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

RobertDyck · 2004-12-05 14:29:54

Six should be the minimum crew size, if it takes 1-2 man days per day to maintain the vehicles, that only leaves two people to do anything else. An additional two crew, one centerd on lab/telerobotics and another for general near-base science would vastly increase the mission return for nominal additional cost.

"1-2 man days per day to maintain the vehicles"? I don't think I want you to design the vehicles. If you're referring to the 2.5 man days per day to maintain ISS, let's just say I don't want the Mars hab designed that way. Maintenance should be restricted to cooking, laundry, suit recharge/refill. Although suit CO2 sorbet canisters would have to be put into an oven to regenerate, habitat CO2 sorbent should be auto-regenerating. Repairs should be the exception, not the rule.

Using the MAV as TEI stage is impractical, because the MAV would then be too big and too heavy to carry. The quantity of fuel required to get to Earth from LMO is one thing, the quantity of fuel (and engines & tankage) required to get THAT fuel into LMO is another.

The two options are to carry fuel for return to Earth from Mars surface, or from Earth surface. Mars surface is closer to LMO and Mars has lower gravity.

As discussed before, the marginal bennefit of making a self-launching manned anything is zip compared to building a TransHab based vehicle and launching it on a standard booster.

Self-launching uses the launch vehicle as the spacecraft. The difference is a vehicle the size of a single core module of Atlas, vs. Delta-IV Large with 3 core modules plus an upper stage to lift TransHAB.

Nor can the Delta-IV HLV carry enough LH2 and NTR engines for a reasonably sized Mars vehicle of any kind in a single flight in its current form. This stage and all required fuel must be launched within one month of Mars departure. Can Boeing launch two Deltas within a month of eachother?

If Boeing can't maintain a reasonable launch schedule, even with a pair of vehicles built before either is launched, then we have to look at someone else. Russia can launch Proton that quickly.

The Alpha Lifeboat is too heavy to include too.

12.5 tonne mass for Alpha Lifeboat vs. 3 tonnes each for 2 Soyuz descent modules. It does appear Soyuz is the better choise, but Soyuz is designed for 3 crew each. If you put 2 crew members in each Soyuz DM then you have cargo mass for Mars samples equivalent to 1 crew member, his suit and seat. That's half the mass of samples. Furthermore the Alpha Lifeboat had a solid rocket de-orbit motor and cold gas thrusters. The Soyuz DM has N2O4/UDMH thrusters and no de-orbit motor; the service module provides de-orbit. In case the emergency escape pods are necessary, could you count on the ITV to release the escape pods on the correct trajectory for Earth atmospheric entry? Or are you suggesting we abandon Mars samples in case of emergency and fit a Soyuz descent module with OMS rockets for significant trajectory change. That would mean normal insertion into Earth orbit is necessary to retrieve Mars samples. Hmm. Reducing mass of escape pods to 6 tonnes total would reduce the TMI stage, and permit both escape pods to be delivered by a single Soyuz launch vehicle and Progress service module and rendezvous radar.

Construction at ISS will cause a signifigant payload penalty and the need to rendevous with it carefully, which will require a guidence system or at least a space tug to be developed.
Overall, too many launches by Delta-IV HLV, just use an additional HLLV shot instead and skip orbital assembly.

Are you arguing for an Ares launch vehicle? I thought you argued against it. Now compare 3 Delta-IV Large launches @ $170M each (1999 price), plus 2 Energia @ $120M each (1994 price), plus 1 self-launching (custom built), plus 2 reusable space taxi launches, vs. just 2 Ares launches. Ares is a SDV so would it cost any less than Shuttle?

OSP crew taxi development will also add a great deal of cost to the whole operation and is not justifiable. If any crew access to the ISS at all is desired, CEV will be a better choice and would serve as the crew return vehicle for a Mars mission.

One major requirement for ISS is down mass. How do you get delicate science experiments down? You only need science drawers, not whole racks, but I doubt a European dumpbox would be delicate enough. Northrup Grumman is currently asking $25 billion for development of CEV, HL-20 had a budget of $2 billion and X-38 was $1.2 billion before they started making changes. At the price Northrup Grumman wants we're better off with a reusable vehicle.

Again, the pressurized rover must ride with the crew decent vehicle in the event of a missed landing unless accurate landing with high degree of confidance is demonstrated. A superlight "ATV" style rover with a pressure tent to fetch the pressurized rover to get the crew to the MAV? I don't think so... pup tent indeed... the poor astronaut would freeze to death even if he could get the thing closed. One of the whole points of having the rover with the lander is that there would be a second working LSS/power system as backup.

