Sunday, May 9, 2010

Thoughtful comments on Decadal Priorities

My post on the Decadal Survey Update: Sticker Shock Ahead has resulted in several readers posting very thoughtful comments on how priorities should be set for planetary exploration.  I encourage you to read them and post your own thoughts. 

You may also want to read a post I did early in the year about how different the priorities would be if large missions are chosen versus a series of smaller missions.  Check out My Stab at a Decadal Priority List.  It explains my reasoning behind the lists that follow.

 Here are the two lists I came up with:

Example of a priority list and budget for a program that emphasizes Flagship missions.  Figures are in $Bs, and use either published estimates or my own best guesses.  New Frontiers and Discovery figures include the PI budget (~$650M and ~$450M) plus launches and other overhead.

How I would prioritized my list of missions based on mission concepts that have been studied to date.  This list recognizes that budgets may be cut, and has smaller missions that can substitute for larger missions or that can be enhanced if funding continues as currently planned.  Since this list was published, I've learned of the AVIATR Titan plane proposal, and I would consider dropping another mission to fit it in (assuming that the technology is ready for flight, something hard for armchair mission planners to test).

There's of course nothing special about my list, and I publish them to stimulate thought and discussion.  If anyone cares to send me their list, I will be happy to post it.  Please do try to make it fit within the expected budget of $12.5 for the decade (not inflation adjusted).  New Frontiers missions run about $1.4B and Discovery missions about $0.8B after all costs of launching, tracking, and overheads are included.


  1. There are some more details about the Robotic Precursor line here:

    These would probably factor into the Decadal Priorities decisions. The slides on page 7 show:

    2014 - NEO
    2015 - lunar lander
    2016 - Mars
    2018 - Mars
    2019 - NEO

    Actually this schedule is hard to reconcile with one of the other slides which shows a goal of small robotic precursors at $100-200M each, with 1 launch every 1-2 years, and large robotic precursors limited to $800M. The schedule doesn't show any launch in 2013, and 1 every 2 years starting in 2013 would cover 4 of the 5 listed missions. That would leave only 1 large mission. If all missions hit their maximum cost, that would be $800M * 1 + $200M * 4 = $1.6B, quite a bit under the $3B robotic precursor budget from 2011-2015 (assuming the new change adding "Orion crew return vehicle" doesn't come largely at the expense of the precursors).

    Maybe the schedule only shows the large precursor missions, and they are hoping those average well under $800M? That sounds hard to believe, unless they're planning to share rides with other missions in some cases.

  2. I appreciate you pointing this presentation out to me.

    I'm not sure what to make of these precursor missions. It would be be great if they fly. However, the plans don't seem to be very solid, as your analysis points out, while the dates are aggressive. I also suspect that this budget line will be the first place to cut to support development of manned capabilities such as keeping the Orion space capsule.

  3. NASA Administrator Bolden's statement to the Senate Committee on Commerce, Science and Transportation clarifies NASA's intent:

    "Exploration Robotic Precursors: A series of annual exploration robotic precursor missions is being planned, beginning with launch of a Near-Earth-Orbit (NEO) mission in 2014, followed by a lunar lander in 2015, and two Mars missions in 2016 and 2018, respectively. In addition, smaller robotic scout missions will be launched every 12-18 months to support reconnaissance, evaluate hazards, and develop systems and operations in support of future human exploration."

    So, the slides I linked to didn't include the line of "Scout" robotic precursors. That means that the larger ones will have to average considerably under their $800M cap if the program is to keep within the $3B budget through 2015, even if that budget isn't drained for other items.

  4. NASA is gradually releasing more information on its astronaut exploration plans, and some of these have implications for robotic exploration. I won't go into cross-over potential for new exploration technologies - just actual missions. Of course this all depends on how budgets work out - the plan will undoubtably change.

    Astronaut Exploration Robotic Precursors:

    This includes the schedule I described above, but also includes more details on each mission. A timeline for the smaller robotic scouts and Missions of Opportunity (HSF precursor instruments on SMD or internation missions) is also available. There are notes on other items of interest to planetary exploration (eg: possible involvement in the Planetary Data System datasets).

    Exploration Technology Demonstrations:

    FTD-1: Advanced In-Space Propulsion Demonstration (possibly reaching Mars)

    FTD-4: Aero-Assist Demonstration (possibly reaching Mars):