To Mars in 39 days (plasma propulsion)

[tirlimpimpim]

Hi everyone,

This is my first post on this forum so please don’t flame if Im

I have stumbled upon some articles on the new plasma propulsion system http://www.nautel.com/rocketscience/ [youtube]http://www.youtube.com/watch?v=RdZ-idbRz_8[/youtube]
developed by Nautel collaborating with Ad Astra Rocket Company of Texas which looks like a dream-come-true (honestly, at first glance I thought it was a hoax). However I am surprised not to find any info covering it on space.com - how come?

And what do you think - what kind of possibilities does this technology bring for science and business?

Cheers,
t.

 

[annodomini2]

Welcome!

Basically the company you listed is a supplier to the group developing the VASMIR engine. Which is a NASA program, if you look back through this forum there are already some threads on this.

Happy reading

Anno

 

[DarkenedOne]

Its name is VASIMR (Variable Specific Impulse Magneto-plasma Rocket). If you type in that name you can space.com articles on it.

There is also the website that is developing it with help from NASA.
http://www.adastrarocket.com/VASIMR.html
http://www.nasa.gov/vision/space/travel ... lsion.html

Yes the technology has massive potential for practically all space missions beyond earth orbit and stationkeeping. It is still in development though. They are planning to mount their latest version on the ISS in 2011 for an test of its capabilities.

 

[Shpaget]

Welcome tirlimpimpim,

This is pretty advanced tech compared to chemical rockets, but the guy at the end is a little too optimistic.
He talks about using VASIMR to get to other star systems because using chemical rockets would take more than a human life time. Well, it should be clear that plasma/ion engines aren't going to make that happen either.

 

[Swampcat]

Well, it should be clear that plasma/ion engines aren't going to make that happen either.

Opinion duly noted, but what do you base that opinion on? Propulsion systems like VASIMR have a lot of potential. The technology is in its infancy. It's rather presumptuous to state it will never develop into something capable of interstellar flight. That may be the case, eventually, but it is hardly clear at this point.

 

[Shpaget]

I base my opinion on a calculation that even if such an engine had a specific impulse of 30000 s (which is not likely for now) to speed up a spacecraft of mere 50 tons (way too small for anything) to 0,01 c (waaay to slow if you plan on getting anywhere outside solar system) it would take 1,3 million tons of reaction mass.

 

[samkent]

Plus what's the likelyhood of getting one of those engines running long enough to reach another star system?

 

[Polishguy]

Yeah, it's VASIMR. The problem with using VASIMR for a Mars mission is that, for the 39-day plan, you need to put over 600 metric tonnes into earth orbit first, just for fuel. By comparison, the Saturn V was 130-140, the Ares V might be 188, and the Russian plan for Energia-Uragan was just 200. So, VASIMR is a good plan for missions to the outer solar system, but chemical is just more efficient for short haul flights to Mars.

 

[bdewoody]

Face it guys and girls, we ain't leavin this solar system anytime soon, except in our imaginations and movies. When I say we I mean people as I know the Voyagers are both on the verge of interstellar space.

 

[menellom]

As I recall NASA planned to install a prototype on the ISS next year. Anyone know if VASIMR's development is still on schedule for that?

 

[DarkenedOne]

As I recall NASA planned to install a prototype on the ISS next year. Anyone know if VASIMR's development is still on schedule for that?

I believe they are planning for 2013.

 

[DarkenedOne]

Yeah, it's VASIMR. The problem with using VASIMR for a Mars mission is that, for the 39-day plan, you need to put over 600 metric tonnes into earth orbit first, just for fuel. By comparison, the Saturn V was 130-140, the Ares V might be 188, and the Russian plan for Energia-Uragan was just 200. So, VASIMR is a good plan for missions to the outer solar system, but chemical is just more efficient for short haul flights to Mars.

Your comparison is not accurate.

The Saturn V, Ares V could not get to Mars even if they wanted to. A chemical rocket going to Mars would have to be far larger.

There is no way you are going to make it to Mars in a chemical spacecraft in any decent amount of time with chemical propulsion. The best I have heard of for chemical is the Phoenix rover which made it there in about 10 months.

