Sunday, January 31, 2010

Decadal Survey Update

Steve Squyres has just published the January update for the Decadal Survey.  I'd characterize the current efforts as laying the foundation for the eventual plan.  Like laying the foundation for a building, this isn't the glamorous work, but without it, the edifice won't stand.  Three sets of activity are underway:

The steering committee has been focusing on two key threats to the ability to carry out a robust program: the rapidly escalating cost of launch vehicles and the plutonium-238 shortage.  Later this winter it will look at the technology development program.

The panels (each focuses on a group of destinations, for example Mars or the outer planet satellites) are nearing completion of their assessments of the key science goals for the next decade.  Eventually, once these lists are merged, these goals will be used to prioritize a set of missions.  Their reports, if memory serves me right, are due out this spring.

In parallel with the goals assessments, 21 mission concepts are being defined and/or having cost estimates prepared.  This effort will lead to determining which concepts are technically ready and can fit within the budget.  Since the last update, one new concept has been added, a Venus Tessera Lander.  While lowland Venus lander studies already were underway, this study focuses on how to land in the rugged highlands of Venus.


Monday will see the release of the President's budget proposal for fiscal year 2011, including for NASA's planetary program.  I'll publish an analysis Monday evening or Tuesday morning.  Then later next week I'll publish an entry on missions to study the trace gases in the Martian atmosphere.

Tuesday, January 26, 2010

What a Budget Freeze Might Mean

Apparently, large parts of the American federal budget will be subjected to a budget freeze for three years in the President's upcoming 2011 budget proposal.  Word on the street is that NASA as a whole will get a slight increase, but my betting is that any increase will go to manned spaceflight and Earth science missions.

In a week we'll know what the proposed budget will be for NASA's planetary program.  In the meantime, I did a little work with Excel to see what a budget freeze in the planetary program would mean.  Typically, inflation runs at around 3% in a year. Consumer inflation in 2009 was 2.7%; I don't know what the inflation rate was for aerospace spending and will use 3% as a guideline.  If the planetary program were subjected to a three year budget freeze and then budgets rose to cover inflation, the loss of spending power would be a fall between the burdened costs of a Discovery and a New Frontiers mission (~$950M FY09 dollars).  If the budget freeze were extended over an entire decade, the loss of spending power would be equivalent to a Discovery and a New Frontiers mission (~$1.8B).

Saturday, January 23, 2010

My Stab at a Decadal Priority List

We're in a bit of a hiatus in terms of Decadal Survey news.  The next round of meetings for the discipline panels (e.g., Inner Planets) aren't scheduled to occur until April and May.  The Steering Committee will meeting in late February, but it appears to be focusing primarily on enabling technologies.

I've been following the Survey's progress probably as closely as anyone outside of the process has.  During the last few months, I've been wondering what criteria I would use to set priorities.  And that led me to thinking what priorities would I choose.

I want to emphasize that what follows isn't an attempt to persuade anyone about what the priorities should be.  Your opinions are as valid as mine, and except for perhaps a lucky one or two readers who may be involved in the process, your and my opinions are likely to have the same impact.  However, I often learn more from a carefully crafted argument than I do from just reading the facts (which is why I read the opinions page of the newspaper more regularly than the front page).  So here goes (and I hope that you find this carefully crafted).

A successful program has to meet a number of goals:
  1. It must be fiscally possible.  That is, it has to fit within the $12-12.5B budget expected for the next decade.
  2. It must be compelling to the public and to the politicians who will have to prioritize dollars spent here over other worthy projects over the course of a decade.
  3. It must significantly advance our scientific understanding of the solar system.
  4. It should provide a balance between types of solar system bodies.  The list of discipline panels suggests the breadth possible: Inner planets, Mars, giant planets, outer solar system satellites, and primitive bodes

There's another criteria that may or may not be adopted by the Survey, but I think should be.  It is quite possible that over the course of the decade that the budget for planetary exploration may be cut.  (Recent reports that NASA will not receive a $1B budget boost for the next fiscal year leads credence to this fear.  Planetary missions will be in competition with the politically popular manned and Earth observation programs.)  I believe that the prioritized list of missions should remain useful if budget cuts occur.