Ok, abandon the pressurized rover all together and include a separate LSS/power system with the lab, delivered by cargo lander before crew leaves Earth orbit. With low-e spectrally selective coating you greatly control heat loss. In fact, you could aluminize the film to be reflective with only a small transparent window. Add an air matress for thermal insulation with ground. Bring a small microwave oven to regenerate the primary suit CO2 sorbent, and zirconia electrolysis cell. That would generate oxygen to refill O2 tanks from CO2 driven from the sorbent, but the zirconia cell requires 900°C. You could insulate the zirconia cell to reduce heat required, but I don't think staying warm would be a problem. You'ld have to ensure the ATV engine stayed working to power the microwave oven and zirconia electrolysis cell.

As far as using the big rover to move the HAB in multiple pieces, dismantling the HAB is impractical. The LSS system will not be easy to disconnect, nor will the food/water supplies easy to transfer, and the rest of the stuff (furnature, clothes/hygene, cooking equipment, etc) won't be practical either if the rover's airlock can't mate to the HAB. Tow it all in one piece, or not at all.

An inflatable habitat is delivered in pieces. You have to inflate and erect it anyway.

Until there is a massive change in the political climate, it is not reasonable to even think about Russia having control over key componets of the mission arcitecture, and even then Russia is very likly just going to stab NASA in the back again and wring as much money out of us as possible, like they did with the ISS componets. We will wind up paying for most of it anyway... forget Zenit and RD-0120, use STS SRB and RS-68R.

I can understand a certain amount of nationalism, but this goes a bit too far for me. Russia very much wants to be part of a Mars mission. If you treat them fairly and with respect, they'll do the same. Pay close attention to the "If".

As for using an STS SRB for a manned vehicle, please tell me you're kidding.

GCNRevenger · 2004-12-05 15:22:24

I think that you signifigantly underestimate the amount of work that will be needed to maintain and operate the vehicles, rovers, and all that which will be involved. Its much more then just changing CO2 filters. I don't see any reason why it won't take just as much work to maintain everything then it will be to maintain the ISS. The price of demanding this level of robustness will likly simply exceed the cost of an extra man.

Bringing the multiple tons of TEI fuel from the Martian surface is harder then using a bigger rocket and sending it from Earth. The MAV vehicle you envision will be bigger and heavier then the MarsDirect ERV most likly.

The cost of developing the inferior and less safe "self launching" concept will easily exceed the cost of reviving TransHab (which you have to do anyway) and putting it on an available launcher. This concept is indefensable.

If you can't launch LH2 quickly enough to fuel up the vehicle, then the problem is your launcher is too small. There is also the problem of getting that fuel the station like everything else.

You are worrying too much about the return capsule, at the moment you don't have any mass budget at all for it when you add the ITV, lander, and TMI stage.

"Ok, abandon the pressurized rover all together"

Absolutely not, the missions' scientific value is all but crippled without it. Again again, I reiterate, the rover must ride down with the crew landers. With the crew lander. It is the only sane way to design the mission where the decent vehicle fails in the very first minute you land on Mars unless we perfect subkilometer accuracy. This is a minimum acceptable abort mode in my opinion... In this case, the foolish, dangerous, rediculously un-robust "ATV pup tent" idea is not nessesarry.

An inflatable HAB will NOT be deliverd in pieces, it will be a complete pre-assembled module, except for furnature, which has expanding walls. Pre-assembled from Earth period, building such a module on Mars is nonsense, especially with the volume of stuff that you need to put in it.

Overall your entire mission plan has even worse mass budget problems then MarsDirect does, it is simply unworkable for a four-man crew intending to get anything done, and so much of the system is thrown away that the reuseable ITV is not worth the trouble.

Furthermore, your seeming love affair with Russian rockets is not going to be shared by Congress or NASA, and the political climate plus the miserable situation over the ISS makes cooperation unlikly. No Soyuz, no Progress, no Proton, no Energia. I strongly hope and somewhat believe that we will simply, quietly, cut the ISS loose. Forget the Russians and the Europeans, if they want it, they can have it... we've got more important places to go.

The scare-tactic use of the $25Bn figure for CEV is also highly unbecoming of you Robert. You know full well that CEV is not just the capsule, but an entire suite of vehicles for getting us from here to the Moon. I also do not think the low $2Bn price tag for the HL-20 was ever credible especially given how complex the vehicle is compared to a capsule. I can't see the CEV capsule costing more then $5-6Bn, perhaps a little more for launcher modifications.

