Tuesday, June 17, 2014

Congress Weighs in on NASA 2015 Planetary Budget

The two houses of Congress have written their proposed 2015 budgets for NASA.  The House bill would add additional funding to almost every category of the Planetary Science budget and would greatly strengthen NASA’s program of planetary exploration.  The Senate bill would add substantial funds to the Mars program but pay for this by cuts to other portions of the planetary budget. 

In American politics, the President proposes federal budgets but it is Congress that decides federal budgets.  Last winter, the President’s budget office proposed a Fiscal Year 2015 planetary budget that was better than proposals for previous years but still well below the levels needed to enact the program laid out by the science community in the Decadal Survey.  Both houses of Congress have now proposed their alternative plans (although the Senate budget has not been approved by the entire body yet).  How has planetary exploration faired? 

It’s useful to start by looking at their changes to NASA’s entire science program.  Each of the science divisions – planetary, astrophysics, heliophysics, and Earth – are operating on budgets well below what’s needed to fulfill the visions in their Decadal Surveys.  However, the political parties have settled on a budget compromise that sets a limit on overall government spending.  Within that limit, the Congressional bills have been fairly generous in proposing increases for NASA’s science programs in lieu of spending on other government programs.  Both Congressional bills would increase funding for astrophysics, but the House favors a substantial increase for planetary exploration while the Senate proposes a modest increase for Earth science (most of which is simply the transfer of satellite programs and their funding from another government agency). 

Changes proposed to the President’s budget for NASA’s science programs.  Credit: V.R. Kane

Within the proposed budget for Planetary Science, both bills propose to increase funding to the Discovery program to enable these small missions to be flown more frequently.  The bills differ substantially though in whether they favor a substantial increase to the Mars program (the Senate) or for defining a Europa mission through increased Outer Planets funding (the House) and to the research and analysis and technology development programs (the House).  Both bills appear to provide funding sufficient to operate all missions already in flight, reversing the proposal in the President’s budget to shut down the Mars Opportunity rover and the Lunar Reconnaissance orbiter.  (The Senate bill does not directly address the latter but does appear to provide sufficient funds for the orbiter.)

Changes proposed to NASA’s Planetary Science Division budgets.  Credit: V.R.Kane

Both the House and the Senate bills propose to increase spending for the Mars program.  The House bill would add $22.7M, a bit more than is needed to continue operating the Opportunity rover as well as all other Mars missions in progress and continue the development of the 2020 Mars rover.  The Senate bill would be much more generous with an increase of $65.7M.  The Senate bill specifically states that it wants to see all current Mars missions continue operating (which would require approximately $15M over the President’s request) but does not specify what the remainder of the funding would go towards.  NASA could use the remaining increase for development of the 2020 Mars rover, which is on a tight budget.

Both the House and the Senate bills would provide increased funding for the Discovery program with the increase targeted to enabling selection of the 14th mission in the series to occur in approximately two years.  (The 12th missions, the Mars InSight geophysical rover is in development and is fully funded, and the selection process for the 13th mission is in progress.)  Both Congressional bills direct that Discovery missions are to be selected every two years in accordance with the recommendations of the Decadal Survey rather than the every five years of the past decade.

If the Discovery program receives funding in future years’ budgets for missions every two years, or five per decade, this is a tremendous boost to NASA’s program. 

Both Congressional bills state the importance of a mission to globally explore Europa, but take very different directions with recommended funding levels.  The House bill would add $85.3M to the Outer Planets budget, which on top of the President’s request would provide $100M to continue preparatory design for the mission.  The House bill directs NASA not to consider any Europa mission that would be substantially cheaper than the ~$2B Europa Clipper it is currently defining.  This is in response to the request of the President’s budget office and NASA senior management seeking ideas for a mission that would cost approximately half as much.  The House bill states that the committee that drafted its bill has not seen any “credible evidence” that a scientifically useful mission could be flown for $1B.

The Senate bill cuts the Outer Planets program by $16.7M, or a little more than $15M the President requested for Europa studies.  (The remaining funds would support the Cassini mission at Saturn and pay for development of US instruments on the European JUICE Jupiter-Ganymede mission.)  The Senate bill gives no explanation for the cut.  In fact, it states in the text that it support’s the President’s funding levels for the Planetary Science program except for increases the Discovery and Mars programs.  The cut to the Outer Planets funding appears in a table, but no explanation is given.