 

[kelvinzero]

There is no way you are going to make it to Mars in a chemical spacecraft in any decent amount of time with chemical propulsion. The best I have heard of for chemical is the Phoenix rover which made it there in about 10 months.

Since the Phoenix rover was unmanned, there would have been no reason to attempt to go faster if this meant less cargo or more cost. The often quoted "Mars Direct" plan mentions 6 month travel times using conventional propulsion. This seems entirely decent to me, especially since I feel that the emphasis should be on long stays.

Not that I would snub one month travel times, but VASIMR could probaby give us something I think is way more valuable: An order of magnitude more cargo tonnage within the same time and cost as a coresponding chemical rocket based mission.

 

[Astro_Robert]

Although I'm certain being able to send more cargo on short haul flights would be a nice benefit, any Astronaut contemplating such a journey would greatly value reducing the time they are vulnerable to solar radiation from flares and the like. A radiation shelter is required regardless of trip duration, but if I were to be the astronaut I would prefer regular quarters such as they are to a shelter, so faster is definitely infinitely better as far as people are concerned.

As to how long it might take before we could have a space certified power plant (nuclear reactor seems to be the only way to go here) capable of providing the reccomended power level for 39 day trip, well that is beyond anyone's guess at this point, and will ultimately depend on how serious governments are in terms of the checkbook.

Right now few politicians seem to think NASA funding deserves more funding than it already gets. Until NASA can either run more efficiently (Hopefully whatever launcher follows Shuttle will contribute here) or get more funding, it will be heavily constrained in terms of such developments.

 

[kelvinzero]

Im not sure how bad the radiation problem really is.

Solar flares are very bad for your health, but I think they contain lower energy particles than cosmic rays that are easier to shield against. When there is a solar flare warning everyone will have to huddle in a cramped shelter for a few hours.

We cannot do much about cosmic rays yet, but I have heard estimates along the lines of a two year mission only increasing your cancer risk by 2%.

I also heard recently that the radiation at the moon's surface may not be significantly less than that in open space, possibly caused by backscattering radiation of high energy particles hitting the regolith. If the same is true at mars then there would not be much value in dashing for the surface. If that is the case then whether you get there in one month or six it might not make that much difference to your radiation exposure if your total mission time is dictated by the two year gap between launch windows.

Although possibly if trip time could be 1 month we could dash there and dash back? I dunno.

My vote is still that a mission with ten times the cargo is more exciting and useful than a dramatically shorter mission.

In any case, no need to choose. If we had the thruster that could get the crew there in one month you could also send your vast cargo on ahead, during the previous launch window.

 

[Astro_Robert]

Surface radiation at either Moon or Mars could be mitigated by burrying the habitate underneath native soil to attenuate the radiation. A quick trip also reduces the time spent in weightlessness. Although the russians in particular have more data on extended spaceflight and ISS is studying ways to alleviate its impacts, it is still severe. There is muscle atrophy, and most importantly bone loss. Minimizing stay in that environment is definitely important from a people perspective.

Short trip times also increase the pool of volounteers. If you have 10 months each way, and potentially 10 or more on the surface waiting for a launch window, you will find some but few people willing to sign up for almost 3 years away from friends and family. Yes some 'internet communication' but that is not the same. If we could actually get to Mars in a little over a month then it is almost like an ocean crossing at the turn of the last century, and there would likely be more volounteers willing to take advantage of it.

To you r point about cargo, even today, people send cargo by slow boat for low cost, so I can see that would be a good use. But the need for large amounts of cargo will most likely be driven by more people on or travelling to the surface.

 

[EarthlingX]

Short trip times also increase the pool of volounteers. If you have 10 months each way, and potentially 10 or more on the surface waiting for a launch window, you will find some but few people willing to sign up for almost 3 years away from friends and family. Yes some 'internet communication' but that is not the same. If we could actually get to Mars in a little over a month then it is almost like an ocean crossing at the turn of the last century, and there would likely be more volounteers willing to take advantage of it.

I don't think we will soon have as much capability as there are potential volunteers, no matter how long the trip.
If they take me, i don't even need to return, but some people would probably want to, at least some day.

