Author Topic: Minimal crew size Mars orbital mission feasible?  (Read 10038 times)

Offline AlexCam

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Minimal crew size Mars orbital mission feasible?
« on: 08/25/2011 02:14 pm »
One of the reasons I believe BEO human spaceflight has been in plans for 40 years and not be accomplished is overcomplication.

What about starting with the simplest possible mission requirements and build from there? For instance, how about a Mars orbital mission with just a crew of 2. An Earth return capsule for a crew of 2 can be purpose built and tested. A spacecraft to Mars orbit for 2 only doesn't have to weight 1000mt and can be brought to orbit in smaller junks.

Should NASA focus on these very small, minimal steps before planning 6-crew, long-duration surface missions to Mars?

Offline colbourne

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #1 on: 08/26/2011 04:00 am »
I view this slightly differently.
To me the risk of any mission is so high that,it is unfair to the volunteers not to offer a Mars landing.
Send as many unmanned missions to test the technology but when humans are  involved I would go the whole way and land on Mars.


It is arguably safer to have a one way mission that does not involve having to launch from Mars and can make the whole mission much cheaper and provide years more surface time.

Offline DLR

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #2 on: 08/26/2011 08:18 am »
The simplest mission we could do would be a flyby, followed by a Mars orbital mission, follwed by a landing.

Flybys don't have a great deal of scientific value, but they allow us to build experience in travelling through deep space.

Offline apace

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #3 on: 08/26/2011 10:33 am »
The simplest mission we could do would be a flyby, followed by a Mars orbital mission, follwed by a landing.

Flybys don't have a great deal of scientific value, but they allow us to build experience in travelling through deep space.

The problem with such missions are the fear of deaths at NASA or any other federal organization. There are talks about the problems of long duration weightless, of radiation, of psychological aspects of such missions... but there will be tons of Astronauts out there which are ready to risk it.

Offline aquanaut99

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #4 on: 08/26/2011 10:58 am »
I view this slightly differently.
To me the risk of any mission is so high that,it is unfair to the volunteers not to offer a Mars landing.
Send as many unmanned missions to test the technology but when humans are  involved I would go the whole way and land on Mars.


It is arguably safer to have a one way mission that does not involve having to launch from Mars and can make the whole mission much cheaper and provide years more surface time.

While there would be no lack of volunteers for such one-way missions, they are not going to happen. Well, at least not in the USA. No way this will ever be politically acceptable. Objectively speaking, it is, after all, equivalent to euthanasia/assisted suicide (in that the mission ends in certain death). With the added factor that this "assisted suicide" will cost many many billions of taxpayer money.

Disclaimer: This is, ofc, not what I think (I would immediately volunteer for the mission if it were offered to me), but it the kind of killing argument by the opposition which will assuredly come if these proposals are ever going to be actively pursued by NASA or some other agency.
« Last Edit: 08/26/2011 10:59 am by aquanaut99 »

Offline colbourne

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #5 on: 08/26/2011 11:58 am »
I do agree that NASA probably will not send people to Mars this century with their current attitudes and it is more likely to be the Chinese or Russians who get there first for the prime spot in the history books.

Americas only hope is the private sector undertaking the mission which should be fairly affordable.

I dont think it needs to be justified by value of raw materials at this stage. Science pride and adventure should be enough.

Offline apace

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #6 on: 08/26/2011 12:39 pm »
Is there anywhere more information about this http://en.wikipedia.org/wiki/Crocco_Grand_Tour on the web? It's a tour to Mars and Venus flyby under one year.

Offline kkattula

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #7 on: 08/26/2011 03:14 pm »
Go to Phobos first.

Establish a base.
Stockpile equipment, propellant and supplies.
Remote operate Mars surface cargo landers and rovers.

When ready, sortie surface missions using minimal lander/ascenders.
Do 'Mission Control' from Phobos for minimal time lag.
Allows rapid re-supply, evacuation or rescue if a surface expedition runs into trouble.
« Last Edit: 08/26/2011 03:16 pm by kkattula »

Offline Archibald

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #8 on: 08/26/2011 04:28 pm »
Sun-Mars L1 > Deimos > Phobos > low Mars orbit.


Han shot first and Gwynne Shotwell !

Offline AlexCam

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #9 on: 08/26/2011 06:08 pm »
I do agree that NASA probably will not send people to Mars this century with their current attitudes and it is more likely to be the Chinese or Russians who get there first for the prime spot in the history books.

Different leadership would mean the world. NASA could easily do a fresh start of an actual BEO program right now.

