Wednesday, March 30, 2011


One key to understanding the recommended program is that the Survey's members sought balance.  While Mars has dominated NASA's program for over 15 years, the goal going forward was to have a balanced program.  There are a couple of ways to look at balance.  One is by type of target -- inner planet other than Mars, outer planets, primitive bodies, etc.  Another way is by the method of study: remote sensing of surfaces or atmosphere, measurements within an atmosphere, measurements on the surface, measurements within a magnetosphere, sample return.  The latter approach is often more telling than the destination.  An atmospheric chemist, for example, can switch between Venus, Titan, or Uranus, but is left out on a lunar mission.

With that in mind, how do the recommended missions compare by target and type of study?

Among the Flagship missions, the Giant Planets were a clear favored destination.  This isn't surprising.  Mounting missions to these distant worlds in inherently expensive and once that initial cost is assumed, the inclination is to fly more capable missions that require Flagship (>~$2B) funding.  Among the New Frontiers candidates, however, there are no clear winners.  Candidate missions are well distributed by type of destination and by type of study.  I believe that the goal of achieving this balance explains why a near Earth asteroid sample return mission was dropped from the list (although it remains a candidate for the selection in progress).  Including it would have meant too many primitive body missions and too many sample return missions.

(I want to emphasize that the chart above has been simplified to focus on major types of study.  The Venus Climate Mission, for example, would include a camera on the orbiter for context images, but this would not a major focus of the mission.  On the other hand, the Comet Sample Return mission has to have capable remote sensing instruments to select landing sites and would make a major contribution to our understanding of the surface of these bodies even though the focus of the mission would be on the sample return.  I also chose to count the Enceladus orbiter as making an "atmospheric" measurement within that moon's plumes, but counted measurements of the near-vacuum atmospheres of Europa and Io as magnetosphere studies.  Please forgive any oversights.)

It's also interesting to look at the program in terms of financial balance.  The Survey members stated that they did not want a single mission to dominate the program.  Here is a list of the estimated mission costs in the Survey report with acceptable costs in parentheses if the full cost was unacceptable:

Flagship missions not recommended
Titan Saturn System Mission $6.7B
Jupiter Europa Orbiter $4.7B
Mars MAX-C and ESA ExoMars rovers $3.5B

Flagship missions with high priority
Descoped Mars rover mission $2.5B
Descoped Europa mission (cost target not given)
Uranus Orbiter and Probe $2.7B

Flagship missions with lower priority
Enceladus Orbiter $1.9B
Venus Climate Mission $2.4B

New Frontiers mission candidates
Lunar Geophysical Network $1.3B
Io Observer $1.4B
Trojan Tour $1.3B
Saturn Probe $1.3B
Comet Surface Sample Return $1.5B

(Cost estimates were not given for the Venus lander and lunar sample return missions; since both have proposals in competition for the next selection, it was assumed their costs would fall within the present New Frontiers cost cap.)

From this list, it appears that Flagship missions around ~$2.5B were acceptable because they would each represent less than a quarter of the then presumed funding for new missions.  (Under the new funding outlook, none can be afforded except for a possible even more descoped joint rover mission with ESA.)

Interestingly, the additional New Frontiers candidate missions all exceed the recommended budget of $1B per mission for candidates selected mid decade and beyond.  The Survey chair, Steve Squyres, has said that they believed that clever proposing teams will find ways to fit several of these missions within that budget cap.   These missions at these prices may represent a new class of mission.  Previously, the principal investigator's budget for the craft, instruments, and operations was capped at ~$650M; the new proposed cap at $1B represents a significant increase in funding per mission.

Sunday, March 27, 2011

Articles on Juno Jupiter Mission

The Juno mission to Jupiter is scheduled to launch this coming summer.  Aviation Week and Space Technology just published two articles on the mission, one focused on design and implementation and the other on the science.  Normally, AWST requires a subscription to read, but both articles are posted on public websites.

The science article is posted on AWST's website.  The other, longer article, appears to be available on the Zinio website, which provides an electronic subscription service to magazines and other media.  I subscribe to AWST through Zinio, so it is possible that the link to this article may not work for those without the subscription.

Monday, March 21, 2011

JET - Cost Capped Titan-Enceladus Proposal

JET Titan and Enceladus orbital tour

Following the release of the planetary Decadal Survey, I’ve discussed the need for missions in the coming decade to be highly focused to fit with fixed cost caps.  Nowhere will that need be greater than for outer planet missions to explore the icy-ocean moons.

For me, there were two major surprises in the Decadal Survey.  The estimated costs of missions, especially the Flagship missions, stunned me.  As I’ve had a week to think about the Survey, though, the bigger surprise has been the lack of focus on the icy-ocean worlds.  Perhaps there is no way to meaningfully explore Europa given limited budgets and its location deep in Jupiter’s radiation belts – perhaps only the surface of Venus is a more hellish location for spacecraft.  Titan and Enceladus are comparatively easy to explore, and their major drawback for further exploration is the many years needed for a spacecraft to reach them.  (I heard in a conference this week that operating a spacecraft during cruise costs $7-10M a year, and Saturn can take up to seven years to reach.)  Cassini’s discoveries at these two moons, in my opinion, however, put them on the short list of the highest priority worlds to explore.

I believe that the Survey’s members concluded that the cost of incremental missions to these moons for the science they could return would be too low to make them priorities.  They prioritized a $2.9B Uranus mission to begin the in-depth exploration of the ice giant worlds over a $1.9B Enceladus orbiter.  As budget projections stand, we are likely to get neither.