Direct launch will simply require a bigger rocket then Energia or Ares anyway, in which case clean sheet HLLV is the best option for America. Absolutely it should use Shuttle solid rocket boosters, four to six of them, as they are quite reliable for their given performance. The HAB module could be launched crewed with acceptable safety if there was some means of emergency escape from the launch vehicle, such as an escape pod built into the nose of the aeroshell. The crew can't ride in the uninflated HAB anyway.

RobertDyck · 2004-12-05 15:46:10

SpaceShipOne plus White Knight cost $30 million to develop and build, and the estimated cost is $80,000 per flight. An orbital vehicle will cost more, but $1.2 billion for development and construction of a 4-crew OSP is not low. The $2 billion figure for HL-20 cost everything including developing a new lifting body and constructing 2 operational vehicles, but not the expendable launch vehicle. The prices that contractors for NASA and the military ask are ridiculous.

If it appears I have a "love affair" with Russian rockets, it's simply because I like available, reliable, and affordable. Who makes it really doesn't matter. The Energia cost $120 million per launch in 1994, including the EUS upper stage. That could throw 25-26 tonnes directly to trans-Mars trajectory. How much would it cost America to re-invent that wheel? The Soyuz FG could lift 2 DM's to ISS for $50 million in 1999 dollars plus the Progress service module and rendezvous system. The Atlas V 401 is the smallest EELV and it cost $77 million in 1998 dollars; an automated docking system isn't available.

John Creighton · 2004-12-05 16:39:25

I think that you signifigantly underestimate the amount of work that will be needed to maintain and operate the vehicles, rovers, and all that which will be involved. Its much more then just changing CO2 filters. I don't see any reason why it won't take just as much work to maintain everything then it will be to maintain the ISS. The price of demanding this level of robustness will likly simply exceed the cost of an extra man.

Price in terms of research or production. If the price is mostly for the research then it will pay off in the long run.

Euler · 2004-12-05 16:49:56

The two options are to carry fuel for return to Earth from Mars surface, or from Earth surface. Mars surface is closer to LMO and Mars has lower gravity.

The problem with this is that you have to send feedstock, a nuclear reactor, and automated fuel production facility, a really big rocket stage, an interplanetary hab, an Earth descent module, consumables, life support equipment, aeroshield, radiation shielding, etc. all the way from Earth to Mars surface, and then you have to launch it all the way back to Earth. And it has to be reliable enough to survive several years in a hostile environment and launch without any maintenance. While you can get a lot more of your fuel from Mars' surface that way, the total fuel requirement for the mission will be much higher, and the total risk will be higher as well.

The technical challenges of building such a vehicle are simply too difficult, and most likely neither Energia nor Ares would be able to launch it.

Can Boeing launch two Deltas within a month of eachother?

The launch pad that Boeing built for Delta IV is designed for 15 launches per year, so it should be possible. Still, I think that using HLLVs would be a much better idea because it would have lower reoccurring costs and lower risks. Plus, you are using an HLLV to launch the ERV anyway, so why not use it for all launches?

RobertDyck · 2004-12-05 18:15:53

The two options are to carry fuel for return to Earth from Mars surface, or from Earth surface. Mars surface is closer to LMO and Mars has lower gravity.
The problem with this is that you have to send feedstock, a nuclear reactor, and automated fuel production facility, a really big rocket stage, an interplanetary hab, an Earth descent module, consumables, life support equipment, aeroshield, radiation shielding, etc. all the way from Earth to Mars surface, and then you have to launch it all the way back to Earth. And it has to be reliable enough to survive several years in a hostile environment and launch without any maintenance. While you can get a lot more of your fuel from Mars' surface that way, the total fuel requirement for the mission will be much higher, and the total risk will be higher as well.
The technical challenges of building such a vehicle are simply too difficult, and most likely neither Energia nor Ares would be able to launch it.

I don't follow. The debate was my idea of using the MAV as the TEI stage vs. NASA's DRM that sends propellant for TEI from Earth. Both systems leave the ITV in Mars orbit. Life support and consumables are the same. NASA's DRM uses ISPP for the MAV anyway, so using the MAV for TEI just means a larger tank, ascent engine, and feedstock. The enlarged mass for the MAV is less than the additional propellant, larger tank, and TMI stage for the ITV.

