Is VASIMR Part Of NASA's New Architecture?

I have been hearing rumors of this for about three weeks now and it is unbelievable that this nutcase idea actually won the favor of the NASA administrator Charles Bolden. Simply put the technology to make this work will not be available for another century or more. In order to make it work, it requires nuclear power with a specific power orders of magnitude better than we can do now, or know how to do. Moreover it would require thermal to electric power conversion efficiencies of 98% or more when the best we can do is about 30%. When all the radiator panels are put in place, a VASIMR that could get to Mars in 40 as advertised days will be the size of a few football stadiums and weight more than a couple of freight trains. Why is it that realistic ideas such as nuclear thermal propulsion are ignored but white elephants like VASIMR are actually funded.

This is exactly the kind of technology development project that the government and particularly NASA should be working on, rather than the money that NASA has been putting into old technology like Ares and Apollo capsules and already operational programs.

The typical government role is doing things that have potential but that commercial sponsors are not yet ready to support.

It would be interesting to know whether Chang-Diaz needs or wants NASA's help. So far he seems to be doing pretty well with commercial and Costa Rican support. His company, Ad Astra, is paying the salaries of a lot of Americans with money that comes outside the country.

A solar powered VASIMR is sufficient to take cargo to the Moon and Lagrange points. The tug will use a tiny amount of fuel but the trip will last about 6 months.

shorter webbja: "Aggh!"

*extra-wide yawn*

The suspiciously soviet-sounding VASIMR has quite a bit of hype, hoopla and showmanship going for it... it also has operational hardware, planned tests on ISS, rational plans for solar powered high-ISP low-thrust cargo tugs... and no need for nuclear power for the initial deployed versions.

The high-end versions of VASIMR, with a sufficient power source, have both high ISP and higher thrust levels available as options... and if Polywell pans out you can have both high thrust and high ISP at the same time.

It would seem to be a viable research path for NASA.

Nuclear-thermal rockets have... none of the above.

And the high-end prospects of NTR cannot match those of VASIMR for thrust and ISP

... and please tell me which private company was it that committed itself to promoting NTR?

I think we will disagree their, but that is what debate is about. When you look at simple mathematics for kinetic jet power required at those high Isp's and the required thrust for manned missions which are inherently massive (on the order of 25 tonnes (at a minimum)) and thermal to electric power conversions that could be achieved in the near or even distance future, you would need to radiate dozens to hundreds of Mega-Watts of excess power to prevent the system from melting down. Nuclear Thermal rocketry in a solid phase can not match the Isp but they are far cheaper to develop and are an evolutionary step forwards with far less risk and far more benefit to manned exploration, and more importantly do not require the football stadiums full of radiators to reject the excess heat. The Air Force conducted a study on the idea of an electric propulsion tug which i was a part of and they came to the same conclusions on VASIMR.

"and if Polywell pans out you can have both high thrust and high ISP at the same time. [cut] Nuclear-thermal rockets have... none of the above."

FYI, ground tests of some NTRs back in the 60's generated 75,000 lb of thrust (with a specific impulse of 850+ seconds). VASMIR's thrust is orders of magnitude less, and it will be a lot less until we start flying nuclear reactors into space.

The main problem I see with VASMIR is political... the general public and politicians don't like launching nuclear material, and for the VASMIR to be of any significant benefit to a manned mission beyond LEO, it would require nuclear power.

For mankind to really open up the solar system, we'll HAVE to use nuclear... there's no other abundant power source you can realistically use to power the propulsion devices we'll need and use in the future.

If Bolden is counting on VASMIR, he better be prepared to push for nukes in space if he wants to get any benefit for exploration.

The bottom line is that VASIMR represents one of several advanced high-power electric propulsion (EP) technologies that deserve a more thorough evaluation. As one poster noted, the key factor for all high-power EP systems is the specific power of the power system (solar or nuclear). The specific powers that have been assumed for assessments of VASIMR in the past have been very high (~1 kW/kg). With these assumptions, VASIMR's competitors (e.g., Magnetoplasmadynamic (MPD) thrusters and Pulsed Inductive Thrusters (PIT)) also look very good.