A Discovery mission to the outer planets would set a new cost-return point that might be quite attractive.  At least two Discovery-class missions have been proposed for missions to Titan or Titan and Enceladus.  The proposers are attempting to implement missions that would be approximately half the cost or less of equivalent missions briefly studied by the Decadal Survey.  However, several observers have pointed out that the Decadal Survey mission concepts tended to have rich payloads, weren't optimized to reduced costs, and were made under conservative design and cost assumptions.

I don’t know if the Discovery budget (perhaps ~$800M with launch) can enable missions to explore the outer solar system.  While the proposers of the three outer planet Discovery missions I know about (Io Volcano Obersver, Titan Mare Explorer, and Journey to Enceladas and Titan) have a great deal credibility, mission champions have also been known to be too optimistic.  I hope they succeed.  It is instructive, however, to look at the tradeoffs that might enable an outer planets Discovery mission.

The Decadal Survey examined an Enceladus orbiter that would also make a number of Titan and other moon flybys.  That mission would carry five instruments and involve a complex 4-4.5 years of moon flybys and orbital operations.  By comparison, the Journey to Enceladus and Titan (JET) Discovery proposal would have just two instruments and one year of operations.  The Principal Investigator for the proposal, Christophe Sotin, was kind enough to give me permission to reprint his team’s abstract on the mission from the just completed Lunar and Planetary Science Conference.  This abstract both shows how Discovery missions to the outer planets must have limited goals and shows how they may be able to still address interesting science.

Example of the improved imaging JET would offer for Titan.

C. Sotin1, K. Altwegg2, R. H. Brown3, K. Hand1, J.I. Lunine3, J. Soderblom3, J. Spencer4, P. Tortora5, and the JET Team, 1Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove drive, 91109, Pasadena, CA, 2University of Bern, Switzerland, 3University of Arizona, Lunar and Planetary Laboratory, Tucson, AZ, 4Southwest Research Institute, Boulder, CO, 5Universita di Bologna, Italy.

Introduction: The Cassini-Huygens mission has demonstrated that Enceladus and Titan represent two crucial end-members in our understanding of planet/moon formation that might have habitable environments. Enceladus is a small icy world with active jets of water erupting from its surface (Fig. 1) that might be connected to a subsurface water ocean. Titan is the only moon with a dense atmosphere and the only object besides Earth with stable open bodies of liquid on its surface (Fig. 2). An organic-rich world, Titan has a methane cycle comparable in atmospheric and geological processes to Earth’s water cycle.

Fig. 1. Jets emanating from faults on Enceladus form a plume that provides access to internally processed material that can be studied in situ. 

Fig. 2. Specular reflection at 5 μm from Jingpo Lacus, Titan [1] demonstrates the lack of scattering in Titan's atmosphere at 5 μm (Credit: NASA/UA). JET exploits this unexpected “window.” 

The questions that JET would answer directly respond to the wealth of discoveries made by the Cassini- Huygens mission. High-resolution mapping of Titan surface is required to determine what processes have shaped and are shaping Titan. High-resolution mass spectroscopy would permit assessment of the astrobiological potential of Enceladus and Titan.

Concept: The JET mission has been proposed in response to the 2010 NASA Discovery Announcement of Opportunity. In order to achieve JET’s rich science return within the Discovery cost cap, a planetary orbiter with a simple, two-instrument, but powerful payload would make a total of 16 flybys of Enceladus and Titan. The only new technology is the NASAprovided Advanced Stirling Radioisotope Generator (ASRG) that would be validated as part of the Discovery Program’s engineering goals.

Along with making new observations of Enceladus and Titan, JET would fill a critical temporal gap in our understanding of the Saturnian system. Enceladus and Titan have near-equatorial orbits around Saturn, and Saturn has an inclination of 26º relative to its orbital plane around the Sun. Consequently, Saturn and its moons have seasons. Voyager briefly observed Saturn and its moons during the Saturnian Vernal equinox. Cassini observations extend from winter solstice to the summer solstice. JET would observe Titan during autumnal equinox, an opportunity that will not arise again until 2054. Observations during the Autumnal equinox are critical to understanding the fate of lakes and seas, Titan’s complex meteorological cycle, and the fate of organic molecules.

Science: The three goals of the mission are to determine the processes that have shaped and are shaping Titan, to assess the astrobiological potential of Enceladus and Titan, and to investigate the formation and evolution of Enceladus and Titan. These three goals are then detailed in eleven science objectives and thirty-one science questions that cannot be answered by the Cassini mission. Three examples are given. First, the Cassini mission has discovered that mass 28 in Enceladus’ plume has possible CO, N2 and/or hydrocarbon components. JET would confirm what fraction is CO vs. N2 vs. hydrocarbons. Second, the Cassini-Huygens mission has discovered that rivers and valleys are carved into plateaus and mountains. JET would search for sedimentary layering in valleys to determine the history of the flows. Third, Cassini has discovered that heavy molecules (m>100 Da) are produced in Titan’s upper atmosphere. JET would determine the nature of these molecules. This list of questions includes ten of the major discoveries of the Cassini mission that await a more capable mission to unveil the geological history and astrobiological potential of these two unique moons in the solar system. JET’s payload—a camera (TIGER [Titan Imaging and Geology, Enceladus Reconnaissance]) and a mass spectrometer (STEAM [Spectrometer for Titan and Enceladus Astrobiology Mission]—would provide the capability for achieving these science goals.

Instruments: The payload is limited to two powerful instruments and the radioscience investigation. The total data volume would be on the order of 120 Gb during the one year nominal mission.

STEAM: The reflectron time of flight mass spectrometer [2] is the Rosetta flight-spare of the Rosina mass spectrometer. It would characterize elements and molecules including complex organic molecules with a 10× larger mass range, 100× higher resolution, and 1000× better sensitivity than Cassini (Fig. 3). It would resolve fundamental issues related to the chemical composition of Enceladus’ jets and their relationship to the structure and evolution of Enceladus’ interior. STEAM would also characterize Titan’s organic-rich upper atmosphere.

