Design of Manned Mission to Mars

prolific1

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In light of the wildly varying opinions on this somewhat polarizing topic I have a proposal that may require this being moved to Theoretical and Speculative or to Alternative History and Future Speculation. Not sure which.

I would like to employ my considerable artistic prowess to creating a illustrated conceptual design for a Manned Mission to Mars [for giggles no less] with the help of any in this discussion who have suggestions (professional or otherwise) and who could direct me to technical resources or links that may aid in the plausibility of this design. I ask that the optimism be restrained to something reasonable yet at the same time I would like to set our theoretical timeline to say 2070. I choose this date as it allows for some liberties regarding the types of technology that will permit useful science via a swift transit time, lengthier surface stays, reusability, better crew protection from the elements, and a superior payload.

This should be realistic but also fun - so I will also consider everyone's suggestions provided they are sound. Also for interest sake I'd like anyone with anything to offer to provide their nationality as well [if you like] so I may place their respective flags on our mission design. ;D

BTW. If I have treaded on any forum formalities regarding my offer I apologize in advance as I try not to run afoul of them.
 
Open to suggestions concerning the following:

1. Propulsion- What system would make for the fastest transit time whilst also being reusable?
2. Artificial G apparatus- What configuration is best for generating gravity aboard the habitat module?
3. Aerobraking or Powered Approach?
4. Rover and L/A craft design?
5. Trajectories?
 
I would like to employ my considerable artistic prowess to creating a illustrated conceptual design for a Manned Mission to Mars [for giggles no less] with the help of any in this discussion who have suggestions (professional or otherwise) and who could direct me to technical resources or links that may aid in the plausibility of this design.

You've already done it! ;)

http://www.secretprojects.co.uk/forum/index.php/topic,8319.0/highlight,orion.html


cheers,
Robin.
 
Hahaha...well I was thinking of something more involved. Also is the Orion the best layout or how about Fusion Rockets like Gas Core or Mirrored Fusion and the like?

I'm open to making something around what everybody here might believe to be the best design/layout. For fun's sake. ;D
 
For a reliable, fast, and reusable mission design I'm liking a Gas Core (Spherical Torus Fusion Engine) at two ends of a symmetrical design for redundancy and/or powered braking, with a central-mounted centrifugal habitat ring, and some kind of magnetic radiation shield. This could be absolutely ridiculous as well.

Thoughts?
 
prolific1 said:
For a reliable, fast, and reusable mission design I'm liking a Gas Core (Spherical Torus Fusion Engine) at two ends of a symmetrical design for redundancy and/or powered braking...

Errrr... one engine will work just fine. If you want two for redundancy, make two smaller ones and put them both at the tail. Even with a propulsion system capable of Lickety Split Speed, you'll have more than enough time to flip the ship around and use the main engine for braking. If you have one up front for braking, it's dead weight for boost, and the boost engine is dead weight for braking.
 
Once we learn how to make a drive system that utilizes the vacuum of space for fuel we'll have it made! Then again, it might make space travel suck.
 
The only way we'll be able to travel at the speed of light is to actually attach ourselves to it and hang on.
 
Errrr... one engine will work just fine. If you want two for redundancy, make two smaller ones and put them both at the tail. Even with a propulsion system capable of Lickety Split Speed, you'll have more than enough time to flip the ship around and use the main engine for braking. If you have one up front for braking, it's dead weight for boost, and the boost engine is dead weight for braking.

Makes plenty sense.

Does placing the spinning 25m habitat torus at the front make sense as well or will it create weird wobble effects on the ship that will require wasteful use of RCS to correct?
 

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Anybody got any reference on Brayton Cycle Conversion Systems? I'm starting on a Gas Core System unless somebody has a more interesting idea.
 

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prolific1 said:
Does placing the spinning 25m habitat torus at the front make sense as well or will it create weird wobble effects on the ship that will require wasteful use of RCS to correct?

To first order, I don't think it much matters where such a torus might happen to be, since the ship should not do much in the way of maneuvering. If it did, then amidship like the Omega class destroyer would make more sense than forward like the Discovery.