Do you want to debate Mars orbit rendezvous vs. Mars surface rendezvous? As you pointed out, surface rendezvous requires dropping the Earth descent module, consumables, life support equipment, aeroshield, radiation shielding, on Mars surface only to waste fuel to lift them off again. You could argue that Mars orbit is a more hostile environment than the surface due to micrometeoroids, greater radiation, and greater temperature swings, but a purpose-built ITV should withstand that. Mars surface has dust storms that sandblast everything, as well as alkali and salty soil. Mars surface is quite cold, not as cold as space in the shade but Mars surface can conduct heat faster than the vacuum of space. Space has 24-hour sunshine on one side, shade on the other. Mars surface has air to even temperature on all sides (although thin air) and has day/night cycles. These differing conditions can be optimized for. The zero-G toilet on Shuttle or ISS is quite complex, a toilet on Earth is simple because gravity feeds waste down the pipe. Mars surface has gravity, space doesn't. Life support can be optimized in separate ITV and surface habitat.

Basically, I don't know which position you're taking Euler.

John Creighton · 2004-12-05 18:43:15

I am trying to get a since of how things are working here I haven’t looked at each mission plan in enough depth. If I understand correctly NASA wants to bring the fuel for the return flight home but it needs a third vehicle to do it because we can’t launch a rocket big enough to drop off a payload at mars and then carry a payload back to earth. Would two heavy lift launches to assemble an ITV be out of the question? We have demonstrated orbital assembly on the ISS.

Dayton3 · 2004-12-05 18:56:10

NASAs reference mission (basically Mars Semi-Direct) uses one launch to put a Mars Ascent Vehicle on the Martian surface.

The MAV uses in situ fuel production to produce the fuel to ascend to Mars orbit for rendevous with the methane/oxygen fueled Earth Return Vehicle.

The reason for this is that if in situ fuel production fails on the Martian surface, the entire mission can still be saved by using another launch to deliver a FULLY FUELED Mars Ascent Vehicle to the surface (without sending the equipment that went down with the original MAV).

But the Mars Semi-Direct and NASA Reference Plan was always to send the Earth Return Vehicle to Mars orbit FULLY FUELED.

Now, Mars "Hybrid-Direct" is to send only the Earth Return Life Support Cabin and Reentry Vehicle to Mars orbit. In this plan, the Mars Ascent Vehicle manufactures ALL the fuel needed to ascend from Mars AND RETURN to Earth.

Dr. Robert Zubrin once said that Mars Hybrid Direct has all the disadvantages of both Direct and Semi-Direct.

The only advantage is that the Earth Return Vehicle Cabin and Reentry Vehicle can be considerably larger than in either of the other plans.

I still think Mars Direct is by far the best option.

Dayton3 · 2004-12-05 19:01:20

In addition my thinking is this:

If you are willing to limit the crew to four (or at most five) then Mars Direct is the best mission plan. If you want to go with a crew of six or more, chances are that Semi-Direct or Hybrid Direct will be the only way to go because of the difficulting in lifting large enough Earth Return Vehicle to the surface of Mars with one launch to support a larger crew.

The only way to lift enough to Mars using the two launches of Mars Direct for a six man crew is probably by using a nuclear thermal rocket third stage.

Euler · 2004-12-05 19:48:22

I don't follow. The debate was my idea of using the MAV as the TEI stage vs. NASA's DRM that sends propellant for TEI from Earth. Both systems leave the ITV in Mars orbit. Life support and consumables are the same. NASA's DRM uses ISPP for the MAV anyway, so using the MAV for TEI just means a larger tank, ascent engine, and feedstock. The enlarged mass for the MAV is less than the additional propellant, larger tank, and TMI stage for the ITV.

Sorry, I thought you were using the MAV as the ERV like Mars Direct. Doing it your way certainly seems more reasonable than Mars Direct, but I am still not sure if it is better than just having a fueled ERV in orbit. Do you have any calculations of how much fuel you will have to bring up?

RobS · 2004-12-05 21:50:34

The Mars Direct ERV has an 11.5 tonne ERV cabin (which includes consumables) and the two-stage ERV uses 82 tonnes of propellant to push the cabin from the Martian surface to Earth (a delta-v of about 7.0 km/sec, I think; that figure isn't in *The Case for Mars*). If you leave the Interplanetary Transit Vehicle (ITV) in a one-sol orbit (250 km by 33,810 km), which is what I think the Design Reference Mission assumes, the delta-v from the Martian surface to the ITV is 5.5 km/sec and the delta-v from that orbit to Earth (6 month trajectory) is about 1.5 km/sec. The mass ratio to push something to Earth from the 1-sol orbit using methane and oxygen is 1.5 (in other words, 0.5 tonnes of fuel to push every 1 tonne of payload).

