would also take a great deal of trouble to retool Michoud to make Energia tankage, and there is no way to get the tanks to landlocked Baikonour anyway.

It would take even more trouble to make Energia tankage anywhere else. Transportation: how do you think they got the original one to Baikonur? Use the same http://www.astronautix.com/graphics/e/enem4top.jpg]M4 aircraft.

And overall, I can't help but feel a bit offended that you think that America would conquer another country in the name of convienance to avoid having to "change our culture" or somthing... come on, we would not do somthing so awful.

One word: Iraq.

RobertDyck · 2004-12-07 02:07:57

One reason I proposed what has been called in this thread "Hybrid Direct" is to create a reusable ITV. This provides greatly reduced cost for a 2nd, 3rd, or subsequent mission to Mars. This highway to Mars enables sustainability. I also argue for reduced crew and vehicle size initially, but remember I advocate sending all missions to the same site so an accumulation of lab equipment and habitats can form the beginning of a permanent base. Once successful habitation on Mars is proven (by a tax funded space agency) it will build a market for tourism and settlement. I suggest keeping the initial Mars mission small enough that it can be funded, 4 crew is the practical minimum for Mars, but I would follow that with a commercial transport to carry 100 settlers at a time. Once a town is established on Mars and demand grows, that can be followed by a transport for 1,000 settlers at a time. Visualize a rotating ring with aerocapture heat shield disk above it, and a propulsion module stretching beneath from the hub. A ship as large as Voyager of the Seas or Queen Mary 2. You see, when I call for a modest size initial mission to Mars, I'm not thinking small, I'm thinking very very big.

Mars Science Laboratory is scheduled for "late 2009". The earliest launch date currently considered for the first sample-return mission is 2011; let's assume it will go then, not 2014. That means the earliest manned mission is early 2014 for the ERV or MAV/cargo ships, then 2016 for the habitat with astronauts. Yup, that means humans on Mars just 12 years from now, but we have to get off our butt.

GraemeSkinner · 2004-12-07 04:53:13

Yup, that means humans on Mars just 12 years from now, but we have to get off our butt.

WHAT!!!

We have to wait 12 years!!!

In regards to crew size, I'd go larger than 4, send a good size crew to the surface with a couple of rovers and let them get on with it.

Graeme

SpaceNut · 2004-12-07 06:07:26

It would be best to send multiple crews with less than a month or two between them to target doing the needed research but to also maximize the number of hands in one spot.

Could the DC-x or I be converted into the lander we need for mars?

RobS · 2004-12-07 09:23:17

Whan I was working on my "Mars-24" project (you can find the thread buried somewhere) I proposed an interplanetary transit vehicle for four that was half way between the hab and ERV in size. The Hab has 100 square meters of floor space, the ERV 50; but half of the hab's floor space is devoted to cargo. My ITV had 75 square meters of space and had a mass of 16-18 tonnes. It had the shape of an elongated capsule or a cone; it had a large bottom with a heat shield, which gave it stability for aerobraking. The "great room" where the crew ate, met, and relaxed was on the bottom. The higher levels were smaller and subdivided into staterooms, work areas, and storage.

I had designed the ITV for a four-person crew. But when I wanted to use my architecture for a novel I wanted six for dramatic purposes; it's easier to write a story with six characters than four, I think (more interactions). So I flew two ITVs with three crew in each for the first Mars mission. That architecture had several advantages:

1. If one ITV had a serious failure, the other could serve as a lifeboat. That meant each ITV had to be designed to handle 3-4 normally but 6 in an emergency.

2. The two ITVs could be docked together nose to nose and serve as counterweights to each other for artificial gravity. An elongated cone is a good design for artificial gravity in that they have a lot of length; my ITVs were 13 meters long. A possible disadvantage: Martian gravity at the bottom level required 5 rpm, which is rather fast. But 3 rpm would still generate a reasonable level of gravity, enough to operate toilets and showers and to cook.

3. If the ITVs are reusable, once experience in operating them is gained, they could be flown to Mars with four each, raising the total crew to eight.

4. I am under the possibly mistaken impression that a five-story ITV may "feel" bigger than a one or two-story vehicle. There's a lot of going up and down in the central ladder/elevator shaft. Each level is different and can be changed using posters and other decorations.

5. An elongated cone shape would fit on top of an EELV quite well. I had assumed a six-meter diameter and that's a meter too large for existing EELVs, but possibly with reduced mass the existing EELVs could handle such a wide load. Six meters makes the great room on the bottom reasonably large. If the ITV is inflatable the larger diameter would not be a problem.

6. An ITV with 75 square meters of floor space (about 180 cubic meters of volume) would be a good size for flying as many as a dozen people to the moon. On shorter flights people can be packed more closely together. So we'd use a single ITV for moon missions and two for Mars.

7. Such an ITV could be launched on an EELV almost any time. It could spiral to the Earth-lunar L1 point using ion or solar-thermal or other low-mass propulsion. It could be used to form a temporary station at L1 or even in lunar orbit. So such an ITV could be useful in many ways other than a Mars mission. No doubt many different interior configurations would be needed using different sorts of life-support equipment. Possibly one ITV could be launched to the L1 point slowly and the other sent out quickly with the crew.

-- RobS

SpaceNut · 2004-12-07 14:26:30

Questions
Does the ITV have the lander or is that a seperate vehicle that is waiting in orbit for crew to transfer into once they arrive.

Also when does the ITV jetison the orbit to orbit stage engines if using the aero braking shield or is this part of the lander and not the ITV.

RobS · 2004-12-07 18:09:58

The ITV I envisioned just goes orbit to orbit. It didn't have engines of its own; at the Earth end, a propulsion stage had to dock to it and push it to Mars. At the Mars end, a Mars shuttle came up from the surface with the returning crew, samples, and the ten or so tonnes of methane and oxygen needed to push it back to Earth. The Mars shuttle had its own heat shield and would fly back to Earth nearby and would aerobrake into terrestrial orbit separately for reuse (if it was reusable). Once a permanent outpost was created on Mars that manufactured fuel, the Mars shuttle itself could push the ITV from Earth orbit to Mars orbit using terrestrial or lunar made fuel, or even using fuel from Mars or its moons.

One advantage of separating the crew transport from the fuel tanks and engines: the cryogenic fuel is one of the most dangerous things on an interplanetary flight (consider the Apollo 13 explosion). If it is ten kilometers from the ITV for the duration of the interplanetary cruise, it's probably just as well. If at times you need the fuel as a partial radiation shield, you can always bring it close and dock the vehicle.

The ITV would need a small amount of propulsion for trajectory corrections and such.

-- RobS

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