Orion Capsule - 2 months to Mars?

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JonClarke

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zergnerd":2l6ypk86 said:
BA330 modules are not mature technology. Why do you need ten of them? why do you need to spin them?

Bigelow Aerospace has proven that inflatable modules are practical with their Genesis modules. They are planning to put Sundancer in orbit in 2012 I believe, which will validate all the life support systems and hold a crew of 3. Their time line is mostly determined by funding and manpower, I understand, rather than by fundamental technical issues. Since, in practicality, the first launches wouldn't begin until the 2018 to 2019 time frame, BA330 will likely be online by then. Why 10? Lab space mostly. If we're going to do exploring, we might as well have the scientific equipment to improvise new experiments based on discoveries we make. It will also give room for decent medical facilities (e.g. cat scan machine, operation table) as this is one major impediment to long term space travel. I'd envision a crew size of about 10-15 people.

Bigelow has only proven that the thecnology works in space over an extended period of time. That is good, but such modules are not going to be any cheaper than rigid ones. So why use them?

If you are talking about 10-15 people you would need two of three BA330 modules. That is more than enough volume for decent lab space and medical facilities.


Why 10 MW? Why a Breeder reactor? You are aware that the technology for a 10 MW reactor in space does not exist? And that it is about a thousand times more powerful that the most powerful reactor ever flown in space.

The technology exists but has never been put into space for political reasons, I believe. We have plenty of reactors on subs and the above mentioned Hyperion system that could be adapted for space. The largest generator in space I know of is the Cassini RTG. IMO comparing an RTG to a modern reactor is sorta like comparing a coal steam engine to internal combustion and then claiming that cars can never be made practical. They wouldn't be if we we're still using steam engines. These small reactors aren't the breeder type, but would work for a single mission. For multiple missions we'd want to adapt breeder technology to a size / weight comparable to the Hyperion. Why? If a rocket launch with a nuclear reactor ever fails to reach orbit you can kiss reactors in space goodbye for the next 50 years. If a rocket launch with inert U-238 ever fails, its not a big deal. Japan (Mitsubishi) and India are the main countries researching and using breeder technology. I am not aware of any portable units. I guess we would need a non-breeder reactor, unless we started reactor development now and planned to launch after 2030. I still think nuclear reactors could be used for $3 billion, rather than $300 b.

Breeders exist for one purpose, to breed nuclear fuel. The only reason to have one in space would be to make fuel elements, this means you need to develop orbital fuel handing, fuel reprocessing, and waste disposal. Such technology is not even remotely on the horizon.

Terrestrial reactors, be they for electrical power of ships, are no good for space. Space reactors need to be much more compact, have much higher power outputs, have operate in microgravity. and require quite different cooling technolgies.

Small nuclear reactors have flown in space, these were all less and 10 kW or so, mostly connected with the Sviet radar satellite program. They are about a thousand times smaller than what you are proposing.

VASIMR is not mature technology. It exists only as a bench top test unit. It has never been flown in space, there are serious questions about its practicality, and would need to be upgraded by a factor of about 10,000 to even appraoch what would be needed for a Mars mission. It is nowhere near "mature technology".

The main problem I have heard voiced about VASIMR is power availability. Only nuclear can supply the power needed to generate decent thrust. My understanding is that NASA plans to add a prototype VASIMR drive to the ISS for station orbit maintenance in 2012 using the station solar panels to provide power, so it can't be too immature. I assume your 10000 factor upgrade is to allow surface to orbit launches with VASIMR. This would never be practical, however, orbit to interplanetary flight should be very reasonable

Power supply is an issue for all electyric propulsion system. One advantage they have over (for exxample nuclear thermal) is that they can be scaled from small station keeping units all the way up to ones capable of sending people to Mars in a few months. Nuclear probably is the only viable option for the big ones, but there is the problem, the engineering of building space reactors that can supply megawats of electricty (and dispose of 10s of megwatts of heat) are huge. Plus all the issues of space-qualifying VASIMR and then scaling it but by three to five orders of magnitude.

