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arstechnica.com
Scientists are ready, what about you?
by KUNIO M. SAYANAGI • MARCH 14, 2011
On Monday March 7th, NASA and NSF received the results of the Planetary Science Decadal Survey, whichrecommended planetary exploration priorities to NASA and the NSF for the 2013-2022 decade. The
highlights of the recommendations are, in order of priority, to (1) collect rocks on Mars; (2) study Europa
from Orbit; and (3) orbit Uranus and drop an atmospheric entry probe. I was a member of the Giant Planets
Panel, and had an inside view of the Survey's creation; what follows is both an overview of the results, and a
look at the process that created them.
The survey's final results were announced by Cornell's Steve Squyres, who chaired the study. They come in
the form of a 400+ page document that reviews the state of planetary science today and spells out what
should come next. The final report is still undergoing editorial corrections, but a copy is already available for
free on the National Academies Press website.
Squyres' description of the final report revolved around NASA's three classes of planetary missions. Flagship
missions are the biggest projects and usually take multiple decades from start to finish. New Frontiers are the
"medium" class missions, and each costs about one billion dollars and takes less than a decade to complete.
Discovery program supports "small" missions that scientists directly manage at their home institution. The
goal of the decadal survey is to set recommendations on all of these research activities, along with
ground-based observations.
The recommendations for the Flagship missions are a big deal because their impacts will be felt for decades
in the future. For example, the current Cassini mission received a green light in 1988, and it took 16 yearsfrom there to arrive at its destination—Cassini has been in operation at Saturn since late 2004. These
recommendations are also a big deal because progresses in planetary science is spearheaded by these large
missions, so carefully crafting a coherent, long-term strategic plan is crucial to staying on track.
The survey's single most important goal was to examine the progresses in planetary science over the last
decade, and to come up with a consensus plan that will lead to new breakthroughs. The survey looked at the
scientific and technological state of planetary science today; as scientists, the message we are delivering with
the survey is simple: we are ready to do these missions.
However, the recommendations come at a tough economic time, and their implementation will depend on whether NASA receives a budget that allows it to afford those plans. Squyres, who are known for his
energetic, engaging presentation style, did not hide the uncertain future facing planetary science. Congress
has not passed the Fiscal Year 2011 budget, and, if the FY2012 budget proposal just announced is
representative of what NASA will actually receive for the subsequent years, there is a strong possibility that
we will not be able to fly even one of the priority missions.
Community consensus
The recommendations reflect the consensus view of planetary scientists about where we want to go next. The
survey is conducted by a team of scientists and engineers selected by the National Research Council, which isone of the four divisions of the National Academies (the other three are the National Academy of Science,
National Academy of Engineering, and Institute of Medicine).
The survey was divided into five sub-disciplines. The Inner Planets Panel dealt with Mercury, Venus, and
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Earth's Moon; Mars had a panel of its own. The Giant Planets Panel covered the four outer planets: Jupiter,
Saturn, Uranus and Neptune, while the Satellites Panel looked at the numerous moons of the outer planets.
All the other smaller bodies that orbit around the sun, such as the asteroids, comets, and Kuiper belt objects
were covered by the Primitive Bodies Panel.
We started working on the survey in the summer of 2009, and the first step was to gather input from the
entire planetary science community, which came in the form of white papers. In the end, we received 199
papers with a total of 1669 authors. As of October 2010, Planetary Science Division of the American
Astronomy Society had about 1415 members, so the survey gathered voices from a majority of planetary
scientists in the US and abroad. It was an extremely active process and many of us participated in multiple
white papers—I was an author on six of them. The white papers spelled out the scientific priorities, requisite
technological developments, and mission plans to be considered by the survey.
Each of these five disciplines had equal weight in crafting the final recommendations, and contributed a
chapter for the final report, which underwent rigorous peer review. The chapters were compiled into a single
document with a unified introduction and final recommendations by the Steering Committee, which oversaw
the entire survey process.