I think that the most critical decision the Survey will face will be setting the balance between the large Flagship missions and smaller New Frontiers and Discovery class missions.  Two Flagship missions are likely candidates, Mars Sample Return (MSR) and the Jupiter Europa Orbiter (JEO).  These missions are large enough that they together would chew up three quarters of the budget.  However, it could be argued that these two large missions would provide the greatest scientific return of any missions on the candidate list.  There would also sufficient budget to fly the Mars Trace Gas Oribiter, support the ExoMars rover (as part of MSR's MAX-C rover), and fly three smaller missions which could visit the inner planets and primitive bodies (MSR and JEO would take care of Mars, the giant planets, and outer solar system satellites).

Example of a priority list and budget for a program that emphasizes Flagship missions.  Figures are in $Bs, and use either published estimates or my own best guesses.  New Frontiers and Discovery figures include the PI budget (~$650M and ~$450M) plus launches and other overhead.

I have two concerns about this priority list.  First, MSR and JEO could easily experience large cost overruns that prevent missions to other destinations.  Second, large missions make tempting targets for politicians looking to cut budgets.  Both of these missions would have to find political support across at least two Presidents and about a half dozen Congresses.  (In America, we elect the entire House of Representatives and a third of the Senators every two years, which counts as a new Congress (even though the reelection rate is so high that 'new' may be a misnomer).)  The counter argument is that scientific support for these big missions would be great enough to shield them from cancellation.  There's some truth to this (look at the survival of the James Webb telescope and the Mars Science Laboratory despite massive overruns).  On the other hand, a number of large science programs have been cut in the past; remember the Comet Rendezvous and Asteroid Flyby (CRAF) sister ship of Cassini cut in the early 1990s.

I instead prefer a priority list that focuses on smaller missions to many solar system targets.  Then if budgets permit, I would fly the full JEO mission and the first component of MSR, the MAX-C rover, as the lowest priorities.  This way, if budgets are cut, there is still a robust program of missions to a number of destinations.

How I would prioritized my list of missions based on mission concepts that have been studied to date.

While this list may seem like a scattered set of missions, there are some themes.  Mars remains the top priority with over a third of the budget.  Icy moons would be a priority with missions to the Jovian moons, Titan, Enceladus, and Triton.  The single Venus mission looks lonesome, but I see it as the NASA contribution to an international flotilla to that world.  However, the primitive bodies scientists would rightfully feel left out with just a single Discovery mission.  (I left both the Venus and primitive bodies missions as placeholders.  Depending on which missions are selected in the current New Frontiers and Discovery competitions, the priorities for these missions may change.)  It was really hard leaving off some missions I really like and that would produce great science like the Io Volcanic Observer (IVO).  (However, I could imagine a scenario where a line of New Frontiers class spacecraft were built using nearly identical spacecraft for the JMO, TEO, and Argo missions and then the savings might fund IVO.)

You'll note that I don't specify specific targets for several Discovery and New Frontiers class missions.  I have concerns about the totally open competitions to date, which make it impossible to know which missions will fly.  A consequence of this is that NASA has a harder time prioritizing its technology development funds.  If, however, NASA knows that it will be flying a lander to Venus, it can prioritize the appropriate development work.  Prioritizing specific targets also makes it easier to put together international collaborations.  If NASA will be flying a Titan/Enceladus observer, then perhaps another space agency would fund a Saturn atmospheric probe or a Titan lander to ride along.

As I said in the beginning, there's nothing special about my list.  However, I hope that it will get you to thinking about what priorities you would set.

Oh, and as the Survey studies additional mission concepts, it is likely that my list of priorities will change.  There's a number of exciting concepts under study.

Thursday, January 21, 2010

Russian and European Venus Ambitions

The VEXAG meeting last October (presentations were posted just a couple of weeks ago) had presentations on Russia's Venera-D mission and ESA's possible European Venus Explorer (EVE).   Both are in the definition stage, with the Russian mission apparently funded and a European contribution under consideration.

The Venera-D mission at its most expansive would consist of a capable science orbiter, a lander, and several balloons, and one or more drop sondes that would profile the atmosphere (and take descent images?).  This would be a very sophisticated mission.  A group of U.S. scientists considered a mission of similar scope, the Venus Climate Flagship (or Flagship Lite), and estimated its cost to be $1.7B.  Russia ended its presentation with a slide that read, "We Invite Everybody for Cooperation," suggesting that it would like to share the expenses.

 From the Venera-D presentation.  This scenario appears to be the most ambitious of several configurations of the mission under consideration.

