NASA: VASIMR to ISS

[Dr Mordrid]

No links yet, but this weekend at the Oshkosh, Wisconsin air show (the largest in the world) NASA administrator Mike Griffin announced that NASA is working out a deal to boost a VASIMR plasma rocket to the ISS for trials.

The VASIMR (variable specific impulse magneto-plasma rocket) is a true interplanetary space drive - some think of it as a real life 'impulse engine'. With the proper fuel and much more development the concept could evolve into a true fusion drive.

The first high powered VASIMR has been under test for the last few months and a space capable one capable of such a mission is under construction.

VASIMR's inventor is former long-time NASA astronaut Dr. Franklin Chang Diaz. It's being developed by Dr. Diaz's company - The Ad Astra Rocket Company - in conjunction with NASA and several other companies.

VASIMR module at right-foreground; its huge vacuum test chamber at left-background.

The advantage of the hex module is that it would allow several VASIMR's to be clustered for more power. Initial power will be solar, but add a small nuclear reactor and you really have something. Mars concepts have clustered VASIMR's running at up to 200 megawatts.

[Nowhere]

I wonder...was there something in the news suggesting that, if the tests go well, the tested VASIMR plasma rocket will be left on the ISS for reboosting of the station? (or at least - will it be designed with that possibility in mind?)

[Dr Mordrid]

As far as I know that's the plan if all goes well.

This has been in the works since 2001 when VASIMR was still a NASA project. Diaz later left NASA to privatize his invention, signing a 'Space Act' contract with NASA for cooperative development while also working with other companies on the tech.

Chemical rockets have a high thrust for a short time using tons of fuel; good for boosters but a lousy interplanetary engine.

VASIMR uses a lower thrust in space only, similar to an ion drive but much more powerful, and it can keep accelerating for months at a time on very little fuel mass. Example: using an ion drive Deep Space One motored all over the solar system on just 65 kg of fuel & much less power.

Think tortoise and hare.

Measured as specific impulse (bigger is better);

Chemical rocket SI: 200-450 (peak - ~9.7 MJ/kg of fuel @ 4,400 m/s exhaust velocity)

VASIMR SI: 1,500 to 30,000 (peak - ~43,000 MJ/kg of fuel @ 290,000+ m/s exhaust velocity)

[Evildead666]

This is all getting better and better

Woohoo for space exploration.
This sort of news makes my day.

[Dr Mordrid]

Here's some video for you.....

Early 100 kw VASIMR working at 70 kw here....

(ISS mission will be 200+ kw - imagine a megawatt class)

Animated NASA Mars mission using VASIMR here....

(the 3 booms are reactors & yellow cylinders are liquid hydrogen fuel which doubles as radiation shielding for the crew)

NASA's numbers for the above mission. Note that it gets to Mars in 39 - 53 days vs. up to a year for chemical rocket mission plans.



Diagram of lab version (note: the magnets are superconducting units)

[Marshmallowman]

heh heh, tortoise and hare I am not sure that is accurate analogy.

I have never seen a Tortoise with maximum velocity 10x that of a hare...but taking 10 times longer to get to that speed. Unless you throw the tortoise off a cliff, in that case I would think the hare would be just as fast

But I get what your saying

[Dr Mordrid]

I have never seen a Tortoise with maximum velocity 10x that of a hare...but taking 10 times longer to get to that speed.

Look at it this way;

A VASIMR taking one to Mars would take 39-53 days counting the time to spiral Earth until it was up to speed, after which the trip to Mars is VERY fast. This spiral time is also a safety feature in that the proximity to Earth provides an abort mode for much of the mission.

A chemical rocket taking one to Mars would blow off all its fuel before even reaching the moon then coast at a much lower speed the rest of the way. No near-Earth abort mode and the trip would not take 39-53 days but almost a year, during which all manner of bad things could happen.

Faster
Smaller
Safer
In the long term: cheaper

[Marshmallowman]

I was alluding more to the theoretical maximum velocity of VASMIR space craft compared to a chemical one, but still it was supposed to be tongue in cheek.

but you are right the wind resistance of hare dropped off a cliff is higher than that of a tortoise, so the tortoise will win anyway Do you know any good tortoise soup recipes

[Dr Mordrid]

OF COURSE!! (NEVER ask a cook if he has a recipe, as you'll get it in detail )

Creole snapping turtle soup that is, but then it's all the same to the turtle/tortoise

Creole Snapping Turtle Soup

Roux:

1c unsalted butter
1/2c all purpose flour

Soup:

4 Tb unsalted butter
1 lb snapping (or any other) turtle meat cut into 1/2 inch cubes
1 1/2c finely diced onion (I prefer the nasty yellow ones)
1 c diced celery
1/4c diced green onions
2 tsp minced garlic
2 bay leaves
1 1/2c diced tomato
1 qt turtle stock if you have the bones; beef stock if you don't
Cayenne pepper to taste (mine leans to flamethrower, so....)
1 pinch ground allspice
2 Tb thyme
1 Tb chopped marjoram
salt and black pepper to taste
1/4c lemon juice (some prefer lime)
4 Tb Worcestershire sauce
3 Tb cooking sherry
3 diced hard boiled eggs (rice the yolks separately)
Lemon slices to taste
5 tsp chopped Italian parsley

Melt the 1c of unsalted butter in a heavy bottomed saucepan, whisk in the flour, cook to make a peanut butter colored Roux. Set aside. If you can't make Roux, stop here.

