Mars Voyage too Soon?

[rocketdodger]

I say we stay on earth until fusion engines are ready.

 

[uruk]

Five manned mission failures out of nineteen with crews of four on each mission would have been a death toll of twenty dead astronauts. I truly hope we can better the perecentages.

Which is why we shloud keep practicing and getting the reliability higher. But you will never get the number doen to zero. We havent done that yet with plane flights or cars for that matter.
We had an excellent rate with the Moon landings. 14 men on the moon and no lives lost going there.

BTW
Unlike us, Russia plans a cautious fly-by on its first manned mission to Mars.

That sounds odd. It does not sound like the ultra-cautious NASA we all know.

We sent a couple of manned circumlunar lunar flights before we landed on the Moon.

Can you show where NASA says we are going to forego the "fly-bys" for a first time direct landing?

 

[sts60]

Five manned mission failures out of nineteen with crews of four on each mission would have been a death toll of twenty dead astronauts. I truly hope we can better the perecentages.

Certainly, but remember that manned missions use systems designed and tested to higher reliability than unmanned ones. And, as I mentioned earlier, piloted vehicles can mitigate some of the failures which doomed unmanned ones. (Like shutting off the descent engine in midair because of a spurious touchdown signal - see Mars Polar Lander).

BTW

Unlike us, Russia plans a cautious fly-by on its first manned mission to Mars.

I'm pretty certain you're confusing a proposed Russian circumlunar tourist scheme with a Mars mission. [t makes absolutely no sense whatsoever to send humans merely to orbit Mars, and as big a proponent of manned space exploration as I am, I would rise up in righteous taxpayer anger should any such scheme be seriously proposed.]

 

[sts60]

The difference between orbiting the Moon (Apollo 8, Apollo 10) before landing on it and orbiting Mars before landing on it is that you can almost hold your breath for the time it takes to go around the Moon and come back on a free-return trajectory. At least by comparison to a Mars mission, which will require far more sophisticated regenerative life support and much better protection against radiation hazards. Also, a first manned Mars landing will have the experience of Apollo and Constellation lunar landings and numerous unmanned planetary landings (Mars/Titan/?) upon which to draw.

Sending a crew to Mars just to orbit it would yield little benefit but would still have almost all of the risks. It would make more sense, but still be very expensive, to send the Mars cruise vehicle/lander unmanned and have them do everything -including a landing, ascent, and return - under (semi)autonomous control. This was not an option for the Apollo program, as the computing power and supporting electronics necessary did not exist (though there was enough for navigation and pilot-in-the-loop control).

 

[Diagoras]

I recently watched the Mars voyage plans as described on the Discovery Channel and could not but feel ill at ease with all the emphasis given to the extreme dangers involved and the possible deaths that might occur. I came away with the impression that NASA is rushing things, or that due to lack of funds, it isn't doing all that's possible to make the trip safer. I for one would not get on that ship based on all the nerve wracking "ifs" and "maybes" mentioned.

1. If rocket doesn't precisely on time and for the precise duration you die.

2. Returning earlier than usual via a Venusian gravity boost might mean missing the earth.

3. Most Russian efforts to land a craft on Mars have failed.

4. The crew living quarters are cramped = the size of an average apartment.

6. Fears of crew going ballistic due to stress were expressed.

7. No rescue mission planned if something goes wrong on the Martian surface.

8. No mention made of any radar to detect incoming objects such as meteorites.


In short, it seems to me as if they will be playing Russian Roulette. The only difference is the hi tech equipment is used instead of a loaded gun. Anyone else get that impression?

Surely I can't be the first person to notice that there's no #5 on that list. Ahh counting...there's one of those things humans really suck at compared to computers.

 

[patnray]

I am not a proponent of manned space exploration because it produces very little scientific return for each dollar spent (99% of the mission cost is to keep the people alive...)

However, most of your objections have creative solutions, especially if you think in terms of an exploration program and not a single mission.

For example, landing large craft on Mars is an extremely difficult problem which has yet to be solved. The atmosphere is too thin to help slow the vehicle or use a Shuttle type craft, but thick enough to create other problems. There was a thread about this issue a few months back. One partial solution is to send multiple smaller craft ahead of the crew with most of the supporting equipment and supplies. It may even be necessary for people to land one at a time in single passenger landers.

Similarly, while there can be no rescue mission, you can provide sufficient redundancy to overcome many problems (short of complete catastrophes such as an explosion on launch). But you could send multiple return craft and fuel ahead of the landing crew. If the program is for a longer presence, and not just a single visit, then you will have a steady stream of traffic both ways using most, if not all, launch windows. So you just need sufficient infrastructure to wait it out if a return launch window is missed.

