Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

Grypd · 2004-12-01 20:08:23

Look, as far as I'm concerned, a 10% chance of astronaut death during the mission and a 20% chance of mission failure (ie, they fail to land on Mars or are force to abandon most of their samples and data) are ACCEPTABLE risks.
And I would wager that you would still get HUNDREDS of very qualified astronauts volunteering.
Also, I'll submit that reducing the danger of space missions has also had the effect of reducing public support as well.

And I can quarantee that the politicians and the powers that be do not think so and as they control the money they control the mission. And you may get your volunteers but the public would be horrified if that amount of risk is put to them.

It really is as close to this that should another disaster resulting in the loss of an American crew happens then it is likely that the US will withdraw from manned spaceflight. For there is enough pressure on the manned flights to be cancelled by the likes of Dr Bell and the ilk that any accident could result in enough media pressure etc being put to bare that it does happen. And any mission to Mars have such a catastrophe then you can forget any further missions, This is the world we live in now. The apollo spirit is gone people really do prefer boring space flight. If something happens that makes it look dangerous then it will likely be so tied up in safety committees that it will be more or less cancelled

GCNRevenger · 2004-12-01 22:13:53

An 80% sucess rate is clearly unacceptable, and since return to Earth largely depends on everything on the Mars end going right, there aren't many abort modes. If the system fails, then the crew is history.

Austin Stanley · 2004-12-01 23:58:31

To be bluntly honest, 80% failure is not unacceptable because there is a 20% chance that the crew will die, it is unacceptable because there is a 20% chance that billions of dollars will go to waste. I'm sure you could find volunteeres even for a one-way mission to mars, but it's not so much the cost in human lives as it is the billions of dollars down the tube.

Euler · 2004-12-02 00:06:47

To be bluntly honest, 80% failure is not unacceptable because there is a 20% chance that the crew will die, it is unacceptable because there is a 20% chance that billions of dollars will go to waste. I'm sure you could find volunteeres even for a one-way mission to mars, but it's not so much the cost in human lives as it is the billions of dollars down the tube.

That is the sensible, pragmatic, engineer's view of the risks. The view of most ordinary people, and also the view of the politicians that control the budget, is that people are more important than even a very large sum of money. People just cannot understand how enormous the sums of money involved are.

SpaceNut · 2004-12-02 07:13:53

I disagree GCNRevenger on the cutting of corners that caused the near fatal mishaps and funerals of Apollo, Soyuz-1, Challenger and Columbia. But rather to the lack of knowledge as to the consequence of ignore engineering warnings and mismanagement decision making process that was flawed.

GCNRevenger · 2004-12-02 09:31:33

When I say "cutting corners" I am not talking soley about dropping hardware items from the mission, I am talking in a more general sense... The sense that it is okay to not design or fly the mission like you SHOULD in order to save money or time. If it is found that cosmic rays are more dangerous then was thought, and it requires a few tons more shielding and more billions of dollars, then it does, that is simply the price of doing business. You build and take what you need to safely fulfill the mission; the cost being higher is not an excuse to build a dangerous or worthless mission.

Challenger failed because the corner of time was cut
Apollo-1 failed because the funding and development time was too low
Soyuz-1 failed because the development time was cut
Columbia failed because NASA didn't invest the money to fix the STS-ET

The shuttle managers lauched Columbia because they felt pressed for time, which made them ignore risks that they should not have.

The early model Apollo capsules were simply badly designed and badly built. O2 atmosphere, lousy wiring, even debries from construction found under panels in this flight-type vehicle.

Soyuz-1 failed because time and money were not alotted to properly design the vehicle

Columbia failed because NASA ignored a serious risk before Columbia ever was rolled to the pad, in order to save money and time, the real reason that the shuttle managers went ahead with the launch anyway.

If doing Mars right costs more money then that is too bad, but that is the way it is.

Cobra Commander · 2004-12-02 09:42:42

How safe is safe enough? We're talking about putting people in a metal can, setting off a controlled explosion beneath them and hurtling them through a radiation-filled airless expanse to a barren, frozen dead planet. It's dangerous no matter how you cut it. There comes a time when you have to say "good enough" and go, the only question is where that point is.