Fig. 3. STEAM (right) has 102 better mass resolution and 103 better sensitivity than Cassini/INMS (left). Mass 28 and 40 will be definitively characterized. 

TIGER: This high-heritage IR camera exploits four IR windows through Titan’s haze and would image the heat of Enceladus’ fractures (Fig. 4). This camera uses the 5 μm window [3] to provide 10× better imaging resolution of Titan’s surface than Cassini, yielding 50 m/pix images of 15% of Titan’s surface. At each Titan flyby, an area twice as large as France would be mapped at 50 m/pixel in addition to Titan full disk at 500 m/pixel. The 50 m/pixel resolution is achieved at 2250 km from Titan’s surface. Currently, only ~10-6 of Titan’s surface area was imaged at this resolution by the Huygens probe. JET would deliver a five order of magnitude increase in coverage of highresolution imagery of Titan’s surface. Similarly, TIGER would provide 10 m/pix images of selected Enceladus’ tiger stripe fractures, permitting detailed thermal modeling.

Fig. 4. Cassini/VIMS spectra of Titan revealed a major surprise: the surface is visible in several atmospheric windows. High resolution surface imaging requires a careful balance between spectral regions of high transparency and low absorption, matched appropriately with detector sensitivity. The red curve shows the transparency of Titan’s atmosphere. The black curve is a typical reflected spectrum of Titan where high values show low absorption. The four TIGER channels (C1 to C4) shown in grey are optimized for these critical parameters. C3 and C4 provide thermal emission maps of EnceladusJets emanating from faults on Enceladus form a plume that provides access to internally processed material that can be studied in situ. 

Mission: The mission would be launched in February 2016 and would be inserted into Saturn’s system in May 2023. The nominal one-year mission would start with 12 Titan flybys with the closest ones at 900 km from Titan’ surface. This distance would vary from one flyby to the other in order to sample different layers of the upper atmosphere. Both Saturn and anti- Saturn hemispheres would be mapped. The Titan phase would be followed by 4 Enceladus flybys to sample the different jets of the South pole. The nominal end of mission would be a Dione disposal. A 6- year science enhancement option would permit to get into Titan orbit, offering the opportunity to further test the ASRG and to relay data from any element present on Titan’s surface or in its low atmosphere at that time.

References: [1] Stephan K. et al. (2010) GRL, 37, L07104. [2] Scherer S. et al. (2006) Int. J. Mass Spectrometry, 251, 73–81. [3] LeMouelic S. et al. (2011) LPS XLII.

Saturday, March 19, 2011

More on Partnership Challenges

It turns out that I wrote my previous post about the process to plan for possible planetary partnerships between NASA and ESA a few hours too early.  Since I wrote that, two articles have appeared that give additional information, especially from the European perspective.

Amy Svitak (whose stories I have come to look forward to) at Space News writes a good summary of the issues focusing on joint Mars and Jupiter system missions.  She reports that industry bids for building ESA's ExoMars rover have come back higher than expected, giving ESA a possible additional incentive to continue a partnership with NASA to share costs.  (ESA originally sought a partnership because its previous cost estimates for the entire mission exceeded its budget.)

On the journal Science's website is a story that focuses on a new redefinition of ESA's three candidate missions for its next large science mission, one of which is the Jupiter Ganymede Orbiter (JGO).  All three candidate proposals depended on a partnership with NASA (and one on a partnership with Japan).  However, none of these missions were top-ranked candidates in the U.S. astronomy or planetary Decadal Surveys.  Given budget issues in both these programs at NASA, ESA has concluded that NASA partnerships are unlikely as previously envisioned.  (For JGO, the previous plan had been for NASA to fly its own complimentary Jupiter Europa Orbiter and contribute instruments to JGO.  NASA can no longer do the former, but still plans to offer to do the latter if JGO is eventually selected as ESA's next large mission.)  ESA has asked the three proposing teams to reexamine their proposals and rescope them as ESA-only missions.  The new mission proposals are due in a year.

Friday, March 18, 2011

NASA Joint Missions With ESA

NASA has begun to explore its options in light of both the Decadal Survey's recommendations and its new reduced budget outlook.  One way to stretch dollars is to share a ride with a partner, in this case the European Space Agency.  NASA already had arrangements in place with ESA to cooperate on two missions, the Europa Jupiter System Mission and the 2018 joint Mars rover mission.  NASA's new budget outlook makes the scale of previously planned the U.S. contribution to those missions impossible.  As a fall back, NASA will honor its agreement to supply up to five instruments to ESA potential Jupiter Ganymede Orbiter.  The U.S. agency will also seek to redefine the Mars mission in conjunction with ESA to enable the mission to fly with a U.S contribution of up to $1B (which is approximately the planned European contribution).  

Editorial Thoughts:  If current plans hold, the next decade will see several moderate sized planetary missions fly: ESA's BepiColombo Mercury orbiter (with a Japanese sub-satellite), a Russian Venus mission, three NASA New Frontiers missions, ESA's Jupiter Ganymede Orbiter if selected as the next large science mission, and potentially a 2018 ESA-NASA Mars rover.  It's difficult to compare costs between  missions because of different accounting rules.  Including spacecraft, instruments, operations, and launch, however, these missions would range from approximately $1B (the next NASA New Frontiers mission) to perhaps $2B (ESA and NASA's contribution to a 2018 Mars rover mission).  These costs are a big step back from past flagship missions like Galileo and Cassini that might in today's inflated dollars cost $4B+.  

ESA and NASA are now planning missions of comparable scale.  Cooperation can allow more capable missions than either could do alone.  NASA's contribution of up to five instruments to JGO might represent half the instrument compliment and 10-20% of the mission costs. 