Radiation exposure, both enroute and on the martian surface, is also a serious concern. But solvable.

On the other hand, Mars' thin atmosphere and lower gravity makes it easier to return. A magnetic rail propulsion system could achieve much higher first stage boost speeds than is practical on Earth.

But I think you are right that we are rushing into this. We need better robotic craft and equipment to support this style mission, and a solution to the landing problem (air bags only work for relatively small vehicles that can withstand the high g forces). Far too much of our space budget is being consumed by pointless manned missions such as the ISS and returning to the moon).

 

[Rob Lister]

5 is classified

 

[uruk]

I am not a proponent of manned space exploration because it produces very little scientific return for each dollar spent (99% of the mission cost is to keep the people alive...)

However, most of your objections have creative solutions, especially if you think in terms of an exploration program and not a single mission.

For example, landing large craft on Mars is an extremely difficult problem which has yet to be solved. The atmosphere is too thin to help slow the vehicle or use a Shuttle type craft, but thick enough to create other problems. There was a thread about this issue a few months back. One partial solution is to send multiple smaller craft ahead of the crew with most of the supporting equipment and supplies. It may even be necessary for people to land one at a time in single passenger landers.

the DC-X program showed that a landing can be done (relativley easy) in a mildly windy atmosphere condition. http://en.wikipedia.org/wiki/McDonnell_Douglas_DC-X

I think Apollo has given us some good bit of experiance of landing a manned craft on another planet(oid). Although more experiance is always better.

Similarly, while there can be no rescue mission, you can provide sufficient redundancy to overcome many problems (short of complete catastrophes such as an explosion on launch). But you could send multiple return craft and fuel ahead of the landing crew. If the program is for a longer presence, and not just a single visit, then you will have a steady stream of traffic both ways using most, if not all, launch windows. So you just need sufficient infrastructure to wait it out if a return launch window is missed.

I think the plan is to send the equipment (including the landing and return vehicle) there first, then send the people. the infrastructure you are refering to would be excellent for a permanent presence on Mars. But one step at a time.
I think there was a plan that used the idea of a "ferry" that was in a continuous orbit between the earth and the moon. Kind of an on going figure 8. You would wait till the right time, load up and ride along. Then you disembark at the right time.

Radiation exposure, both enroute and on the martian surface, is also a serious concern. But solvable.

Agreed.

{snip}
But I think you are right that we are rushing into this. We need better robotic craft and equipment to support this style mission, and a solution to the landing problem (air bags only work for relatively small vehicles that can withstand the high g forces). Far too much of our space budget is being consumed by pointless manned missions such as the ISS and returning to the moon).

I really don't think we'll be sending any people to Mars for probably another three or four decades, considering all the politics and setbacks that are going to be inevitable.

 

[tsg]

I am not a proponent of manned space exploration because it produces very little scientific return for each dollar spent (99% of the mission cost is to keep the people alive...)

Unless you consider keeping the people alive a good scientific return. And no, I'm not saying that to be glib. There are problems with sending humans into space that won't be solved by sending robots into space. The knowledge acquired by keeping people alive in space is very valuable.

 

[dudalb]

Fact is that unmanned space exploration simply does not get the public attention the way that manned exploration does. And in a Democracy,that is important. Public support equals more money.
Or,as they said in "The Right Stuff": "No Buck Rogers,No Bucks".

 

[dudalb]

I agree I cannot see a manned mission to Mars happening for another Twenty to Thirty years ,unless there is some really revolutionary breakthrough in technology.

 

[Jimbo07]

Or,as they said in "The Right Stuff": "No Buck Rogers,No Bucks".

They didn't.

Did they?

I don't remember.

Interesting... well, I'll never get the chance to tell someone that his anecdote was plagiarized, but meh... He said, "No bucks, no Buck Rogers," just to be specific.

 

[Lensman]

Lives tend to be lost in any exploratory endeavour, how many explorers have died in the opening up of the West?

If they had waited until there was better than a 50% chance of surviving, where would the USA be today?

How many people died getting to the poles?

How many have died climbing mountains?

How many died during Magellans circumnavigation of the Earth?

If I was young & fit, I'd jump at the chance of a trip to Mars - even if there was only a 50% chance of returning.

 

[R.Mackey]

Let me echo what several others have said -- NASA is not rushing to Mars. We have no real ETA for a crewed Mars mission of any kind. Any speculation that such a rush involves disregard for safety or testing is simply incorrect.

There are many, many technical challenges. The two biggest, in my opinion, are the following:

1. Mass Fraction

"Mass Fraction" refers to the size of the launch stack that is actual payload. The rest is fuel, engines, more fuel, structure, fuel, other consumables, and so on. Typical launch vehicles are in the 8-1 to 20-1 range, with Shuttle at roughly 15-1.

