Monday, October 11, 2010

Belated report on NASA Night

Sorry for the wait, folks, but I've been slammed with work and such for the past few days and am only now getting to posting some of my conference notes! This one deals with the NASA night that was held during the conference. I'll also have at least one more posting and a wrap posting in a day or two (I hope!) which deals with the random collection of other notes I made. So without further ado, I give you NASA Night at the DPS!

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The NASA logo, affectionately called the Meatball by the community.

Tuesday night was the annual NASA night here at DPS. Basically, it's a town-hall style meeting in which NASA, through the planetary science director, updates the community on what has been happening over the last year, what issues are outstanding. After that they take a number of questions from the community. One of the real treats of last night was a half-hour session devoted to an update on the Planetary Science Decadal survey, given by the chair, Steve Squyres.

Squyres revealed that the first draft of the Decadal Survey has in fact been submitted to the NRC, just this past week. This draft will next undergo peer review and should be available for release by the end of February 2011 and will be presented formally in march at LPSC (The Lunar and Planetary Science Conference). Now while Squyres could not reveal the contents of the report at this stage, he was able to speak in broad strokes about what we should expect. First of all, this decadal survey had an additional constraint compared to previous decadal surveys. Not only was the committee tasked with identifying the best science to be done, but they were asked to determine the cost of doing that science and to use that cost estimate as a factor in ranking what should be done. The result may be less of a guideline, as previous decadal surveys have been, and more of a concrete and implementable plan.

To that end, the survey committee sought out a great deal of mission assessment (millions of dollars worth) and then had the numbers checked over independently by Aerospace Corporation. There are exceptions. First of all, the smallest missions, the Discovery-class, will not be ranked as these are meant to respond to opportunities and discoveries as the decade goes on. As well, the survey committee was asked to not interfere with the current New Frontiers selection process, and so the three surviving candidates - OSIRIS, SAGE and MoonRise - were not evaluated. It should be interesting to see what makes its way into the final report. You could certainly tell that Squyres was excited and wished he could just go ahead and spill the beans right then and there.

Following the decadal survey update, Jim Green, the planetary science director at NASA Headquarters described the highlights of the year past and the year yet to come. Two items stuck out in my mind. First, there is a real bonanza of activity taking place over the next 600 days or so, something that NASA is describing as the Year of the Solar System. Given its length, it's a Mars Year, as Green pointed out. It also has a website, http://solarsystem.nasa.gov/, and a new educational software package named “eyes on the solar system” which was demoed here at DPS and will go live at the end of the month. Over the course of this time, we've got the release of the decadal survey, the arrival of Messenger at Mercury, and the launch of three spacecraft over four months in 2011 (GRAIL [moon], Juno [jupiter] and MSL [mars]).

The second item is the difficulty that NASA is having in getting the Pu-238 that is required for NASA to run planetary missions beyond Mars. As we get further and further out in the solar system, the amount of solar flux available to power spacecraft gets less and less, so much so that by the time you get out to the orbit of Jupiter, where the flux is less than 4% of what it is at Earth, it is especially impractical for spacecraft to be solar powered, although Juno intends to try it.

Instead, spacecraft are powered by the radioactive decay of Pu-238. This material is packaged as alloy at far from weapons-grade concentrations in a series of aeroshells which are intended to survive a launch-pad accident. Meanwhile, the heat given off by the radioactive decay is harnessed as a power source, classically using a thermocouple run in reverse, to produce an RTG, or radioisotope thermoelectric generator.

But the total amount of Pu-238 is limited, and it has been more than 30 years since Pu-238 was last produced by the United States. As such, the stock of material has been steadily diminishing, despite purchases from the russians, so that currently there is insufficient plutonium to power all the NASA missions that are on the books. This includes efforts to extend the lifetime of the current stock by utilizing more efficient heat utilization methods, such as sterling cycles (SRGs) which are much more efficient and thus require less plutonium. There have also been efforts to front-load the usage (since the stock naturally decays away and less is left on the shelf each day) by offering incentives in the recent Discovery AO to teams proposing SRG power sources. A large fraction of the 28 propsers reportedly took them up on the offer.

This is an issue of particular concern to the DPS, which has less of a Mars-component than other planetary science conferences, and the division membership has been writing letters to congress about the issue for several years. This year, there was a positive sign in that the approvals bills for NASA and the DOE (Department of Energy) both talked about the desire for DOE to restart Pu-238 production. NASA was even given approval to spend 15 million dollars on its share of this program.

However, the approval of administration budgets by congress is a complicated process with an approval and appropriational level. That is to say that NASA may be “approved” to carry out activities, but the money required to do them may not be “appropriated.” Sure enough, in the appropriations bill for the DOE, language on the restart of plutonium stated that since NASA was the only public user of Pu-238, it should have to shoulder the entire cost burden, some 90 million dollars all told. So unfortunately, it doesn't look like much is going to happen on this issue this year.

As a final note, an old classmate of mine at LPL, Terry Hurford, was announced as one of the new names at NASA HQ. He will be a program scientist in the OPR (Outer Planets Research) division of the NASA R&A Program, and largely takes over for Curt Neibur who becomes project scientist for EJSM.

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Following NASA night many of us took off for an important "AG" meeting. The AGs are Assessment Groups and many of the popular destinations in the solar system have one to help prioritize our exploration and science activities. For instance, I get a great deal of mail from MEPAG, the Mars Exploration Program Assessment Group. The AGs have their international counterparts too, the WGs. For Mars that would be IMEWG, the International Mars Exploration Working Group. However, the AG I was headed for was much more social in nature. The BWEAG, or Beer and Wine Exploration Assessment Group, was conceived and chaired by Andy Rivkin. It reminds us that conferences are not just a place to listen to talks, but to interact socially with your peers and discuss what you learned that day. Many a new collaboration has been formed at places like meetings of the BWEAG. To my knowledge, there is not yet an IBWWG, but just in case Andy comes up with one, you read it here first!

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