Cooperation can also be made difficult by differing goals.  For the 2018 mission, ESA has as core goal developing and demonstrating rover technology.  It also has a kick-ass instrument compliment for analyzing samples drilled from up to two meters below the surface.  The design of ESA's rover is almost complete.  NASA has the goal to collect and cache samples for future return to Earth.  The requirements include sampling a variety of rocks and soils, which is likely to require a sophisticated robotic arm along with the sample handling hardware.  Conceptually, the arm and sampling handling system could be "bolted" on to the ESA rover.  In reality, merging high tech systems that must survive launch, cruise, and operation on Mars means that this could be a complicated redesign.

One basis for a cooperative mission might be a redesigned rover that hosts the subsurface drill, the instrument compliment, a sampling arm (probably with some instruments of its own), and the caching system.  NASA could provide the entry, descent, and landing system derived from the Mars Science Laboratory mission that would allow precision landing into the most scientifically interesting sites.  NASA could also provide the launch.  Such a mission might have approximately equal financial contributions by both nations.  The devil, however, will be in the details of design, financing, and meshing goals.

To provide additional background on the issues from NASA's perspective, I'm reprinting a portion of the notes from this week's meeting of the Planetary Society Subcommittee meeting.  The quotes come from the meeting notes and NASA's director of Planetary Science presentation.  You can download both at

From the Notes:

A back of the envelope calculation suggests that after accounting for the higher priority elements (R&A, technology development, Discovery, and New Frontiers), we will have about $1B between now and 2018 to discuss a Flagship. This is nowhere near what even the recommended descoped MAX‐C will cost. Sanjay Limaye asked if that $1B includes launch costs, to which Jim responded that it does if we launch it (as opposed to ESA or another partner).

In response to a question from Mini Wadhwa on how MAX‐C [NASA's proposed rover for the 2018 mission] might be descoped, Jim replied that our first step will be to go back and talk with ESA, starting with a clean sheet of paper to see if we can build a joint Mars mission that meets both our needs and theirs within a budget both sides can afford. John Grant asked whose requirements would be used to develop the new mission, Jim noted that ESA has certain technology development needs and we have requirements on our side, sample caching in particular, that will all need to be addressed. Discussions on this front already began at LPSC and they will continue in earnest at the NASA/ESA bilateral on March 30th ‐ 31st.

Mark Sykes asked what would happen if there is no viable flagship option. Jim responded that the decision‐making rules for Flagships are clearly laid out in the decadal. The emphasis is placed on a balanced program. Flagships provide an enormous science per $ value. There are opportunities to move forward by partnering in the international arena, we need to carefully explore those options, then, and only then can we say no flagship. 

Jim noted that at the NASA/ESA bilateral, we will reconfirm our commitment to support ESA’s Laplace mission (Jupiter Ganymede Orbiter), should it be chosen. The PSS also confirmed their support for Laplace and for working with ESA in general. Jim Slavin asked when ESA might make a decision about the Laplace mission. Jim Green noted that ESA will not make a down‐select for their L‐class mission anytime
soon, they are putting together Science Definition Teams to explore what ESA‐only missions might look like, and it will take about a year for those studies to complete.

In response to a question from Bill McKinnon, Jim noted that for the time being, PSD is not undertaking a cost exercise to look at a descoped Jupiter Europa Orbiter. There has been no discussion of how to get a useful Europa mission for ~$1B. In response to a question from Julie Castillo about the future of the JEO community, Jim stated that from a US perspective, the JEO SDT [Science Definition Team] has been thanked and disbanded; any new discussions will be in concert with ESA.

From James Green's presentation:
  • Determine if Mars 2018 can be accomplished starting with the minimum set of requirements and “a clean sheet of paper” as Planetary’s top priority flagship mission
  • Reaffirm NASA’s commitment to support ESA’s Laplace mission if it is chosen as the CV‐Large class mission
    • Up to 5 (as budget allows) of the scientific instruments on JGO as a Mission of Opportunity and support for their PI‐led teams
    • Support for Interdisciplinary Scientists
    • A NASA Project Scientist to co‐chair the international Project Science Group (PSG) with ESA Project Scientist

Wednesday, March 16, 2011

One Figure Decadal Survey Summary

James Green, director of NASA' Planetary Science program, included this one figure summary of the Decadal Survey's recommendations.  No new news, but a handy summary.  You can read the entire (short) presentation at

Sunday, March 13, 2011

Decadal Survey Observations

The most important figure in the Decadal Survey report for me was buried at the back in Appendix C.  It was not until I read the journal Science's article on the survey (subscription required) that I realized its importance.

Before I get to that, it's been a week since we learned the key elements of the Decadal Survey through a Space News story based on a leaked summary.  We have been surprized by the cost cost estimates of the Flagship missions.  We heard in detail how the projected funding for NASA would support something like half the program recommended by the Survey.

During the past week, I've read most of the report and numerous summaries and commentaries on the report.  I've also watched the full question and answer period following Squyres's presentation of the report, the joint press conference with James Green, and Green's NASA update.  (Squyres was the chair of the Decadal Survey and James Green is the head of NASA Planetary Program.)

From Green's comments, it appears that it will be months and perhaps almost a year before we understand the full response to the Survey's recommendations and declining NASA planetary budgets.  Green, his staff, and the planetary community will take that time to scrub the budget, re-examine assumptions, think through mission costs, and negotiate with ESA on the 2018 Mars rover mission.

For now, though, here's what the picture looks like.  The first half of this decade will be a golden age of planetary exploration for NASA.  A number of missions are already in flight and will reach their targets or continue their studies.  Four NASA missions will launch in the next two years.  New Frontiers and Discovery missions will be selected in the next year or so for launch around the middle of the decade, and the ESA-NASA Mars Trace Gas Orbiter (MTGO) should leave Earth in 2016.