Good news is that a new solar photovoltaic (PV) technology called FAST could offer specific powers of 0.14 kW/kg in the vicinity of Earth orbit and 0.07 kW/kg out to the orbit of Mars. The development of this technology is being funded by DARPA, and involves several NASA centers, including Glenn and Ames Research Centers. The potential impact of FAST is huge! Now you have a power technology that makes VASIMR, MPD and PIT technologies competitive for a variety of applications, including crewed transportation within the inner solar system.

All I can say is that you may be hearing more about this on Monday. Stay tuned.

This discussion really helps to point out where NASA human space flight has gone awry.

In the first couple decades, NASA's goals were to push the envelope, work on the frontier; which was what it had done in the aircraft business for sixty years. NASA developed streamlining in the 1930s, then turned it over to the major aircraft manufacturers. NASA developed fly-by-wire, digital technology in the 1950s and 60s, where Neil Armstrong was sone of the leaders in development, and he used it on the X-15, and then they refined the technology for the use on Apollo. Later it was turned over to the manufacturers where it was first used on the F-16 and is now in common use on all modern airliners.

That is how NASA adds value to industry.

In episodes like Orion and Ares, for some reason NASA thinks they know things that industry does not.

NASA needs to figure out what a proper role for itself is. Inexperienced program management trying to manage everyone else's work is not the right way.

I've favored SLASR arrays when calculating near-future power needs for spacecraft and the SLASR teams expect a specific power level of 330 W/Kg in initial deployment and then scaling up to 500 W/Kg as they progress.

This is opposed to the FAST specific power goal of 130 W/Kg when first deployed.

What gives? :)

The FAST technology effort exemplifies the new business model for NASA. NASA's role is to help facilitate development of the technology and demonstrate its applicability. The current FAST effort is focused on completion of Phase II, a full-scale test of the array at NASA Glenn. A hoped for Phase III with flight-test the technology on a Solar Electric Propulsion (SEP) spacecraft.

Near-term applications include robotic servicing of Earth orbital satellites, national security and NASA science missions. In the far-term, the technology could be used with VASIMR, MPD or PIT propulsion systems for cislunar/planetary cargo transport and possibly human deep space missions.

Rest assured folks, the future is going to be very exciting.

Mr Gray,

You might want to recheck your history sources. I'd recommend reading "Beyond the Limits" by Paul Ceruzzi regarding the development of fly-by-wire. And of course it was NACA in the 1930s (and before and after as well) that developed aircraft technologies later adopted by industry...which NASA continued into the 1980s (such as the winglet, now seen on many airliners).

But I agree with your overall point.

@zapkitty

330 to 500 W/kg would be even better, but I suspect that this is the specific power for the PV array alone. The FAST number also factors in structure, and represents a system-based calculation.

Don't get me wrong, stretched-lens arrays are great. Many folks are very exciting about their application, especially for missions to the near-outer solar system.

I should mention that an additional advantage of FAST is its very high voltage. This makes it particularly appealing for electric propulsion applications. It has the added advantage of reducing requirements on the Power Processer Unit (PPU), a big component of propulsion system mass.

(cue resonant voiceover) "We interrupt this commercial for an important announcement."

NASA doing most anything new is laudable... I was just trying to figure out if FAST had any specific advantages over SLASR for someone designing a power system for a commercial spacecraft from scratch.

If it's a case of NASA simply finishing something it's started then that's not to be belittled, but from what I gather both SLASR and FAST seem to be aimed at the same niche in the same time frame... with SLASR having the better raw numbers by far.

So I'm curious.