If the 11.5 tonnes of ERV cabin were divided into a 4-tonne ascent capsule (which could also serve as the life boat) then 7.5 tonnes is left to serve as fuel. The ERV can now push that fuel all the way to Earth and only needs to push it to the 1-sol orbit, so that means at the 1-sol orbit there is 11 tonnes of fuel left (because the ERV would have had to use 50% as much mass of fuel to push it to Earth). The 11 tonnes of fuel is enough to push 22 tonnes to Earth. Including the 4-tonne capsule, that leave about 18 tonnes for the ITV.

So that gives you a rough idea of the larger size of an ITV that is possible using the existing Mars Direct equipment (more or less).

Another way to figure it: to push something to a delta-v of 5.5 km/sec, you need a mass ratio of about 4.25 (in other words, 3.25 tonnes of fuel for every tonne of payload). Methane/oxygen is a pretty dense fuel combination, so tanks and such mass only about 8% as much as the fuel. So if you need to push, say, 25 tonnes to Earth from a 1-sol orbit, you need about 13 tonnes of fuel there, which in turn requires 2 tonnes of tanks and engine, so now you have to get 15 tonnes to the 1-sol orbit; this requires 63 tonnes of fuel, which requires 5 tonnes of tanks that in turn require another 15 tonnes of fuel that require another 1.2 tonnes of tanks. . . at that point I'd dtop iterating because the calculation is rough anyway, and you get a vehicle that has to hold 91 tonnes of fuel, which is in very good agreement to the numbers above.

-- RobS

P.S.: I should add this: I have not assumed staging and most likely any Mars Ascent Vehicle for the initial missions will not be reusable and will have two stages. That improves your lifting capacity to the 1-sol orbit by a tonne or two for a Martian surface take-off mass of 100 tonnes or so. But I'd ignore it in these calculations and consider it safety margin.

GCNRevenger · 2004-12-05 21:52:39

Skimming through the third section of the NASA DRM study, the TEI burn requires 52MT of Methane/LOX fuel, with the ERV weighing about 65MT dry including return capsule.

The MAV vehicle from same weighs 5.5MT empty, about half of which is tankage, and 26MT of fuel.

Now lets calculate some pertinant figures for the MAV, assuming that its dry mass is not added to the ERV dry mass. With a little extra for the extra engines, you have a mass ratio of about 20% to orbit, which means you will need to make 338MT of fuel to reach orbit with enough to push the ERV home.

Now since the tankage penalty is around 5% of fuel mass, lets say that the MAV now weighs around 20MT. The fuel bill for launch is now 412MT. Adding the vehicle dry mass to the ERV mass, with "free" additional tankage, now you need 508MT of fuel for the ERV... A little bit bigger now ey?

How much Hydrogen feedstock would that require? I bet that the extra Hydrogen feedstock and extra MAV tankage is probobly about the same as just shipping the ERV fuel from Earth directly.

Now about the HL-20 redux:

"SpaceShipOne plus White Knight cost $30 million to develop and build..."

Has exactly zero to do with building an orbital vehicle. The scale of size, performance, and complexity of the X-Prize toys is so small they don't fall into any worthy comparison with real orbital vehicles.

but $1.2 billion for development and construction of a 4-crew OSP is not low..."

Yes. Yes it is too low. I maintain that the $2Bn (closer to $3Bn today) was never a sane figure to begin with. The fact that other OSP concepts cost so much more clearly underscores that this number cannot be taken seriously in any context, and is the product of either lies or incompetance. As this figure is too low, so is yours.

And to poke a big hole in your "self launching" idea: The Atlas rockets are only about 3.5-4.0m wide. About twelve to fourteen feet. That clearly is not enough for even a crew of four.

As for Russian rockets, Energia does not exsist... in fact, it has never exsisted in the heavy lift version with all the Zenits. Only America has the money to rebuild build and use Energia, and that isn't going to happen... Congress would rather spend far more and have it stay here then go to Rosaviakosmos.

ftlwright · 2004-12-05 22:40:45

Hell, the x-38 CRV was a $2 billion dollar program and that was a dead stick - parasailing contraption that had no reusability requirement. An HL-20/42 type program would be twice the cost w/o a doubt.

With respect to In-Situ production, absolutely NO manned flight equipment can rely upon it until FULL SCALE production capabilities can be proven, preferably on the martian surface. You can send humans people on a mission of this scale with unproven hardware,... that's unacceptable.

With respect to engine in general... they will be American-made, end of story. What we should push for is an efficient production methodology by whom every is slated to build the engine(s). We need clear, honest communication from those involved in the project (rather than the abomination that nasa.gov is). If that mean Mars Society provides funding for Russian rocket scientist to conduct an independent review of component development, so be it.

