Nuclear-powered Discovery Mission? Options

[Mongo]

Emily's blog entry from today seems not to have been mentioned here yet: Maybe, possibly, a nuclear-powered Discovery mission

This would be absolutely huge, if it pans out. From the blog:

Alan explained to me that the Stirling generator is almost ready for prime time. They have years of simulated time running the generator, and next month, they're going to fire up a flight model and run it for a year. Once it's run for a year without incident, he told me, he'd be quite comfortable seeing it on a Discovery mission, though not on an outer planets flagship mission. He said he wouldn't risk putting a never-flown power supply on the flagship mission, not without seeing it run successfully on a cheaper mission first.

You might wonder what principal investigator would be willing to take on this risk, but Alan told me there's a lot of appetite out there for a nuclear-powered Discovery mission because of all the possibilities it opens up. He said that Jim Green (director of the Planetary Science Division of NASA's Science Mission Directorate) put out a call for mission concept proposals, asking the science community what they'd do if the next Discovery mission was nuclear-equipped. He said they got more than forty proposals, of which they plan to select ten and fund them for a yearlong study. The proposals included all kinds of stuff previously inconceivable for Discovery: go look for ice at the lunar poles with a rover; go rendezvous with a Centaur, one of the small bodies like Chiron or Pholus that orbits in the outer solar system and may be an interloper from the Kuiper belt; send a probe into Saturn's atmosphere; go land on Mercury.

Huge, huge news.

Bill

[mchan]

Moving parts. Stirling prototypes have run for years in Earth labs, but have yet to run in space for any long duration. Even the ion thrusters on Dawn (actually their immediate forebears) have flown before on Deep Space 1. This would as much a New Millenium type technology mission as a Discovery mission.

The ASRG is being supplied gratis and the cost cap is $450 million to include launch. Discovery / Scout implies (politically) at least the Dawn levels of US content, e.g., the launch, at least 1 major instrument, and the spacecraft itself. Using Dawn as an example, get an ESA country or Japan to supply as many major instruments that they can contribute.

US launch in the timeframe mean an EELV which will run at least $130 million going by the recent NASA contracts. Assuming the cheapest EELV gives twice the payload capability as a DeltaIIH opens up sizable missions from Mercury to Mars and perhaps beyond if Earth gravity assists are used. So you have $320 million for the spacecraft plus 1 instrument plus operations costs, plus 2 or 3 more instruments from international partners.

The ASRG needs to be an enabler, so someplace with little or no sunlight, so here are a few rather derivative missions:

A Phoenix which operates thru the Martian polar winter.

A New Horizon on the 2016 Jupiter, Saturn, Neptune, KBO flyby trajectory mentioned in the OPAG thread with intenational partners supplying a simple probe for Saturn or Neptune might be possible if an international partner would also supply the launch, or using Earth gravity assists with trying to reduce long flight time operations cost with increased use of hibernation during cruise.

A Dawn that goes out to the Trojans or possibly even Chiron.