And as I suggested in the OP, a minimal crew size Mars orbital mission (to Phobos) is entirely possible with minimal mass requirements.

NASA might even start thinking straight when it comes to interplanetary spaceflight and push the development of a reusable VASIMR propulsion stage that can be refueled after each mission.

Quote
Americas only hope is the private sector undertaking the mission which should be fairly affordable.

I dont think it needs to be justified by value of raw materials at this stage. Science pride and adventure should be enough.

I have yet to come across a single several billion dollar project undertaken by the private sector without the taxpayer paying for it which was done for "scientific pride and adventure". The private sector has a profit motive. Without a profit, no private sector spaceflight. That is why most of the revenues e.g. SpaceX has comes from taxpayer money.

Offline gbaikie

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #10 on: 08/26/2011 10:57 pm »
One of the reasons I believe BEO human spaceflight has been in plans for 40 years and not be accomplished is overcomplication.

What about starting with the simplest possible mission requirements and build from there? For instance, how about a Mars orbital mission with just a crew of 2. An Earth return capsule for a crew of 2 can be purpose built and tested. A spacecraft to Mars orbit for 2 only doesn't have to weight 1000mt and can be brought to orbit in smaller junks.

Should NASA focus on these very small, minimal steps before planning 6-crew, long-duration surface missions to Mars?

A simpler mission than Mars manned flyby would landing crew on the Moon. Which shouldn't be confused with making a permanent lunar base.
NASA should explore the moon to determine whether there is minable water. And again not to be confused with making a permanent lunar base.

Some people might think a Mars flyby could a waste of time and money, just as a lunar flyby could seem as waste of time and money. But there could be significant advantages for a Mars flyby. One advantage of Mars flyby could be the reduction of the time delay for controlling anything on Mars if using teleoperation. Any flyby of Mars which then returns to earth with the crew, will have months of time in which crew are significantly closer to Mars than anyone on Earth.
The closest Earth gets to Mars is about 55 million km, so if crew is less than 50 million km, they have less time delay, and significant difference could at distance of 25 million kms or less.
Regardless of whether of whether your trip time to Mars is 6 months or 4 or 3 months, you have about 1 month of time in which you are significantly closer to Mars than is possible from Earth. And same applies leaving Mars.
So a flyby could used to help set up a manned landing. And one could have other missions designed to use time delays of minutes to seconds.

The other obvious advantage is you can test the manned Mars vehicle up to the point re-entry and landing. And instead landing on Mars, you could areobrake using Mars atmosphere and then dock in orbit with a return booster. Then returning the earth you also test reentry earth from Mars trajectory.
If NASA explores the Moon, one thing it could also work out is not landing on Earth surface but instead areobraking and going to LEO. And perhaps this could also be used from return from Mars.

Offline Andrew_W

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #11 on: 08/27/2011 12:27 am »
I don't think that a manned flight to Mars that doesn't include a manned landing on the planet is marketable.
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline KelvinZero

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #12 on: 08/27/2011 04:57 am »
I don't think that a manned flight to Mars that doesn't include a manned landing on the planet is marketable.
In many ways a phobos mission interests me more than a mars one. Flags and footprint missions horrify me.

On the other hand while it is fashionable to lament how long we have spent just floating around in circles for the past decades what I lament is how little effort we have put into mastering the art. We seem to be facing the exact same ‘dragons‘ we faced 30+ years ago. gravity, radiation and the reliability of our lifesupport and rockets after multiyear missions. The problem IMO is why we never really put serious budgets into any of these problems. The purpose of hsf up to now has been to provide missions for the launch architectures. As soon as the ISS leaves the construction phase and might get real reseach budgets there is a call to drop it in the sea and build a big rocket.

Mars missions concern me because they are another reason to delay basic technologies to actually live there while all the money goes to rockets. Mars is a great destination but if you are not working on those really very vanquishable dragons now then you are not serious about going.

Offline DLR

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #13 on: 08/27/2011 08:31 am »
Why is a Mars surface mission flags & footprints and a Phobos mission not? In both you have to spend 500 days on or around Mars, if you want to use minimum energy trajectories.

Going to Mars surface allows you to do much more meaningful science (searching for life etc.) than landing on Phobos.

Offline AlexCam

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #14 on: 08/27/2011 08:43 am »

A simpler mission than Mars manned flyby would landing crew on the Moon.


Actually a Moon landing is much more costly and complicated to develop than either a Mars flyby or orbital mission.