The crew needs to come down w/ some sort of pressurized shelter. If there is a problem with the HAB or conditions at the MAV site begin to deteriorate for some reason (unstable surface, sinkholes); the crew needs to be able to get to the MAV site immediately and launch ASAP.

The question of SSTO or staged for the MAV is an important one. In my view, your better off going SSTO and dealing w/ the weight penalty. Flight engineers have a hard time with staging equipment sitting on the launch pad one-hundred feet away; image the issues you would need to account for with equipment 35M mi away (on a good day). At the end of the day, you have to eat some of these weight penalties for the sake of safety.

PurduesUSAFguy · 2004-12-05 22:57:36

It seems to me our quickest option for developing a HLV is a revived updated Saturn V with some updated version of the F-1 with cryogenic propellents or some other very high thrust modern engine, I don't know about scalability though. Along with 4 or 6 five segement SRBs and you've got a recipe for a Mars booster.

RobertDyck · 2004-12-06 01:00:37

The X-38 was originally announced to carry 4 astronauts and use metallic heat shield. It was changed to 7 astronauts and the same heat shield as Shuttle. Then they cancelled it and Europe started conversion to an OSP launched on Ariene 5. Changing mid-project what you're trying to do will always increase the cost; this increased cost from $1.2 to $2.0 billion. I think it would have cost $1.2 billion for the 4 person OSP if they started with that and stuck to it.

I just submitted my mini-MAKS/HL-20 idea to NASA (without any cost estimate). We'll see what they do with it.

And to poke a big hole in your "self launching" idea: The Atlas rockets are only about 3.5-4.0m wide. About twelve to fourteen feet. That clearly is not enough for even a crew of four.

The Russian service module Zvezda is 4.2 metres wide at its widest point, but 13.1 metres long. Think cylinder on its side rather than on its end.

As for Russian rockets, Energia does not exsist... in fact, it has never exsisted in the heavy lift version with all the Zenits. Only America has the money to rebuild build and use Energia, and that isn't going to happen... Congress would rather spend far more and have it stay here then go to Rosaviakosmos.

The strap-on boosters are Zenit first stages; Zenit is in production for Boeing's SeaLaunch. I asked KBKhA about RD-0120 engines; they have all the jigs, they just need a new CNC machine and are willing to swallow the tooling cost themselves if they get a paying customer. The launch pads are still intact, the vehicle assembly building needs a new roof and any water damage since May 25, 2002. Its biggest problem is lack of tank manufacture. One Mars Society member reported the head of Rosaviakosmos talked to Sean O'Keefe at a conference this year about Energia. It's not quite dead yet.

With respect to In-Situ production, absolutely NO manned flight equipment can rely upon it until FULL SCALE production capabilities can be proven, preferably on the martian surface. You can send humans people on a mission of this scale with unproven hardware,... that's unacceptable.

That's why I want to see a Mars sample return mission before the first manned mission. And I want it designated a technology demonstrator where ISPP is the primary mission objective and Mars soil sample secondary. That should prevent anyone from attempting to remove ISPP from the mission architecture.

SpaceNut · 2004-12-06 05:29:51

Thanks RobertDyck, for sending the ideas Nasa's way. The help was illustrated as always being there if they would only ask was just one of the themes that ran throughout the commissions hearings.
As for the Zvezda, was that not the module that was made by us but not flown since the Russians came though with theirs. Even if not completed it would be a good starting point to making what is needed.
Some of the many projects that have been cancelled seem to be making there way back into reality as being necessary to carrying out the Space explorations goals.

GCNRevenger · 2004-12-06 06:13:27

I don't find that excuse credible. Please explain why exactly your proposed vehicle would be on the order to four to five times as cheap as competing OSP designs? The descrepency between these prices follows along nicely with the realitive complexity for OSP versus the stock X-38, which was far, far too simple to serve as the vehicle you envision. I would like to remind you that the HL-20 never really made it past the concept phase, so its actual cost was highly speculative, and I believe that it or any vehicle like it of smaller scale will cost much more, if for no other reason that the complexity will not scale with the size.

So, you would send people to Mars in a vehicle not bigger then an ISS module? No larger then a train car really... A step up from MarsDirect, but I still think it would be too cramped. For a vehicle of similar dimensions, TransHab offers much more volume without weighing signifigantly more. And you will have to build one or two for the mission anyway.

"...Energia. It's not quite dead yet."

Yes it is... 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. Hence, since NASA is the only one with the money to use Energia, then there will be no more Energia. Not to mention that much of vehicle assembly, testing/fueling, and manned flight operations would have to be bodily moved to Russia... Energia is under-powerd for a single flight direct mission anyway.