ESA is considering contributing to the mission by providing a balloon platform that would study the upper atmosphere for seven days.  Apparently Japan is considering a second balloon platform that would explore the mid atmosphere.  (It's hard to tell how serious ESA's consideration is.  The presentation to be originally from mid 2008.  EVE was not selected as a candidate for the next round of mission selection.  However, I've read that interest in contributing to Venera-D is growing in Europe.)

From the European Venus Explorer Exploration

Editorial Thoughts: The Venera-D mission is ambitious and would significantly advance our knowledge of Venus.  It's not clear how important international participation would be to see it fully implemented.  If Europe decides not to participate, the mission likely would be less ambitious.  It's not clear how Russia might reduce the scope of the mission.  It might drop the balloon element, or alternatively it might implement its own balloon platform and reduce the capabilities of the orbiter, for example.

NASA's role in the proposed Russia-ESA-JAXA mission apparently would be minor.  However, NASA could potentially make significant complimentary studies.  If the SAGE New Frontiers lander were to be selected, then the NASA and Russian landers could be sent to complimentary sites.  (It appears from the Venera-D presentation that the landers would have similar capabilities.)  Both missions would launch in 2016.

In addition, the Venera-D orbiter apparently would not carry a mapping radar instrument (although a sub-surface sounding radar might be carried).  A NASA mission such as the proposed RAVEN Discovery mission could fill this hole and re-image Venus' surface.

 Venus is currently being explored by Europe's Venus Express mission, and Japan will soon launch an orbiter to study the climate.  Combine these missions with Venera-D and possibly a NASA mission or two, and our knowledge of Venus could see the kind of explosion that has come from the series of Mars missions over the last decade and a half.



European Venus Explorer:

Monday, January 18, 2010

SAGE New Frontiers Proposal (Enhanced)

Bruce Moomaw found the time to pull some more information out the the SAGE presentation (see link below), so I'm reposting this with his additions (in italics).

At the October VEXAG meeting (presentations were posted just a few days ago), Larry Esposito the principal investigator for the proposed SAGE lander presented some details of the mission.  In addition to the information in the slides reproduced below, there were several interesting tidbits:

  • The lander should last several hours on the surface
  • Surface composition would be measured at depths of 3-10 cm (depending on surface material) using a surface excavation sampling arm
  • Composition measurements would be made using a LIBS/Raman instrument steerable in one direction.  [This suggests that the choice of sampling area might be limited by both the reach of the sampling arm and the pointing capabilities of the LIBS/Raman instrument.]
  • Images of the surface would be made during descent in the near infrared.  Surface panoramas and microscopic images of the excavation site would be taken on the surface.
  • Descent through the atmosphere would last ~ 1 hour and the lander would survive ~3 hours on the surface

In addition to Esposito's presentation, the meeting also had a short presentation on LIBS/Raman instruments for Venus.  Check it out if you want to know more about this approach.

Bruce's additional comments follow:

I suspect that arm is going to extend straight down from the side of the craft to grind into the surface, which would explain how the Microscopic Camera could obtain "views of the excavation area" with maximum resolution.  Whether the tiltable LIBS/Raman instrument will swing its viewfield farther out from the spacecraft or just sweep it from one side to the other is unknown to me.

Page 10 of that presentation includes the listed acronyms of the onboard experiments, which I translate as follows:

FBC = FlyBy Camera (on the carrier, to image local cloud patterns and thus perhaps winds)

DPC/MC = Descent-Panoramic Camera/Microscopic Camera.  (The Descent Camera part of this package will take "NIR" -- that is, near-IR -- images of the suface during descent; if taken through several different filters, it could also provide some mineralogical data.)

ASI = Atmospheric Structure Instrument (temperature, pressure and wind sensors and accelerometers to measure entry deceleration and thus upper-air density)

DWE USO = Doppler Wind Experiment/Ultra-Stable Oscillator (the latter to allow precise tracking of the craft during its descent for the Doppler wind data)

NMS = Neutral Mass Spectrometer (atmospheric analysis)

TLS = Tunable Laser Spectrometer (to analyze important trace isotopes in the atmospheric gases -- especially, I imagine, carbon and oxygen)

NAGRS = Neutron-Activated Gamma Ray Spectrometer.  (This instrument would both measure natural gamma rays from uranium, thorium and potassium in the surface, and -- when the vacuum-tube neutron source is on -- it would measure a very wide variety of other elements, including trace elements.  It would presumably be located inside the lander's body and might analyze as much as a cubic meter of material underneath the lander.  Note also from the little bar chart of instrument operating altitudes on page 12 that it would start its natural gamma-ray measurements as high as 60 km above the surface.)

