VASIMR Rocket can take you to Mars in 39 days

[PWiz]

Apparently, this news is all over the net. NASA has given a Texas-based company called Ad Astra Rocket a 10 million dollar grant (the money will be given over a 3 year period) to help develop a functional VASIMR rocket (Variable Specific Impulse Magnetoplasma Rocket), which will supposedly take you to Mars in just 39 days. I've attached a photo of the engine design. Here is a link to the company's website - http://www.adastrarocket.com/aarc/VASIMR

The VASIMR engine will use radio waves generated by two radio wave couplers to ionize noble gases. The first coupler will generate a "cold" plasma using a helicon RF antenna, and the resulting plasma will be narrowed down into a stream using a strong electromagnetic field (generated by a superconductor), and an ion cyclotron heating coupler will then raise the temperature of the ionized mixture to an incredible degree (about 10 million Kelvin, or the same temperature as the Sun's core), and a massive thrust will be produced as the high pressure plasma will be ejected ( although, as the website says, a magnetic "nozzle" will be required to allow linear propulsion) . By precisely controlling ionization levels and electromagnetic field strengths, it is believed that the thrust can be controlled and changed very well (and very quickly too). The engine also boasts an "electrodeless" system and improved fuel efficiency compared to other electric thrusters.

The biggest challenge with this technology is power supply. The entire mechanism requires huge amounts of electricity, and solar and nuclear power are considered to be the only viable sources of energy to run this engine through space at present.

The VASIMR engine technology has come under some criticism as well. NASA however, appears to have taken a liking to the design.

Personally, I think this "wonder" engine seems too good to be true (I'm not an expert in this by any means though). What do you have to say about it?

 

[Dotini]

Apparently, this news is all over the net. NASA has given a Texas-based company called Ad Astra Rocket a 10 million dollar grant (the money will be given over a 3 year period) to help develop a functional VASIMR rocket (Variable Specific Impulse Magnetoplasma Rocket), which will supposedly take you to Mars in just 39 days. I've attached a photo of the engine design. Here is a link to the company's website - http://www.adastrarocket.com/aarc/VASIMR
The VASIMR engine will use radio waves generated by two radio wave couplers to ionize noble gases. The first coupler will generate a "cold" plasma using a helicon RF antenna, and the resulting plasma will be narrowed down into a stream using a strong electromagnetic field (generated by a superconductor), and an ion cyclotron heating coupler will then raise the temperature of the ionized mixture to an incredible degree (about 10 million Kelvin, or the same temperature as the Sun's core), and a massive thrust will be produced as the high pressure plasma will be ejected ( although, as the website says, a magnetic "nozzle" will be required to allow linear propulsion) . By precisely controlling ionization levels and electromagnetic field strengths, it is believed that the thrust can be controlled and changed very well (and very quickly too). The engine also boasts an "electrodeless" system and improved fuel efficiency compared to other electric thrusters.

The biggest challenge with this technology is power supply. The entire mechanism requires huge amounts of electricity, and solar and nuclear power are considered to be the only viable sources of energy to run this engine through space at present.
The VASIMR engine technology has come under some criticism as well. NASA however, appears to have taken a liking to the design.

Personally, I think this "wonder" engine seems too good to be true (I'm not an expert in this by any means though). What do you have to say about it?

The discovery of vast glaciers, thought to be pure water ice, just under the surface of equatorial regions of Mars will lend new encouragement to the quest for the Red Planet.
http://phys.org/news/2015-04-mars-belts-glaciers-frozen.html

Although I am skeptical of the safety of manned space flight much beyond low Earth orbit, (I wear a belt and suspenders), anything which can reduce travel time to Mars should be investigated.

 

[PWiz]

The discovery of vast glaciers, thought to be pure water ice, just under the surface of equatorial regions of Mars will lend new encouragement to the quest for the Red Planet.
http://phys.org/news/2015-04-mars-belts-glaciers-frozen.html

Although I am skeptical of the safety of manned space flight much beyond low Earth orbit, (I wear a belt and suspenders), anything which can reduce travel time to Mars should be investigated.

I'd hate to experience those g's...