Then, if current budget projections hold, funding for new mission development will drop by approximately half around the middle of the decade.  The Flagship missions recommended by the Decadal Survey probably will not fit within that funding.  Steve Squyres said that with this funding level, the second half of the decade likely will see only New Frontiers and Discovery missions funded.

NASA and ESA had plans for a joint 2018 dual rover mission with NASA providing the launch, entry, and descent systems and a rover to cache samples for an eventual sample return.  ESA would provide its own rover to carry out sophisticated analysis of samples drilled from beneath the surface.  Unfortunately, adding the ESA rover would increase NASA's costs by approximately $1B, or a bit less than the cost of the ESA rover and instruments.  Today, even the cost of a NASA-only mission at $2.5B probably would be more than the projected budgets could afford with current budget projections

James Green, head of NASA's Planetary Science division, has said that NASA and ESA will spend the next several months  trying to craft a joint mission that fits within both agencies' budgets and meets both agencies' goals.  If that's possible, perhaps the resulting mission will be a single rover with ESA's instruments and NASA's sample caching hardware.  Whatever the solution, it will have to be designed to a cost cap.

Which brings us back to the figure I believe is so important.  The Science article pointed out that 50 years of planetary exploration have led to many "firsts": first flybys, first orbiters, first landers, first rovers for many worlds.  "But," and the article points out, "the next first is always more complicated than the last.  And greater complexity always means more expense."

Click on the image for a larger view

The figure from the Survey's report shows the relationship between cost and mission complexity.  As mission complexity increases linearly, mission cost increases exponentially.  A mission with a relative complexity of 40% would cost approximately $100M.  Double that complexity to 80% and costs jump to almost $1B.

In a fixed budget, the key is to design to cost, with corresponding caps on the complexity of the mission. New missions extend the capabilities of previous missions in some new way: a sample return from a new region of the moon, or the first Venus lander with modern instruments, or the first mission to a Trojan asteroid.  Complexity and resulting costs are constrained by narrowly focusing the mission on only the core requirements.

New Frontiers and Discovery missions have always been planned with a design to cost philosophy with costs capped at ~$425M and ~$8650M, respectively (Principal Investigator costs for the spacecraft, instruments, and operations).  Flagship missions, on the other hand, traditionally were designed to meet a set of mission goals with the costs allowed to rise to meet those goals.

Flagship mission do not have to be designed that way.  Several researchers in the question and answer period pointed out that the original JEO proposal was for a cost capped ~$2+B mission.  NASA then asked for a more capable mission that would hit the sweet spot for maximizing science return, and the result was a $3+B mission, which the Survey estimated would actually cost $4.5B.

Cost capped missions are an intelligent way to fit more missions within a budget.  However, these missions must focus on narrower questions.  The initial cost-capped proposal that became the JEO concept, for example, had fewer capabilities to study the larger Jovian system.  Lower budgets and resulting cost capped missions will mean slower progress in understanding the solar system.

I learned one other key aspect about the Survey's recommendation this week.  In the press conference, Squyres said that the Survey concluded that the past almost twenty years focus on Mars had resulted in too little attention on the rest of the solar system.  With the exception of the relatively inexpensive MTGO mission, no missions are recommended for Mars unless they are part of a sample return sequence (which a 2018 rover mission would be).  Otherwise, the Survey believes that the goal should be a breadth of missions to many solar system locations and not return to Mars in the coming decade.

All in all, the future planetary program looks much different tonight than it did a month ago.  Since then, we've learned that future budgets are projected to be substantially lower, cost capped missions with tightly focused goals are likely to be the norm, and that Mars has lost its special status as the focus world.

With this post, barring news, I'll take a break from the Decadal Survey for a bit and look at some mission proposals.

Wednesday, March 9, 2011

Enabling a Decadal Survey Flagship Mission

I want to start this post by saying that all the details I'll present are certainly wrong.  However, I believe that the overall conclusion probably is approximately right.  And breaking with my tradition of having this blog focus on fact and not editorializing, this post is an editorial.

For the last several years, I've examined NASA's planetary program budget proposals to learn where it invests and how much its fully burdened costs for missions appears to be.  This is roughly the equivalent of looking through a business' annual statement to try to understand its operations and financial position (for example, to try to decide whether it might be a good stock investment).  There are always lots of hard concrete numbers, but you always have to make some assumptions.  Some of those turn out to be wrong, hopefully by a small amount but sometimes by a meaningful amount.  That's why the some of the assumptions embedded in the spreadsheet behind this post are almost certainly wrong, but the larger picture should be approximately right.

In this post, I'll summarize the key findings of my analysis.  For readers interested in the assumptions, I'll post those as a comment.  Since my detailed assumptions are likely to be wrong to some degree, I will give ballpark figures here.

Since the release of the Decadal Survey, I've gone back to re-examine the budget outlook presented in the FY12 NASA budget proposal.  The proposed budget for FY12 supports all missions in flight, in development, or committed.  Starting in FY13, however, budgets are projected to decline.  At the presentation releasing the Survey's recommendations, Steve Squyres (the Survey's chair) stated that given the out year budget projections, NASA would not be able to develop Flagship class missions in the coming decade.

Adding everything together, I estimate that missions in development and committed would cost somewhat more than $3B, leaving something more than $6B for additional missions.  Assuming two additional New Frontier and two additional Discovery missions, that leaves $1-1.5B  to apply to an additional mission.  To account for any costs I missed, I rounded down to $1B.  Depending on whether or not future budgets are increased to adjust for inflation, this remaining funding wedge might be lost to inflation.