A Mars mission requires several launch phases -- Earth to Earth orbit, Earth orbit to Mars transfer orbit, transfer orbit to Mars orbit, Mars orbit to Mars surface, and all that in reverse. All those mass fractions add up. The studies I've read show the overall mass fraction is in the range of 2000 to 1, if done traditionally.

This isn't going to happen.

Either we need breakthrough propulsion, or we need some other clever way to get this number down. One hot idea is to mine the Martian surface for fuel, but so far, this is purely hypothetical. Lots and lots and lots of research is needed before this could possibly be attempted for real.

2. Radiation Exposure

This is harder than it sounds. In the Apollo missions, the astronauts were in danger of being killed by solar weather. This was an accepted risk, because the mission durations were short, and bad solar flares rarely spring up in a few days without first producing warning signs. For a Mars mission, this no longer holds.

We need shielding, and we need better space medicine. There's no escaping this conclusion. There have been many ideas floated about the best way to achieve these, but it's not a simple choice. The weight of shielding, no matter what form it takes, will drive the entire mission design. So will the size of the shielding. This is an open question.

It should be obvious that no Mars mission will be attempted, not even reserved on the calendar, until these and a myriad of other technical hurdles can be overcome. Right now we're focused on the Moon, which is vastly easier, yet still a tremendous challenge. Yes, we've been there before, but we never tried to stay before. We cut corners last time. We developed an architecture that really wasn't sustainable or flexible. Hey, we were in a race. This time it's different.

As always, my opinions alone, I do not speak for NASA, post made on my own time, all information available in open literature, etc.

 

[Radrook]

Which is why we should keep practicing and getting the reliability higher. But you will never get the number down to zero. We haven't done that yet with plane flights or cars for that matter.
We had an excellent rate with the Moon landings. 14 men on the moon and no lives lost going there.



That sounds odd. It does not sound like the ultra-cautious NASA we all know.

We sent a couple of manned circumlunar lunar flights before we landed on the Moon.

Can you show where NASA says we are going to forego the "fly-bys" for a first time direct landing?

The TV program, Mars Rising, pointed this out and contrasted the Russian cautious approach with ours. It did however say that we intend to gain experience via establishing a moon base first. The program also mentioned that the trip to Mars could be cut back to nine days. This would be done by stripping the ship of fuel and relying on some type of energy beam set up on the ISS and aimed at the ship. An orbiter would have to be waiting in Mars orbit to slow the ship down. But that technology is still in development and would force us to wait. Here is a brief synopsis of the program contents and airing times:

http://av.rds.yahoo.com/_ylt=A9ibyK...ery.com/convergence/mars-rising/episodes.html

 

[m_huber]

If only we had a source for dilithium crystals...

 

[Radrook]

Surely I can't be the first person to notice that there's no #5 on that list. Ahh counting...there's one of those things humans really suck at compared to computers.

Ooops!

 

[sphenisc]

I suspect that considerable savings in weight could be made by sending pygmies in terms of food stores, living space design etc.

 

[Radrook]

I suspect that considerable savings in weight could be made by sending pygmies in terms of food stores, living space design etc.

Isn't it ironic how the government is willing to slurge on wars but every dollar assigned to NASA is like having a tooth pulled without novacain?

 

[NobbyNobbs]

I recently watched the Mars voyage plans as described on the Discovery Channel and could not but feel ill at ease with all the emphasis given to the extreme dangers involved and the possible deaths that might occur. I came away with the impression that NASA is rushing things, or that due to lack of funds, it isn't doing all that's possible to make the trip safer. I for one would not get on that ship based on all the nerve wracking "ifs" and "maybes" mentioned.

1. If rocket doesn't precisely on time and for the precise duration you die.

2. Returning earlier than usual via a Venusian gravity boost might mean missing the earth.

3. Most Russian efforts to land a craft on Mars have failed.

4. The crew living quarters are cramped = the size of an average apartment.

6. Fears of crew going ballistic due to stress were expressed.

7. No rescue mission planned if something goes wrong on the Martian surface.

8. No mention made of any radar to detect incoming objects such as meteorites.


In short, it seems to me as if they will be playing Russian Roulette. The only difference is the hi tech equipment is used instead of a loaded gun. Anyone else get that impression?

With minor modification (such as the "Venusian gravity boost"), it could easily be said that all of these hold true for a jaunt up to the space station and back, as well. Yet we've been doing just fine with that.

Not to equate a trip to Mars with a trip to orbit, but just to point out that there are similar risks in any spaceflight.