 

[Astronuc]

Here is a link to the company's website - http://www.adastrarocket.com/aarc/VASIMR

The VASIMR engine will use radio waves generated by two radio wave couplers to ionize noble gases. The first coupler will generate a "cold" plasma using a helicon RF antenna, and the resulting plasma will be narrowed down into a stream using a strong electromagnetic field (generated by a superconductor), and an ion cyclotron heating coupler will then raise the temperature of the ionized mixture to an incredible degree (about 10 million Kelvin, or the same temperature as the Sun's core), and a massive thrust will be produced as the high pressure plasma will be ejected ( although, as the website says, a magnetic "nozzle" will be required to allow linear propulsion) . By precisely controlling ionization levels and electromagnetic field strengths, it is believed that the thrust can be controlled and changed very well (and very quickly too). The engine also boasts an "electrodeless" system and improved fuel efficiency compared to other electric thrusters.

One important parameter missing in the description of the engine is the thrust (N), or mass flow rate (kg/s). Instead there is only a claim of 'high thrust', which is not informative. A thrust vs power curve would be nice.

Also, the trip time will depend on the mass being accelerated. The mass will include the capsule, the rocket motor, and the power plant.

As far as I know, the VASMIR concept has provided little thrust.
http://www.adastrarocket.com/aarc/technology (VX-200 is designed for 5 N at 200 kW). But has that been achieved, and have they done a 40 to 50 day test.

I would like to see the design calc and assumptions for a 39 day trip.

 

[PWiz]

@Astronuc

The VASIMR® engine is able to process a large amount of power, meaning that it can then generate a larger amount of thrust. This larger thrust capability promises to make the VASIMR® engine useful for moving large payloads around low Earth orbit, transferring payloads from the Earth to the Moon, and transferring payloads from the Earth to the outer solar system. The VASIMR® technology is also highly scalable, meaning that higher power versions can be easily designed; making human missions powered by electric propulsion a reality

Yes, you've definitely got me thinking. I really don't know how they plan on "scaling" up their operations to allow that Mars trip. NASA sure has placed a lot of trust in the company with that 10M bill though..

 

[Astronuc]

The mass will include the capsule, the rocket motor, and the power plant.

I should have explicitly mentioned the propellant and propellant storage tanks. Assuming something like hydrogen, methane or ammonia, in liquid form. There is the propellant required to get to the destination, then the propellant required to return - assuming this is roundtrip. A one way trip can be done faster, or with less energy.

The key performance parameter is kW/kg, or MW/kg.

 

[PWiz]

Can you please compare the roles of thrust and power to weight ratio for this engine?

 

[Doug Huffman]

5.7 N and 5,000 seconds specific impulse at 200 kW
https://en.wikipedia.org/wiki/Comparison_of_orbital_rocket_engines

 

[mheslep]

The VASIMR engine technology has come under some criticism as well. NASA however, appears to have taken a liking to the design.

The technical criticisms by Zubrin are unanswered as far I know. A short list includes: i) a short trip is undesirable; it should be 6 months outbound with a lower delta-V because, in case of failure, that allows a big loop return to a place Earth is going to be allowing an Apollo 13 like coast home, ii) the radiation concerns of a longer trip are overblown, equivalent to smoking for some months, iii) VASIMR energy overhead from ionization energies and the like don't allow the high Isp's claimed.

Zubrin's also offers political speculations that are not provable but also not unreasonable in my view. That being that NASA does not actually want to do a manned Mars mission in the near term without a huge budget that would leave existing rice bowls untouched. VASIMR is not ready yet even according to proponents, unlike a traditional chemical lift to Mars. So too nuclear powered designs. Per Zubrin, these reach technologies are being used as delay tactics.

None of this is to say research on ion engines or nuclear powered designs should not continue; it should. I contend these higher tech alternatives be considered in a fair technical manner against chemical lifters, for which the price has fallen considerably.

 

[mheslep]

5.7 N and 5,000 seconds specific impulse at 200 kW
https://en.wikipedia.org/wiki/Comparison_of_orbital_rocket_engines

So they hope. The data is http://www.adastrarocket.com/Ben_IEPC11-156.pdf. In particular, it appears the thrust tests only last for short periods, minutes, maybe seconds, before heat forces shutdown.

 

[rollingstein]

The biggest challenge with this technology is power supply.

Sounds like a fatal flaw to me.

e.g. What size of nuclear reactor would be needed? How many MW of electric power needed?

 

[D H]

VASIMR Rocket can take you to Mars in 39 days

It is 2015, and per the movies I am supposed to be able to pop the hood of my car and see Mr Fusion. All I need to do is add a tiny bit of garbage and voila! out comes 1.21 gigawatts. The only problem: That's pure science fiction.

If that science fiction was reality, and if VASIMR operated according to theory at those untested power levels, then yes, we could use VASIMR to get people to Mars in 39 days. But Mr Fusion is science fiction, and VASIMR engines have only been constructed and tested at the hundreds of kilowatts level. That's great (maybe) for reboosting the International Space Station.

