Friday, May 28, 2010

Robotic Precursor Missions

In a previous blog entry (Robotic Precusor Missions), I described a proposed new NASA initiative in the manned exploration program to develop key technologies and scout future locations for manned exploration.  At that time, the program was pretty sketchy.  NASA just held a conference on this program that begins to fill in the blanks.  I want to emphasize, however, that the presentations are full of disclaimers stating that these are early plans likely to change.  Congress also has to go along with the Administration's proposal and fund the programs, which is anything but certain.

(All illustrations except the budget projection are from FY 2011 Exploration Precursor Robotic Missions (xPRM) Point of Departure Plans)

If these programs are funded, they would be great news for planetary exploration.  The entire program has many parts, and the full picture is too complex to describe here. Most of the programs are specific to manned spaceflight capabilities to reach near Earth asteroids and Mars.  Two programs, however, directly bear on unmanned planetary exploration.  This post will focus on the Robotic missions, and a subsequent post will focus on the technology development missions.

The role of the Robotic missions is to scout ahead of human exploration.  To provide an analogy, the Apollo missions to the moon had the robotic Ranger, Surveyor, and Lunar Orbiters that scouted the terrain and provided essential information prior to human flights as well as fundamental scientific exploration.  The in-progress Lunar Reconnaissance Orbiter and the recently completed LCROSS missions are modern versions of the same idea.  NASA is proposing a series of missions in the $500-800M range that would scout near Earth asteroids, the moon, and Mars.  This budget figure, which would include the launch vehicle, puts these missions in the class of Discovery missions.  (The fully burdened cost of each Discovery mission appears to be about $800M, with ~$450M going to the PI for spacecraft and instruments.)

Projected spending on precursor missions based on FY11 NASA budget proposal projections

The mission profiles and instruments would be selected to answer key questions relevant to human missions.  Is the surface safe to land on?  Are there hazardous substances?  Can we find resources to use?  The missions that can answer questions like these can also provide good science and good vicarious armchair exploration.

The robotic precursor program appears to be quite ambitious.  In addition to the major missions, several Scout missions costing less than $200M would also be flown.  The presentation is vague about what these missions might do.  The program would also fund individual instruments on scientific missions to make instruments useful for planning manned missions.

Example of how an investigation can approached from both the perspective of a precursor and a scientific mission.  In many cases, the data collected for one will inform the other.

Current roadmap of precursor missions.  xPRP missions would be $500-800M, MOOs are missions of opportunities that would usually pay to place an additional instrument on a science mission, and xScouts are small missions $100-200M in cost.

The slide above provides the current strawman list of missions under consideration.  Here, I’ll expand on a couple of the missions.  The 2014 near Earth asteroid mission would characterize one of these objects in terms of hazards, proximity operation conditions, and resources.  The instrument list, though, reads like that of a scientific mission: sub-meter pixel imaging, LiDAR for topography, instrument(s) for compositional mapping, and radar for subsurface structural mapping.  The mission would end with the spacecraft landing on the asteroid.

The 2016 Mars orbiter would leave for the Red Planet the same year as the Mars Trace Gas science orbiter.  While the MTG orbiter would focus on atmospheric composition and dynamics, the precursor mission would focus on radiation hazards, near surface ice detection, potential landing site imaging, and radar imaging to peer beneath the surface dust.  While these measurements would be essential to planning an eventual manned mission, all (except perhaps the in orbit radiation instrument) would address questions that have high scientific value for understanding Mars.

Additional large xPRP missions in the strawman roadmap include:

  • 2015: Teleoperated Lunar Lander in a sunlit polar region and enhanced hydrogen signature to explore resources, hazards, and mission operations.  Would include a Sojourner class rover.  (Noted as being aggressive for budget allocation.)
  • 2018: Mars lander with a MER class rover with instruments to investigate human safety issues.
  • 2019: Near Earth Asteroid mission that is still to be defined but has a goal of including 3-6 spacecraft to explore multiple targets

Editorial Thoughts: If these missions fly, they would constitute a major program of scientific exploration.  While no total budget is given, a quick back of the envelope calculation suggests that the program might be as large as $5B, or a little less than half the budget of the scientific planetary program. I suspect that the program is too ambitious for the projected budget.  The lunar and Mars landers, for example, have the feeling of a New Frontiers class mission (>$1B with all costs included) rather than a Discovery class mission.  I personally am most intrigued by the possibility of sending multiple smaller spacecraft to explore multiple near Earth asteroids and by the Mars orbiter.  I suspect that others would find the two landers more intriguing.

The cynic in me, though, is skeptical.  This program depends on the Obama administration’s proposed changes to the manned space program being accepted and funded by Congress.  Right now, Congress seems to be somewhere between doubtful and hostile to the proposed program changes.  It is possible that the Administration and Congress will compromise and keep elements of the old and new manned programs.  New programs such as these precursor missions that don’t have established political constituencies and don’t keep existing workforces employed may not fare well.

I hope that I am wrong, but I will not get excited until I see these programs progress to hardware being built.

1 comment:

  1. Jay Jenkins made the presentation on the Precursor missions at the Workshop and he seemed very enthused. He made some good points.
    First, launch tempo is very imnportant. He wants frequent missions.
    Second, he anticipates geneating a lot of data, like LRO.
    Third, the xScouts are to be PI-led. Main focus is to get competition and innovation. Each mission is budgeted for $200 million, but he believes that they can be done for a lot less.
    Fourth, the Mars 2016 Orbiter is a bit tight to meet. He mentioned that SMD is not looking for resources, not looking for hazards.
    Fifth, regarding Near-Earth Asteroid mission one objective might be determination if you can, or would want to, anchor to one of these objects.
    Sixth, he mentioned sensor technology development. One example would be miniaturization of wet-chem labs.
    Seventh, they are using Objective Definition Teams, much like Science Definition Teams.