Thursday, January 31, 2013

Sequestration and Planetary Exploration

I’d hoped that I’d never need to write this post.  The latest news in the United States is that a poison pill known as the Sequester is looking increasingly likely.  If it happens, it will be a body blow to NASA’s planetary science program.

First, a bit of background.  The two political parties in the US have been fighting over how to reduce the federal government’s budget deficits, but have been unable to reach a compromise.  To enforce discipline, they passed a law that would require an 8.2% cut to all discretionary federal spending including the NASA budget.  The cuts were considered so arbitrary and onerous that it was thought that the two parties would work to find a compromise.  Numerous news articles are reporting that Congressional leaders are coming to accept that the sequester will happen; arbitrary and onerous apparently seems more acceptable than compromise.

In this post, I’ll look at what the sequester, due to take effect March 1, might mean to NASA’s future planetary exploration.  I want to emphasize that NASA’s managers have properly been all but silent on how they plan to implement the cuts if they come (with one exception noted below).  This post will illustrate the magnitude of these potential cuts.

I don’t know the details of the sequester law.  For example, does every program within every agency have to be cut by the same amount?  It appears not, because NASA’s managers have publicly stated that the James Webb Space Telescope’s budget will be spare the impact of the sequester.  (Rightly so.  Delaying launch would mean substantial increases in the costs to complete the telescope.)  If NASA protects some programs, then the cuts that would have been applied to them will have to be borne by increased cuts to other programs.

Already budgeted cuts to NASA's planetary mission budgets.  R&A is Research and Analysis, which supports the scientific research community.  From this presentation.

After two years of small budget increases (inflation plus a little), the President’s proposed budget for Fiscal Year 2013 imposed a 20.6% cut to the planetary program.  (Congress hasn’t passed NASA’s FY13 budget, and so the program is operating based on the President’s proposal.)  The sequester cuts would be in addition to the already planned cuts.  Those planned cuts forced NASA to drop out of a joint Mars program with the Europeans, ended any chance for now of a mission to Europa, and reduced the planned rate of Discovery (~$500M) missions from several a decade to one.

One challenge to looking at how NASA might further cut the planetary program if the sequester happens is that we don’t know how much of its overall budget it will protect.  NASA’s top three priorities are operation of the space station, developing its next human spaceflight system, and completing the James Webb Space Telescope.  Given this, I guessing that the minimum cut for planetary science might be the 8.2% and the maximum might be double that (i.e., NASA protects half of its budgets for programs it considers higher priority).  In dollar terms, here’s how that would break out:

FY13 budget

NASA’s planetary program basically does just four things: develops technologies to enable the next generation of missions, develops missions, operates missions, and supports research to study the data returned from missions.  NASA divides these activities between several budget lines (see the first chart), but I went through the FY13 budget proposal and combined funding across budget lines into these four categories (plus a small, everything else category).  I’ve sure I missed some items and perhaps combined some items that shouldn’t have been.  In broad outline, however, I think the budget figures below should be about right plus or minus some.

So, let’s start with the big picture (click on any image for a larger version):

Approximate FY13 budget by type of activity.

One obvious option would be to simply spread the cuts across all the planetary programs (the ‘spreading the peanut butter’ approach).  This, however, likely would mean that some missions in development would slip (is there, for example, a good backup asteroid to the rare type planned to be sampled by the OSIRIS-REx mission if its launch were slipped?).  Missions budgeted beyond their initial lifetime (and budgets) operate on fairly lean extended mission budgets and further cuts can mean operating with very lean staffs meaning that mistakes are more likely and data collected doesn’t get properly analyzed.

The managers of the Cassini mission detailed the impact of further cuts on that mission in a presentation last spring.  Cuts to other operating missions likely would have comparable effects.  From this presentation.