The reality is that ion propulsion engines such as VASIMR are power thirsty beasts. Until we know how to produce massive amounts of power without having to use massive amounts of mass, getting humans to Mars in 39 days will remain in the realm of science fiction.

 

[DiracPool]

The technical criticisms by Zubrin are unanswered as far I know.

I follow the manned mission to Mars movement pretty closely, and I think that Chang Diaz or one of his team should have shown up for Zubrin's challenge. Bad form. We are not elitists here, we ostensibly have the same goal and although admittedly Zubrin can be chaffing at times, that's no reason not to show up and defend your project. Mars society is not only a legitimate organization, it's conferences host some of the premier figures in the space exploration field, including many NASA administation, astronauts, university researchers, and characters like Elon Musk and representatives from Virgin Galactic.

 

[mheslep]

I follow the manned mission to Mars movement pretty closely, and I think that Chang Diaz or one of his team should have shown up for Zubrin's challenge. Bad form. ...

Valid challenges should best be made and answered in the literature. Zubrin had some valid points imo but they should be addressed in writing. Bad form is attached to Zubrin for public bombast, not his target, regardless of technical validity.

 

[DiracPool]

Valid challenges should best be made and answered in the literature. Zubrin had some valid points imo but they should be addressed in writing. Bad form is attached to Zubrin for public bombast, not his target, regardless of technical validity.

Well, if you watch the videos, I think Zubrin did address this in print, Spacenews or something like that. I disagree about bad form being attributed to his public bombast. He makes a good point about NASA doing nothing other than going in circles for the last 40 years in terms of their manned space program. The manned space program has devolved into a scattered distribution of pet projects with no focus or cohesion for a targeted mission. It's a bunch of individual greedy researchers painting some pie in the sky nonsense for a 2050 Mars Mission so they can get funding to do some BS local work in the lab and draw 7K a month. IMHO.

 

[DiracPool]

The fact is that we the people are doling out 19 billion dollars a year to fund this charade and somebody's got to call BS on it. Thank god for Zubrin's bombast. I could go into details but just visit the Mars Society website or Youtube channel. We need to engage now in a Mars mission and we can justify funding the ISS for the next ten years if we have that mission engaged. Otherwise, I personally say we cut ISS funding.

 

[mheslep]

No, a column or whatever in Spacenews is more shooting his mouth off. By in the literature, I mean the peer reviewed literature. Avoiding the proper forum is bad form, period. As Chang Diaz published in the literature, he owes Zubrin nothing.

Look, Zubrin can influence policy somewhat by gathering a public following in these public discussions, articulate his encyclopedic knowledge of spacecraft propulsion and mission mechanics and pound the table about it all, insult those with whom he disagrees. At this he's apparently very adept, good for him. Or, he can forego the table pounding and address simply the technical issues, and no more, in the peer reviewed literature. He can't do both at the same time, and for good reason.

 

[mheslep]

The fact is that we the people are doling out 19 billion dollars a year to fund this charade and somebody's got to call BS on it. ...

That may well be so. I might well support US space spending as Zubrin indicates. That doesn't mean Chang-Dias owes Zubrin or the Mars Society even the time of day.

 

[DiracPool]

That may well be so. I might well support US space spending as Zubrin indicates. That doesn't mean Chang-Dias owes Zubrin or the Mars Society even the time of day.

Not even the time of day? Why not? Here's a debate Zubrin had with a NASA proponent of solar electric propulsion (SEP) in relation to the proposed asteroid retrieval mission. Zubrin basically lambasted this effort as well but we got both sides and it was an interesting and informative civil discourse. It's not about Chang Diaz owing anything to anybody, it's about him moving through the relevant communities and pushing/defending his program. The fact that he doesn't show up for the premier deepspace/manned mission conference makes me supremely suspect. At the end of day, it really gets down to funding, and that was Zubrin is all incensed about. Make a plan, set a deadline, and issue the funds accordingly. Funding this VASIMR nonsense in the context of the first manned mission to Mars is a hoax. It's should not even be considered as a viable propulsion option until is has payed it's dues in nearer deep space missions, IMO.

 

[rootone]

It sounds like a good idea, but the power plant required to run the thing would need to be truly massive in itself.
I think it would need a low mass source of a huge energy supply to make it work, either by directly converting mass to electrical energy, or having some sort of matter/antimatter annihilation going on. to make it look like an improvement on existing ion engine design.

 

[rollingstein]

Zubrin had some valid points imo

Seems a bit of an understatement.