This remaining approximately $1B could fund an additional Discovery mission.  However, this could be the seed money for a Flagship class mission -- presumably a 2018 Mars rover mission with ESA.  About another $1.5B in additional funding would be needed, or a total increase in the budget of about 15% over the coming decade.  (Maybe 20% to cover the simplifying assumptions I had to make.)

Steven Squyres emphasized in his presentation Monday night that all budgets beyond the current year are 'notional' and subject to change through the political process.  If we as the community that cares about planetary exploration want to see a Flagship mission from NASA in the coming decade, we need make the case to our politicians to increase the planetary budget by 15-20% above the plan presented in the FY12 budget.  We would not be asking for large budget increases.  Adding this money to the budget would result in a significantly smaller budget than if FY12 funding were to continue for the coming decade (the difference could fund a second Flagship mission).  The Planetary program still would share the pain of reducing Federal deficits.

I believe that the case for a Flagship mission in the coming decade is compelling.  I think this is a case we can and should make to the politicians.

Note: If any readers have better budget estimates than I used, contact me and I will post them.

Decadal Survey Articles

Many articles summarizing the recently released planetary Decadal Survey have been appearing in the press.  I found the following three articles to be among the best:

Scientists tell NASA to focus on smaller science probes at Spaceflight Now - While the title doesn't quite catch what the survey would like NASA to do, it does provide a good summary of the the budget pressures facing the planetary program

A sobering planetary exploration plan at Space Politics hits some of the highlights of the previous article but with a bit more focus on the political side

Difficult decision ahead on Mars on the BBC site discussions some of the issues of trying to redesign the 2018 joint ESA-NASA twin rover mission to fit within a reduced budget

Monday, March 7, 2011

Decadal Survey is Available

The Survey's report is available at with an overview page at that also has a download link should the first link not work.  You can also watch the video of Dr. Steve Squyres' presentation of the report at

The leaked Survey summary reported on by Space News turned out to accurately reflect the priorities and challenge for NASA's planetary program.  Context on NASA's view of its situation can be found at

I will have more later in the week as I have time to think through the report (423 pages!) and listen to other reactions.  Here, I'll give the very brief summary of priorities for flight missions given by the Survey:

Overall priorities (I believe these reflect the priorities expressed in Squyres' presentation; they are not listed in priority report in the small part of the report I've been able to examine):

  1. Discovery program funded at the current level adjusted for inflation; 
  2. Mars Trace Gas Orbiter conducted jointly with ESA; 
  3. New Frontiers Missions 4 and 5; (NF mission 3 is currently in selection)
  4. Flagship mission chosen from list below  

Based on the the previous, much more generous FY11 budget projections, the committee recommended flying two Flagship missions, either MAX-C or JEO and a Uranus orbiter and probe mission.  During the presentation, Dr. Squyres said that in a reduced budget environment, one Flagship mission would be selected in the following priority order; higher priority missions would be passed over if conditions noted not met:

  1. Mars Astrobiology Explorer-Cacher (MAX-C), at $2.5B cost (vs. $3.5B estimate) and prepares for sample return and continues partnership with ESA 
  2. Jupiter Europa Orbiter (JEO), at significantly lower cost than $4.7B estimate 
  3. Uranus Orbiter and Probe, $2.7 billion 
  4. Venus Climate Mission, $2.4 billion
  5. Enceladus Orbiter, $1.9 billion

The Survey recommends that the New Frontiers 4 mission be selected from the following missions:

  • Comet Surface Sample Return,
  • Lunar South Pole-Aitken Basin Sample Return*,
  • Saturn Probe,
  • Trojan Tour and Rendezvous, and
  • Venus In Situ Explorer*
*may previously be selected for New Frontiers 3

For the New Frontiers 5 mission, these two missions would be added to the list:
  • Io Observer,
  • Lunar Geophysical Network.

Editorial Note: Based on my quick look, I am amazed by the depth of the report and the amount of obvious thought that has been put into it.  While I personally would have favored changes here and there, this is a set of recommendations that I can and do support.  Given the much higher cost estimates for the MAX-C and Jupiter Europa Orbiter missions and the recent much lower projected budgets, I suspect that some aspects of this report may be revisted.  The Survey explicitly calls for attempting to descope MAX-C and JEO.

Correct url for Dr. Green's presentation

The link I posted in the previous post for Dr. Green's presentation doesn't work.  The correct link is 

Sunday, March 6, 2011

Context for Decadal Survey Report

Tonight, I came across a presentation by James Green, director of NASA's Planetary Science Division, given on March 3 of this year.  It places the situation of the planetary program within the context of the latest FY12 budget proposal.  You can read the entire presentation at

Early on, Green presents the program's strategy:

The five programs that can no longer be supported in total presumably are the Lunar Quest program, Discovery, New Frontiers, Mars Exploration, and Outer Planets mission programs.  This portfolio will be restructured using guidance from the Decadal Survey.  In addition to these programs, the Division also supports planetary science research and technology development programs.

After a review of the FY12 budget proposal, Green presents the results of the decline in projected out year funding (click on the images for larger versions):

The key pieces of news I see in this slide are the indefinite delay of the Jupiter Europa Orbiter, the Mars 2018 MAX-C mission (which is currently planned to also land the ESA ExoMars rover), and Mars Sample Return.  The number of planned Discovery launches in the next decade will be reduced because of higher launch vehicle costs.

Missions in flight or in development will continue.  The slide states that the joint ESA-NASA Mars Trace Gas Orbiter mission will continue, presumably meaning that it will be developed and flown.  There's a reference to establishing a "Joint Mars Exploration Program" with ESA.  It's not clear to me what this means since I thought that one already existed.  Possibly, this refers to replanning the joint Mars program if the MAX-C rover and its delivery system that will also deliver ESA's ExoMars rover cannot be afforded by NASA.

