NASA launches search for greener propellant
The launch of the Phoenix spacecraft on a Delta II rocket in 2007. NASA is looking for alternatives to hydrazine monopropellant, used en route by Phoenix's navigational thrusters (Photo: NASA/Sandra Joseph and John Kechele)
NASA has put out the call for greener propellant fuel for use on the spacecraft of the future. Though it does not appear that NASA has stipulated that alternative propellants must match the performance of current mainstay hydrazine, it's clear that only high-performance substances need apply. Environmental credentials are where the new fuel must demonstrate an edge over hydrazine, which is a corrosive, toxic pollutant. As well as the environmental benefits, use of greener propellants should prove more economical, reducing the need for involved safety procedures that can lengthen launch times.
Though not generally used as a fuel to put rockets in orbit, hydrazine has seen wide use as a monopropellant to power in-flight thrusters and course correctors that maneuver spacecraft such as Space Shuttle's auxiliary power units and the Phoenix spacecraft.
An inorganic chemical compound, hydrazine molecules are composed of two nitrogen and four hydrogen atoms (nitrogen hydride is another of the liquid's many names). It first saw use as a rocket fuel during World War II when the fuel was mixed in relatively small proportions with with methanol and water to power Messerschmitt Me 163Bs. That it can be stored for long periods is one trait that makes it appealing to NASA for science and exploration missions to this day, as well as for use in commercial and defense satellites.
But it's nasty stuff. Even short-term exposure can hospitalize people, with the US Environmental Protection Agency publishing one of those almost comical lists of symptoms of ascending severity that begins with eye irritation and dizziness and ends in seizures and comas. It must be handled with extreme care, which entails significant expense, and so there's little wonder that NASA wants rid of it.
NASA has come up with the Technology Demonstration Missions Program to help technologies that have proven themselves in the laboratory navigate the long path to mission readiness. Its through this program that NASA is seeking to foster the development of at least one green propellant, with one or more awards of up to US$50 million available to the most viable proposals.
If you have an idea for a green propellant that may be of interest to NASA, you have until April 30 to submit.
About the Author
James lives in East London where he punctuates endless tea drinking with freelance writing and meteorological angst. Unlocking Every Extend Extra Extreme’s “Master of Extreme” achievement was the fourth proudest moment of his life.
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can you say vinegar and baking soda
Lift the launch site to the top of the atmosphere with hydrogen. Tether with helium filled \"potato chip bag\" tubing. Lift hydrogen propellant via tether. Concentrate 02 in situ.
how about a green engine instead of a fuel? Chemical rockets, Bah!
There is plenty of sea water not being used as fuel....
This is just another example of NASA\'s current \"Lack of Real Vision\" situation. We used to launch space shuttles back when the US was a space faring nation and their main fuel (ignoring the boosters) was Hydrogen with Oxygen as the oxidizer producing nice clean water as a product. You can\'t get much greener than water. (yes, I now water is generally regarded as blue)
Granted hydrazine is nasty stuff but it is a widely industrial chemical and is a less toxic but more energy intensive to produce fuel really greener?
For station keeping and deep space operations an ion engine will provide much greater efficiency.
Liquid hydrogen is overrated as a fuel, rocket or otherwise. It energy density is a joke plus it migrates through everything and is energy intensive to produce, and concentrate. (liquify or compress) Dealing with LH requires expensive alloys to deal with the ridiculous cold.
Ultra refined kerosene is a much better liftoff fuel although the high quality diesel fuel produced by the Fischer-Tropsch method might work just as well and be cheaper.
I am not a real fan of LOX as the oxidizer, being a cryogenic liquid it doesn't store well and any were in the system that can not be really well insulated will get freezing condensation but for non-weapon use it does appear to be the best.
Laser powered space elevator with power generated by remote reactor. this can eliminate breakout velocities and enable and allow greater cost/payload ratios. While we wait for this, how about a magnetic rail gun style slingshot. The technology seems there already and ready to modify and adapt.
A space elevator requires a orbital tower. An orbital tower must be built from the top down, this requires moving a lot of stuff around in space which requires rockets and rocket fuel. This space to space fuel is what NASA is looking for a replacement for. The orbital tower will also provide a much better energy delivery route than a laser.
Rail guns are not really suited for orbital insertion, they require a super surge of electricity subject the load to ridiculous acceleration and an EMP event. There are much more efficient linear accelerators that also would provide a survivable launch.
A laser powered rocket might work but for space you will still require reaction mass.
use hydrogen with the skylon spaceplane
NASA has been using dimethyl hydrazine for decades. Less toxic than hydrazine. There are other monopropellants available, such as nitromethane (used in dragsters and model aircraft fuels), isopropyl nitrate (AVPIN used to start early jet engines), concentrated hydrogen peroxide (used in many rockets, with or without a fuel) - doubtless NASA has tried them all. There's no "secret compound" that they haven't thought of yet. Very silly to suggest that the general public would know more than they do!
"If you have an idea for a green propellant that may be of interest to NASA, you have until April 30 to submit." Gosh thanks - a bit late aren't we?
Go NASA. I'd say hydogen peroxide with alcohol even though hp is alittle corrosive.
I believe a space tether would work. This would require a large mass placed in the right orbit.
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