The ISS will be long gone b y the time we have this type of technology.

The ISS is slated to be around until 2015. You would have to plan a lifetime extension for another decade at least. I have heard talk of extending it, but don't know the proposed duration.

Hopefully the ISS will be round until after 2020. But it is going to be a long time after that before the technology you are talking about will be available.

Nobody is using Orion to take people to Mars. It's a ferry. Bigelow modules aren't ferrys. You can't compare two very different spacecraft.

Agreed, Orion is a ferry. This simply means actual costs will be even higher once you build the Ares compatible habitation vehicle.

Of course, but it will still be cheaper than the SF mission you are proposing.

Where is your lander, surface support equipment? They are substantial items.

I don't really have an interest in Mars and would much rather visit an asteroid or orbit a gas giant. Hence, the lander costs become much smaller.

Why are you contributing to a Mars mission thread then?

I did forget to include lander costs. You would need a reusable lander.

Why resuable?

Assuming you visit a gas giant you would have ready access to water, ammonia and other volatiles from which fuel could be made.

Doing this is much more ambitious than going to Mars and will cost a lot more. It requires a great deal more conceptual technology as well.

I don't know what such a lander would cost, but it would be similar to the Apollo moon landers and could probably be done for less than $5 billion.

The Apo0llo landers were not reusable, could operate only on the Moon, did not use ISPP, offer much in the way of radiation protection, and had an endurance of obly a few days. Whay you propose is much more sophisticated and therefore expensive than Apollo.

I still think such a mission could be done for under $50 billion. Much less than what is proposed using Ares /orion / etc.

There is no way that something that requires vastly more complex and in many cases completely undeveloped technology is going to be cheaper than DRM 5.0 which uses much more extant technology.

The main problems are political, not technical. Many of the products needed exit development (mature) in the 2010 -2015 time frame, so it's unlikely we'd see things completed until the 2020 - 2025 time frame.

There are considerable technical propblems associated with developing multi-megawatt space reactors and electric populsion systems, not to mention ISPP on the Moons of Jupiter or the asteroids. Much more than with Mars.

Ultimately, I don't think the political will exists to do this as the primary goal of the current Ares program is to satisfy political constituents and keep jobs in the congressional districts that supported the shuttle.

Evidence?

After all it wasn't the Spanish people who ponied up for Columbus's crazy idea (they thought it was impossible), it was funded by a rich king and queen who hoped to get even richer and immortalize their names and who could ignore red tape. Most likely this will someday be done by a Bill Gates-type, or by some rich sultan in Arabia. But that won't happen until the price drops from $50 billion to under $15 billion or we find something out there that makes it worth their investment.

The world has changed a lot since the 15th century.
 
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JonClarke

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cec937":12i2hfrk said:
NASA is not going to Mars. For that matter, NASA is not going back to the moon. I have been a fervent supporter of space exploration since January, 1958 when Explorer 1 discovered the Van Allen belt and there is no comparison to the budgetary support and engineering ingenuity of the 1960's and today. I worked for a Federal bureaucracy for thirty years and I can recognize a bureaucracy when I see one and NASA is a bureaucracy; pure and simple.

Any organisation large enough and complex enough to do what NASA does has to be a bureaucracy. There is nothing wrong with that.

And, as a bureaucracy, its' bureaucrats are dedicated to self-preservation.

All organisations large or small are dedicated to self preservation to this is irrelevant.

NASA has done next to nothing in the area of manned space exploration since the end of the Apollo lunar missions and Skylab..

Other than over 120 Shuttle missions, tens of thousands of research papers, and helping build a space station you mean?

and has wasted time and billions of dollars on unproductive programs.

Wasted time and unproductive programs defined by what criteria?

NASA has done more to hinder manned space exploration then move it forward.

Such as?

If Americans return to the moon, it will be as members of an international space effort and the Chinese will be waiting for us as they will have gotten there using everybody else's technology.

Nothing wrong with international efforts and the Chinese mostly use their own technology.

The Chinese understand the benefit to international prestige that a viable space program gives them.