If the sequester were the first cut to the planetary science budget, some version of the peanut butter approach might work.  However, the sequester on top of the FY13 cuts could add up to as much as 30% or more in cuts in a single year.  The post-sequester budget also becomes the new baseline budget for developing future budgets.  NASA would have to live with this cut in following years.

At some point, it’s better to cut entire missions so that the remaining missions can be done well.  So, what might be cut?

 FY13 proposed budget for missions development

FY13 proposed budget for mission operations

There’s not a mission in the list that I would want to see cut.  To save tens of millions of dollars in costs, some big mission would have to be cut (cutting the Messenger mission, for example, just doesn’t save much).  

I will leave it to each of you to pick which cuts you find least terrible.  Should the Discovery program, and it’s just selected next mission, the Mars Insight geophysical station, be ended?  Should the Cassini mission be terminated?  Should NASA cut funding to a substantial portion of its researchers (and this means ending careers; think of this as laying off highly trained people who are the reason these missions fly)?
If the sequester happens, have empathy for the management of NASA’s planetary science program who will have had to make these choices.  In the meantime, support efforts to get Congress to increase future planetary budgets (see here and here,).

Sunday, January 27, 2013

Hayabusa 2

Hayabusa 2 approaching asteroid 999 JU3.  All illustrations from this presentation.

The last twenty years have been good for asteroid exploration – eight asteroid flybys (nine if you count tiny Dactyl which is a moon of the asteroid Ida) and three extended rendezvous.  (For a visual tour of the asteroids visited, I recommend Emily Lakdawalla’sposter.)  One of those rendezvous by the Japanese Haybusa (Peregrine Falcon in Japanese) returned the first ever samples from an asteroid by a spacecraft.  (Many samples have come as meteorites.)   The next fifteen years promises to be even better with at least three additional rendezvous (Ceres - Dawn, 199 RQ 36 – OSIRIS-REx, and 1999 JU3 – Hayabusa 2) with samples to be returned from the latter two.  Two additional sample return missions have been proposed for the 2020s – Hayabusa 3 and the European Space Agency’s Marco Polo-R.

The number of sample missions will allow scientists to return samples from a breadth of asteroid types.  Astronomers have recognized that asteroids have compositions that correlate with the distance of main belt asteroids from the sun.  Closer in, stony S-type asteroids (silicate-rich) predominate, while further out more volatile-rich C-type (carbon-rich) asteroids predominate.  At the outer edges of the asteroid belt and extending into the Trojan asteroids that share Jupiter’s orbit are types such as B and D believed to be especially rich in volatiles.  Researchers theorize that the heat of the early sun boiled off volatiles from what would become the stony asteroid types, while cooler temperatures further out allowed asteroids to form with their volatiles.  (See this Wikipedia page for a summary of asteroid types.  To help ensure confusion for the novice, the main asteroid types have subtypes that are also named with letters (B’s area subtype of C’s, for example), and there doesn’t seem to any order, at least for the uninitiated.)

Our collection of meteorites, which are free asteroid samples, are approximately 75% C type, 15% S type, and most of the remaining are M type (metal-rich) believed to come from cores of what originally were large asteroids.  Unfortunately, the most primitive, volatile-rich meteorites are also the most fragile and hence the rarest in our collections.  They tend to disintegrate in the atmosphere, and if they do reach the Earth’s surface, rain and weather rapidly decompose their fragile volatiles.  It is news when scientists can get to these meteorites within days of their fall (see this Space News article or one of my earlier blog posts).   

Researchers would prefer to get asteroid samples directly from the asteroids.  This would not only preserve all materials in the asteroids, it would also allow planetary scientists to place the samples in the context of the overall geology of the parent asteroid.  Fortunately, collisions in the asteroid belt have delivered fragments of different composition asteroids to orbits near Earth where spacecraft can easily sample them.  Hayabusa sampled an S-type asteroid, Hayabusa-2 will sample a C-type, and OSIRIS-Rex will sample a B-type asteroid.  If approved, the Marco Polo-R mission would sample a second C-type and Haybusa-3 would sample a D-type asteroid. (Marco Polo-R’s target asteroid would be a binary asteroid, so it may get samples from two distinct original asteroids.) From the approved missions, we will have samples that should span the composition range of asteroids from the inner asteroid belt to near its outer edge; Hayabusa-3 would extend that range potentially out to the orbit of Jupiter.

