Artist rendering of the VASIMR powered spacecraft heading to Mars. Credit:  Ad Astra

Zubrin Claims VASIMR is a Hoax

13 Jul , 2011 by

[/caption]

A next-generation plasma rocket being developed by former NASA astronaut Franklin Chang Diaz called the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) has been touted as a way to get astronauts to Mars in weeks rather than months, as well as an innovative, cheap way to re-boost the International Space Station. But in a biting commentary posted on Space News and the Mars Society website, “Mars Direct” advocate Robert Zubrin calls VASIMR a “hoax” saying the engine “is neither revolutionary nor particularly promising. Rather, it is just another addition to the family of electric thrusters, which convert electric power to jet thrust, but are markedly inferior to the ones we already have,” adding, “There is thus no basis whatsoever for believing in the feasibility of Chang Diaz’s fantasy power system.”

The VASIMR uses plasma as a propellant. A gas is ionized using radio waves entering into a plasma state. As ions the plasma can be directed and accelerated by a magnetic field to create specific thrust. The purported advantage of the VASIMR lies in its ability to change from high impulse to low impulse thrust as needed, making it an ideal candidate for a mission beyond low Earth orbit.

Chang Diaz’ company, the Ad Astra Rocket Company successfully tested the VASIMR VX-200 plasma engine in 2009. It ran at 201 kilowatts in a vacuum chamber, passing the 200-kilowatt mark for the first time. “It’s the most powerful plasma rocket in the world right now,” said Chang-Diaz at the time. Ad Astra has signed a Space Act agreement with NASA to test a 200-kilowatt VASIMR engine on the International Space Station, reportedly in 2013.

The tests would provide periodic boosts to the space station, which gradually drops in altitude due to atmospheric drag. ISS boosts are currently provided by spacecraft with conventional thrusters, which consume about 7.5 tons of propellant per year. By cutting this amount down to 0.3 tons, Chang-Diaz estimates that VASIMR could save NASA millions of dollars per year.

For the engine to enable trips to Mars in a reported 39 days, a 10- to 20-megawatt VASIMR engine ion engine would need to be coupled with nuclear power to dramatically shorten human transit times between planets.

Robert Zubrin. Credit: The Mars Society

Zubrin is the president of the Mars Society and author of the book “The Case for Mars: The Plan to Settle the Red Planet and Why We Must.” He has long touted the “Mars Direct” approach of getting humans to Mars to create a sustainable human settlement. The plan includes a series of unmanned and human flights to Mars using existing technology, as well as “living off the land” on Mars by creating rocket fuel to return to Earth, and using underground reservoirs of water on Mars.

In his commentary on VASIMR, Zubrin says, “existing ion thrusters routinely achieve 70 percent efficiency and have operated successfully both on the test stand and in space for thousands of hours. In contrast, after 30 years of research, the VASIMR has only obtained about 50 percent efficiency in test stand burns of a few seconds’ duration.”

On the ‘39 days to Mars’ claim, Zubrin says VASIMR would need to couple with a nuclear reactor system with a power of 200,000 kilowatts and a power-to-mass ratio of 1,000 watts per kilogram, while the largest space nuclear reactor ever built, the Soviet Topaz, had a power of 10 kilowatts and a power-to-mass ratio of 10 watts per kilogram.

Zubrin has invited Chang Diaz to a formal public debate the VASIMR at a Mars Society convention in Dallas next month.

Read Zubrin’s commentary on Space News or the Mars Society website.

More info: Ad Astra Rocket Company

, , , , ,



Sort by:   newest | oldest | most voted
Eccentric scientist
Guest
July 13, 2011 12:57 AM

These sorts of debates are tiresome. Debating is not science or engineering. Test it and there will be nothing to debate about, it either works and is efficient by the numbers or it is not. There is no opinion, just math and math doesn’t lie or exaggerate.

David Sharp
Guest
July 13, 2011 1:57 PM
In an ideal world you would be right but this is not an ideal world. We have seen both in the commercial world and in politics that often the best way is not chosen but the best publicized is. I have no idea where Zubrin gets his information from on this matter however it seems to me that he wants to put it out there that waiting for the perfection of the VASMIR system will only delay further a Mars exploration program that can be performed now with existing technology. I do not know by this article if Zubrin thinks that getting the VASMIR up to it’s claimed performance numbers is impossible. He only says that the engine… Read more »
David Sharp
Guest
July 13, 2011 1:57 PM
In an ideal world you would be right but this is not an ideal world. We have seen both in the commercial world and in politics that often the best way is not chosen but the best publicized is. I have no idea where Zubrin gets his information from on this matter however it seems to me that he wants to put it out there that waiting for the perfection of the VASMIR system will only delay further a Mars exploration program that can be performed now with existing technology. I do not know by this article if Zubrin thinks that getting the VASMIR up to it’s claimed performance numbers is impossible. He only says that the engine… Read more »
Xop Xops
Guest
Xop Xops
July 23, 2011 7:43 PM

“These sorts of debates are tiresome.”

