NASA Gives Solar Ionic Propulsion A Monster Boost (networkworld.com)

coondoggie quotes a report from Network World: NASA this week took a giant step toward using solar electric power for future space missions by awarding a $67 million contract to Aerojet Rocketdyne to develop an advanced electric propulsion system. Network World writes, "Specifically, Aerojet Rocketdyne will develop and deliver an integrated electric propulsion system -- known as the Advanced Electric Propulsion System (AEPS) -- consisting of a thruster, power processing unit (PPU), low-pressure xenon flow controller, and electrical harness. Such a system would deploy large solar arrays that can be used to convert sunlight into electrical power that ionizes atoms of xenon which is the propellant for the spacecraftâ(TM)s thrusters. In addition, such a power plant could potentially increase spaceflight fuel efficiency by 10 times over current chemical propulsion technology and more than double thrust capability compared to current electric propulsion systems, NASA said." NASA's plan is to use this propulsion system on its future Asteroid Redirect Mission, as well as on its mission to Mars.

Comments

Re:'monster' ?

[Camel Pilot]

Monster is about the size of one Library of Congress

Worked one time for Rocketdyne on the SSME... started one month before the Challenger. Not good timing. Rocketdyne spent the next few months under suspicion as the cause for the accident. I help prepare a report to Richard Feynman during the investigation. I use to walk the executive corridors at lunch and marveled at some of the pictures on the walls of cool past research engines like Nerva a Nuclear powered engine and of course the massive Saturn 5 engines.

Re:'monster' ?

[fred911]

Monster as a qualifier cam be described as more than mondo and less than gianormous. Thanks for asking.

'10 times more efficient' and xenon gas

[kheldan]

I'd like to know how you can talk about a drive system being '10 times more efficient' when it's 'fuel' is one of the rarest gasses in Earth's atmosphere? Shall we just design a spacecraft drive system that uses giant diamonds or something instead, so it'd be cheaper and easier to obtain fuel?

Re:'10 times more efficient' and xenon gas

[ControlFreal]

It's all about delta-v, not about the occurence of said gasses on Earth.

Rockets work, whether we like it our not, according to the Tsiolkovsky rocket equation: the delta-v you can obtain it only logarithmic in your start mass / payload fraction, but linear in your exhaust velocity. That velocity is in ~3 km/s for chemical rockets, but 20-50 km/s for ion engines. That allows you to push a probe/ship from LEO into a transfer orbit using a massively lighter ship, which in turn allow you to launch that into orbit using a massively smaller launch vehicle.

Re:'10 times more efficient' and xenon gas

[HeadSoft]

Ions Are Forever.

Re:'10 times more efficient' and xenon gas

[Anonymous Coward]

Ten thousand Xenon nuclei, when all you need is an electron- isn't it ionic; don't you think? /ducks

Re: why xenon gas

[Henarchaga]

I had the same question, and found the answer readily enough in layman's terms on wikipedia: https://en.wikipedia.org/wiki/....

It seems like there are three key reasons (which I am listing also in layman's terms):

1) As a "noble gas" xenon is typically inert, which reduces corrosion in storage and long-term usage as a thruster fuel
2) The gas can be stored in liquid form (more dense) at room temperature, unlike liquid oxygen or hydrogen, which makes it easier to transport and handle
3) It is far up enough on the periodic table that its electron shells can be excited with less energy input than other inert gases, making it more ideal for low-power
systems such as the solar panels that power the ion engine.

Bear in mind that I may be interpreting those wrong, but I do only have two years of university chemistry.