LIBS/Raman = Laser-Induced Breakdown Spectrometer and Raman spectrometer.  (This instrument, as noted by Van, would use brief bursts from one color laser to strike sparks of glowing plasma off the surface material and take visual spectra of them for detailed major and minor element analysis, and another color laser to scatter traces of "Raman scattered" light off the surface and analyze their spectrum to obtain really detailed and comprehensive data on the mineralogy of the surface.  A LIBS spectrometer is carried on the Mars Science Laboratory, and a Raman spectrometer on ExoMars -- the latter in part because Raman is also good at detecting trace organics, although not nearly as good as mass spectrometric analysis.)

Note that the "excavation sampling arm" (which has "calibration targets" on it, doubtless for the LIBS/Raman instrument) would grind 3-10 cm into the surface depending on surface hardness.  I don't know how they'll decide when to stop grinding -- probably a combination of grinding time and penetration depth -- but, given that Venus' surface is likely very intensely chemically weathered by that superhot and high-pressure CO2 atmosphere and its trace gases, trying to expose and analyze an unweathered (or at least less weathered) surface is very important.

The science payload is significantly different from the one on SAGE the first time it was proposed.  In particular, that first time it carried a combined X-ray diffractometer and X-ray fluorescence spectrometer -- in fact, exactly the same "CheMin" instrument as on the MSL -- for its element and mineralogy analysis, which required a big heavy setup of sampling drill and airlock to take a Venus sample actually inside the hull.  The new combination of NAGRS-LIBS-Raman should get much the same data with a much lighterweight and less vulnerable package of equipment.



SAGE Proposal:

LIBS/Raman instruments for Venus:

Thursday, January 14, 2010

Bad News: Plutonium Supply and Launch Vehicle Costs

The Decadal Survey's Steering Committee met in late November to consider a number of topics that affect the entire planetary science community.  For two key areas, the news is bad.

The first area relates to Russia's decision not to continue sales of plutonium 238 to the United States to support the latter's planetary exploration program.  In addition, the U.S. Congress decided not to fund a restart of P-238 development in the FY10 budget.  (It's not clear to me whether this latter decision was due to uncertain NASA needs -- much of the planned need was for human lunar exploration that seems in doubt -- or whether the hit of the additional cost should be borne by NASA or the Department of Energy.)  As the chart below shows, the combination of these actions -- unless reversed -- effectively ends NASA's use of plutonium power supplies sometime in the near future.  Exactly when depends on how NASA decides to use any remaining plutonium.  The new ASRG technology could enable several small to medium several missions or the Jupiter Europa mission.  However, this technology is unproven in flight and has a 14 year lifetime, a key limitation for missions to the outer planets.  At this point, NASA is not willing to implement the $3.2B Jupiter Europa orbiter mission using unproven ASRG technology. (Editorial thought: If this continues and Russia does not resume sales, then NASA may be in a position of approving several small missions that would use ASRGs and use up the remaining supply.)

The second piece of bad news comes from launch vehicle costs.  Here, the planetary program appears to be hit from two directions.  First, the medium class (read low cost for planetary mission) Delta II launcher is being phased out without an apparent successor.  This means that NASA must launch even small planetary missions on expensive heavy class launchers.  Second, the U.S. launch business has essentially a single customer -- the U.S. government -- since commercial customers have almost entirely moved to foreign launchers.  This limits the ability to amortize costs over many users.  The $450M MAVEN Mars orbiter will have an additional cost of $212M for the launch vehicle.  To give an idea of how quickly costs are increasing, just delaying the MAVEN launch from 2011 to 2013 resulted in an increase in launch vehicle costs of $57M.  One partial solution would be to use foreign launchers, but the U.S. Congress seems reluctant to ship hundreds of millions of dollars to foreign suppliers.  (And moving planetary missions to foreign launchers would just increase the costs of other U.S. government launchers, many of which are military and would not be moved overseas.)