 

[rollingstein]

e.g. What size of nuclear reactor would be needed? How many MW of electric power needed?

To answer my own question apparently on the order of 200 MW electric power plant would be needed. WTF?

How do they propose to fit this on a Mars mission?

 

[mfb]

200 MW electric power for 5kN thrust?
We need ~17mm/s^2 acceleration, that allows a total mass of 300 tons.
Scaling up from the Apollo mission, you certainly want 100 tons for the astronauts. We need radiators for ~1GW thermal power (might be possible to use them for photovoltaics at the same time although temperature is an issue), we need fuel for the VASIMR units and those units have a mass as well.
That is a very small nuclear reactor.

 

[rollingstein]

200 MW electric power for 5kN thrust?

I could be wrong. The 200 MW figure I remember from the Zubrin video.

He says the largest space-flight Nuclear Reactor built so far delivers in the 100 kW range. So this would be a big step up.

 

[mheslep]

We are not elitists here,

the premier deepspace/manned mission conference

Sounds like a "humble" request for Galileo to appear before the papal authorities to me, where emotional appeals and championing heroes are likely to rule the day. The conference you reference neither funds nor is responsible for any NASA mission, thus NASA contractors owe them no more than they do Joe tax payer. The Architects and Engineers for 9/11 Truth crank group also has called for this or that figure to appear before them, though they can't be bothered with doing the work to engage in the literature either.

Again, from what I can tell Zubrin's arguments have technical merit (unlike A&E 9/11) but the rules still apply to him.

 

[mheslep]

...
That is a very small nuclear reactor.

By ground standards. From I can tell of the history 200 MWe would be many orders of magnitude higher than anything ever flown. US SNAP-10A ('65) was 650W(e), 45 kW thermal; the Soviets launched dozens of 3 kW (thermal or electric?) satellites.

 

[rollingstein]

NASA contractors owe them no more than they do Joe tax payer.

Are you saying NASA owes no responsibility to taxpayers? Or only their contractors?

 

[pervect]

My $.02. I didn't care for Zubrin's Obama-bashing AT ALL. That's not science, it's politics. (Politics I don't agree with, it should be added.) That said, there is way too much hype about Vasimir and Mars - a quick google search will find lots of articles with titles like "VASIMR Needs 1,000-Time Increase in Power Source to Reach Mars in Six Weeks".

Vasimir certainly has applications, but unless we have a MAJOR breakthrough in power sources, manned missions to Mars probably aren't one of Vasimir's applications. The media treatment of Vasimir is notably skewed. I don't agree with Zubrin's politics at all, but I would agree with the objections to the media presentatios of Vasiiar as "Mars in 6 weeks". I would guess that in an effort to get funding, "Vasimir for umanned space exploration" is a lot more realistic, but not very "sexy".

Who is responsible for the hype? I have no idea. How much are the researcher's responsible? I don't know. I'd have to speculate.

Zubrin's is a well-known proponent of a competing propulsion idea, called a "nuclear salt water rocket" or NSWR. You can find the details in Wikipedia. I'm not sure if Zubrin got around to discussing NSWR's in his speech, I got so turned off by his political tirade I stopped listening. Going back to the science, though, a nuclear salt water rocket seems a lot more promising for a Mars mission than Vasimir. So - why don't we have NSWR technology in development? Well, part of the answer is that even testing a NSWR on the Earth's surface would release enormous quantities of radioactive material. So it's probably not going to happen. Testing it in space would avoid this issue, but it would be very expensive with the current rates for ground-orbit transportation.

Frankly, I think manned missions to Mars are going to require cheaper ground-orbit transportation before they happen. Unless a way is found to make longer manned trips possible, perhaps.

 

[rollingstein]

Vasimir certainly has applications, but unless we have a MAJOR breakthrough in power sources, manned missions to Mars probably aren't one of Vasimir's applications.

Which ones, for instance? Could you elaborate?

I don't know much about propulsion physics but VASIMR seems to me a solution in search of a problem for now.

 

[mfb]

By ground standards. From I can tell of the history 200 MWe would be many orders of magnitude higher than anything ever flown. US SNAP-10A ('65) was 650W(e), 45 kW thermal; the Soviets launched dozens of 3 kW (thermal or electric?) satellites.

I meant small in terms of mass, not in terms of power. 100 tons for 1 GW thermal would be 10kW/kg = 10W/g. I don't see how this is supposed to fly.

 

[mheslep]

Are you saying NASA owes no responsibility to taxpayers? Or only their contractors?