I think you hit the nail dead on the head. VASIMR as an engine works great, but that is not the issue, power system mass and power conversion is! This was sold to Bolden on the idea that while we would loose the moon, we as a nation could take the lead in some other advanced tech for solar system exploration that would give us an edge on the next go around. Even with PV arrays (near earth), the gravity losses at specific powers that are achievable will end up forcing mission designers to add as much propellant to make up for those gravity losses as the high Isp took away, so the net gains are not that much. And if you go beyond the moon, you are going to need nuclear to provide the energy. But when that happens you end up with a Brayton or Rankine power conversion on the order of 35% at best, a reactor that needs to sustain up to 2200 K for long durations (creep, fission product induced swelling, etc...) and that also weighs a few thousand pounds and now you are down to an abysmal low thrust to weight ratio. I think the research from this program would be beneficial. I am just saying that we are currently developing and testing CERMETS for NTP on a shoe string budget but it works, it has a thermal to kinetic conversion ratio of 0.95 compared to EP values of 0.2 (at best). I am just hoping that we are not passing over something with a small programmatic risk and a huge pay off for something that may end up having no near or mid term benefits to manned space flight. That was exactly the path we took when we tried to develop a first stage solid motor for a large scale booster (ARIES-I) and the cost over runs with this due to the programmatic risk of first stage solid main boosters killed it from day one.

It is important to note that the propulsion technologies required for near-term Flexpath missions (next 5-10 years) are minimal. Most missions in this timeframe will be performed with systems currently under development or upgrades to existing ones. For missions to Lagrange Points, lunar orbit and near-vicinity NEAs, work will focus on incorporating man-rated reliability standards into existing systems, including the man-rating of current upper stage engines, and completing development of the J-2X (if needed). Electric propulsion may not have a direct role for these early Flexpath missions, but it will be required for other applications, such as commercial orbital servicing. The key is that the course will be set for evolving these systems (based on ion and/or Hall thrusters) to the more powerful systems needed for more ambitious Flexpath missions in the future.

The evolution in propulsion capability for Flexible Path will feature in-space propulsion systems capable of transporting human crews to Mars, NEAs and possibly Venus orbit. It would also be wise to make some investment in far-term technologies capable of extending the reach of human exploration beyond Mars to the Asteroid Belt and perhaps Jovian space. Propulsion technology needs become more demanding with missions to Mars orbit, Phobos, Deimos, more remote NEAs and Venus orbit. The new propulsion advancements required include cryogenic fluid management for long-duration storage of liquid hydrogen, other propellants and life support fluids; nuclear thermal propulsion; high power electric and plasma propulsion (VASIMR, PIT and MPD), along with advancements in very high specific power solar energy systems.

The long-term culmination of Flexible Path favors the development of several advanced propulsion technologies and active research into their demonstration in the near-term. These include In-situ Resource Utilization (ISRU) to support large robotic and eventually crew systems on planetary surfaces; advanced nuclear propulsion (e.g., bimodal nuclear thermal rockets, gas-core nuclear rockets, fusion, antimatter); advanced plasma propulsion; aerocapture; and momentum exchange tethers.

If funding was plenty this would be a good idea, but as things stand it's just going to be yet another R&D money pit. Been there, done that, with Deep Space 1 as far as fancy/useless novel propulsion concepts goes. The most we'll get out of this is a 'Deep Space 2' proof-of-concept modest mission because that's all solar panels can power. From a political perspective there's just no chance in h*ll NASA will ever launch a nuclear reactor, and the power it in orbit.

So far the leaked 'ESAS-3' is quite unimpressive. As for the 'cislunar missions' were told about I'm increasingly certain these will require EOR assembly using an absurd number of Falcon-like launches for an unimpressive NEO mission to a small lump of rock close to Earth.

Oh well, it increasingly looks like this will be a one term admnistration so we're probably worrying about nothing.

Here are three(3) options of the Flexible Plan I came across online. Not sure how realistic any of these are but, they certainly don't seem unambitious to me.

(1) Manned mission to construct huge GEO and deep space telescopes proposed:

http://www.nasaspaceflight.com/2010/01/manned-mission-to-construct-huge-geo-and-deep-space-telescopes-proposed/

(2) Taking aim on Phobos – NASA outline Flexible Path precursor to man on Mars

http://www.nasaspaceflight.com/2010/01/taking-aim-phobos-nasa-flexible-path-precursor-mars/

(3) NASA’s Flexible Path evaluation of 2025 human mission to visit an asteroid

http://www.nasaspaceflight.com/2010/01/nasas-flexible-path-2025-human-mission-visit-asteroid/