Resources: Status of NASA's Solar System Exploration Program, James Green, NASA Headquarters

Tuesday, January 12, 2010

Osiris-Rex New Frontiers Proposal

The Osiris-Rex team was kind enough to send me a public version of a presentation describing the mission.  Because this is a public version, most mission details are not included.  Discovery and New Frontiers mission competitions are highly competitive, and most proposals are selected (if ever) after several submissions.  (All three New Frontiers proposals this time around have been finalists in previous mission selections.)  So teams keep the details close to the chest in case they have to submit again.  No point to enabling the competition in a future competition.

I'm at a busy point, so Bruce Moomaw was kind enough to go through the presentation and summarize key points:

(1)  The target asteroid is the same as for OSIRIS' previous incarnation as a Discovery-class mission: 1999 RQ36, a "B-class" carbonaceous asteroid made of primitive material from the Solar System's early history that has not undergone extensive heating and thus modification since it was incorporated into the original Main Belt asteroid of which RQ36 is a broken-away fragment.

(2)  1999 RQ36 has several important characteristics.  It's the darkest-colored asteroid yet measured (reflecting only 3% of the sunlight that hits it), which means that it must be made of particularly carbon-rich minerals exposed to minimal heating -- almost certainly including substantial amounts of fairly complex organic molecules.  It has been substantially examined and mapped both by the ground-based Arecibo radar observatory and the infrared Spitzer Space Telescope -- which have provided data both on its overall size, shape and rotation, and on its overall composition (the asteroid not only has "a spectral signature suggesting a carbon- and volatile-rich surface", but apparently has a good deal of loose regolith on its surface that can be easily sampled by a spacecraft). 

(3)  And 1999 RQ36 also happens to have "the highest probability of impacting the Earth of any known Potentially Hazardous Asteroid" -- specifically, a one-in-1800 chance of hitting Earth in 2170.  OSIRIS REx, during its year or so of orbiting the asteroid before finally dipping briefly to its surface for sampling, will allow Earth tracking stations to determine the asteroid's orbit with extreme precision -- thus further allowing forecasts of the probability of its striking Earth (as well as allowing the best measurements yet of the "Yarkovsky Effect" by which the absorption and reflection of sunlight by different parts of a rotating asteroid can actually produce a faint but significant thrust that modifies its orbit).

(4)  OSIRIS REx is scheduled to collect and return an absolute minimum of 60 grams (about two ounces) of material from the asteroid's surface -- but it has the ability, if conditions are favorable, to return as much as two kilograms of material (about 4 1/2 pounds).  It will not only map the global chemical, mineralogical and physical structure of the asteroid to put the returned sample in perspective, but will "document the texture, morphology, volatile chemistry, and spectral properties of the regolith at the sampling site in situ at scales down to the sub-millimeter" -- presumably using some instruments attached to the boom-mounted sampling device itself (which can flex like an arm to load the sample into the Earth return capsule mounted on the spacecraft's side).

(5)  The craft will use scanning lidar (laser radar) to steer itself to precise courses around the asteroid and down to appropriate spots on its surface, enabling it to acquire samples "with no time-critical events" -- that is, once it has descended to near the surface and matched the asteroid's rotation rate, it can collect its samples in a leisurely way according to what its navigational instruments tell it, instead of having to work against a tight time deadline.  It will also provide more practice to ground controllers in carrying out such precision movements around a small body such as an asteroid or comet nucleus.

(6)  OSIRIS REx is a cooperative effort by the Goddard Space Flight Center, the University of Arizona, and Lockheed Martin (which would build the craft) -- but it also includes one science instrument from Arizona State University (a thermal infrared spectrometer), and another unspecified one from the Canadian Space Agency.

Sunday, January 10, 2010

A Solar Powered Europa Orbiter?

The most interesting poster for me at the AGU conference in December was one from the Boeing company that presented a proposal for a solar powered Europa orbiter (Outer Planet Science Missions enabled by Solar Power P43A-1428).  With the recent decision to prioritize the plutonium-powered Jupiter Europa Orbiter, why would one consider a solar powered mission?  The first issue is cost -- JEO is a battleship and future budgets may only buy destroyers.  The second issue is the supply of plutonium 238.  NASA currently does not have sufficient supplies of P-238 to fly JEO, and depends on Russia selling P-238 to make up the shortfall.  Unfortunately, the Russians recently announced that they would not honor the existing plutonium contracts (to get more money?).  Even if a new agreement is reached, the delay in delivery may push JEO even further into the future.