The Senate bill directs NASA to plan to use the Space Launch System (SLS) booster to launch a Europa mission, while the House directs NASA to consider using the booster.  The SLS has the ability to deliver a Europa mission to Jupiter in around 2.7 years compared to a 6.4 year transit if commercial boosters are used.  However an SLS launch would cost ~$1B compared to a few hundred million dollars for a commercial launch.  Congress plans to fund the development and building of several SLS boosters so their cost is already covered. 

While the House and Senate bills both would increase net spending to develop future missions with one favoring Mars and the other Europa, the Senate bill would cause harm elsewhere.  While the House bill supports small increases to the Planetary Science program’s research and technology programs, the Senate bill would impose significant cuts to these programs.  Cutting the research program likely would reduce grants to scientists.  At best, this would stall work to analyze data returned from NASA’s missions.  At worst, this would force a number of scientists and graduate students who depend on these grants to leave the field.

Eventually, the two bills will be reconciled into a single budget that will set NASA’s funding for current and future missions for 2015.  From my news reading, it’s widely expected that the final reconciliation of the House and Senate budgets won’t occur until late this year following the Congressional elections in early November.  

Thursday, June 5, 2014

A Checkup on Future Mars Missions

NASA’s Mars Exploration Analysis Group (MEPAG) recently reviewed plans by Europe, the Japanese, and the U.S. for future Mars exploration.  The prognosis is for another kick ass decade of Mars exploration.

We have enjoyed two decades of increasingly more focused exploration of Mars.  After a lull of twenty years, the 1996 Mars Pathfinder lander began what has became a flotilla of orbiters, landers, and rovers to examine the Red Planet in increasing detail.  Missions in flight or in development will explore the processes that are stripping away the atmosphere, measure its trace gases, and study the interior of another planet for the first time.  Two missions will land rovers to poke and prod two locations in detail.  This is in addition to the three orbiters and two rovers currently exploring this world.  Only for our moon do we have such a rich understanding of another world.

The MEPAG meeting last month included the usual program review, but it also coincided with the second workshop in the long selection process for the landing site for NASA’s 2020 rover mission.  In this post, I’ll share highlights from the two meetings. (You can read the presentations here.)

Credit: J. Green, NASA

The European Space Agency (ESA) has an active Mars program with the Mars Express orbiter currently at Mars, two ExoMars missions in development, and planning under way to select follow on missions.  It will jointly develop and fly the two ExoMars missions with the Russian space agency Roscosmos.  The first, set to launch in 2016, will have an orbiter that will focus on atmospheric chemistry and dynamics along with a small European technology demonstration lander.  The second, to launch in 2018, will deliver a highly capable rover and station that will search for signs of past or present life.

The current tensions between the US and Russia over the Ukraine have the potential for disrupting these missions.  NASA plans to deliver its Electra communications package for the 2016 orbiter that will allow it to relay data from surface landers and rovers back to Earth.  Both ESA’s 2018 ExoMars rover and NASA’s 2020 rover missions plan to use the ESA orbiter to relay data back to Earth.  Because Russia will launch the mission, shipping equipment to Russia with the current political tensions over Ukraine may prove difficult.  With launch just two years away, there’s little time to recover from any delays if they occur.  NASA also plans to deliver a key parts of one of the 2018 rover’s instruments, but there is more time to deal with that issue.