The other side being that, as mentioned in earlier posts, any major catastrophe could kill manned spaceflight entirely in this country, we have little or no stomach for such things and strictly speaking none of it is necessary.

???

GCNRevenger · 2004-12-02 09:51:07

Minimum safety is somthing of a subjective issue, granted, but I think it would be just plain immoral to call for volunteers for a mission if it would be much less reliable then a satelite launcher or somthing... that if you would feel bad about pushing the "ignition" button in mission control, then that is a bad sign.

RobertDyck · 2004-12-02 16:34:36

If the ERV/MAV is a seperate vehicle from the HAB module/lander, then carrying the long range rover in the initial vehicle is non-negotiable, the risk of landing error with today's technology is too great.

Apollo 12 landed within walking distance of Surveyor 3. If we could do it in 1969, why can't we do it now? Airbag landing systems are low accuracy, and Mars Pathfinder didn't have any means of recognizing topography for last-minute manoeuvres. Modern lidar combined with landing rockets/legs have pin-point accuracy; especially with a beacon to target. A long-range rover is a good emergency backup, but you only need an open rover with extra supplies for suit life support, and a pressure tent to sleep in.

BWhite · 2004-12-02 16:49:23

If the ERV/MAV is a seperate vehicle from the HAB module/lander, then carrying the long range rover in the initial vehicle is non-negotiable, the risk of landing error with today's technology is too great.
Apollo 12 landed within walking distance of Surveyor 3. If we could do it in 1969, why can't we do it now? Airbag landing systems are low accuracy, and Mars Pathfinder didn't have any means of recognizing topography for last-minute manoeuvres. Modern lidar combined with landing rockets/legs have pin-point accuracy; especially with a beacon to target. A long-range rover is a good emergency backup, but you only need an open rover with extra supplies for suit life support, and a pressure tent to sleep in.

A sensible robotic precursor mission would be to deploy guidance transponders in a nice grid pattern all around the ERV/MAV. During the 10 months or so between the landing of the ERV/MAV and the launch of Mars One scurry about with robot drones dropping guidance beacons to ping the incoming crewed descent module.

Didn't both MERs hit very nicely within their landing ellipses?

In the meantime, throw rovers and supplies and practice.

GCNRevenger · 2004-12-02 19:10:55

If the ERV/MAV is a seperate vehicle from the HAB module/lander, then carrying the long range rover in the initial vehicle is non-negotiable, the risk of landing error with today's technology is too great.
Apollo 12 landed within walking distance of Surveyor 3. If we could do it in 1969, why can't we do it now? Airbag landing systems are low accuracy, and Mars Pathfinder didn't have any means of recognizing topography for last-minute manoeuvres. Modern lidar combined with landing rockets/legs have pin-point accuracy; especially with a beacon to target. A long-range rover is a good emergency backup, but you only need an open rover with extra supplies for suit life support, and a pressure tent to sleep in.

The Apollo LEMs didn't have to contend with an atmosphere though, which made idealized easy Newtonian billiard ball physics workable. The density and height of the atmosphere varies depending on its exposure to solar radiation and temperature.

We just aren't that good at landing realiably on Mars yet. We have to be able to hit within walking or driving distance of the return vehicle one way or another.

Even if we do figure out how to land with single-kilometer accuracy, the rover should be sent with the HAB anyway in the event that the system fails and the Hab lands off course. This would also provide limited LSS capability if the HAB fails after decent.

I don't like the idea of carrying a light rover with some silly "pressure tent" on the back, the rover should be capable of long multi-week treks in the event of navigational failure.

Shaun Barrett · 2004-12-02 20:26:04

I agree with Robert and Bill.
Technology is only getting better. There are always solutions to problems and I think we need to shift the focus away from concentrating on the problems and toward concentrating on the solutions.