This is not the first time solar powered Jovian orbiters have been studied.  NASA's Juno orbiter will be solar powered.  ESA considered a solar powered Europa orbiter in its Laplace study, while the proposed Jupiter Ganymede Orbiter would be solar powered.  I had been under the belief that the radiation levels at Europa would degrade solar arrays too quickly to be of use for a Europa orbiter.  (Juno and JGO avoid the high intensity radiation belts.)  The gentleman from Boeing told me that they didn't believe this would be a problem.  (I'm still not 100% convinced on this point and would like to see the results of a study that directly addresses this problem, but this is a hopeful indicator.)

The goal of the Boeing study was to do a conceptual design a New Frontiers class mission to orbit Europa to show that a solar powered spacecraft derived from commerical satellites could be the basis for a Europa oribiter.  This was not an in depth analysis, particularly I suspect of the ability to survive in the intense radiation found near Europa.

Still, the idea is intriguing, so I thought I'd do a thought experiment to see if a New Frontiers class mission might be possible.  The Boeing study suggested some key compromises that would have to be made.  Using solar panels would be one tactic.  Another would be to design for just three months of life in Europa orbit, instead of JEO's 9 months, reducing the costs of radiation hardened parts and shielding.  In addition, the craft would carry just 50 kg of instruments, although the poster doesn't specify whether this would be the unshielded or shielded weights.  JEO's instrument compliment would be 106 kg unshielded and 165 kg shielded.  So, the science capabilities would be drastically reduced under this proposal.

For discussion purposes, we'll assume that a solar powered craft could fly ~50 kg of unshielded instrument weight and the additional weight of shielding.  The JEO science team listed a core, not worth flying without, list of instruments for an Europa orbiter.  That list appears below, too which I added the next highest instrument priority, a narrow angle camera.  This last instrument would be useful for spot high resolution imaging of Europa from orbit, but would be crucial for studying the other Galilean satellites and Jupiter prior to Europa orbit insertion.

Figures are unshielded instrument masses in kilograms.

Based on this thought experiment, an unshielded payload mass in the range of 50 kg is in the right ballpark.  Note, however, that the proposed JGO radar is much less capable than the proposed JEO radar.

So, is a New Frontiers class Europa orbiter really feasible?.  We are talking about going from a $2.7B (FY '09 dollars as I recall) to a $650M mission.  From the Io Volcano Observer studies, it appears that $450M (not including launch vehicle) buys you a Jupiter orbiter-satellite flyby mission in a relatively benign radiation enviroment (thanks to the high inclination orbit of IVO that minimizes time spent in the high radiation belts near Io).  JGO is estimated at $800M euros.  ESA includes launch vehicle but not instrument costs.  Figure instruments would cost $100M or so (see What Instruments Cost).  NASA includes instrument costs in its New Frontiers budget but not launch costs.  Add ~$250M for a launch vehicle, and the New Frontiers budget is ~$900M versus JGO's $800M euro.  (I'm ignoring currency exchange rates here, which are set by currency traders based on interest rates and supply and demand.  Based on my last trip to Europe, 1 euro purchased less in consumer goods than did $1 spent in the United States.  I neglected to buy any planetary spacecraft, so I'm not sure of the relative purchasing power for aerospace components)  However, JGO doesn't included radiation hardening that a Europa orbiter would need, so add $100M?, $200M? to the JGO price.

Long story short, I think that a solar powered (or ASRG powered) Jovian orbiter with multiple flybys of the three icy moons probably would fit in a New Frontiers budget.  A Europa orbiter seems a stretch, and probably a full mission cost with radiation hardening, instruments, and a launch vehicle would be in the neighborhood of $1 - 1.25B.  Still, this would be much cheaper than the JEO mission, at a cost of much less data returned.  If exploration budgets or plutonium supplies prove to be tight, this would seem a reasonable tradeoff to me.

One nice extension of this idea is that a solar powered Europa orbiter design could also be used as the basis for a Saturn orbiter, Titan and Enceladus flyby (and maybe even orbiter of one of those moons) spacecraft.  In fact, the real goal of the Boeing poster was to discuss solar power for both Jupiter and Saturn missions.  With current solar power technology, a Saturn mission might be on the edge.  However, the poster discussed new technologies using concentrators that would enable 1kW of power at Saturn.