In a large saucepan or dutch oven, melt the 4 Tb of unsalted butter over medium-high heat, add the diced turtle meat and saute until browned.

Lower the heat to medium, add both types of onions, the celery and garlic. Season with salt and black pepper. Saute until the vegetables are tender.

Add the tomatoes, season with a little salt so they will break down, cook for 10 minutes.
Add the stock, Worcestershire, cayenne, allspice, and bay leaves. Bring to a boil, then turn down to a simmer. Simmer for 20-30 minutes, stirring occasionally and skimming off any impurities that may rise to the surface.

Whisk in the Roux, simmer until thickened and smooth. Add the thyme and marjoram, simmer for 15-20 minutes more.

Add the lemon juice, 3 tsp of the parsley and the riced egg yolk, heat through.
Serve garnished with the lemon slices, diced egg whites and Italian parsley. Add the sherry at the table; about 1-2 tsp/bowl.

[Marshmallowman]

hehe, I thought you might.

I have enjoyed turtle soup last time I had it , unfortunatly all the local species are protected.

The the local aboriginals are allowed to hunt them as native food though.
When they gave me some(sea turtle), they get the whole turtle and take out the guts and turn the turtle over and put it straight on the fire and make a kind of soup usualy quite rare(still red).

Do you think your recipe would work with crocodile, I migh be able to get that.

Just to stay on topic, do you think VASMIR would be good to sear the meat before saute'ing

[Dr Mordrid]

It should work nicely with croc, lizard meat, frogs legs, chicken, snake meat or even rabbit. I personally love frogs legs, rabbit and rattlesnake in soups. Shellfish like lobsters or large prawns might work good to, but I'd add them later in the process lest they get tough from over cooking (they only take a few minutes in gumbo, so...)

VASIMR might be a bit hot given its plasma temp of tens of millions of degrees. That said there are some looking at the VASIMR tech for an advanced plasma waste disposal system. Not too many compounds could survive that thing.

[Evildead666]

http://www.nytimes.com/2008/08/01/science/01muscle.html?_r=1&oref=slogin

saw this thing about a pill instead of exercise.
It immediately made me think of long space travel.
Mix this with an artificial coma, and you have long distance space travel, basically, um, a sort of hibernation, but without actually stopping time for the Humans, just slowing it down a tad...

It could also help people who are spending long times in zero gravity...

[Nowhere]

Look at it this way;

A VASIMR taking one to Mars would take 39-53 days counting the time to spiral Earth until it was up to speed, after which the trip to Mars is VERY fast. This spiral time is also a safety feature in that the proximity to Earth provides an abort mode for much of the mission.

...

Faster
Smaller
Safer
In the long term: cheaper

So...long time spent in Van Allen belts?...

And this short time of travel makes me wonder...I think they might travel above escape velocity from the Solar System. Which means if something goes wrong...they're more likely to be...gone (vs. chemical rocket, which, I guess, could somehow swing gravitationally, perhaps few times, to get back to Earth - with the crew using supplies meant for Mars stay and normal return)

[Dr Mordrid]

The outer Van Allen belt is from 3-10 Earth radii from the surface - about 19,134.3 to 63,781.0 kilometers and the "radiation" is in the form of charged particles, not gamma.

A satellite with a 3mm aluminum skin and no surrounding magnetic field orbiting in that region would receive about 25 Sv (Sievert = 1 Joule/kg) of exposure per year.

A VASIMR Mars mission would spiral around Earth for about 8 days resulting in an exposure of about 0.548 Sv without additional shielding, but a manned mission would have a rather significant shielding around the crew cabin; water blankets and high density polymers which also contain a lot of hydrogen. Providing most of shielding would be those big yellow fuel tanks around the crew cabin which contain liquid hydrogen - an excellent radiation shield.

Now for the mind blower:

Space agencies along with universities on both sides of the pond have been working on a system where power would be channeled through a superconducting web arranged around the surface of a spacecraft. Once a field is established using this web plasma would be introduced into it creating an artificial magnetosphere.

Yes: SHIELDS

[Nowhere]

Oh my, sounds like it could protect against phasers (not photon torpedoes thought...)

But I wonder how it'll interfere with external magnetospheres when it comes to movement - like sail or...like drag chute?...

PS. I wonder, how do you pronounce VASIMR? I have a hard time pronouncing it differently than Vasimir (with a Slavic accent of course )