My next post(s) will be the official summary of the Decadal Survey's report and possibly the official response from NASA if one is available

Space News Link

I forgot the link to the Space News article previewing the possible contents of the Decadal Survey report:

A Decadal Survey Preview?

Decadal Survey reports are kept confidential until their release.  Space News provides a purported preview of the report based on a draft summary it obtained.  We'll have to wait until Monday to find out if the summary represents the final report.

The article reports that the Survey's three recommended Flagship missions in order of priority would be:

  • The Mars MAX-C/ExoMars dual rover mission with a price estimate of $3.5B [Editorial note: This would be over $1B higher than other estimates that I've seen].  The report purportedly recommends that the mission be approved only if it can be flown for $2.5B.
  • The Jupiter Europa Orbiter is estimated at $4.7B [Editorial note: This would be approximately $1.5B more than previous estimates that I've seen].  The report apparently will recommend it be flown only if the cost can be reduced and NASA's planetary budget increased.
  • A Uranus orbiter and atmospheric probe at $2.7B, which is recommended for approval in the coming decade at this cost

The article states that the Survey based its recommendations on the FY11 budget forecasts.  The new FY12 budget forecasts would substantially reduced that funding outlook.  The article has two quotes that suggest that the FY12 forecasts will be the ones that NASA uses.

Reportedly, the Survey will recommend selecting two New Frontiers-class missions from the following list: A Venus in-situ explorer, lunar South Pole-Aitken Basin sample return, lunar geophysical network, comet sample return, an Io mission, a Jovian Trojan asteroid mission, and a Saturn atmospheric probe.  It's not clear from the article whether or not these two missions would include the New Frontiers mission selection currently underway or would be two additional missions.

The Decadal Survey will also recommend continuing with new Discovery missions.

Editorial Thoughts: This article leaves me in sticker shock.  If the Flagship mission cost estimates are correct, they are substantially higher than previously reported.  And if the FY12 budget forecasts are the ones that NASA will use to respond to the Survey's recommendations, then I don't see how either the Mars or Jupiter-Europa missions as defined can be fit into a reduced budget that includes Discovery and New Frontiers missions.  Funding the Uranus orbiter and probe mission may be difficult.

If the sticker shock is as bad as the article suggests, I would expect that attempts may be made to redefine the two big flagship missions to fit within a budget NASA could afford.  If that fails, the Uranus mission plus the New Frontiers and Discovery missions may be the program for the coming decade.   Another alternative might be for the Survey to reconvene to reconsider its recommendations in light of a tighter budget.   The mission concept studies included several smaller flagship missions that were less expensive than the Uranus orbiter and probe concept.  (However, the cost for the Uranus mission quoted in the article is approximately $800M higher than the one quoted in the mission concept study; other smaller Flagship missions may also suffer cost increases with greater examination.)

The article does not discuss the status of the joint ESA-NASA 2016 Mars Trace Gas Orbiter mission.  It also does not discuss whether the 2018 ESA ExoMars rover mission could be afforded by ESA without NASA participation.  ESA had decided to enter a joint program because it needed the additional funding from NASA's participation.

I'm personally disappointed that no mission to Titan or Enceladus reportedly are included.  I'll be interested to see if the report gives reasons why neither moon was a priority.  If there is no Mars mission in the coming decade, that will be another disappointment for me.  I had also hoped for a new mission to Neptune's moon Triton in my lifetime, but that now seems unlikely.

Saturday, March 5, 2011

Your List of Decadal Priorities

With the release of the Decadal Survey just 48 hours away, I thought that I would report on the list of missions that you, the readers, selected in your poll on the website.  Since you are the reason for this blog, I wanted the last post before the release of the Survey to be your opinions.

Missions were listed by cost categories: Larger Flagship (>$2B), smaller Flagship (~$1.4-2B), and New Frontiers (~$1B).  Costs were taken from the mission concept reports.  Where multiple options for a concept resulted in a range of costs, I selected the version that seemed to best represent the spirit of the concept.  Not entirely scientific, but this seemed the best that the simple Blogspot poll tools would allow.

Within each cost category, two mission concepts were clear favorites, gathering 68% or more of the votes between them:

Larger Flagship Missions

Smaller Flagship Missions

New Frontiers Missions
 n=263 individuals, but individuals could vote for 2 choices

Outer planet missions were clear favorites.  Among the top two choices for each category, only the Venus lander was not an outer planet mission.  Sample returns, primitive body missions, and inner planet missions were not highly ranked.

The strong polling for the Uranus orbiter and the Neptune mission suggests that you like the idea of revisiting to distant worlds only briefly visited once.  The strong interest in the Jupiter Europa Orbiter, the Titan Lake Lander, and Io observer indicated a desire to also go to the next level of exploration for three moons that have already received a lot of attention.  This wasn't a blanket choice for outer planet moons; Ganymede and Enceladus missions did not poll well.

I was surprised that Mars did not fare better given the strong popularity of the MER rovers.  Perhaps this was a reaction against starting down the road towards an eventual and expensive Mars sample return.

We will know if two days if the Decadal Survey shares these opinions.

Friday, March 4, 2011


Today, we learned of the loss of the Glory Earth science satellite in an accident today.  This satellite would have studied the role of aerosols and clouds in climate, a crucial area needing study to understand climate change.  My sympathies to the many who worked on the mission and the many scientists who counted on its data for their studies.