Thursday, January 7, 2010

Venus Flagship Lite

VEXAG (Venus Exploration Analysis Group) was established by NASA "to identify scientific priorities and strategy for exploration of Venus."  Over the last two years, it has developed a robust, full fledged Venus flagship mission consisting of a highly capable orbiter, two balloon platforms, and two landers that would survive on the surface for a day and bring surface sample into the lander for analysis.

The mission also has been estimated to cost over $3B, putting it outside what NASA likely could afford in the coming decade given plans for an aggressive Mars program and the Jupiter Europa Orbiter.  A group of scientists has proposed a lite version of the mission call the Venus Climate Flagship.  Preliminary estimates put the mission at perhaps $1.7B.

To achieve those costs, the orbiter would have a less capable radar imager and the mission would fly a single balloon and lander.  The biggest change would be that the lander would no longer bring samples into the craft but would instead remotely study the surface chemistry through gamma ray spectrometry and Laser Induced Breakdown Spectroscopy (LIBS) with a Raman spectrometer.  With this technique, a laser would vaporize surface material and spectrometers would analyze the resulting gases.  (The Mars Science Laboratory will carry an LIBS instrument.  Lab experiments have shown that the technique should work on the surface of Venus.  Combining an LIBS instrument with a Raman spectrometer would enhance the analysis capabilities.) [The proposed lander sounds very much like the SAGE lander that is a candidate for the next New Frontiers mission.]

Editorial Thoughts: This proposal seems to retain the critical elements necessary to move Venus science forward.  I suspect that the $1.7B price tag would still be hard to fit in NASA's budget for the coming decade.  However, the capabilities proposed could be implemented by a consortium of space agencies.  Both ESA and Russia are pursuing joint programs, and the latter has announced plans for the Venera-D lander for mid decade.  I would like to see NASA dedicate $750M to a $1B to Venus exploration, with the specific mission chosen to maximize synergy with contributions by other agencies.


Venus Flagship Lite Presentation

Venus Flagship Proposal

LIBS/Raman Spectroscopy for Venus


Tuesday, January 5, 2010

Two Articles on Instruments

Bruce Moomaw pointed me toward two articles that discuss instruments for future missions.  The first discusses an enhancement to the Mars Science Laboratory, Curiosity, that will enable it to better analyze complex organic molecules (if any are found): Goddard Scientist's Breakthrough Given Ticket to Mars.  The second discusses a thermal emission spectrometer for the proposed New Frontiers Osiris-Rex mission: ASU instrument plays key role in NASA mission.

Plans for 2016 ESA-NASA Mars Mission Firm

Two documents have begun to flesh out the plans for the 2016 ESA-NASA Mars mission.  This mission will send an ESA orbiter with ESA and NASA instruments to Mars in 2016.  An ESA lander will prove technologies for delivering a mid-sized payload to Mars.

From 2016 to 2018, the orbiter will focus on it's science mission to measure trace gases in the atmosphere, study Martian climatology, and image the surface at high resolution.  From 2018, the orbiter's prime mission will be to relay data from ESA and NASA's rovers on the surface, although science activities will presumably continue.

ESA's Entry, Descent and Landing Demonstrator Module (EDM) will be a technology demonstration.  "The EDM is expected to survive on the surface of Mars for a short time (about 8 sols) by using the excess energy capacity of its batteries. The science possibilities of the EDM are limited by the absence of long term power and the fixed amount of space and resources that can be accommodated within the module; however a set of scientific sensors will be included to perform limited surface science."

A Joint Instrument Definition Team has recommended a reference suite of instruments (final instruments will be selected through a competitive announcement of opportunity).  The straw man list has:

"Solar occultation measurements: This technique provides the best means of surveying atmospheric composition with high sensitivity as it measures absorption of a bright source (sunlight) passing through a large atmospheric path (along the tangent occultation path) with very high spectral resolution to reduce effects of line mixing, etc. A Solar Occultation Fourier Transform IR Spectrometer (SFTIR) can cover a wide spectral interval enabling detection of a broad suite of trace gases. "

"Thermal emission measurements: Sub-millimeter (Sub-mm) and thermal infrared (TIR) spectrometers can be used to look at atmospheric thermal emission when viewing nadir or at the atmospheric limb. These characterize the atmospheric state by providing vertical profiles of temperature and profiles or column abundances of key source gases such as water vapor."