Quote
Some people might think a Mars flyby could a waste of time and money, just as a lunar flyby could seem as waste of time and money. But there could be significant advantages for a Mars flyby. One advantage of Mars flyby could be the reduction of the time delay for controlling anything on Mars if using teleoperation. Any flyby of Mars which then returns to earth with the crew, will have months of time in which crew are significantly closer to Mars than anyone on Earth.
I do not think teleoperation is worth the money. The MERs definitely can do a lot more science within the years spent on Mars than a few days of teleoperated rovers (without the time lack) could ever do. In contrast a mars orbital mission to Deimos or Phobos is worth the money from a science point of view.

Quote
If NASA explores the Moon, one thing it could also work out is not landing on Earth surface but instead areobraking and going to LEO. And perhaps this could also be used from return from Mars.

Aerobracking into LEO is not feasible from a mass point of view or desirable. If we were to use different propulsion systems we might consider getting back to LEO after a mission, but NASA has long forgotten to envision big steps and use them in their baseline planing (like a nuclear powered VASIMR propulsion stage for a cycler spacecraft).

Offline CitabriaFlyer

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #15 on: 08/27/2011 12:59 pm »
I view this slightly differently.
To me the risk of any mission is so high that,it is unfair to the volunteers not to offer a Mars landing.
Send as many unmanned missions to test the technology but when humans are  involved I would go the whole way and land on Mars.


It is arguably safer to have a one way mission that does not involve having to launch from Mars and can make the whole mission much cheaper and provide years more surface time.

I would be very happy to fly a Mars orbital mission without a landing opportunity.  In fact, I think the Apollo CMP (especially on the J flights) was a much more delightful job.  I even heard Neil Armstrong say at Oshkosh in 94, "Pilots don't like to walk."  While it would be nice to walk on the Moon to be able to experience 1/6g, check out the Appenines, etc., But if there were weekly Apollo flights and I was an astronaut going to the Moon several times each year I would far prefer to be a CMP.  Let the geology geeks huff and puff down on the surface while I cruise 50,000 feet over the surface.  Totally high speed, low drag.

Same goes for Mars.  Again I am a pilot, flight surgeon, etc.  so obviously I am biased toward the things that interest me, but I would love to fly the Deimos Red Rock mission in 2033.  Sign me up.

Offline JohnFornaro

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #16 on: 08/27/2011 01:32 pm »
Per the OP:  Four.
Sometimes I just flat out don't get it.

Offline gbaikie

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #17 on: 08/27/2011 09:12 pm »

A simpler mission than Mars manned flyby would landing crew on the Moon.


Actually a Moon landing is much more costly and complicated to develop than either a Mars flyby or orbital mission.

If you had a lump sum or prize for a particularly task, one should able to land on the Moon cheaper than a Mars flyby.
In terms of delta-v, a Mars flyby could be slightly less if humans weren't involved. In terms of time of trip, there is no comparison- Moon a week or so, Mars a year or so.

Manned Mars flyby would require a trip time to Mars of 6 months or less. 7 months or more one way wouldn't be desirable, and 2 to 3 month one way in comparison would be far more desirable. If you desire 6 months or less each way to Mars [year or less in travel time to Mars and back] this will require more delta-v than compared to landing on the Moon with crew and returning to earth.
Or a single Saturn V can land crew on the Moon. A Saturn V couldn't do a flyby of Mars and bring back living crew.

You don't need a Saturn V class rocket to land crew on the Moon- the lift capacity of Saturn V is about 5 times the payload of existing heavy lifts. Using 5 to 6 of existing hvy lifts could easily land crew on the Moon.
And at about 100 million per lift, one should be able to do a landing on the Moon for a bit more than a billion dollars. NASA could do this. A 1/2 billion dollar prize to land a crew on the Moon, would probably get a few individuals trying to get this prize. And it's likely within 5 years someone trying for this prize would be successful.
To offer 1/2 billion dollar prize for a Mars flyby or for a lunar landing, most people would regard the lunar landing much easier to achieve. Though Musk probably be tempted if the Mars flyby was a billion dollars- though I doubt he would succeed in less than 5 years.

Quote
Some people might think a Mars flyby could a waste of time and money, just as a lunar flyby could seem as waste of time and money. But there could be significant advantages for a Mars flyby. One advantage of Mars flyby could be the reduction of the time delay for controlling anything on Mars if using teleoperation. Any flyby of Mars which then returns to earth with the crew, will have months of time in which crew are significantly closer to Mars than anyone on Earth.
Quote
I do not think teleoperation is worth the money. The MERs definitely can do a lot more science within the years spent on Mars than a few days of teleoperated rovers (without the time lack) could ever do. In contrast a mars orbital mission to Deimos or Phobos is worth the money from a science point of view.