Good on them.

NASA has wasted twenty years and over a $100 billion dollars on the ISS...

The US has notr spent 20 years on the ISS Nor has it spent anywhere near 100 billion on the ISS to date. And how is this a waste?

and they have yet to give a viable reason for its' existence and don't say that it is proving that humans can live in space as the Soviets proved that with the Salyut missions of the '70's and '80's and the Mir station.

The ISS is much larger and more capable than Salyut or Mir. It's objectives are not about "proving that humans can live in space".

If NASA wants a manned lunar spacecraft, they should take their budget and establish a prize for the private company that can produce a safe and productive system.

Which is pretty nmuch what NASA is doing, calling for tenders and awarding contracts

Any company worth their salt would want such a system in their possession and NASA can buy rides when they need them.

So how is this different to what is being done?

Until then, NASA should stand for; "Not A Space Agency" because they certainly aren't doing anything for manned space exploration.

You obviously don't have a clue about what NASA does.

Jon
 
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JonClarke

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radarredux":1fci6y5i said:
One proposal that has been floating around is a mission not to land on Mars but to go to Mars' moon Phobos. Because it is tidal locked, if you "land" on the Mars facing side you are largely protected from radiation from the Sun. When Phobos is between Mars and the Sun, your landing site is in Phobos' shadow, and thus protected by Phobos itself. When Phobos is on the far side of Mars, your landing site is in Mars' shadow. Clearly you will get the Sun's rays at oblique angles, and there is galactic radiation not from the Sun, but I found the idea interesting.
The advanatge of going "just" to Phobos is that you don't need to build a lander. Once we have Orion and Ares V we chould do this using a space station-derived module.

Some people have argued fopr teleoperated machines on the martian surface controlled from orbit. but nobody has done a detailed comparison with a convention mission to see if it is worthwhile, at least to my knowledge.

Look up "Mars Cycler" or "Aldrin Cycler". It turns out there are regular orbital trajectories between Earth and Mars. Once you get a spacecraft into that trajectory, it will continue to orbit between Earth and Mars with virtually no propellant needed. You could create a larger spacecraft with plenty of radiation shielding (and maybe creature comforts), and accelerate it only once to reach the Aldrin Cycler trajectory. It would never leave the trajectory, endlessly orbiting between Earth and Mars. Then you would pack astronauts into a small spacecraft and accelerate it to meed the larger spacecraft as it flies by Earth, dock with it, and then the astronauts spend the 146 days or so in the larger spacecraft. Then when they approach Mars, they transfer back to the smaller vehicle, and then decelerate to enter Mars' orbit or land on the surface.

of course the trouble is it takes more propellant, in many cases much more propellant, to get into and out of the cycler orbit than going direct to Mars. And because the orbits don't repeat exactly, you need between two and six cycler spacecraft to transport your crew. Ands there are the unpleasant consequences of a failed deep space rendezvous.

Cyclers are an interesting idea and the orbits may be useful for something, but perhaps not for going to Mars (at least initially).

Jon
 
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FoxholeAthiest

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cec937":14jv7l3i said:
NASA is not going to Mars. For that matter, NASA is not going back to the moon. I have been a fervent supporter of space exploration since January, 1958 when Explorer 1 discovered the Van Allen belt and there is no comparison to the budgetary support and engineering ingenuity of the 1960's and today. I worked for a Federal bureaucracy for thirty years and I can recognize a bureaucracy when I see one and NASA is a bureaucracy; pure and simple. And, as a bureaucracy, its' bureaucrats are dedicated to self-preservation. NASA has done next to nothing in the area of manned space exploration since the end of the Apollo lunar missions and Skylab, and has wasted time and billions of dollars on unproductive programs. NASA has done more to hinder manned space exploration then move it forward. If Americans return to the moon, it will be as members of an international space effort and the Chinese will be waiting for us as they will have gotten there using everybody else's technology. The Chinese understand the benefit to international prestige that a viable space program gives them. NASA has wasted twenty years and over a $100 billion dollars on the ISS and they have yet to give a viable reason for its' existence and don't say that it is proving that humans can live in space as the Soviets proved that with the Salyut missions of the '70's and '80's and the Mir station. If NASA wants a manned lunar spacecraft, they should take their budget and establish a prize for the private company that can produce a safe and productive system. Any company worth their salt would want such a system in their possession and NASA can buy rides when they need them. Until then, NASA should stand for; "Not A Space Agency" because they certainly aren't doing anything for manned space exploration.