 

[Polishguy]

Short trip times also increase the pool of volounteers. If you have 10 months each way, and potentially 10 or more on the surface waiting for a launch window, you will find some but few people willing to sign up for almost 3 years away from friends and family. Yes some 'internet communication' but that is not the same. If we could actually get to Mars in a little over a month then it is almost like an ocean crossing at the turn of the last century, and there would likely be more volounteers willing to take advantage of it.

I don't think we will soon have as much capability as there are potential volunteers, no matter how long the trip.
If they take me, i don't even need to return, but some people would probably want to, at least some day.

Agreed. You don't even need 10 months. That's travel time on a low energy Hohmann transfer orbit (or is it a Venus flyby that Phoenix took?). But if you go on a Hohmann orbit and burn your engines longer, you can achieve the delta-v needed for a 6 month one-way flight. And frankly, if I were offered a one-way, one-man trip to Mars, like the Spirit of the Lone Eagle plan (http://www.thespacereview.com/article/669/1), I'd agree in a heartbeat!

As for launch capability, there's a solution. Launch an Ares V core stage into LEO (the big external tank will reach about 98% orbital velocity anyway), and outfit it as a wet-workshop space station. Then, push it into an orbit that takes it by earth every two years, and then moves over the course of 4.5 months, approaches Mars. You'd just need a small capsule to launch your colonists to the space station, and then land them on Mars. I'm sure that the SpaceX Dragon will be fully capable of such a mission.

@Darkened One: Actually, through the use of the Tsiolkovsky rocket equation, we can see that both Ares V and Saturn V can make it to Mars. Assuming the use of aerobraking to reduce the necessary delta-v, we see that a six month flight would require a delta v from LEO of 4.2 km/s.

The equation, therefore, is 2.72 with an exponent of 4.2/(specific impulse multiplied by earth gravity, km/s). The exponent we're attaching to 2.72 is therefore 4.2/(448, which is the Isp of J-2X engine, times 0.0098). This works out to an exponent of .957. 2.72 to the exponent .957 is 2.61. Dividing the Saturn V LEO payload by this number reveals a dry mass to Mars of 45.5 tonnes. Assuming about 8 tonnes for rocket motors and fuel tanks, that works out to over 35 tonnes delivered to Mars's surface with each launch. That's just for the 118.8 tonne to LEO Saturn V. That same equation applied to Ares V goes up to over 60 tonnes to Mars. That's almost the mass of the skylab space station. I'm sure that that kind of weight will be sufficient to house and carry a crew of 4 or 5 to Mars, just on chemical rockets.

 

[DarkenedOne]

Short trip times also increase the pool of volounteers. If you have 10 months each way, and potentially 10 or more on the surface waiting for a launch window, you will find some but few people willing to sign up for almost 3 years away from friends and family. Yes some 'internet communication' but that is not the same. If we could actually get to Mars in a little over a month then it is almost like an ocean crossing at the turn of the last century, and there would likely be more volounteers willing to take advantage of it.

I don't think we will soon have as much capability as there are potential volunteers, no matter how long the trip.
If they take me, i don't even need to return, but some people would probably want to, at least some day.

Agreed. You don't even need 10 months. That's travel time on a low energy Hohmann transfer orbit (or is it a Venus flyby that Phoenix took?). But if you go on a Hohmann orbit and burn your engines longer, you can achieve the delta-v needed for a 6 month one-way flight. And frankly, if I were offered a one-way, one-man trip to Mars, like the Spirit of the Lone Eagle plan (http://www.thespacereview.com/article/669/1), I'd agree in a heartbeat!

As for launch capability, there's a solution. Launch an Ares V core stage into LEO (the big external tank will reach about 98% orbital velocity anyway), and outfit it as a wet-workshop space station. Then, push it into an orbit that takes it by earth every two years, and then moves over the course of 4.5 months, approaches Mars. You'd just need a small capsule to launch your colonists to the space station, and then land them on Mars. I'm sure that the SpaceX Dragon will be fully capable of such a mission.