But since the ship is probably long, and in general materials do well in tension, an easier approach to artificual gravity would be to simply tumble the ship end over end. No moving parts, no rotary joints. Use RCS to spin up after boost; use RCS to spin down before decelleration.
 
XB-70 Guy said:
Once we learn how to make a drive system that utilizes the vacuum of space for fuel we'll have it made! Then again, it might make space travel suck.

Aha-ha-ha-ha-ha-ha-ha-ha........... ;D

Sounds a bit like a Bussard ramjet, though (and yes, I do really like those).

Regards & all,

Thomas L. Nielsen
Luxembourg
 
Orionblamblam said:
prolific1 said:
Does placing the spinning 25m habitat torus at the front make sense as well or will it create weird wobble effects on the ship that will require wasteful use of RCS to correct?

To first order, I don't think it much matters where such a torus might happen to be, since the ship should not do much in the way of maneuvering. If it did, then amidship like the Omega class destroyer would make more sense than forward like the Discovery.

But since the ship is probably long, and in general materials do well in tension, an easier approach to artificual gravity would be to simply tumble the ship end over end. No moving parts, no rotary joints. Use RCS to spin up after boost; use RCS to spin down before decelleration.

Also, by using the "tumbling pigeon" approach, you avoid having to make bearings and seals that would stand up to long periods of vacuum and rapidly changing temperatures (light-to-shadow-to-light sort of thing). Although I have no doubt that these problems could be (or have been?) overcome, you can avoid them by just spinning the entire ship.

Disadvantages of the "tumbling pigeaon" are that the gravity vector changes between boost (thrust gravity) and coast (spin gravity) phases, and in my opinion it looks damn silly!

The only other alternative I can think of is to keep the rotating structure entirely inside the pressure hull, a la "Discovery" from 2001. But this creates a whole host of other problems.

A good source, I find, is http://www.projectrho.com/rocket/, dedicated to putting the "science" back in "science fiction".

Regards & all,

Thomas L. Nielsen
Luxembourg
 
prolific1 said:
Anybody got any reference on Brayton Cycle Conversion Systems? I'm starting on a Gas Core System unless somebody has a more interesting idea.

Good sources, in my limited scope, for advanced propulsion technology, is the previously quoted http://www.projectrho.com/rocket/, as well as http://www.diddling.info/encyclopedia/A/advanced_propulsion_concepts.HTML

Regards & all, and good luck with the design,

Thomas L. Nielsen
Luxembourg
 
http://www.projectrho.com/rocket/ is a good site I have bookmarked.

I thought of tumbling the spacecraft on simplicity grounds but the internal layout would be challenging between boost and cruise phase I imagine. By having a disc habitat (think Discovery's centrifugal system outside rather than in) the artificial g can be maintained throughout the voyage.
 
Fascinating Russian Mars mission via what appears to be some derivative of the 1989 NPO Energia Solar Electric Design.

http://www.youtube.com/watch?v=1yZlbYQXg0k&feature=fvsr

http://www.youtube.com/watch?v=nUeQxqM6jT8&feature=related
 
OK...after I saw that Russian design I decided to scrap the long Gas Core pusher design in favor of a two VASIMR tractor layout in a kind of wider than longer design.

Any ideas on the habitat module and L/AC?

I'll pass on the artificial g arrangement they have though. I thought 25m was the min needed for 1g at 1.5 rpm so everybody doesn't get motion sickness. The Russian design is massive. Also I figure 1g is unnecessary for going to Mars if space and mass is a concern so maybe a 10m layout can do if one just wanted to mimic Martian grav. Thoughts?
 

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prolific1 said:
http://www.projectrho.com/rocket/ is a good site I have bookmarked.

I thought of tumbling the spacecraft on simplicity grounds but the internal layout would be challenging between boost and cruise phase I imagine.

Depends on the ratios. If it spends a few minutes or hours boosting, and weeks or months coasting, then who cares? On the other hand if it spends days boosting at 1 gee, and takes only days to get where it's going, then it matters.
 
That's not a gas core engine; that's a fusion engine (spheromak, I believe).