Sadly, I agree with you.....As an american citizen I feel extremely let down by nasa and our reps....I'm 36 and I don't really believe I'm going to see a mars mission in my lifetime and the now it looks like even getting back to the moon is too costly and demanding. It seems like there is nothing to look forward to...and with that 10 year forecast of a 10 to20 trillion dollar national debt and another 50 or 60 trillion in unfunded liabilities after that how will we ever be able to afford anything coll in the future...very depressing. ( at least there is the MSL, for now ;)
 
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JonClarke

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FoxholeAthiest":f5qqy4ra said:
Sadly, I agree with you.....As an american citizen I feel extremely let down by nasa and our reps....

Don't blame NASA, blame your elected representatives. NASA does the best it can with the mandate it is given.
 
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shuttle_guy

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EarthlingX":37rgt3m2 said:
I just started new thread 'VASIMR based heliosphere spaceship' viewtopic.php?f=15&t=19638
and invite you there to continue discussion.

Now let's not jump the gun too much, VASIMR is taking a steady road to commercial use. It is a long way to getting men to Mars. There are a lot more problems to solve than just propulsion.

Here is the latest on the VASIMR.....planning a test of the engine on the ISS in 2013

http://www.adastrarocket.com/EXECUTIVE% ... 051109.pdf
 
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radarredux

Guest
shuttle_guy":dtt5h215 said:
ALSO note the VASIMR could get a payload to Mars in 39 days not 2 months.
I read (or heard) something about a VASIMR mission profile where it would remain in Earth orbit a while gathering speed before making the run to Mars, so is it possible that both numbers are correct? 2 months from the time the spacecraft leaves Earth's surface but 39 days from the time the spacecraft leaves Earth's orbit?
 
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HopDavid

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MaxWithershins":3dhpfvb2 said:
The basis for this forum is ridiculous. Two months in a NASA "Orion" (someone should be shot for stealing that name in the first place!) is absurd. The only way to go to Mars that makes any sense (using current or near-current technology) is via Aldrin's "Cycler" concept. FWIW, the REAL [Ulan / Everett / Dyson] Orion ... designed in the mid-50s ... would have made the trip in a matter of days, with a crew of up to 150.

Last time I looked, Aldrin's cycler required delta V every 2.14 year for rotating it's line of apsides 20 degrees thereabouts. Some of this can be accomplished with earth's gravity but still a major burn is required. If the cycler is large, this will require lots of propellent.

The apogee for Aldrin's cycler is well past Mars, almost into the Main Belt. The cycler crosses Mars orbit at 70 degrees thereabouts. The taxis moving between the cycler and Mars would need 11 km/sec.

Niehoff Cyclers are somewhat better in regards to delta V needed to occasionally adjust orbit and the delta V required of the taxis is much lower. However Niehoff cyclers don't pass the earth and Mars every synodic period as do Aldrin's.
 
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scottb50

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HopDavid":5yzx7hwv said:
MaxWithershins":5yzx7hwv said:
The basis for this forum is ridiculous. Two months in a NASA "Orion"

Niehoff Cyclers are somewhat better in regards to delta V needed to occasionally adjust orbit and the delta V required of the taxis is much lower. However Niehoff cyclers don't pass the earth and Mars every synodic period as do Aldrin's.

What I have thought of as a cycler would travel from a highly elliptical Earth orbit to a highly elliptical Mars orbit, spending time in orbit between departures. Earth orbit would be longest because more cargo would need to be brought up and maintenance upgrades would be needed after a round trip.

Solar/ion engines would be practical, much lighter then reactors and such.
 
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