GCNR is telling us to work up to a standard, not down to a price, which is highly commendable. It's an especially defensible position when human lives are at stake, of course, and its sober logic, with compassionate overtones, sounds just like the oh-so-reasonable, schmaltzy, liberal droning you hear from the progressive social engineers on T.V. ... everything is a zero-sum game and we mustn't take any risks! (Oops, sorry! I think my politics are showing.)
But it doesn't have to be like that. It doesn't have to be a stark choice between trillion-dollar Mars missions and total disregard for safety, which is what GCNR seems to be telling us - with what I'm starting to perceive is the usual, subtle subliminal message that human space exploration is just not going to happen, it's all too hard or too expensive, so forget it! (Is that what you're saying, GCNR? Mars Direct won't work? Space Elevators won't work? Burt Rutan's plans for cheap orbital spacecraft won't work? ... Is there a pattern here or am I imagining things?)

America never used to be like this. All problems had solutions and, God damn it, the yanks were going to find those solutions! If one idea didn't work, they'd toss it out and think of another one.
Robert and Bill seem to think pin-point landings are perfectly possible and doable, and I agree with them. Radiation shielding technology, e.g. Demron, is advancing, and using the mission's water supplies and a radiation storm shelter have all been worked out.

From memory, Alan Shepard knew he stood a one-in-ten chance of dying in the ensuing fifteen minutes when they ignited his rocket engine back in 1961. Before his Apollo 8 flight, Bill Anders rated his chance of dying due to catastrophic mission failure at 1-in-3! Did they worry about that? Nope.

Come on! We're the Mars Society. We're supposed to be telling people how we can start a brand new chapter in human history. We're supposed to be full of optimism and enthusiasm and a can-do attitude. We need to be sending out a positive message here.
A new world is waiting for us. :rant:

[O.K. Rant over! :;): ]

SpaceNut · 2004-12-02 20:59:54

Rant or not thank you,
I try to put forth the best that a common man can give in all these discussions, many of which are well over my head. I feel that the best option for lowering costs is to design one ship template to have all needs fall under for the Mars destination.

Lets look at the lander:
What is the max down mass needed to land with the end result is to aim for accuracy. I realize that the crew size, consumables will determine some of this mass and the remainder would be the fuel to land.

Now all unmanned landers must be capable but have there components turned off that would be used for a manned presence or at worst have them removed for increased down mass for the heavy cargo needs all in the same ship shell size.
This allows for lower construction costs and a ready available spare parts inventory.

Is there a need to leave anything in mars orbit like what was done for the lunar apollo missions. IMO I would say no unless the plan is to join them together to create a small orbiting work station or a resupply depo for the return home.

Another thought is since the lander must also be the launcher back to orbit using methane I think it would also be prudent to design the engines from the start to use that fuel source from earth and for its eventual landing on the martian surface.

Euler · 2004-12-02 21:20:37

Mars Direct won't work? Space Elevators won't work? Burt Rutan's plans for cheap orbital spacecraft won't work?

On those three issues, I agree with GCNRevenger. Human spaceflight is going to happen, and it is worth it. However, in the near term I expect gradual and incremental improvements, rather than sudden changes that magically make everything drastically cheaper. If it sounds too good to be true, it probably is.

RobertDyck · 2004-12-02 23:51:40

By the way, I attended NASA's Capability Workshop on Tuesday and made a couple presentations. My presentation on a reduced weight PLSS and spacesuit optimized for Mars (and the Moon) was well received. One point was the need to replace the silver-zinc battery that lasts only 6 EVAs with a lithium-ion battery like a lap-top computer; suitable cells are available commercially now that will last 800-1500 EVAs. Manufacturers specs are based on constant temperature and consistent discharge, so may be fewer in practice, but this is significantly greater than 6. A NASA guy said they are currently working on one and the life so far is 500 EVAs. Since a mission will stay on the surface 500 sols (Martian days) that matches. Yea! This is a dramatic leap in space capability, but it's simply laptop technology applied to spacesuits. We need more stuff like that; applying simple available technology in ways that provide dramatic results.

I also saw a presentation on a liquid oxygen compatible all-composite propellant tank based on a fluoropolymer. I mentioned the fluoropolymer I found for that purpose, and contact information to buy it. The person who made the presentation hadn't heard of the one I found. Hopefully my free advice will result in a low-cost reliable composite LOX tank.