In two previous posts, I discussed NASA’s OSIRIS-REx asteroid sample mission that is currently in development for a 2016 launch and a 2023 return of its samples (see Asteroid Sample Return Mission Selected and OSIRIS-REx: More than a Sample Return Mission).  Today, I’ll cover the Hayabusa 2 mission.

Hayabusa 2 mission timeline

In its broad scope, the Hayabusa 2 mission shows that it is an evolution of the original Hayabusa mission.  Like its predecessor, the Hayabusa 2 spacecraft will use ion engines to propel itself to and from its asteroid target, 1999 JU3.  It will spend 18 months at the asteroid, drop landers to hop across the surface, and the main spacecraft will remotely study the asteroid.  Then the spacecraft will descend to hover briefly just above the surface while a sample is collected by an arm.  After that, the spacecraft will return to Earth where the sample will be delivered by a small re-entry capsule.

But – to paraphrase an American car commercial – this won’t be your father’s Hayabusa.  The main spacecraft will have a number of improvements including more powerful ion engines, higher communications bandwidth, and four reaction wheels.  (The failure of two of the three reaction wheels on Hayabusa almost ended that mission.) Where the primary goal of the Hayabusa mission was to demonstrate and gain experience with a number of technologies, the primary goal for Hayabusa 2 will be science with a secondary goal of demonstrating additional new technologies.

The mission will also carry two entirely new packages that will significantly enhance its capabilities compared to the original Hayabusa mission.  The first will be a hopping lander supplied by the German space agency, DLR, named the Mobile Asteroid Surface Scout asteroid lander, or Mascot.  This lander will operate on the surface for 16 hours until its batteries run out during which it will hop at least twice to explore new locations.  Mascot will carry four instruments: a wide angle camera, radiometer, magnetometer and infrared microscope.  In addition, the two Japanese Minerva2 lander/hoppers will have solar panels to enable a longer surface life, but will carry only a camera and thermometers for studying the surface.  (The original Hayabusa mission carried a single Minerva lander that failed to reach the surface.)

The most novel addition to the mission, however, will be an impactor designed to create a small crater, exposing fresh material for the spacecraft to sample.  (Material directly on the surface will have been exposed to the sun’s radiation and the environment of space, which may alter its composition.)  The mother spacecraft will release a daughter spacecraft with the impactor.  Once the main craft darts behind the asteroid’s body for protection, an explosive device will hurl a projectile at high speed into the asteroid’s surface.  Fortunately, Hayabusa2 will deploy a second small spacecraft with a camera to witness the explosion and the impact.  (Like many men, there’s still a bit of boy in me that likes to watch things go bang, and I look forward to those images!)

For those of you who followed the original Hayabusa mission (there’s a good summary here), it was a mission full of drama and near miraculous recoveries and an ultimately successful sample return.  The mission demonstrated the technologies needed for more ambitious missions to explore and sample the diversity of asteroids that retain records of the earliest stages of the solar system’s birth.


German DLR space agency presentation with slides on the Mascot lander

Space News article on the Hayabusa 2 mission

Wednesday, January 16, 2013

Future New Frontiers and Discovery Missions

Before I write my post on an upcoming planetary mission (promised in my last post), I wanted to complete my reporting on the Outer Planet Analysis Group (OPAG) meeting last week and the portion of the Small Bodies Analysis Group (SBAG) that I listened to Monday.  These analysis groups (with their Mars and Venus counterparts) review NASA's planetary science program and provide feedback.