In writing the report, we were handed common Crosscutting Themes to maintain coherence across the five
panels, and were asked to focus on scientific questions that address the origin and formation of solar system,
the processes presently acting to maintain it in its current state, and conditions that support life.
Big missions, more rovers
For the Flagship class, the top priority identified by the survey is the Mars Astrobiology Explorer-Cacher, or
MAX-C. MAX-C is the first of the three missions that will eventually bring rock samples from Mars back to
Earth. The plan is for MAX-C to collect samples and store them in a special long-term cache box. The second
step in the proposal is called the Mars Sample Return-Lander, which will lift the samples collected by MAX-Cinto orbit around Mars. Then, the third mission, Mars Sample Return Orbiter, will finally bring the rocks
back to Earth. The recommendation for the next decade is to execute MAX-C only, with the rest of the
sample-return campaign to be carried out in the subsequent decades.
This mission to Mars is a continuation of NASA's Mars exploration strategy that got kickstarted by the last
decadal survey. That recommended, among other things, the Mars Science Laboratory and MAVEN as
lead-off missions that will open way for a Mars Sample Return campaign—MSL is on schedule to be launched
later this year, and MAVEN, which will study the Martian atmosphere, in 2013.
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Mars exploration today and future plans.
NASA Planetary Science Division.
In the current design, MAX-C is a six-wheeled rover with about the same size as Spirit and Opportunity. The
plan considered by the survey will launch MAX-C with another rover provided by the ESA called the ExoMars
Rover in 2018, and land them together in one shot using the Sky-Crane landing system originally developed
for the MSL.
As the name suggests, MAX-C is a mission to search for signs of life on Mars. Past missions' objectives
focused on the environmental conditions and whether they were friendly to life, but we now have a lot of
evidence that Mars could have harbored life in the past, if it does not today. So, the MAX-C mission will now
search for direct evidence of living organisms. The ESA's ExoMars has a similar mission, but it is designed to
analyze the samples on board without bringing them back to Earth.
Waiting for a new start
The second priority, the Jupiter Europa Orbiter, also has an astrobiology emphasis—it will employ
ice-penetrating radar to peer through the moon's surface ice and measure its thickness. There is now a strong
evidence that the moon has a deep saline ocean underneath the surface ice, which may harbor living
organisms.
This mission concept has a long history, which has already been covered in depth. It was recommended as
the single highest Flagship priority by the last decadal survey, and NASA and ESA made an agreement two
years ago to work together to develop a joint mission. The plan calls for NASA and ESA to separately send
their respective orbiters to Europa and Ganymede, two of the four Galilean satellites, (planet-sized moons of
Jupiter). The joint mission is now called the Europa Jupiter System Mission. Since then, the mission plans
have been made more specific, and meetings and workshops have been held to help scientists develop
instruments to be carried onboard for both the NASA and ESA orbiters.
However, the mission has not been started to date—past large missions to the outer planets, such as the
Voyagers, Galileo, and Cassini, were funded through a special line of budget specifically passed by Congress.
The creation of a new budget line is called a new start—but a new start for JEO has not happened to date, so
the mission concept, which is basically ready to be implemented, has come back before the decadal survey
again. The survey's recommendation confirms that a mission to Europa remains one of the top priorities in
planetary science, and makes it clear that the mission is waiting for a new start to be passed by Congress.
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Artist's conception of the joint NASA-ESA Europa Jupiter System Mission.
NASA/ESA.
Let's probe Uranus
The third Flagship priority is to send an orbiter to fly around Uranus and drop an atmospheric entry probe to
study its atmosphere in-situ. In contrast to the first two priorities, this is a brand new recommendation
coming out of the decadal survey.
The four outer planets can be categorized into two broad groups—the first contains Jupiter and Saturn, which
are commonly called the gas giants because they are made up mostly of hydrogen and helium gas. In
contrast, the two outer-most planets Uranus and Neptune, have considerable amounts of condensable
chemical elements that can freeze to form ices of water, methane and ammonia, so they are categorized as ice
giants.