If you find it tiresome, why are you chipping in with your two cents worth ?

“Test it” “no opinion, just math”

Testing it, and doing the math are not the same thing, so which do you mean ?

Testing it would mean building it and flying it to Mars to see how long it takes.

Zubrin says the math shows it isn’t suitable for getting to Mars.

M Peter Selman
Guest
July 13, 2011 2:13 AM

Oh, Zuby, I really enjoyed your book. Very exciting and inspiring, but using this silly debate to attract attention is not helping.

Lawrence B. Crowell
Member
Lawrence B. Crowell
July 13, 2011 2:21 AM
The VASIMR works, and in principle is should be able to perform. It has the advantage of having a throttle. One can increase the specific impulse of the device and reduce the thrust, or conversely increase thrust and decrease specific impulse. It is a bit analogous to a transmission on a car. Also clearly to run this in the 10-megawatt domain you are going to require a nuclear reactor. It does open up the question of nuclear power in space, but it has some distinct advantages over a standard nuclear rocket engine. Primarily the propulsion system is not the reactor itself. The VASMIR is an electrically driven plasma device and the power supply is separate. This avoids the… Read more »
Xop Xops
Guest
Xop Xops
July 23, 2011 7:50 PM

“The VASIMR works, and in principle is should be able to perform.”

It works? You mean it does something? Yes it does.

Perform? Perform what? Get to Mars quickly ? No way.

Lawrence B. Crowell
Member
Lawrence B. Crowell
July 23, 2011 11:55 PM

It works on the lab bench. The first ion propulsion systems were of that sort. The concept is workable as a laboratory instrument.

LC

--
Guest
--
July 13, 2011 6:33 AM

The problem is the power density requirement for the source of electrical power. The VASIMR to be tested on the ISS will only run for short periods after charging up for a longer period of time, and that is enough for boosting the orbit now and again, but a fast spaceship to Mars requires serious, continuous power production running non-stop for weeks. We do not have such a power source yet, period.

Dany Rodríguez
Guest
July 13, 2011 6:45 AM

I´m Costarrican and I´m so glad to know Franlin Chang Diaz was born in Costa Rica. It is a real proud for us. We are so grateful for his work in Liberia helping out physics students, providing them of advanced and new knowledge.

Dany Rodríguez
Guest
July 13, 2011 6:51 AM

I´m Costarrican and I´m so glad to know Franlin Chang Diaz was born in Costa Rica. It is a real proud for us in this country and we are so grateful for his work in Liberia, Costa Rica, helping out physics students, providing them of advanced and new knowledge they will need throughout their careers.

¡¡¡ VIVA FRANKLIN, VIVA COSTA RICA !!!

EarthlingX
Guest
July 13, 2011 9:41 AM

For me, he just crossed over into the UFO-logists and Nibiru camp. Dumb publicity stunt.

GBendt
Member
GBendt
July 13, 2011 10:32 AM

To need a lot of electric power to run that VASIMR engine. That amount of power cannot be provided by solar cells, so you may need a nuclear reactor of some megawatts. A nuclear reactor in space needs shielding and cooling. Sufficient shielding adds a lot of mass to the craft, and the problem of cooling a powerful reactor in space is still unsolved.
But power is not the only problem. You need propellant for the engine, and the more and the faster you accelerate, and the higher the mass, the more you need.

Martin Lefebvre
Guest
July 14, 2011 3:59 AM

There is one way to get away from shielding without much extra mass. Shield the reactor on the side facing the inhabited side of the ship and put the reactor on a string. The distance can act as a shield in of itself for radiation drops by the inverse square of the distance.

Martin Lefebvre
Guest
July 14, 2011 3:59 AM

There is one way to get away from shielding without much extra mass. Shield the reactor on the side facing the inhabited side of the ship and put the reactor on a string. The distance can act as a shield in of itself for radiation drops by the inverse square of the distance.