Shaun Barrett · 2004-12-03 01:12:06

Brilliant!

Go Robert!!! :up:

SpaceNut · 2004-12-03 06:00:08

Thanks for going, Not all of us here blogging on this site have that ability, let alone the time available nor the financial capacity.
Thanks again, and tell us more....

I know that where I am working, we are designing a cooling suit that is using Lithium Ion rechargeables. The pack though only lasts a little over an hour due to high load currents. The recharge takes roughly 6 hrs on them. Also the pack at the end of run time is at 60 C. The suit is designed for desert use.

I think that they will be hopefully looking at a heating suit in the future.

But enough about work, now back to space talk...

RobertDyck · 2004-12-03 08:25:13

I know that where I am working, we are designing a cooling suit that is using Lithium Ion rechargeables. The pack though only lasts a little over an hour due to high load currents. The recharge takes roughly 6 hrs on them. Also the pack at the end of run time is at 60 C. The suit is designed for desert use.
I think that they will be hopefully looking at a heating suit in the future.

A French company called http://www.saftbatteries.com///120-tech … m.asp]Saft has a few large Li-ion batteries, the link takes you to their list. I was looking at the VL27M battery for spacesuits: 6 batteries in series provide the voltage and current required for the EMU, and 7.5 hour duration. To see that one click the link for VLM series then click "More Information". It's a 27Ah cell; the larger VL41M has 41Ah capacity. The "M" in VLM stands for Medium Range. They also have VLE for Energy, more capacity but less current, and VLP for Power, more current but less capacity. Unfortunately the VLE is not available in the shorter cell size. Besides, the VLE cell dramatically looses capacity with changes in temperature. The problem with Saft is they want to work with large volume manufacturers. To quote from my correspondence with Michael Saft:

At the present time SAFT's VL family of Lithium ion products are being supplied directly to OEM's for Prototype and Serial production programs and are not available to the general public or through our distributors.

I mentioned I want to manufacture a product for a customer so I am an OEM, not "general public", but production of batteries for a spacesuit isn't "Serial production".

A German company called http://www.gaia-akku-online.de/ENG/SEIT … Link1]GAIA also has a 27Ah battery, this one is model HP-601300. The link will take you to it's specs and the "Download" link at the bottom will give a bit more detail in a PDF document. It's a little heavier but the US contact was more interested in doing business than Saft.

I was going to keep these contacts proprietary, but since NASA is already working on a Li-ion battery and isn't interested in hearing a sales pitch, I might as well post them here. There are other batteries available, just do an internet search, but these ones were the right size to replace the battery in the EMU.

SpaceNut · 2004-12-03 08:49:50

Thanks for the links, our particular requirement is weight restrictive, hence the performance times. I have found 2 other companies that will deal with the low volume or proto style quantities.
EaglePicher
MicroSun Technologies

GCNRevenger · 2004-12-03 11:03:40

Technology is only getting better. There are always solutions to problems and I think we need to shift the focus away from concentrating on the problems and toward concentrating on the solutions.
GCNR is telling us to work up to a standard, not down to a price, which is highly commendable... GCNR seems to be telling us... that human space exploration is just not going to happen, it's all too hard or too expensive, so forget it!
...pin-point landings are perfectly possible and doable, and I agree with them. Radiation shielding technology, e.g. Demron, is advancing, and using the mission's water supplies and a radiation storm shelter have all been worked out... We're supposed to be full of optimism and enthusiasm and a can-do attitude.

I certainly don't think that manned flight is too expensive or impractical, it can be done and should be done in order to preclude the possibility that the Earth cannot sustain a developed humanity on its own, to enrich our lives through fulfillment of the psychological need for exploration, and perhaps to fulfill the material and psychological desire to expand.

What I see going on around here is that people are getting too excited, particularly about MarsDirect and Doc Zubrin, and not looking at the mission like it should be looked at and how it will be looked at by congressmen, scientists, and engineers. In the excitement and zeal, this fallacy that going to Mars is no big deal... that its easy and not as hard as the naysayers make it out to be... is a serious threat to the credibility of Marsies'. That and its side-effects is what I am trying to address.