NASA is advised by an advisory council, which has a planetary science subcommittee that met this week to review NASA's FY12 proposed budget.  According to an article published on the Space News website,  The article quotes the chair of the subcommittee as saying, “ 'The out-years budget means no major new starts of a flagship planetary [mission],' Ronald Greeley, a regent’s professor at Arizona State University in Tempe and chairman of the NASA Advisory Council’s planetary science subcommittee, said during a March 1 conference call with panel members. ;That’s a major, major issue for our community.' ”  The subcommittee's report on the meeting included the following:

"Regarding whether funds for a new flagship mission would come from existing programs (Discovery, R&A, extended missions, etc) or new money: We have to stay within the President’s budget. We may have to reprioritize based on the priorities that emerge from the decadal survey.

"Regarding the future of New Frontiers: Right now there are planned funds for NF3 and some planning for NF4, but that is subject to change depending on priorities established by the decadal survey.

"Regarding a joint ESA/US Jupiter system mission: We talked to ESA when the budget was released, and we continue to talk with our counterparts, a bi‐lat is scheduled for the end of March. You should not assume that we wouldn’t participate in an ESA‐led Ganymede orbiter; we may provide instruments of opportunity. It is doubtful that they would for any reason change their destination to Europa at this juncture."

Thursday, March 3, 2011

A Personal List of Decadal Priorities

In my last post, I discussed what I see as the key issues that the Decadal Survey's recommendations will need to take into account.  With just days until the release of the recommendations, I thought I would have some fun and list my priorities.  While I have no pretense that there's anything special about my list -- any of your lists are equally valid -- this also gives me a chance to show how the issues I discussed last time might weave their way through a list of recommended missions.  (The Survey also will make recommendations in other key areas such as technology development that I won't touch on here.)

I said in the last post that I believe that the budget assumed by the Decadal Survey likely will drive many of its recommendations.  As I understand the process, the recommendations were sent out for review last summer.  If so, the U.S. federal budget picture then might have seemed much more generous than it might today.  Then, a projection of a decade's worth of funding for new missions might have added up to $12-13B.  Today, a pessimistic view might be $8B in FY11 dollars if the projected budgets in the FY12 budget are followed for the next five years and then continue at the same rate for the next five years without adjustment for inflation.  With adjustments for inflation, the spending power might fall in the range of $9.5-10B.  The FY12 budget projections may also be placeholders as NASA has said, waiting for a compelling Decadal Survey that justifies a larger budget.  So the upper end might be $12-13B.

I'll try to have my cake and eat it, too, by listing what are to me are a compelling set of missions that might fit into an $8B budget and have a list of additional missions if as much as $12B becomes available.

This initial list of missions likely would cost around $8B, the lower end of the budgets I'm assuming.  (Individual mission costs can be hard to assess since different funding years can be assumed and not all estimates include all of NASA's full set of costs.  In my spreadsheets, I used the best numbers I could obtain.  For NASA's Mars Trace Gas Orbiter costs, I used an educated swag.)  My list of core missions is:

2 Discovery missions
Venus New Frontiers mission
 Sample return New Frontiers from moon, asteroid, or comet
 Outer planets small Flagship 
 Mars Trace Gas Orbiter
 MAX-C/ExoMars/geophysical network instruments

In last week's post, I said that a second key decision would be whether the key questions to be addressed focused on a single type of target -- e.g., Mars or icy-ocean moons -- or a single type of mission -- e.g., sample return missions from Mars, the moon, and primitive bodies.  I would give highest priority to a diversity of targets.  There would be New Frontiers missions to Venus (specific mission might be picked to complement missions from other nations, otherwise I'd prioritize a descent probe/lander) and for a sample return (target to be picked from a submitted proposals) to cover what I consider two high priority goals.  A small Flagship mission would continue outer planet exploration, with the target (Ganymede/Jovian system, Titan, Enceladus, Uranus, or Neptune) picked from submitted proposals.  (As a target, I prefer Titan, but the proposal for another destination might be more compelling.)  Two Discovery missions would round out the diversity missions with the targets picked through a competitive competition.

For my focus target, I would chose the two Mars missions currently planned to be carried out jointly with the European Space Agency.  This was a tough choice; the alternative large Flagship program, the Jupiter Europa Orbiter is a compelling mission.  As a stand alone science mission, my judgement is that JEO is the more compelling mission.  Several factors led me to personally favor the Mars missions:

  • As I understand ESA's budgets, if NASA does not fund its portion of these missions, the Mars Trace Gas Orbiter and ESA's ExoMars rover cannot fly.  These are compelling missions.  Science and sample collection by a NASA rover landed with ESA's rover only adds to these missions.
  • JPL has spent over a decade developing rover and Mars entry, descent, and landing engineering expertise.  Without a Mars rover mission on the books, I've read in presentations that this expertise likely will be lost.
  • Plutonium to power JEO is in short supply.  As I understand it, the supply on hand is insufficient without Russia resuming supplies.  Restarting U.S. production is dependent on Congressional funding, which so far has proven difficult to secure.

The choice of the Flagship mission was a tough call.  Without the added bonus of enabling the ExoMars rover, I probably would have gone with JEO.

If more funding becomes available I would add an additional set of modest to low costs missions.  This would allow NASA to select compelling missions as funds were available, but would not place it in the situation of needing to keep funding a mission that's too large to be allowed to fail.  If all three were funded, my best estimate is that their cost with the missions above would approach $12B, the upper limit budget I have been assuming.

  2nd outer planets small Flagship mission
 Add'l New Frontiers mission
 Add'l Discovery mission

After a year and a half of reading and writing about the Survey, these are my conclusions summed up to a list.  The program the Decadal Survey members recommend next week probably will be quite different than mine.  Any exercise like this involves many compromises, and the Survey members have better information than I, have greater expertise, and have spent more time thinking and talking about it.  They may have also had to make some tough choices based on information that I don't have.

I look forward to hearing their recommendations.

In my next post, I'll show the list of missions selected by you through the poll on the website.