Frederick Espinosa
Guest
July 13, 2011 11:26 AM
I think his underlying point is that this is become a part of the current administrations shell game for space. They are fronting this new technology as the future of space travel, but they haven’t done anything to actually advance it. They haven’t flown the engine, they haven’t started work on the reactor, they haven’t even declared mars as a firm destination for any mission. They want to do an asteroid mission but they’ve killed the big rockets, they haven’t written contracts to fly commercial, they’ve taken out the shuttle, and they’ve set the replacement vehicle deadline so that nothing has to materialize until Obama is almost through with his second term. Its just being abused as another… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
July 13, 2011 12:40 PM
I don’t think this is a matter of politics. The VASIMR may develop in the same way the chemical rocket did. That started out small, such as Goddard’s little rocket, and from there evolved over a few decades into larger systems. The VASIMR has been around since the 1990s, and evolved out of some technology for accelerating plasmas. Obama made the statement about new technology just a little over a year ago, and VASIMR had been on the lab bench for years before then. The politics of manned spaceflight has a bipartisan cynicism. GW Bush proposed a return to the moon in the wake of the mars rovers and to also defray attention from the torture at Abu… Read more »
Frederick Espinosa
Guest
July 13, 2011 3:08 PM

If it was just the Vasmir then I’d agree its a matter of time before we get our new ships. But I see this as a follow on to Nerva and the atomic Orion concept from the 60’s. They’ve had the keys to going faster for a while and have no intention of using them.

Even if its seen as a bipartisan failure, Zubrins point still stands.
We can go at any time. We just can’t find the will to go, and holding out a warp drive like a carrot on a stick is continuing decades of administrative dishonesty towards manned spaceflight.

Lawrence B. Crowell
Member
Lawrence B. Crowell
July 13, 2011 4:34 PM
The Orion program involved detonating atom bombs at the back of a spacecraft. The open air test ban, which prohibited nuclear bomb tests in space, put an end to that. The early nuclear reactor rocket program was also cancelled out in part because of issues with radioactive releases and safety. It also fell under Nixon’s hatchet which dismantled the Saturn-Apollo program, where by 1972 it appeared the entire manned space program was going to be cancelled permanently. Vice President Agnew pushed for the shuttle program and this is what sustained the manned space program. Nixon cancelled out the lunar manned space program and future developments such as NERVA because there was a much bigger money black hole; the… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
July 13, 2011 4:34 PM
The Orion program involved detonating atom bombs at the back of a spacecraft. The open air test ban, which prohibited nuclear bomb tests in space, put an end to that. The early nuclear reactor rocket program was also cancelled out in part because of issues with radioactive releases and safety. It also fell under Nixon’s hatchet which dismantled the Saturn-Apollo program, where by 1972 it appeared the entire manned space program was going to be cancelled permanently. Vice President Agnew pushed for the shuttle program and this is what sustained the manned space program. Nixon cancelled out the lunar manned space program and future developments such as NERVA because there was a much bigger money black hole; the… Read more »
Frederick Espinosa
Guest
July 13, 2011 10:17 PM

I agree, but then why do we let politicians get away with making a promise we know they wont keep?
We let them have the good press on the front page and, when they disappoint us on page ten, we quietly slink away and sulk about the downfall of society.

What we should be doing is, just as publicly, showing everyone when a politicians promise turns out to be another dead end.

Embarrassing a few politicians with some big headlines is going to do alot more for manned space than just accepting the fate they’ve written for it.

Lawrence B. Crowell
Member
Lawrence B. Crowell
July 13, 2011 11:17 PM
This country has a political system that only PT Barnum could have invented. The whole thing is a circus show. The two-party system did emerge because of the winner take all approach to elections laid down in the Constitution. This has lead to a system where the two parties are ultimately manipulated by financial and corporate power. Campaign support is given by corporate interest proportionate to the immediate interests. It is a little known fact that Obama got about twice the corporate dollars McCain did. The reason is that a Democrat is more likely to turn on the Keynesian levers and switches to keep the financial ship afloat. Obama then followed on with GW Bush started with the… Read more »
Greg
Member
Greg
July 14, 2011 6:05 AM
Very nice summary. I like the parallel comparison to how Nazi Germany used the emerging mass media so effectively to enthrall and public with lies while their leaders drove that nation down a mad path to ruin. It was not long ago when the big corporations realized their vision for America and that was the robber baron era of the late 19th century. Workers were essentially slaves living on corporate plantations forced even to buy essential goods from corporate stores. The U.S. was a third world nation then. How quickly we forget. Looking at the latest Rupert Murdoch example such corporate powers now purchase the mass media outlets, and only a fool would say they are not manipulating… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
July 14, 2011 2:17 PM