MarsDirect is one such side effect, that the desire and beliefe that "doing Mars" is easy has produced a mission arcitecture that is unworkable and unsafe without sacrificing all the scientific payload and then some or even perhaps with a politically touchie and expensive revival of NTR propulsion. The fact that it is too optimistic seems to be glossed over by proponets who are desperate to prove the "no big deal" fallacy.

Another issue is the idea that technology improvements will somehow ride to the rescue. The problem is still inherintly a fundimental one, that because of the limited energy density of chemical or solid-core NTR engines plus the high minimum degree of complexity and robustness. These facts quite simply demand a mission that is bigger and more expensive then at least Doc Zubrin is willing to accept, and this is an almost fatal blow to taking a smart man like him seriously. The same goes for talk of the AltSpace folks magically overcoming the energy density problem with capitalist innovation magic, and that Boeing/LockMart/etc are greedy liars that make space travel (some perhaps) far far more expensive then it "could be" or somthing.

John Creighton · 2004-12-03 11:26:37

I think it all comes down to marginal cost and not a question about what level of safety is appropriate. If we have the capability to make a mission considerably safer and more reliability with out substantially increasing the cost then we should. People should stop thinking about one do or die mission and start thinking of a program over several years. Which is better to sacrifice on safety and science equipment and loose 1/3 of your missions and get much less science done or spend 1/3 more money and fly 1/3 more missions but not loose any of them and getting much more science done each mission. Morality aside there is the question of getting the maximum bang for the buck and cutting corners is usually not the way to achieve that result. But with regards to morality do you think it is worth spending a million to improve an astronauts chance of survival by 1/3. How much do you value life? BTW even the shuttle I bet is more dangerous then extreme skiing? How much more risk do you want these people take to demonstrate a false sense of heroism and pride?

SpaceNut · 2004-12-03 11:43:47

I would say that we have an even bigger problem with the cost for if we are unwilling to pay 1Billion per shuttle flight then how can we expect people to not balk at the cost being that and more for a single manned mission to mars or to the moon for that fact regardless to how many ships this will actually equate to.

Lets not forget the investment of the design dollars which will be more than 20 billion before we even get one ship off the ground no matter who's plan is used.

BWhite · 2004-12-03 11:53:25

Technology is only getting better. There are always solutions to problems and I think we need to shift the focus away from concentrating on the problems and toward concentrating on the solutions.
GCNR is telling us to work up to a standard, not down to a price, which is highly commendable... GCNR seems to be telling us... that human space exploration is just not going to happen, it's all too hard or too expensive, so forget it!
...pin-point landings are perfectly possible and doable, and I agree with them. Radiation shielding technology, e.g. Demron, is advancing, and using the mission's water supplies and a radiation storm shelter have all been worked out... We're supposed to be full of optimism and enthusiasm and a can-do attitude.
I certainly don't think that manned flight is too expensive or impractical, it can be done and should be done in order to preclude the possibility that the Earth cannot sustain a developed humanity on its own, to enrich our lives through fulfillment of the psychological need for exploration, and perhaps to fulfill the material and psychological desire to expand.
What I see going on around here is that people are getting too excited, particularly about MarsDirect and Doc Zubrin, and not looking at the mission like it should be looked at and how it will be looked at by congressmen, scientists, and engineers. In the excitement and zeal, this fallacy that going to Mars is no big deal... that its easy and not as hard as the naysayers make it out to be... is a serious threat to the credibility of Marsies'. That and its side-effects is what I am trying to address.
MarsDirect is one such side effect, that the desire and beliefe that "doing Mars" is easy has produced a mission arcitecture that is unworkable and unsafe without sacrificing all the scientific payload and then some or even perhaps with a politically touchie and expensive revival of NTR propulsion. The fact that it is too optimistic seems to be glossed over by proponets who are desperate to prove the "no big deal" fallacy.
Another issue is the idea that technology improvements will somehow ride to the rescue. The problem is still inherintly a fundimental one, that because of the limited energy density of chemical or solid-core NTR engines plus the high minimum degree of complexity and robustness. These facts quite simply demand a mission that is bigger and more expensive then at least Doc Zubrin is willing to accept, and this is an almost fatal blow to taking a smart man like him seriously. The same goes for talk of the AltSpace folks magically overcoming the energy density problem with capitalist innovation magic, and that Boeing/LockMart/etc are greedy liars that make space travel (some perhaps) far far more expensive then it "could be" or somthing.