The only mission to visit Uranus and Neptune to date is Voyager 2, which made brief fly-by measurements of
the planets in 1986 and 1989. Jupiter and Saturn have since been studied in detail by orbiting spacecraft
—Galileo for Jupiter and Cassini for Saturn—so the decadal survey is now recommending an orbiter for the
next one out, Uranus.
The study of ice giants have gained a renewed importance in recent years because they appear frequently in
the list of hundreds of new planets being discovered around other stars. As of this writing, 536 planets
outside our solar system have been detected, and a majority of them exhibit chemical and physical
characteristics that suggest that they are ice giants. So, studying the local ice giants in our solar system will
offer us an insight on what many planets outside our solar system are like. Also, the unique chemical
compositions of Uranus and Neptune are keys to deciphering the formation of the solar system, which will
also tell us something about the origin of these other worlds.
Uranus Orbiter and Probe Concept.
Ice Giants Mission Decadal Study Report, NASA.
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Descope, descope, descope
The decadal report also looks at the mission plans as submitted to the survey, and employed Aerospace
Corporation to come up with independent assessments of the cost and risks associated with these missions
-this process is called Cost and Technical Evaluation, or CATE. Even for those of us who are used to looking
at big numbers, the estimates for the Flagship missions induced extreme sticker shock. MAX-C came out to
be $4.0 billion, JEO is likely to cost $4.7 billion, and Uranus Orbiter & Probe is estimated at $2.7 billion.
The survey recommends that MAX-C and JEO must be scaled back so that their costs come down below $2.5
billion, which would require significant redesigns of both missions. This would be done mostly by removing
some of the mission goals from the scope of the project, or, descoping. The primary basis for the $2.5 billion
target is the balance between different programs within planetary science—NASA simply cannot afford to
spend that much money on any single target. In any event, even if a descoped JEO can be done in less than
$2.5B, its implementation will still require a congressional new start.
The budget projections included in the survey report makes the situation clear—the solid line is the total
budget projection for NASA's Planetary Science Division—most of the things fit below the line, except for the
light-blue item, which represents the cost for a descoped JEO. MAX-C draws its funding from the existingMars Exploration Program and does not require a new start. In his presentation, Squyres further noted that
this projection is already old—the new budget proposal for FY2012 recently submitted by President Obama
on February 14th include sharp cuts in the funding for NASA, so the situation now is a lot worse than what's
shown in this figure.
The budget outlook used in the survey process, based on the numbers for Fiscal Year 2011 proposal providedduring the survey.
Decadal Survey Pre-Publication Copy.
So, what's next?
For MAX-C, the report mentions that one obvious way to bring down the cost is to deliver only one rover to
mars in 2018; however, as the MAX-C/ExoMars mission is an agreed plan between NASA and ESA, removing
either of the rovers must involve re-working the agreement. Squyres mentioned in his presentation that
NASA and ESA already have a meeting scheduled in April, where the discussion is expected to focus on
reworking their agreements.
Squyres also urged the JEO team to immediately start looking for ways to make the mission smaller without
sacrificing too much science—it's that, or none of the science is likely to actually happen. To be sure, the JEO
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plan considered by the decadal survey was a bloated version of the mission that had been competing against
the Titan Saturn System Mission for the next big mission to outer solar system- the nature of that selection
process favored grand, all-encompassing missions, so some scientists noted that it was no surprise that the
CATE estimate for its cost became so high. The JEO team developed multiple versions of the orbiter, so they
should not have to start from scratch to come up with a mission that fits within the $2.5B cap.
However, a sobering message was delivered by Jim Green, who is the head of NASA's Science Missions
Directorate and oversees the Planetary Science Division. In Green's presentation, which immediately
followed the one by Squyres, he said "do not expect or plan any new start to be passed by the Congress in the
coming years"—this came as a real shock to the supporters of JEO.
The press release issued by the Planetary Society reflects the deep disappointment about the possibility of not
seeing a mission to Europa for yet another decade. The statement quotes the society's former Executive
Director Louis Friedman; "Europa does not care if we arrive there in 2030, 2050, or never, but this
generation of children will wonder what was wring with our generation."