 "Visual monitoring of atmospheric phenomena: Wide-angle cameras (WAC) can provide daily monitoring of the global atmosphere and its regional atmospheric phenomena: clouds, storm systems, aerosol layers, dust storms and boundary layer phenomena such as dust devils and wind streaks."

"High-resolution surface imaging/mapping: Very high spatial resolution imaging or mapping instruments (e.g., cameras and multi-beam active lasers) can provide geological context and location of small-area sources should they exist (e.g., a volcanic vent, rift or crater)."


The ESA-NASA ExoMars Programme Orbiter and EDL Demonstrator, 2016

Final Report of the 2016 Mars Orbiter Bus Joint Instrument Definition Team

Monday, January 4, 2010

Decadal Survey Cautionary Tales

This post is not about the planetary Decadal Survey that is currently underway, but the recently completed (2007) Earth sciences Decadal Survey.  Space News has an article, NASA Budget for Earth Science Lags Behind Rising Expectations, about the issues NASA are facing, but this quote summaries the situation:

"The [Earth sciences] decadal survey, however, which lists 15 high-priority Earth science missions, also calls for adding $500 million or more annually to NASA’s $1.4 billion Earth science budget. Freilich [director of NASA’s Earth Science Division] and others have estimated previously that doing all 15 missions by 2020 would require spending as much as $4 billion during peak development years. Under the five-year plan Obama sent Congress last February, NASA’s Earth science budget would grow to only $1.65 billion by 2014. 'Frankly, we’ve got to come up with an executable program for the future,” Freilich said. “The decadal survey objectives were great, but they require a much larger budget. There is no point hitting our heads against a wall and trying to do more than we can do well.' "

The Earth sciences Decadal Survey proposed an excellent set of missions, but the priorities apparently assumed a budget that wasn't possible.  (Although there are reports that NASA's budget will receive $1B more per year to be split between manned exploration and Earth sciences.)

Editorial Thoughts: Fixed or even shrinking budgets are a real risk to any 10 year plan.  I hope that the planetary Decadal Survey recommendations will be structured to remain meaningful even if budgets shrink or missions in development go over budget.


SpaceNews Article:

Earth Sciences Decadal Survey:

Saturday, January 2, 2010

Posts From Last Two Weeks

I'd expected the holidays to be a quiet time for future planetary mission news.  Not so!

For those of you who sensibly ignored news to concentrate on the holidays, here's a list of the major blog entries:

New Frontiers Candidates Selected 
Decadal Survey Missions in Study - The Official List

Russian Exploration Plans/Ideas

AGU: The Science

More on MoonRise New Frontiers Proposal

Bruce Moomaw contacted Brad Jolliff, the PI, and learned a bit more about this proposal:

"We are planning a single lander, but this should not be considered a 'descope.'  The MoonRise proposal for this New Frontiers opportunity was a new proposal.  As such, we think (and have made the case) that we can accomplish the science objectives of the mission with a single lander and an appropriately selected landing site within the South Pole-Aitken Basin. With all of the remote-sensing information collected by recent and current orbital assets (SMART-1, Kaguya, Chang'e-1, Chandrayaan-1, and LRO), we can optimize our landing site both for science and landing-site safety considerations."

MoonRise will return 1 kg of samples.  They will also be including a relay comsat, which is not exactly a surprise.  They hope to put up a website on "Moonrise" later this month.

Friday, January 1, 2010

More Tidbits on New Frontiers Proposals

Again, thanks to Bruce Moomaw for hunting these down.

The first is a presentation that discusses the SAGE Venus lander tests and provides this picture of a possible design:

Bruce contacted SAGE's PI, Larry Esposito, and writes, "Larry Esposito, however, was willing to tell me that SAGE does indeed include a combined LIBS/Raman spectrometer, although he was unwilling to tell me yet whether the sampling arm can be swiveled to a specific sampling site."

Next are tidbits on the Osiris-Rex near-Earth asteroid sample return mission.  This is from an article describing the 2006 Discovery mission proposal from which the current proposal evolved.  The target asteroid was a tiny 580 m asteroid, 1999 RQ36:

"Because of that low gravity... the spacecraft will be able to circle the asteroid at an altitude of just 100 meters, photographing it with its five cameras -- each operating in a different part of the spectrum -- analyzing it, measuring its gravity field and making a gentle descent... the sample arm, with a trapdoor on the bottom intended to scoop up asteroid dirt, will have up to three shots at getting material to bring back."