Frankly, I have more sympathy for this position that it may sometimes appear.

However, for the Zubrin-ites to disarm absent an agreement from the "O'Keefe is God" people & "the VSE is all we need" people also to disarm would be a bad political move.

I do doubt we can straighten out those spirals (spiral development) quite as much as Zubrin wants, yet they do need to be straightened out - - in large part because the politicians have yet to openly debate the Saganaut; von Braunian and O'Neillian motivations for space exploration.

I fear a "bait and switch" - - talk coyly about exploration and 15 or 20 years from now, surprise, surprise, surprise. . .

The VSE aint nothing but a bunch of uniformed military guys - - on loan to NASA - - collecting rocks. Making the Saganauts mildly happy, the von Braunians very happy and the O'Neill-ians 100% left out in the cold.

= = =

There are good national security reasons why we need a domestic launch industry, however, if the Russians can lift mass to LEO for a fraction of the price Boeing charges, then for commercial purposes it becomes the same question as whether to buy a Honda Accord or a Ford Taurus.

Whats the better value?

The Russians have beaten us rather soundly on reliable low cost medium lift. Either our companies get down below $2000-$2500 per pound (Proton/Zenit) or we import or we openly admit what we are doing is protectionist.

What is ironic is that America now has the capability to build BIG rockets, far larger than puny Energia but all we want to do is build EELVs.

Edited By BWhite on 1102096480

GCNRevenger · 2004-12-03 12:44:58

I doubt that VSE is some ploy for the military conquest of space Bill... there really isn't that much to conquer that you need soldiers for. The USAF probobly wouldn't mind bigger rockets, cheaper smaller ones, and limited manned flight capability to Earth orbit... but a military base on the Moon?

"There are good national security reasons why we need a domestic launch industry..."

You bet there is! Even the political problems of having to rely on Russia for launchers for civilian government programs would be a nightmare... Russia pitches a fit and cancels flights? Well what are you gonna do now NASA? Complain to the State Department? American has made a big enough mistake in letting itself be dependant on foreigners who aren't dependant on it in other industries (eg oil).

There is another economic consideration too, that the money being sent to Boeing/LockMart isn't leaving the country instead of being sent to Rosaviakosmos, which is a real issue to consider that is different from businesses since the gov't is interested in cultivating economic growth and not profit.

And as far as being protectionist... protectionism has its place... the idea is to maximize national wealth, not global wealth.

And why wouldn't we want to build EELVs? They do everything we need them to do, including get us to the Moon. Only Mars is out of their reach.

BWhite · 2004-12-03 13:06:00

I doubt that VSE is some ploy for the military conquest of space Bill... there really isn't that much to conquer that you need soldiers for. The USAF probobly wouldn't mind bigger rockets, cheaper smaller ones, and limited manned flight capability to Earth orbit... but a military base on the Moon?

I didn't say that. I said that a von Braunian & Saganaut vision would exclude the O'Neillians.

Rock collecting is not "entering space" - - besides clark is the big military moonbase guy. A military moonbase is really not all that useful, IMHO.

= = =

As for protectionism, I agree IF we also hold the areospace industry's feet to the fire and require them to be more productive. To be protectionist yet pretend we are not is the worst possible combination.

After all, Detoit responded to the Japanese challenge by making better cars.

= = =

And why wouldn't we want to build EELVs? They do everything we need them to do, including get us to the Moon. Only Mars is out of their reach.

Perhaps. But Putin and Chirac would be foolish to let NASA return to the Moon first if a French-Russian mission can gte there sooner and cheaper. And with Zenit / Proton / Kliper it will be much cheaper for them than it will be for us with our liquid EELVs.

Edited By BWhite on 1102100943

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