Verne - Around the world in 80 days -> NASA - to Mars in 40

[cabri]

Link

VASIMR Rocket Could Send Humans To Mars In Just 39 Days

A new type of rocket that could send humans to Mars in less than six weeks instead of six months or longer may be one step closer to reality.

NASA has selected Texas-based Ad Astra Rocket Company for a round of funding to help develop the Variable Specific Impulse Magnetoplasma Rocket, or VASIMR. The new rocket uses plasma and magnets, not to lift spacecraft into orbit but to propel them further and faster once they've escaped the planet's atmosphere.

“It is a rocket like no other rocket that you might have seen in the past. It is a plasma rocket," Dr. Franklin Chang-Díaz, a former shuttle astronaut and CEO of Ad Astra said in a video describing the rocket. "The VASIMR engine is not used for launching things into space or landing them back but rather it is used for things already there. We call this ‘in-space propulsion.'"

In ideal conditions, the rocket could propel a spacecraft to Mars in just 39 days.

So far, a non-nuclear prototype has been able to fire for less than a minute at a time:

The NASA contract, worth about $10 million over three years, would go toward creating a prototype that could operate at high power for a minimum of 100 hours, the company said in a news release.

If it works; then we still need to get into LEO first efficiently.

If not; then it is an advance in technology that hopefully can be built upon


/edit Corrected Verne's travel time

 

[Matthiasa]

Current prototypes working for less than a minute to over 100hrs with only 10 million. I guess good luck to them. Or actual costs being a fair bit higher.

 

[Jodell88]

It was 80 days, not 60.

 

[Paratus]

I got to see the lab version of this in action over a decade ago.

It's basically a fusion rocket without the fusion. Dr. Chang-Diaz was a fusion researcher who was having trouble containing the plasma for fusion due to leaks. He realized that if the magnetic bottle couldn't contain the plasma, letting it leak out in one direction turns it into a rocket.

The benefit of VASIMR is that it acts like a cars transmission. It can provide significant thrust at low Isp when starting on mission, (like being in first and second gear in car - good acceleration bad gas mileage) and progressively increasing Isp for better efficiency but with lower acceleration once the vehicle is moving, (like being in 6th gear cruising on the high way - low acceleration great mileage).

It works using two radio antennas and several magnets. Any of a number of neutral gasses is injected into the chamber through a Quartz tube past the first antenna called a helicon. The helicon is tuned to excite any free electrons in the gas. The excited electrons slam into other electrons knocking them free in a cascade. This forms a low temperature plasma around 50,000degrees.

The plasma follows the magnetic field lines through the chamber until they come to the other antenna at the magnetic choke that leads through the magnetic nozzle. The second attenna called the Ion Cylotron Resonance Heating attenna is tuned to heat the nucleuses in the plasma. This heats the plasma to millions of degrees. Which then exhausts through the magnetic nozzle.

By putting more power to the helicon and relaxing the magnetic choke VASMIR can produce more thrust. Choking the plasma and adding more power to the ICRH means only the hottest gas escapes giving low thrust but great Isp.

The Space Shuttle main engines were rated at 450Isp and were the most efficient chemical rockets. ION drives run around 3000Isp. VASMIR can vary from 3000 to over 30,000 Isp.

That being said Franklin needs A LOT of electrical power. 39 days to Mars would require a nuclear reactor of over 100MW, (naval reactor size). Even the test article for the ISS would draw more power than the electrical system can provide. So last I heard it was going to trickle charge its own batteries and then run of them for some period of time.

It's a neat technology and I'm glad it sounds like NASA is still funding them.

 

[Excelsior]

This kind of stuff blows my mind.

Paratus - Would it even be reasonable/feasible to put such a nuclear reactor on a ship?

 

[Ruptga]

This kind of stuff blows my mind.

Paratus - Would it even be reasonable/feasible to put such a nuclear reactor on a ship?

It would be ridiculously heavy, so it wouldn't be worthwhile at all unless the plan was to leave it up there for use as a tug or power station for future missions. Also I'm pretty sure no real reactors have been launched before, other nuclear craft (like voyager) have been powered by RTGs which create power from the heat of a decaying isotope sample. Those can be made relatively light but don't put out nearly as much power as a real reactor.

 

[Paratus]

Here's some pics and diagrams:

 

[MagnusTheBrewer]

It was 80 days, not 60.

Next you'll be telling us it wasn't the 3/4 Time Machine or, 15,000 Leagues Under the Sea.