What I was thinking was that flyby that would done before Mars landing. And was thinking of model where one lands a Mars return vehicle, and Mars hab before sending the crew to surface. Therefore all the infrastructure needed at Mars for Manned landing could be improved in terms of operational aspects by have flyby crew use teleoperation. One might also add other missions, such as Mars sample return, and such.

Edit: Geoffrey Landis basically describes this in 1995.
"Landis's first footstep, which he asserted could occur "immediately," was a piloted Mars flyby mission based on existing U.S. and Russian launch vehicles and space station hardware. The 18-month mission would test a piloted Mars transfer vehicle and demonstrate long-duration interplanetary flight and high-speed Earth atmosphere reentry. While close to Mars, the astronauts would take advantage of short radio signal travel time to teleoperate a rover on the planet. The rover would be launched to Mars on a separate launch vehicle ahead of the piloted flyby spacecraft. Teleoperation would enable planetary quarantine to be maintained until the question of life on Mars was resolved."
http://beyondapollo.blogspot.com/2010/10/footsteps-to-mars-1995.html

I was looking for how how much lift capacity they would have considered they needed, and haven't found it yet. I also noticed the Russians during Apollo period were thinking about doing a similarly a long duration flyby with N1 rocket.
Landis cites a 18 month long stay on Mir, as evidence of being able to do such long missions. Though I was previously aware of record long duration stay on a space station, they are other challenges involved with long duration and difference between a space station in LEO and in beyond earth orbit.
The Russian, Valeri Vladimirovich Polyakov stayed 437 days [14 months] aboard Mir and:
"Polyakov underwent medical assessments before, during, and after the flight. He also underwent two follow-up examinations six months after returning to Earth. When researchers compared the results of these medical exams, it was revealed that although there were no impairments of cognitive functions, Polyakov experienced a clear decline in mood as well as a feeling of increased workload during the first few weeks of spaceflight and return to Earth. However, Polyakov's mood stabilized to pre-flight levels between the second and fourteenth month of his mission. It was also revealed that Polyakov did not suffer from any prolonged performance impairments after returning to Earth. In light of these findings, researchers concluded that a stable mood and overall function could be maintained during extended duration spaceflights, such as manned missions to Mars.
http://en.wikipedia.org/wiki/Valeri_Polyakov
« Last Edit: 08/27/2011 10:28 pm by gbaikie »

Offline KelvinZero

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #18 on: 08/28/2011 04:56 am »
Why is a Mars surface mission flags & footprints and a Phobos mission not? In both you have to spend 500 days on or around Mars, if you want to use minimum energy trajectories.

Going to Mars surface allows you to do much more meaningful science (searching for life etc.) than landing on Phobos.

Good points and I don't dispute Mars is a great destination.

On the other hand (and scrabbling to recover my point a bit I admit ;) ) as I understand it people have seriously suggested high energy trajectories and mere month long stays. The notion of all that effort to avoid a long stay horrifies me too, but perhaps the term flags and footprints is a stretch.

Let me restate it a bit. Im horrified by what happened to Constellation. I really liked the notion of a permanent manned base, but then the permanent base became sorties which seemed a bit pointless but it didnt end there, the lander was dropped and so on. Everything was dropped except the launcher because the political support in fact only stretches that far.

How this affects Mars vs Phobos is just that I think Phobos would be a lot cheaper (especially for the vehicles) so I think it is more likely that some money would make it to the other portions of the architecture such as the exploration technology and the reliable life support etc. (edit: exploration technology would include telepresence robots on mars so there is plenty to explore.)

« Last Edit: 08/28/2011 05:06 am by KelvinZero »

Offline A_M_Swallow

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Re: Minimal crew size Mars orbital mission feasible?
« Reply #19 on: 08/28/2011 11:01 am »
Why is a Mars surface mission flags & footprints and a Phobos mission not? In both you have to spend 500 days on or around Mars, if you want to use minimum energy trajectories.

Going to Mars surface allows you to do much more meaningful science (searching for life etc.) than landing on Phobos.

I suspect people were hoping that the mission would create a base on Phobos, including a hanger for the reusable Mars lander.

edit: grammar
« Last Edit: 08/28/2011 11:02 am by A_M_Swallow »

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