NASA Administrator Highlights Advanced Propulsion Systems at JPL

An ion engine will be used on the proposed asteroid retrieval mission

Posted by Casey Dreier

2013/05/23 06:18 CDT

Topics: Future Mission Concepts, future technology

I stopped by the Jet Propulsion Laboratory today to see NASA Administrator Charles Bolden talk about the proposed Asteroid Retrieval Mission. The Planetary Society is ambivalent about the mission; though the concept of moving an asteroid and exploring it is compelling and could produce fascinating science, it's not clear how NASA plans to pay for it. We don't want this mission to raid existing science programs.

The Planetary Society

NASA Administrator Speaks to Press at JPL about ARM

The NASA Administrator, Charles Bolden, spoke to the press about the advanced propulsion research being done at JPL that will be used in the proposed Asteroid Retrieval Mission.

NASA is going around the country trying to sell this mission to its various constituencies. Today, the NASA Administrator was highlighting the advanced solar electric propulsion engine developed at JPL. Similar hardware has already flown in space, most notably on the Dawn mission to Vesta and Ceres.

This special type of engine uses ionized xenon to generate small amounts of force over long periods of time. It's more efficient than chemical propulsion, but it does require extra time to achieve similar amounts change in velocity. Even though this engine is currently in use on a real mission, the requirements of the asteroid retrieval mission call for a much larger, more robust ion engine than previously existed. For example, Dawn had about 450 kg of xenon "fuel" to utilize throughout the course of its lifetime. For asteroid retrieval, NASA needs about 10,000 kg. This is due to the much larger size of the spacecraft plus the heavy asteroid itself.

The Planetary Society

Xenon-powered Ion Engine

An ion engine powered with xenon is demonstrated here inside a test chamber at the Jet Propulsion Laboratory. This engine is used on NASA's Dawn mission and a larger version is envisioned for use on the proposed Asteroid Retrieval Mission.

Bolden said that he considers asteroid retrieval to be not a science or human exploration mission, but an investment in technology. This is the slightly strange way NASA is selling the concept, even though humans will visit the captured asteroid and science will be done on any samples they retrieve. My guess is that neither science nor human spaceflight wants to pay for this mission, so NASA administration emphasizes the technology focus in order to ease their minds.

I was able to ask about NASA's plans to reprogram away the additional funding allocated to Planetary Science in the 2013 budget. Bolden responded that NASA is committed to the Decadal Survey with the 2020 Mars Rover and making it a caching mission. I wasn't sure if he didn't understand my question or just didn't want to answer it. My guess is the latter.

Comments:

Bob Ware: 05/23/2013 11:21 CDT

Based on the above Administrator comment I take it to mean that Science has a Decadal Survey mission (my word, token mission) in the pipe line. (my word, now go away please) . In family matters it looks like there is a sibling rivalry taking place between the kiddies ... science and non-science. The parent, (Congress) is being ignored. Thanks for asking Casey. I'm glad you did.

Paul McCarthy: 05/24/2013 01:33 CDT

Sibling rivalry at least! Is it more like gladiatorial combat - only one survives? I'm sorry to say, but with every year gone by, and every $Bn spent, it is clearer and clearer that, other than hero-inspiration, there's no meaningful role for non-science (aka "The Jocks") beyond Earth-orbit. I'm particularly struck by what Freeman Dyson (not many smarter) said in the adjacent blog post "Report from the Starship Century Conference: Tuesday": "economics, politics and space itself will dictate small, inexpensive, increasingly miniaturized spacecraft on missions to explore and map". Really, isn't this what's happening already (or certainly should be)? Technology and miniaturization proceeds at roughly Moore's Law. So look at the gizmos on the Curiosity Rover! Given the relatively fixed costs of lofting 1Kg into space, this is the clear way forward. Meanwhile, due to ever-increasing tendencies to gold-plate and safety-insure astronauts, for inevitable political reasons, the cost of government-funded human adventures spirals. The exception to these vice-like inevitabilities, is probably private space flight - which can be more like the original US frontiersmen, cowboys and wagon-trains: epitomising daring, exploration and entrepreneurialism. That's where the hero-inspiration should come from! That's what the US is all about. There'd be inevitable deaths and disasters along the way - but only like the US's salad days, which we all admire so much! Is the US bold enough and self-aware enough to allow a full-fledged return to a free-enterprise free-for-all in this domain, and abandon the current nanny-state approach? If they wanna fund it with reality TV, let them do it. If it includes fame, glory, co-habiting couples, deaths (and the history books), let them do it. In a tin-can if they wish - like a barrel over Niagara Falls. Meanwhile, the gov't fund increasingly miniaturized, increasingly economical (in relative terms) "official" missions, to do the science and mapping.

Bob Ware: 05/24/2013 09:46 CDT

Oh yes, I like that basic themed approach you outlined... libertarian. I am politically Libertarian, get the gov't out of my life. This way we can explore space as you alluded to and that would be both ways, astronauted and auomated; {my favorite, Astronauted spaceflight (tried to be an Astronaut/Pilot - politics and then mommy nature stopped that : ( drat...} At that point we (TPS) could really take off as a focal point between the companies by promoting and participating in the space ventures as well as creating our own packages for flight (as we do now). Without the gov't intervention and companies maintaining socially responsible decisions we could become an off home planet space dwelling species overnight! Gov't equates to hindrance and deliberately created problems in many cases..

Stephen Uitti: 05/24/2013 11:55 CDT

Sounds like a cool mission. Going to Mars was a cool mission, even when Bush said it. But Bush didn't get funding for the Mars mission, so it didn't happen. The other issue is radiation shielding. We were lucky going to the Moon. Going to the Earth/Moon L1 is similar. Is the plan to be lucky? Not my first choice. I'd be happier if the plan included radiation protection for astronauts. I'd be happier if the funding came from SLS.

Pete Jackson: 05/25/2013 12:43 CDT

If they are going to build large electric drives, why not install one on the ISS to eventually move it to a more equatorial orbit for support of lunar and interplanetary manned missions. And when the ISS is finally decommisioned, to move it to Mars orbit and gently drop it onto Phobos or Deimos for support of Mars manned exploration and investigations.

Bob Ware: 05/26/2013 12:43 CDT

Hi Pete -- Your ISS idea is a good one overall... recycle the ISS to another life. The main issue is that ISS cannot be ground based and the maintenance issues will require it to be nearby. Plus the additional age on some parts may not give it a long enough life to make a Mars journey worth the effort. Perhaps closer in at Luna would be a better location. Maybe just reusing the modules with a different type of power & cooling source would be better. A different configuration could possibly be made with another set of docking ports. Your idea has potential if the hardware is still structurally sound at the end of the stations life.