[X] My Assistant

[Mark6]

Today I heard this on NPR: Exploring a moon by boat

The mission could launch around 2016 and be sailing on Titan around 2022 — if this team gets through a highly competitive selection process to get funding from NASA. Stofan and her colleagues are busy working up their proposal for when NASA begins to accept ideas for future Discovery-class missions.

Quick Google search on Dr. Stofan's name found this: What Next for Titan?

Ellen Stofan has a Discovery-class Titan lake lander proposal. I've not seen the presentation, but a friend who has tells me that it is less capable than the ESA lake lander proposed for TSSM. (This would make sense – ESA had a budget of ~$1B for just the lake lander and balloon. Stofan has just $450M and has to fit a carrier craft and launch vehicle into that budget.) The 2007 report did not look at lake landers. I know of Stofan by reputation, and she's highly competent. However, fitting in a carrier, lander (with entry shell), and launch vehicle within a Discovery mission budget seems ambitious. Perhaps this could be done with a New Frontiers budget ($650M with the launch vehicle provided by NASA outside this budget), although the 2007 budget suggested that a budget twice this amount would be needed just for an atmopheric probe.

Aside from above quote's understandable skepticism of the Discovery-class price tag, where would plutonium for this mission come from? I thought it is all already allocated?

[Drkskywxlt]

I heard this presentation by Dr. Stofan at the Satellites Panel of the Decadal Survey (I was the notetaker). There was a great deal of interest by the Panelists and other members of the audience, but some skepticism as to whether this could ever fit in a Discovery budget. The reason Dr. Stofan's team believe they might have a shot at that $450M cost cap is that for this Discovery AO, the launch vehicle and ASRGs are provided as government furnished equipment. When you subtract those two giant costs out of the equation...you get a nearly New Frontiers-level budget for a Discovery mission. The mission is targeted for one of the larger "seas" at the North Pole and the probe could have a lengthy lifespan (during an extended mission) of possibly as much as 6 months, if memory serves. The instrumentation would be limited with an imager and meteorological/physical properties suite that could do some analysis of the lake fluid and weather conditions. A descent imager and thermometer would also be part of the deal. Comms would be DTE with a slow (but sufficient) data rate.

The IVO also got several eyebrows raised and lots of questions.

[vjkane]

I heard this presentation by Dr. Stofan at the Satellites Panel of the Decadal Survey (I was the notetaker). There was a great deal of interest by the Panelists and other members of the audience, but some skepticism as to whether this could ever fit in a Discovery budget. The reason Dr. Stofan's team believe they might have a shot at that $450M cost cap is that for this Discovery AO, the launch vehicle and ASRGs are provided as government furnished equipment. When you subtract those two giant costs out of the equation...you get a nearly New Frontiers-level budget for a Discovery mission. The mission is targeted for one of the larger "seas" at the North Pole and the probe could have a lengthy lifespan (during an extended mission) of possibly as much as 6 months, if memory serves. The instrumentation would be limited with an imager and meteorological/physical properties suite that could do some analysis of the lake fluid and weather conditions. A descent imager and thermometer would also be part of the deal. Comms would be DTE with a slow (but sufficient) data rate.

The IVO also got several eyebrows raised and lots of questions.

All Discovery missions get a launch vehicle outside of the $450M PI budget, so no advantage for the Titan Mare Explorer there. A mission that uses an ASRG also gets a free power source, but I don't think that solar panels for competing concepts are likely to be deal busters (and there are lots of other concepts for Discovery missions using ASRGs). I believe that Stofan's proposal also includes a mass spectrometer and gas chromatograph, unless that has been dropped very recently. Not really worth doing the mission in my opinion without that instrument.

The key for this proposal, like a lot of Discovery proposals, is the risk. Depending on how hard you judge it will be to develop the needed capabilities (such as surviving is a frigid place at the interface of two fluid that can suck away a lot of heat fast), a lot of proposals can fit within the Discovery budget. Review boards often seem to judge otherwise, and many a good sounding proposal has been thrown out as too risky for the budget. Whether that applies to this proposal, I have no idea.