@Darkened One: Actually, through the use of the Tsiolkovsky rocket equation, we can see that both Ares V and Saturn V can make it to Mars. Assuming the use of aerobraking to reduce the necessary delta-v, we see that a six month flight would require a delta v from LEO of 4.2 km/s.

The equation, therefore, is 2.72 with an exponent of 4.2/(specific impulse multiplied by earth gravity, km/s). The exponent we're attaching to 2.72 is therefore 4.2/(448, which is the Isp of J-2X engine, times 0.0098). This works out to an exponent of .957. 2.72 to the exponent .957 is 2.61. Dividing the Saturn V LEO payload by this number reveals a dry mass to Mars of 45.5 tonnes. Assuming about 8 tonnes for rocket motors and fuel tanks, that works out to over 35 tonnes delivered to Mars's surface with each launch. That's just for the 118.8 tonne to LEO Saturn V. That same equation applied to Ares V goes up to over 60 tonnes to Mars. That's almost the mass of the skylab space station. I'm sure that that kind of weight will be sufficient to house and carry a crew of 4 or 5 to Mars, just on chemical rockets.

I believe both Astro_Robert and kelvinzero are right. As Astro_Robert pointed out there are problems with a space ship moving slow, including radiation, effects on the human body, and supplies. At the same time, as kelvinzero said, going faster requires one to sacrifice mass.

The answer is simply to seperate the cargo and people into seperate spacecraft. An ATV could be launched first, and use the most energy efficent transfer orbit to get the most mass to the planet. Then several months later a much faster manned spacecraft can be launched like the one that they said could get there in 39 days. The two spacecraft could be timed to reach the planet at the same time.

This way you get the best of both worlds. You get fast transit times for humans, while getting the most cargo to the planet as possible.

EarthlingX - First of all the Saturn V and the Ares V are rocket designed to get a spacecraft into LEO, thus neither craft could make it to Mars. Now you might say they can a spacecraft that can make it to Mars, but then again the Atlas V, the Delta IV, and half a dozen other rockets can as well. It takes more delta-V to get to Mars than it takes to get to the Moon. As a result both the Earth Departure Stage of both the Apollo and Constellation program probably do not have the power to make it to Mars. Thus in their current form the rockets and spacecraft of either program could not make it to Mars.

 

[EarthlingX]

I believe both Astro_Robert and kelvinzero are right. As Astro_Robert pointed out there are problems with a space ship moving slow, including radiation, effects on the human body, and supplies. At the same time, as kelvinzero said, going faster requires one to sacrifice mass.

Agreed. LEO access has different requirements than vacuum rocketing. There are solutions to this, just not tested and implemented anywhere that i would know of as of yet. We will get VASIMR on ISS, and when BA-330 is launched, we will find out how is it about it's radiation protection, if there is any doubt left, and Hyperion Power Module can be space worthy in a couple of years, as stated by their representative.

The answer is simply to seperate the cargo and people into seperate spacecraft. An ATV could be launched first, and use the most energy efficent transfer orbit to get the most mass to the planet. Then several months later a much faster manned spacecraft can be launched like the one that they said could get there in 39 days. The two spacecraft could be timed to reach the planet at the same time.

Not needed with enough onboard power.
VASIMR based spaceship for heliosphere
Ad Astra made an estimate with 10x that power. It doesn't change total mass that much, just shortens time.

This way you get the best of both worlds. You get fast transit times for humans, while getting the most cargo to the planet as possible.

EarthlingX - First of all the Saturn V and the Ares V are rocket designed to get a spacecraft into LEO, thus neither craft could make it to Mars. Now you might say they can a spacecraft that can make it to Mars, but then again the Atlas V, the Delta IV, and half a dozen other rockets can as well. It takes more delta-V to get to Mars than it takes to get to the Moon. As a result both the Earth Departure Stage of both the Apollo and Constellation program probably do not have the power to make it to Mars. Thus in their current form the rockets and spacecraft of either program could not make it to Mars.

Forget Saturn V, and yea, Ares V has nothing to do beyond LEO, hopefully doing that.
No rush to Mars, but Phobos might be something else, if we can stay out that long. Easier than Moon, but longer.