My apologies for having posted so infrequently lately. I had a deadline for submitting a paper to a journal, and that consumed all my time and energy. The paper is in, and I plan to post more regularly.
I’ll start my new series of posts with a report of the key issues raised at this week’s OPAG meeting. Next post will describe an upcoming planetary mission.
While predicting the future is always a risky business, I’ve been seeing clues that NASA and the planetary science community are moving towards a new way of constructing mission portfolios. The cause of the move is familiar to anyone who follows this blog or space news in general: NASA’s budget for planetary exploration has shrunk each year for the last several years. Good news in future years may be flat budgets, and further cuts are quite possible. The planetary science program is caught between political forces that want to reduce the overall government budget and NASA’s own priorities that put this program fairly far down the list. (Higher up according to news reports: Operating the International Space Station, developing the next human spaceflight system, completing the James Webb Space Telescope (JWST), and the Earth science program.)
For the last two days, I’ve listened to portions of the Outer Planet Analysis Group’s (OPAG) meeting. This is one of several groups of scientists that meet once to twice a year to review NASA’s plans for their corner of the solar system. OPAG’s members fear that they are witnessing and end of an era. After the Juno Jupiter mission and the Cassini Saturn missions end within months of each other in 2017, NASA has no plans for future missions to the outer solar system. While the concepts for a mission to Europa keep getting better, there’s no way to fit these $2 billion missions into any foreseeable budget.
The meeting participants had long discussions about how hard it is to fit an outer planet mission into the Discovery program. Reaching Jupiter typically takes five years and Saturn seven years, at a cost of around $5-7 million per year in mission operations. Subtract that from a mission budget of $425-500M, and it’s hard to have a science return that competes with missions that take months or a year or two to reach their targets. (Rendezvous missions to comets and non-near Earth asteroids face a similar problem.)
Hopes for a new outer planets mission that would fly in the next decade rest on the results of the single Discovery and single New Frontiers competitions likely to occur later this decade. The competition from other destinations will be stiff. New Frontiers competitions are limited to a preselected list of missions, and the only outer planets candidate will be a Saturn atmospheric probe mission. (The rest of the list includes a comet sample return, a lunar sample return, a mission to the Trojan asteroids, and a Venus lander. For the competition after that, an Io and a lunar geophysical mission are planned to be added.)
During the OPAG meeting, there was considerable talk about how to expand the list of outer planet candidate missions. The approved list came from the Decadal Survey performed earlier this decade. Here, the politics of the Survey put the outer planet community at a disadvantage. They only had so many missions they could propose for consideration, and two of those were for very large (>$4B) Flagship missions to Jupiter-Europa and Saturn-Titan and a third was for a more modest ($2B) Uranus orbiter. These missions were considered when it appeared that NASA’s future budgets would support at least two Flagship missions, in additions to a new Discovery mission every two years and a New Frontiers mission every five years. Now it looks like Discovery missions will come every five years and New Frontiers missions every seven years.
Several times, the talk at the OPAG meeting returned to how the community would have looked harder at New Frontiers-class missions to the Jupiter system, Titan, and Uranus if they could have foreseen the new budget realities.
In the new budget reality, Flagship missions seem to be out; Discovery missions put large parts of the solar system at a competitive disadvantage; and many of the outer planet community’s highest priority targets aren’t on the New Frontiers list. A NASA official at the OPAG meeting referred to the recently announced $1.5B 2020 Mars rover as New Frontiers class. Historically, anything over $1B has been considered a Flagship mission, but the intent seems clear. While the budget cap may be flexible, New Frontiers-class missions are the new big mission class.
In the 2020’s, the situation may not be much better. NASA recently put out a request to industry for information on future launch upper stages for planetary missions for “the potential for a Mars mission every two years along with an additional science mission every three to five years beginning in the 2017 time frame,” http://www.aviationweek.com/Article.aspx?id=/article-xml/asd_12_20_2012_p03-02-530846.xml (Note: I’d prefer a 50-50 split between missions to Mars and the rest of the solar system.)
The budget squeeze on Flagship missions isn’t unique to NASA’s planetary science community. The recently completed heliophysics Decadal Survey called for a focus on more frequent smaller missions en lieu of future large missions. The astronomy and astrophysics community has planned on a Flagship mission to study dark matter and search for exoplanets to follow JWST. NASA now is wondering if that is politically possible and has commissioned a study to examine a new Probe-class program of ~$1B missions for this community. http://www.spacenews.com/article/nasa-hedging-its-bets-as-it-looks-past-james-webb-telescope
If something around $1B is the new cap for missions, then NASA’s mission classes will come to resemble those of the European Space Agency (ESA). ESA structures its science program into Large- (~$1.2 B) and Medium-class (~$625 M) missions and into a separate Mars program where each individual mission falls into similar price ranges. (There’s also a Small-class program that is ~$50M.) ESA and NASA account for mission costs differently, so the Large- and Medium-class missions are roughly equivalent to planned budgets for the New Frontiers and Discovery programs respectively. NASA’s science budget is expected to be larger than ESA’s, so the United States should fly more missions, but they would be of a similar scope to those of Europe.
If this change comes to pass, then several good Flagship mission concepts will not fly, at least in the coming decade or two. But there are a plethora of good ideas for missions in the lower price ranges. However, the planetary community in its Decadal Survey still counted on Flagship missions, so the list of missions that were considered for the New Frontiers may not represent the best pool to pick from in the coming decade. (This varies by community. For comet, asteroids, and the moon, no Flagship missions were considered. For the outer planets, Mars, and Venus, Flagship missions were assumed.)
The OPAG members spent considerable time talking about whether to ask NASA to add outer planet candidates to the list for the next New Frontiers competition expected later this decade. The consensus at the end of the meeting seemed to be that this was likely to be politically awkward – should the list be re-opened for all other communities, too?
Congress requires a mid-term assessment of decadal surveys, which would come around 2016 for the planetary community. That seems to me a good time to review and possibly expand the list of New Frontiers missions. That likely would be too late for the next New Frontiers selection but would be well before the first selection in the 2020s.
In the meantime, the OPAG members were discussing whether to ask NASA to raise the cost cap for outer planet Discovery proposals by ~$5M for each year that would be spent in transit to the destination. In the past, NASA has offered to raise budget caps for proposals using selected new technologies. If the flight-time adjustment were extended to all proposals so that proposals for comets and asteroids could also benefit, this seems fair to me. Without a change similar to this, hope for a continued NASA presence in the outer solar system after 2017 rests on the results of the fiercely competitive New Frontiers competitions planned to occur every seven years or so.