 

[Paratus]

It would be ridiculously heavy, so it wouldn't be worthwhile at all unless the plan was to leave it up there for use as a tug or power station for future missions. Also I'm pretty sure no real reactors have been launched before, other nuclear craft (like voyager) have been powered by RTGs which create power from the heat of a decaying isotope sample. Those can be made relatively light but don't put out nearly as much power as a real reactor.

The U.S. launched SNAP 10A which was a several 100W reactor. The Russians have launched several nuclear reactors upto a few KW, (TOPAZ).

Back in 05 before it was cancelled the Jupiter Icy Moons Mission was supposed to get a 100Kw reactor.

 

[Ruptga]

The U.S. launched SNAP 10A which was a several 100W reactor. The Russians have launched several nuclear reactors upto a few KW, (TOPAZ).

Back in 05 before it was cancelled the Jupiter Icy Moons Mission was supposed to get a 100Kw reactor.

TIL

I actually had no idea that a reactor could be made to produce less than a kilowatt, what with critical mass and all that. Still, comparing those to a 100 megawatt unit doesn't seem fair.

 

[Excelsior]

TIL

I actually had no idea that a reactor could be made to produce less than a kilowatt, what with critical mass and all that. Still, comparing those to a 100 megawatt unit doesn't seem fair.

So considering the size it would have to be, sending it up by itself (actually, in parts) then assembling it and connecting it to the vessel in space would be the only way. Interesting. I've never really thought about needing to generate so much power in space but it's a fascinating topic to me.

 

[Paratus]

This kind of stuff blows my mind.

Paratus - Would it even be reasonable/feasible to put such a nuclear reactor on a ship?

A nuclear reactor, sure. As I mentioned above JIMO was supposed to get one on an unmanned mission launched on a normal launcher.

However for a Mars trip they were talking about 100-200MW for 40 day transit, and 10-15MW for 3-6month transit.

To give you an idea about the mass required, I recently read a wiki article about modular nuclear reactors. There was one design that was for a 10MW reactor, meant for the ground, that weighed 200 metric tons. In comparison the SLS heavy launcher NASA is building for Orion, will max out at 130 metric tons, (similar to the Spacex heavy launcher). The ISS weighs 400 metric tons by comparison.

Needless to say there are some definite design challenges to bringing power up and weight down.

Currently there is no direction from NASA to work on space based nuclear. Which is a shame because to really explore the solar system we need a dense power source. Solar isn't going to cut it for anything beyond Mars and even then it's barely good enough. (Replacing the ISS arrays designed in the 80's with the latest and greatest would only give you an instantaneous maximum output of about 750KW at Earth, much less at Mars.)

We need nukes.

 

[Paratus]

TIL

I actually had no idea that a reactor could be made to produce less than a kilowatt, what with critical mass and all that. Still, comparing those to a 100 megawatt unit doesn't seem fair.

Mostly I was pointing out that we have flown reactors before as proof of concept. But yes, there are several orders of magnitude to go to reach the power densities this article was talking about. It's not impossible, just difficult and currently the political will to do so isn't there.

 

[Brovane]

That being said Franklin needs A LOT of electrical power. 39 days to Mars would require a nuclear reactor of over 100MW, (naval reactor size). Even the test article for the ISS would draw more power than the electrical system can provide. So last I heard it was going to trickle charge its own batteries and then run of them for some period of time.

It's a neat technology and I'm glad it sounds like NASA is still funding them.

When are they planning on adding a VASMIR system to ISS?

 

[Paratus]

So considering the size it would have to be, sending it up by itself (actually, in parts) then assembling it and connecting it to the vessel in space would be the only way. Interesting. I've never really thought about needing to generate so much power in space but it's a fascinating topic to me.

Do I have a job for you!

This was a big part of my job for over a decade.

 

[Excelsior]

Do I have a job for you!

This was a big part of my job for over a decade.

Yeah, uh, I wish I was smart enough and qualified enough to have that job.

 

[Paratus]

When are they planning on adding a VASMIR system to ISS?

Good question.

I've known of meetings off and on since the late 00's. When shuttle retired, which i think they wanted to go up on, I stopped hearing much about it. Maybe this new contract isn't for ISS. Maybe its for technology maturation. Although, knowing the power requirments I'm not sure where else they could eventually test it in space. It requires a very serious spacecraft.

Anyway here's a direct link to their press release.

http://adastrarocket.com/AdAstraRelease033115final.pdf

They're getting 6N with 5000Isp, that's not to bad!

 

[Paratus]

Yeah, uh, I wish I was smart enough and qualified enough to have that job.

To be a flight controller requires an engineering or science degree. And to be a steely eyed missile man of course.

 

[rh71]

American components, Russian components... all made in Taiwan!

 

[Fritzo]

So..impulse...like in "impulse power"???