For HLLV, I don't like the idea of rebuilding Saturn and upgrading it, I think a more efficent launcher can be built clean-sheet. For Saturn, you would have to restart production of the old F-1 engines, the J-2 engines, and redo the control systems from scratch with modern electronics... and then have to worry about modifying it structurally for booster attachment which was never intended in the base design.

Instead, build somthing new... Large main tank based on Shuttle's but bigger, with structural reinforcements for top mounting with optional upper stage. The main tank would have five RS-68R regenerative cryogenic engines with SSME-like ISP, and would be ringed by 2 to 6 four or five segment Shuttle SRBs depending on payload being launched. The upper stage could be powerd by a single RD-68R or a simplified one-shot SSME, which would be preferable to clusterd J-2 or smaller engines.

Target maximum payload: 200-250MT

SpaceNut · 2004-12-06 06:32:38

What would the other parameters of this clean slate be for height and width of all stages? Would it taper from the lowest stages to the top as apollo did? Can you post a picture of rocket or nice glossy drawings? Some people need to see in order to evaluate any design concepts.

GCNRevenger · 2004-12-06 09:54:29

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.

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). 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.

I think this would be the ideal vehicle if single-flight direct launch to Mars was required, and a rocket of this scale would leave large design margins for safety, for extra payload, and for future growth and versatility.

If two-flight-to-Mars is accepted, then such a vehicle would be vastly overkill most likly.

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.

It should be safe enough for limited numbers of manned flights, and the crew ought to ride in an escape pod on top of the faring/aerobrake sheild anyway.

John Creighton · 2004-12-06 11:16:44

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.
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). 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.
I think this would be the ideal vehicle if single-flight direct launch to Mars was required, and a rocket of this scale would leave large design margins for safety, for extra payload, and for future growth and versatility.
If two-flight-to-Mars is accepted, then such a vehicle would be vastly overkill most likly.
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.
It should be safe enough for limited numbers of manned flights, and the crew ought to ride in an escape pod on top of the faring/aerobrake sheild anyway.

I'm Sold. So you are talking one flight to Mars as opposed to two as recomended by mars direct?

GCNRevenger · 2004-12-06 12:07:47

No, the reason for building such a big rocket would be to avoid the need for on-orbit assembly entirely and provide maximum practical payload with exsisting hardware and facilities, hence maximizing marginal payload.

Such a vehicle would use a much fewer number of engines then Comet or any of the large Saturn derivitives, with a total of only six ~$20M engines and six Shuttle SRBs are recycled for ~$30M each. A pair of Shuttle-C/Z launchers would require two SRBs and 2-4 cryogenic engines each. The main tank, while much larger, would not have anywhere near the surface area (or cost) of two smaller tanks and a single vehicle will be less costly to build then a pair of smaller ones.

The two-shot aproach would use two launches in the 100MT range, one with the payload + aeroshell and the second with the TMI stage, which would be mated on orbit and only then sent to Mars. The problem with this is, liquid hydrogen fuel has a practical on-orbit lifespan of about one month, so you must launch two large rockets in rapid sucession.

I am thinking of a NASA DRM style mission except that the Lab/Hab is omitted and each flight bulked up, with the main HAB being partially inflatable perhaps except for the windowless nose cone command section, which could double as the escape section in the event a launch abort is needed. The aim is to make enough room for six people plus lab space or eight without lab space.

This would require you either make the sides of the Hab capable of withstanding reentry, or else make the inflatable envelope retractable with a recloseable aerobrake shield hinged around the nose cone and opening radially. Or perhaps have the aerobrake cone sans command section extend forward and clear the vehicle, giving enough room for the inflatable walls to expand. Somthing of a nasty failure mode... perhaps only the lower skirt of the vehicle would have a deployable volume once the rovers, reactor, drill, and other gear is unpacked.

If launching crew with the vehicle is considerd too big of a risk, the superlauncher could place the entire vehicle in LEO followed by a CEV flight on Delta-IV+, which would permit plenty of time for rendevous, checkout, and getting settled in before the liquid hydrogen would boil off. This is not so easy with a two-launch scheme.

If smaller flights become a big demand, a smaller core based on Shuttle tankage could be made available later, accomodating two boosters, 2-3 RS-68R engines, and a cluster of RL-60 engines for the upper stage if needed.

RobertDyck · 2004-12-06 12:12:20

Please explain why exactly your proposed vehicle would be on the order to four to five times as cheap as competing OSP designs?