No

 

[pervect]

Which ones, for instance? Could you elaborate?

I don't know much about propulsion physics but VASIMR seems to me a solution in search of a problem for now.

From what I've read, VASIMIR, with existing solar cell power sources has potential applications as the engine for a reusable "space tugs" for various orbital transfer missions. Ad Astra specifically proposed low-earth-orbit to low-lunar-orbit transfers, with an analysis supporting Vasimir's superiority over existing chemical propulsion. I'm not aware of any figures for low Earth orbit-geostationary orbit "space tugs", but it seems like a logical idea along similar lines.

 

[Monsterboy]

Zubrin said in the video that radiation levels in deep space is only twice that of low Earth orbit ,can anyone give any reference to this claim ?

 

[rollingstein]

From what I've read, VASIMIR, with existing solar cell power sources has potential applications as the engine for a reusable "space tugs"

To me, even a space tug sounds somewhat like a solution in search of a problem.

Does anyone want one? Has anyone commissioned one?

 

[Dotini]

Zubrin said in the video that radiation levels in deep space is only twice that of low Earth orbit ,can anyone give any reference to this claim ?

This is a good question. I will start with a peek at low Earth orbit.

http://www.esa.int/Our_Activities/S...ology/Space_Environment/Radiation_environment
RADIATION ENVIRONMENT
Radiation in the space environment comes from the trapped particle belts, solar particle events and cosmic rays.

Trapped Particle Belts
The radiation belts consist principally of electrons of up to a few MeV energy and protons of up to several hundred MeV energy. These are trapped in the Earth's magnetic field; their motions in the field consist of a gyration about field lines, a bouncing motion between the magnetic mirrors found near the Earth's poles, and a drift motion around Earth.

Basic motion of trapped particles in the Earth magnetic field

Radiation is an obvious concern for manned missions. In the near-term, manned activities are limited to low altitude, and mainly low-inclination missions. The International Space Station (ISS), Space Shuttle, EnviSat and other low altitude missions will therefore encounter the inner edge of the radiation belt. This region is dominated by the "South Atlantic Anomaly (SAA)" - an area of enhanced radiation caused by the offset and tilt of the geomagnetic axis with respect to the Earth's rotation axis.

Earth radiation belts with the South Atlantic Anomaly indicated
Besides the SAA, the polar horns also play a role for radiation analysis at low altitudes (e.g. ISS type orbit). Polar horns are parts of the outer radiation belts, which are close to Earth. As can be seen in the simulation below, increased radiation flux due to the polar horns can be expected between 60 and 90 degrees lattitude. The SAA is clearly visible at the South Antlantic region around 30 up to 50 degrees lattitude.

http://wrmiss.org/workshops/sixth/golightly.pdf
http://hps.org/publicinformation/ate/faqs/spaceradiation.html

The Cruise Phase poses a significant radiation problem due to the cumulative effects of isotropic Galactic Cosmic Radiation over 400 days. The occurrence during this period of a large Solar Energetic Particle (SEP) event, especially if it has a hard energy spectrum, could be catastrophic health wise to the crew. Such particle events are rare but they are not currently predictable.
http://www.sciencedirect.com/science/article/pii/S0032063311002030

Design and test of Orion capsule for radiation.
http://www.engineering.com/Educatio...-Shield-designed-by-High-School-Students.aspx

http://motherboard.vice.com/en_ca/read/orion-radiation-survival
"...radiation can corrupt data. It can turn a 1 into a 0. It can make a processor think that 2+2=5."

On the road to Mars:
http://phys.org/news/2013-05-exposure-journey-mars.html

Energetic protons constitute about 85 percent of the primary galactic cosmic ray flux and easily traverse even the most shielded paths (reds) inside the MSL spacecraft . Heavy ions tend to break up into lighter ions in thick shielding, but can survive traversal of thin shielding (blues) intact.

The solar particles of concern for astronaut safety are typically protons with kinetic energies up to a few hundred MeV (one MeV is a million electron volts). Solar events typically produce very large fluxes of these particles, as well as helium and heavier ions, but rarely produce higher-energy fluxes similar to GCRs. The comparatively low energy of typical SEPs means that spacecraft shielding is much more effective against SEPs than GCRs.

"A vehicle carrying humans into deep space would likely have a 'storm shelter' to protect against solar particles. But the GCRs are harder to stop and, even an aluminum hull a foot thick wouldn't change the dose very much," said Zeitlin.On the road to the Moon; proton backsplash hazards mentioned.
http://www.sciencedaily.com/releases/2013/11/131118133044.htm