Tuesday, April 19, 2011

More on NASA's New Directions for Planetary Exploration

 As NASA has time to reflect on the implications of the now six week old Decadal Survey and its new budget projections, more details on planning for the coming decade are emerging.  The head of the Planetary Science Division gave the latest account of current plans at a meeting of NASA Advisory Council’s Planetary Science Subcommittee on April 18.

The laid out plans for Discovery and New Frontiers missions over the coming decade.  The announcement of opportunity (AO) that begins the selection process for the next Discovery mission should be in sometime in 2013 (~36 months after the previous AO).  After that, AO's should be issued every 24 months.  That will mean the selection of 4-5 new Discovery missions over the coming decade, including the the selection in progress.  New Frontiers AOs will continue to be issued every five years, with the next AO due around 2015.

Much of the presentation repeated information that I've presented in previous posts on the ramifications of the Decadal Survey's recommendations and NASA's budget.  A few tidbits from the presentation are:

  • From the presentation, it appears that the selection of three finalists for next Discovery mission will be in April/May.  Selection of the next New Frontiers mission apparently will be in May/June.
  • Planning of a new joint ESA/NASA Mars 2018 rover and sample cache mission is underway.  A key decision by ESA on whether to proceed or not will occur at a meeting on May 26/27.  Space News has an article on the early thinking behind a redesigned mission.  From the article, it appears that NASA would contribute $1.2B to the joint mission.  With ESA's contribution, this would be a mission on the financial scale of the Mars Science Laboratory planned for launch this year.
  • Restart of plutonium-238 production was not authorized in the continuing resolution funding NASA for the rest of FY11.
  • NASA's planetary science FY11 budget PSD likely to be around $1.4B versus the President's request of 1.486B
  • Technical studies for a smaller Europa mission will be done over the next two years.  Such a mission presumably would fly only if the budget picture improves sufficiently to add a Flagship mission to the budget.


  1. Good to see that NASA is trying to get good missions out of its tight budget. However, I don't understand why the PSD is reluctant to look at missions to Europa that are less than Flagship level. I have already referenced the White Paper to the Decadal Survey that proposes a series of small Europa Orbiters. Each mission tackles only a few "bites" of the Flagship pie, but does so in a financially and technically sustainable manner. I guess that we can wait until "the budget picture improves sufficiently to add a Flagship to the budget." How long will that be? 20 years? 40 years?
    Or we can accept that the first Europa Orbiter MUST be FBC in philosophy. If the Europa community will not demand that the first Europa Orbiter must have every possible instrument onboard, then perhaps we can return to that moon in the near future and begin to learn its secrets.
    One of the suggestions of the Decadal White Paper was that the series of smaller, cheaper Europa Orbiters utilize solar power instead of RTG's. With your report that the FY2011 law does not re-start Pu-238 production, this suggestion looks reasonable. The presence of solar panels will put limits on the payload and the mission, but it does provide several advantages. Take a look at page 5 of the 2007 report, "Solar-Powered Europa Orbiter Design Study," by Eliot and Langmeier. They point out that the orbit required for a solar-powered mission "could allow radar to achieve its objectives sooner." Also, the orbit would allow for better imaging of Europa's morphology. In other areas, there is little or no science impact.

  2. Unfortunately, the greatest hobble to radar would be the need to continually articulate the solar panels to be in view of the sun. Reconstructing a chirp from an articulated platform will be a monster of a task--in fact it is the greatest barrier facing the Ganymede orbiter. Simple track patterns are complicated enough given chirp geometries without adding spinning spacecraft. But...there's no real need for an orbiter either for radar to succeed.