I based (the first illustration) on the NASA fusion engine. I thought it was also considered a Gas Core but I guess not. You are the expert. The new illustration is a VASIMR.

BTW...that Orion Battleship rocks. Saw the finished one a minute ago following the thread.
 
Well it's for a 30 day one way transit to Mars. I was thinking of a Pilgrim Observer style of retracting spinning apparatus. Folded for boost phase and extended for spin during cruise phase.
 
prolific1 said:
That's not a gas core engine; that's a fusion engine (spheromak, I believe).

I based (the first illustration) on the NASA fusion engine. I thought it was also considered a Gas Core but I guess not.

Nope. "Gas core" specifically refers to nuclear *fission* engines, but with internal temperatures so high that the uranium is in a gasseous form. I don't think I've ever seen a detailed engineering design for a practical gas core engine (discounting nuclear light bulbs)... largely because nobody really know how to make one. The best thinkign tends to have the whole engine spinning at a very high rate along the central axis; the centrifugal force would thus, presumably, make the much denser uranium gas hug the outer wall, while the hydrogen propellant is stuck in the core of the engine. Thus, hopefully, the uranium gas would be contained within the engine, and not simply blown out the nozzle.

Looks great on paper. High thrust, high Isp. But complete vaporware.

The spheromak is a vastly higher Isp, far lower thrust fusion system.
 
prolific1 said:
Well it's for a 30 day one way transit to Mars.

For such short transits, you might want to ditch the whole arti-g idea entirely. At the very least, make it as simple as possible, generating no more than Mars-g (about 3/8 Earth g). Tumbling is about as simple as you can get. Next up would be separating the engine from the manned section, and tethering them together and spinning them. Long moment arm allows for easy, minimum-puking arti-g, and also allows you to orient the peoplepod however you like.

Think of it like the Apollo CSM... once underway to the Moon, it separated from the S-IVb stage, did a 180, and docked with the LEM. Instead, your "CSM" detaches from the booster, does a 180, redocks to the tether assembly, spins up, and slowly spools out. Theoretically easy.
 
prolific1 said:
What kind of reactor should I use to power the VASIMR since I know they require a ton of power?

A nice big fission reactor with a whole lot of radiator area, like the old-fashioned flat-panel type with a liquid coolant pumped through it, or if you want to get Neato, go with a thin film radiator made from woven diamond fibers (since diamond is nearly a thermal superconductor), or if you want to go Spiffy, use an oil droplet radiator.

But whatever you use for power production, be it a fission reactor fueled by Libyan plutonium, or a more advanced Mr. Fusion, just make sure it has the power you'll need. If you want to se VASIMR for fast manned transits, you'll need a whole metric assload of engines, since the max thrust level is kinda pitiful. And that means a whole metric assload of electrical power.

128919852209765616.jpg
 
Yeah I wondered about that. How is it that the VASIMR spacecraft [postulated in the NASA document by Mr. Chang Diaz] is supposed to be able to pull off 39 day one way Mars? I know it can change gears and what not but...
 
prolific1 said:
Yeah I wondered about that. How is it that the VASIMR spacecraft [postulated in the NASA document by Mr. Chang Diaz] is supposed to be able to pull off 39 day one way Mars? I know it can change gears and what not but...

I believe that's for a stripped down minimum probe craft... reactor, engine, a camera or two. Could be wrong, though.
 
Yeah I couldn't find clear info on that. The pic accompanying the article shows a manned craft with three small engines that speaks of 39 day manned mission one way. That said what kind of powerplant would you find ideal for a 30 day mission. Im a skeptic (as you have kind of tuned me in to that in the last few years) so I dont see anything happening sooner than the latter half of this century. So maybe 2060-70 ish. I'm still skeptical of antimatter stuff even by then so Im open to suggestions.
 
prolific1 said:
That said what kind of powerplant would you find ideal for a 30 day mission.