Probably the most insightful essay on this topic was written by Umberto Eco

http://www.pegc.us/archive/Articles/eco_ur-fascism.pdf

LC

David Sharp
Guest
July 13, 2011 2:00 PM
In an ideal world you would be right but this is not an ideal world. We have seen both in the commercial world and in politics that often the best way is not chosen but the best publicized is. I have no idea where Zubrin gets his information from on this matter however it seems to me that he wants to put it out there that waiting for the perfection of the VASMIR system will only delay further a Mars exploration program that can be performed now with existing technology. I do not know by this article if Zubrin thinks that getting the VASMIR up to it’s claimed performance numbers is impossible. He only says that the engine… Read more »
David Sharp
Guest
July 13, 2011 2:00 PM
In an ideal world you would be right but this is not an ideal world. We have seen both in the commercial world and in politics that often the best way is not chosen but the best publicized is. I have no idea where Zubrin gets his information from on this matter however it seems to me that he wants to put it out there that waiting for the perfection of the VASMIR system will only delay further a Mars exploration program that can be performed now with existing technology. I do not know by this article if Zubrin thinks that getting the VASMIR up to it’s claimed performance numbers is impossible. He only says that the engine… Read more »
Kawarthajon
Member
Kawarthajon
July 13, 2011 2:34 PM
I don’t understand why propulsion is an issue in getting to Mars. Yes chemical rockets are less efficient and require huge amounts of mass, but couldn’t you just use chemical rockets to fire a bunch of containers into space with just fuel? That way, you’d have all the fuel you wanted, whether it’s chemical fuel, ion drive fuel or fuel for a VASMIR. Once in space, moving that fuel around (i.e. to Mars) shouldn’t be such a big deal. It could all be waiting for humans once their interplanetary craft arrives at Mars. You could even send food, water, spare parts and the landing craft ahead of time, so it’s in a nice floatilla, sailing above Mars ready… Read more »
captchas
Guest
captchas
July 13, 2011 2:45 PM

Can you imagine the uproar when everyone suddenly realizes a nuclear reactor will be launched into space to power this thing? I can remember the hysteria when Cassini launched with a relatively safe Plutonium isotope power generator.

— CHAS

Bil Irving
Guest
July 13, 2011 7:48 PM

I have to wonder about Bob Zubrin sometimes.

On the one hand, he’s unquestionably a genius, a planetary science zealot, and a leading light in the PR fight to get humans off planet.

But on the other, a lot has been spent (by him and others like him) on sociological studies and experiments on just how humans react to being couped up in a spaceship for 6-8 months getting to Mars. Not to mention his books… which are all about how to get to Mars cheaply using current tech only.

Why do I get the impression he’s just protecting his own theories by denying the possibility of something that rips through all of that?

Xop Xops
Guest
Xop Xops
July 23, 2011 7:54 PM

“Why do I get the impression …”

Uh, because you find it easier to jump to such a conclusion than actually trying to understand the math.

Bil Irving
Guest
July 13, 2011 7:48 PM

I have to wonder about Bob Zubrin sometimes.

On the one hand, he’s unquestionably a genius, a planetary science zealot, and a leading light in the PR fight to get humans off planet.

But on the other, a lot has been spent (by him and others like him) on sociological studies and experiments on just how humans react to being couped up in a spaceship for 6-8 months getting to Mars. Not to mention his books… which are all about how to get to Mars cheaply using current tech only.

Why do I get the impression he’s just protecting his own theories by denying the possibility of something that rips through all of that?

Ken Lord
Guest
July 13, 2011 8:08 PM

“A gas is ionized using radio waves entering into a plasma state” Radio waves? But the phone companies keep telling us that radio waves are non-ionizing radiation.

Sobhi Malas
Guest
Sobhi Malas
July 13, 2011 5:32 PM

why is he ridiculing the issue with such inconclusive statements. He sounds like a man of politics with elections plans. This in no way serves the greater goal of uniting efforts in order to accelerate the exploration of space. Hope Dr. Zubrin fixes it by offering aid to improve the technology rather than bashing it. Moral support for the scientists is considered as aid too.

Anonymous
Guest
Anonymous
July 15, 2011 2:06 AM

Some men have big dreams, and some have big mouths.

They are mutually exclusive.

Dr. Chang is building his dream.

His critics are building hot air.

Hot air will not rise to the challenge of Mars.

VASIMR will.

Xop Xops
Guest
Xop Xops
July 23, 2011 7:55 PM

“Hot air will not rise to the challenge of Mars.
VASIMR will. ”

Have you got any evidence that it will ?

Anonymous
Guest
Anonymous
July 15, 2011 6:20 AM
Last August at the Human Spaceflight Forum held at the Columbia Memorial Center in Downey (directly across form what is now Downey Studios but what was the assembly facility of Apollo and the first home of Shuttle manufacture) Dr. Zubrn said much the same… he is not a stupid man, he IS controversay and gets on some folk’s nerves at times but he ain’t stupid. Plus I believe that it is NOT his intention to hold up work on long duration human flights and is instead his sincere passion to get things off of the perpetual “paper rocket” phace an into actual resutls. But then, i have seen him a few times and spoken with him a few… Read more »
Jason
Member
July 15, 2011 12:54 PM

VASIMR will work exceptionally well in deep space, but in the atmospheric environment, during takeoff, phase-shift plasma turbine can work better. http://www.youtube.com/watch?v=GSkxPghXTCg

wpDiscuz