Other highlights from the ESA presentations:
  • Both the 2016 and 2018 missions are on track other than the potential export issue (although no mention was made of whether or not funding has been fully secured for the 2018 mission which has been an open question).
  • Russia is still scheduled to provide the key entry, descent, and landing system for the 2018 rover.  This will be a major project for a space agency that hasn’t had a successful planetary mission in decades.
  • Russia plans to host a surface station in the 2018 lander platform for long-term studies of the atmosphere and geophysics of Mars.  Instrument selection will begin this spring.
  • ESA is considering three missions to follow the 2018 rover.  The current favorite, Phootprint, which might launch in 2024, would be a possible third joint mission with Russia and would return a sample from the Martian moon Phobos.  Other options would be for three small geophysical landers to establish a network to study Mars interior or a small rover to explore a new region of Mars.
Japan’s space agency, JAXA, is considering several mission options for a future Mars mission, but has no currently approved Mars missions.  (It’s only previous attempt to reach Mars, the NOZOMI orbiter, failed.)  For its next try, JAXA’s managers are considering several small missions including an engineering demonstration to use the atmosphere to slow the spacecraft to enter orbit (aerocapture), an airplane to survey magnetic anomalies this will provide clues on Mars’ ancient but now defunct magnetic field, and a meteorological station or seismic station.  The presenter, however, spent the most time describing the most ambitious concept, a rover that would be smaller than the Opportunity rover at ~60 kilograms.  Two goals for the rover were described in some depth – an environmental package to study dust movement by the atmosphere (including dust devils) and a relatively simple microscope that would use fluorescence to detect biosignatures in the soil.  Launch would be sometime in the 2020s.

A presentation on the NASA MAVEN mission that will study loss of the atmosphere into space gave the good news that all is well with the craft.  It arrives at Mars on September 21st this year. 

The Europeans and Russians will not have the only mission to Mars in 2016.  NASA’s InSight geophysics station will launch that year to study the interior of Mars.  The lander also will carry a capable weather station to enable scientists to determine the influence of temperature and winds on its measurements.  The InSight mission has always planned to carry a camera to aid in instrument deployment, with one panorama planned early in the mission.  The project will attempt to replace the currently planned black and white camera with a color camera, but there are no promises.  The mission development is proceeding well and the team has received permission to start hardware development following an in-depth review of the design.

The InSight Mission will greatly enhance our understanding of the interior or Mars. Credit: M. Golombek, B. Banerdt, JPL/Caltech

The focus for the two meetings, though, was NASA’s 2020 rover.  Like the Curiosity rover currently on Mars, the 2020 rover will pursue the question of whether Mars could have hosted life in the past (or even in the present).   While the Curiosity rover does that only with the scientific instruments it carried to Mars, the 2020 rover also will select and cache 25+ rock and soil samples that could be returned to Earth for study with much more sensitive instruments in terrestrial laboratories. 

Credit: B. Ehlmann, JPL/Caltech

In addition to exploring a site in terms of its past habitability, a well chosen site could also allow studies related to the key questions for Mars identified by the Decadal Survey that set priorities for solar system exploration.  The 'Noachian' era was the earliest on Mars when abundant surface water may have created conditions suitable for life.  Credit: B. Ehlmann, JPL/Caltech
NASA plans to build and fly the 2020 mission for just half the cost of the Curiosity mission, adjusted for expected inflation.   The need to collect samples and control costs will ripple through portions of the mission plans.  (An additional new goal, to gather measurements and test hardware that would be useful to a future human mission will also drive some changes.)

One portion of the mission that will be familiar will be the design of the rover and the hardware that delivers it to Mars.  NASA believes that up to 90% of the Curiosity mission’s design (by mass) can be reused (which enables a highly capable mission at bargain price).  Some changes will fulfill the new mission requirements (for example, the caching hardware) and others will apply lessons gained in operating Curiosity (for example, beefier wheels after Curiosity’s showed unexpected early wear). 

The instrument suite the 2020 rover will carry is likely to be substantially different than Curiosity’s.  Curiosity carries instruments that both can make quick measurements to rapidly assess the geology of a location and a highly capable laboratory that can make detailed measurements.  The latter, though, is costly both in dollars and in the time needed to make the measurements.  In almost two years of operation, Curiosity has collected just three samples for its laboratory instruments.  In that same time for the 2020 mission, scientists want to fill most or all of their cache.  As a result, the 2020 rover may carry only rapid assessment instruments in addition to its caching system (although technology advances may mean that some will be much more capable than their Curiosity equivalents).   NASA is expected to announce the instrument selection this July. 

The desire to cache samples also is leading scientists to prize the diversity in evaluating landing sites.  Scientists want its samples to represent the broadest range of ancient environments and processes as possible.  While almost half of the Martian crust is older than 3.7 billion years when life might have formed (compared to less than 1% for the Earth), many of those locations would provide limited diversity within the range a rover could explore.  (Many also would be unsafe to land at.)