Contingency plans
The decadal survey report does contain contingency plans in case NASA's budget becomes tighter. Its
recommendation is to give higher priority to smaller projects and preserve those rather than investing all the
money in a small number of big missions. If NASA cannot afford the Flagships, the survey draws a set of
guidelines that will still get us a good set of New Frontiers missions—the New Frontiers opportunities are
truly exciting in any case.
Artist's rendition of Saturn Probe mission that enters the atmosphere of the ringed planet.
Decadal Survey Pre-Publication Copy.
For the upcoming decade, we are expected to have two New-Frontiers missions, and the mission candidates
recommended by the survey include plans to bring home samples from a comet's surface, drop an
atmospheric entry probe on Saturn, and land on Venus. These are all exciting plans that promise significant
scientific returns, so not everything will be lost if there are no Flagship missions in the next decade, even
though that is a painful possibility to consider.
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Squyres even mentioned the possibility that we will not be able to afford any New Frontiers missions—in this
case, Discovery programs will become the mainstay of American planetary science. But Squyres did say that
the core Research and Analysis budget, which supports the day-to-day research activities of most scientists,
should see a steady increase even in the worst budget scenario—that's the portion marked as SRA (for
Supporting Research Activities) and appears in bright cyan in the budget projection above.
Baby in the room
I was the youngest member of the survey this time, and it was very noticeable to be surrounded by people
who could recount their involvements in the Pioneer projects of the early 1970s and the Voyagers in the
80s—I was born in the year the Voyagers were launched, in 1977.
One lesson I learned from the process is that the kind of leadership demonstrated by my panel chairs, Heidi
Hammel of Space Science Institute and Amy Simon-Miller of Goddard Space Flight Center, is exactly what a
field like planetary science needs to keep moving things forward. I was also involved in the mission concept
study for the Saturn Probe, led by Reta Beebe of New Mexico State University, where I also got a first-hand
experience in hammering a high-priority science idea into space mission concept.
Projects in planetary science have long time spans, and the field has emphasized maintaining a balanced
team that has both seasoned researchers and those of us who are still in early stages of our careers. So, it
made sense that they would have someone like me get involved in the process, and expose me to the long
tradition of doing big projects in planetary science. But still, it's really not that long ago when I was just a
high school student spending hours during weekends in libraries to read all the spacy stuff I could get my
hands on, so it was just amazing to have a preview of all the mission possibilities that might happen during
my lifetime. Of course, the best part is that I got to be part of planning what comes next.
These are your missions, too
Planetary science is almost 100 percent supported by public funding distributed through NASA and the NSF,
so it is not a surprise that the funding situation is heavily affected by the political climate on the Capitol Hill.
At the same time, these projects are run by tax money—your dollars—so you deserve to know how the money
is being spent, and we are obligated to tell you about all the new exciting discoveries. That is why planetary
science has a strong tradition of communicating with the public. The best example I always look to is (of
course ) Carl Sagan—Steve Squyres, who is also a great science communicator, is a student of Sagan's.
These scientific projects are not just paid by you, but you also have a direct say in how they are run. The
Planetary Society has a template letter on their website that can be sent to your Congressional representative,
urging support for NASA in the FY2011 budget . The webform allows you to personalize the letter's text sothat you can also mention specific planetary mission. Congress is voting on the budget next week (by March
18th), so the time to act is now. The current document calls for $19B to be allocated to NASA, of which about
$5B will cover all four of NASA's scientific disciplines; Planetary Science, Astrophysics, Heliophysics, and
Earth Science. The total expenditures in the FY2011 proposal is $3.82 trillion, so when we talk about NASA's
science, it is about 0.1% of the federal budget.
President Obama concluded this year's State of the Union Address with a rousing declaration; "We do big
things. The idea of America endures. Our destiny remains our choice. And tonight, more than two centuries
later, it's because of our people that our future is hopeful, our journey goes forward, and the state of our
union is strong."
Does your idea of big things include a little bit of planetary exploration?
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