I'm taking the original $2 billion budget for HL-20 and subtracting work already done. Another budget approach is to take the X-38 original budget unmodified. The two approaches result in very similar results. You shouldn't ask why my budget figure is low, rather ask Boeing and LockMart why their budget is so high.

So your idea of a mission profile is a single throw using a giant rocket, and you blindly criticize everything else. I have news for you, not going to happen. The age of the giant rockets is over. A launch vehicle as big as Saturn V will never be built until after a major industrial economy is established in space. That means asteroid mining and other profitable industries must first be built with Energia (an existing left-over) or medium lift launch vehicles like Delta IV Large, Atlas V 55x, Ariene 5, Proton, or Angara 5. A manned mission to Mars is a great way to get that industry started, but it will never have Ares much less Nova. Use what you have or be forever stuck in LEO.

John Creighton · 2004-12-06 12:15:37

So your idea of a mission profile is a single throw using a giant rocket, and you blindly criticize everything else. I have news for you, not going to happen. The age of the giant rockets is over. A launch vehicle as big as Saturn V will never be built until after a major industrial economy is established in space. That means asteroid mining and other profitable industries must first be built with Energia (an existing left-over) or medium lift launch vehicles like Delta IV Large, Atlas V 55x, Ariene 5, Proton, or Angara 5. A manned mission to Mars is a great way to get that industry started, but it will never have Ares much less Nova. Use what you have or be forever stuck in LEO.

I don't know. It shoulds like GCNRevengers rocket can pretty much be assembled from what we have now. I don't really think there will need to be much of an expansion in terms of factories.

GCNRevenger · 2004-12-06 12:39:21

You seem to be under the mistaken impression that signifigant work was ever done on the details of the vehicle. The HL-20 never left design study phase, very little actual work was ever done on it beyond aerodynamics and ingress/egress practice.

This being the case, why isn't the nonexsistant huge savings you are trying to cash in reflected in the other derivitive OSP concepts? Surely the people that worked on HL-20 wouldn't have thrown away the concept if it was that viable and half-finished as you claim.

The X-38 CRV would have hardly been finished for that kind of money, and would not become a fully orbital, launchable, maneuverable or reuseable vehicle without billions more. I am not willing to entertain any notion that that the large aerospace companies are overcharging by more then 25%, which would be about tripple your price, for a vehicle that is three times as complex.

I am not blindly critical of other concepts, I simply favor this one. I like it better because it minimizes the number of launches, so you can in theory eliminate larger numbers of the KSC Shuttle army and the chance you will lose a payload is reduced. This scheme also offers large margins for any forseeable heavy payload of flexible size we want to send to Mars/Moon/Jupiter/etc, does not require any all new hardware or facilities, and quite simply will make access to space on a larger scale then any smaller mission arcitecture possible... After all, the ultimate objective is to go to stay, is it not? You can't do that with a puny "just barely" tin can like MD or ITV.

That said, I don't favor this method over a two-HLLV Payload+TMI scheme by much, and if development cost becomes the life or death limiting factor, it may be worthwhile. The cost of one launch versus two should be carefully studied.

Since America would never tolerate outsourcing our space program to the Russians and their Energia, how much will it cost to develop Ares? Shuttle-C? Shuttle-Z? Why not spend the extra few billion and develop somthing truely powerful, powerful enough to not only carry us to Mars, but to establish on Mars... or the Moon... or Jupiter with GCNR engines.

This is one of those things I've been trying to get into your head, that the mission of science and construction should demand six crew plus about double the payload of MarsDirect and cyrogenic Ares, which although can be accomodated by multiple SDV launches, the marginal cost of making a system with much more capacity, capability, and flexibility is small enough that it is worth the extra expense for a rocket that will carry us beyond "just there and back."

Furthermore: This notion that it is any kind of viable, plausable idea to build a useful Mars mission out of today's puny tinker toy orbital assembly by satelite launcher somehow is nonsense, even a flags & footprints mission with a two-man crew is questionable. HLLV is an absolute nessesitty, and since Energia is not going to happen, then some kind of home grown HLLV of some sort will be a part of the minimum ticket price to Mars... there is no way around it.

John Creighton · 2004-12-06 12:48:01

This is one of those things I've been trying to get into your head, that the mission of science and construction should demand six crew plus about double the payload of MarsDirect and cyrogenic Ares, which although can be accomodated by multiple SDV launches, the marginal cost of making a system with much more capacity, capability, and flexibility is small enough that it is worth the extra expense for a rocket that will carry us beyond "just there and back."

I agree and if we ever do orbital assembly with such a big vehicle imagine what we could build.

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