The NE Syrtis Major site (second from the bottom) has a wide range of diversity.  This chart is a draft and may change as the diversity of other sites is further assessed.  Credit: B. Ehlmann, JPL/Caltech
At the end of the landing site workshop, the participants held a straw vote to indicate which sites they found most compelling.  The winner, located on the northeast edge of the plains of Syrtis Major, illustrates the diversity they would like to find.   Within a few kilometers, this site provides access to samples that record key stages of Mars’ early evolution:
  • Blocks of rocks hurled from nearby massive impacts record the early bombardment of the terrestrial planets by comets and asteroids.  These are also convenient samples of the ancient crust delivered from outside the landing zone.
  • Ancient crust with minerals preserving the record of the early wet environments of Mars that may have provided conditions for life to develop or at least that record biotic precursors.  The NE Syrtis Major site has an unusually wide range of aqueous minerals that suggest a diversity of environments that came and went across millions of years as the climate dried out.
  • A nearby volcanic flow represents the massive volcanism that covered large areas of the planet in its early history.  These rocks could record the chemistry of Mars’ ancient mantle, provide clues on when Mars’ ancient magnetic field shut down, and in terrestrial laboratories provide unambiguous dating of a wide-scale event to calibrate dating of Mars’ early history.

Location of the proposed NE Syrtis Major landing site.  Credit: J. Mustard, Brown University

The proposed NE Syrtis Major landing site includes geologic formations from the two most ancient eras on Mars, the Noachian and the Hesperian.  The site has remnants from ancient impacts, several types of aqueous minerals, and access to volcanic rock formations.  Credit: J. Mustard, Brown University
At this point, NASA is not looking to rule out any of the nearly thirty sites that have been proposed.  While the NE Syrtis Major site won the initial beauty contest, other sites may prove to be more desirable with further analysis.

While NASA doesn’t need to select the 2002 mission’s landing site until 2019, two factors are pushing it to evaluate sites early.  One is that high resolution mapping of the sites for geologic sites and landing hazards requires the sharp-eyed cameras of the Mars Reconnaissance orbiter.   That spacecraft reached Mars in 2006, and NASA wants to make maximum use of it while it remains healthy and has an adequate fuel supply.

The mission’s engineers also want an early look at the most desirable landing sites to determine whether the 2020 rover will need a significant upgrade in its landing system.  The closest the mission’s operators currently can target the lander is to an ellipse 25 by 20 kilometers.  A simple design change can reduce that ellipse area by 40%.  Unfortunately, the richest sites for exploration often don’t have the smooth surfaces needed to ensure a safe landing within their landing ellipses.  The Curiosity rover, for example, will spend more than two years getting from its safe landing site to the starting point for its actual target area.  (Fortunately, there’s been great science along the way.)

For the 2020 mission, NASA would like to avoid another long road trip at the start of the mission.  If the sites of greatest interest turn out to turn out to have hazards, then NASA will consider a technology called Terrain Relative Navigation (TRN).  With TRN, the landing system will compare images taken during the final descent against a stored map of safe landing zones.  It will then steer the landing to one of those safe harbors.  Without TRN, a mission to the NE Syrtis Major site, for example, has an 87% chance of a safe landing; with TRN the chance of safe landing increases to over 98%.  However, the TRN technology would be expensive to develop and test.  NASA wants to know that it is likely to be needed before committing to it for a mission that’s already being done on a bargain budget.

The two meetings showed that despite an incredible run over the last couple of decades, for Mars the best may still be to come.

Note: All the presentations promoting landing sites from the landing site workshop are available on-line.  If you’re not a geologist, you may want to read Emily Lakdawalla’s posts on Mars’ geologic eras and on key minerals that suggest past aqueous environments.  Wikipedia also has articles on the Noachian era and  its successor the Hesperian era during which Mars’ surface transitioned from an impact ridden world, to one with possible abundant surface water, and then progressively dried out.  The 2020 mission is likely to focus on sites that contain remnants from one or both of these eras (as the NE Syrtis Major site does).