Overly simplistic math:
1) distance from Earth to Mars at closest: 36 million miles
2) Average speed needed for a 30-day transit: 36 million miles/30 days = 1.2 million miles per day = 50,000 mph =~22,000 meters per second
3) Time to accelerate to 22Km/sec at 1 g = 2242 seconds (about 2/3 hour)
4) Time to accelerate to 22km/sec at 0.001 g (common enough sort of acceleration for a high Isp system) = 622 hours = 25 days

You can see that just getting up to speed in a hurry is important if you want to get somewhere in a hurry. Low thrust, high Isp systems are fine for *deep* space probes, as the painfully long time needed for the boost winds up being a small fraction of the total mission time. But for shorter range missions, such systems are useless if your goal is fast transit. Getting from LEO to the moon with an ion engine is silly if you want to beat a chemical rocket... but if you want to get there *cheaper* than a chemical rocket, it just may be the way to go. Mars is kinda at the edge where such engines start looking good for fast transits.

If you want to get to Mars in 30 days with a manned vehicle, low thrust systems are probably not the way to go. Fusion engines or Medusa will do it for you. Advanced Orions with lots of pulse units and not so much payload will do it for you. NERVA type engines might work for you, so long as your vehicle and payload are stripped bare (put the crew in suspended animation, pick them up at Mars witha local "tug").
 
Now I'm thinking a Trimodal LANTR (which ironically is what I modeled my design after, right down to the Brayton Radiators) but I have doubts to the power side of that. Maybe it should be Spheromak again.
 
Since I made a tractor design, can I make a weaker structure than the one that attaches to the habitat module. It's still a work in progress so I put a placeholder on the truss.
 

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prolific1 said:
The latest.

Open to scrutiny, criticism, and the like.

Structurally, that would be... umm... HEAVY. And performancewise... well, if one of your engines craps out for some reason, you're boned, since you have to shut the other off as well.
 
prolific1 said:
So tractor designs suck huh?

Not necessarily, but they have definite practical limitations. Pellegrino's "Valkyrie" starship, Solems "Medusa," Ehricke's "Helios" were all tractor designs, and for good reason (generally a dire need to get the crew hell and gone away from the propulsion system due to radiation concerns).

A good rule of thumb: all the main engines should point through the center of gravity of the vehicle. If this is done, then if one of the engine craps out, the ship can keep moving in a straight line (even if it's crabbing sideways a bit). If you have you engines way out on moment arms, then if one of the engines dies, you need to be able to gimbal the other so that it points through the CG. And in this case, that would mean a virtual 90-degree sideways change in thrust line. Not good.

If you have a cluster of engines, the resultant thrust vector line should run through the CG. Can be either ahead of or behind the CG... dones't much matter. But if one engine in the cluster craps out, realize that the overall thrust vector is going to shift. Gimballing can take care of that easily if the engines are all clustered together.

Also note: it appears that you have your radiators on poles, pointing forwards. If this is a high acceleration vehicle, then get ready for a good shudder to snap 'em off.
 
Sweet. This is the kind of feedback I want to hear. I think I'll revert this design back to a low thrust NEP setup like the STCAEM NEP study that had a similar engine layout. Then I will crank out a newer version of this with the [fusion] engine locations under consideration.
 

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Orionblamblam said:
Pellegrino's "Valkyrie" starship, Solems "Medusa," Ehricke's "Helios" were all tractor designs, and for good reason (generally a dire need to get the crew hell and gone away from the propulsion system due to radiation concerns).

Pellegrino also claims that the tractor design reduces structural mass, since the spacecraft structure is in tension rather than in compression during boost. It sounds reasonable to me, but I'm no rocket scientist ( ;)), so I can't say whether this is a valid argument or just a marketing gimmick.

Regards & all,

Thomas L. Nielsen
Luxembourg
 
here Pellegrino work for AVATAR: IVS Venture star
is push by Laser Solarsail (folded in picture) on 0.20 the speed of light
the Laser is in Solarsystem on planet Mercury
then a Antimatter drive pull ISV to approximately 0.874 the speed of light
voyage takes 6.8 years from Earth to Pandora

Source Picture (20Th century Fox©)
http://1.bp.blogspot.com/_RRYNK-caPgI/SyeXjD9X28I/AAAAAAAAALA/zQeMLv53sEw/s1600-h/Planet+Pandora+Avatar.jpg
 

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