I picked up one key point in Monday’s meeting while listening to James Green, the head of NASA’s planetary science program.  In reviewing his program’s projected budget, his team believes that it can start two additional New Frontiers missions ($1B each) and a single Discovery mission ($500M) in the next ten years. The balance between the two programs is NASA's choice; for approximately the same funding it could select one New Frontiers and three Discovery instead.

The Discovery program has been incredibly successful -- just look at the currently operating MESSENGER mission at Mercury and the Dawn spacecraft that just left Vesta headed for Ceres.  However, many of the easy (read inexpensive) exciting missions have been done.  And it is hard to fit an outer planets mission, and I suspect many potential comet and asteroid rendezvous missions, in its budget.

Alfred McEwen at the University of Arizona proposed an Io Discovery mission for the recently completed selection competition.  He is also principle investigator for the HiRISE camera on the Mars Reconnaissance Orbiter.  McEwen provided a proposal to the OPAG meeting to help make Discovery missions more competitive in future Discovery selections.  In the justification, he said that the Discovery program as currently structured doesn’t provide sufficient funding for outer planet missions with adequate budgetary reserves.  (His proposal was to help mitigate this problem by adjusting the Discovery cost cap by the length of time required to conduct the selected mission.)

If that remains true, the Discovery program may remain an inner solar system (say from Venus to the asteroid belt) program.  However, in the last Discovery competition many Venus missions were proposed but none made it as far as the finalists list, suggesting that the next step for Venus may require a larger New Frontiers class mission.  NASA  is looking to fly approximately five new missions to Mars starting in 2017 (see my previous post) outside of the Discovery program.    So the single new Discovery mission may target another inner solar system destination.  

Two New Frontiers missions gives an outer solar system mission, a comet sample return, a Trojan asteroid mission, and a Venus lander mission better chances of being selected.  I don't know if NASA used this reasoning in laying out it's roadmap, but it's a balance between New Frontiers and Discovery that I agree with.

A couple of other points from the OPAG meeting:

I have often wondered why the Europa multi-flyby proposal (nicknamed the Europa Clipper) has been estimated to cost $2B when ESA can fly a Ganymede orbiter with Callisto and two Europa flybys for ~$1.2B and NASA estimates a multi-flyby mission for Io would cost ~$1B.  The answer may be as simple as, “it’s the radiation”.  In a recap of the multi-flyby Europa concept, the presenter mentioned that the Jupiter Juno New Frontiers mission (perhaps $1B in 2015 dollars) will receive around 1/10th (worst case 1/3rd) the radiation of the Europa mission.  Those thirty or so Europa flybys the Clipper would do would expose the spacecraft to an incredible radiation load, and that may drive the cost difference compared to the other missions.

The availability of plutonium 238 for power supplies for future planetary missions has been a concern for the last several years.  An update on the situation at the OPAG meeting stated that NASA has on hand two additional Curiosity radioisotope systems (MMRTGs), one of which will be used for the 2020 rover mission.  The second set could be used by the Europa mission or potentially another mission.  In addition, NASA continues to develop the next generation of power supplies (ASRGs), and plans to have one available for a New Frontiers or Discovery mission.  However, the Pu-238 supply is becoming old and out of spec.  It’s essential that production of new Pu-238 begin to enable missions in the next decade.

A closing note:  Curiosity has hit the jackpot, already.  Water flowed across its landing site, possibly multiple times.  If you haven’t read Emily Lakdawalla’s post on the latest Curiosity news, I encourage you to do so.  Remember, this is just the start of what promises to be an incredible stroll through Martian history.  And we can look forward to equally exciting locations for ESA’s 2018 ExoMars rover and NASA’s 2020 rover to explore.

Saturday, January 12, 2013

New Frontiers as the New Big Missions?

My apologies for having posted so infrequently lately.  I had a deadline for submitting a paper to a journal, and that consumed all my time and energy.  The paper is in, and I plan to post more regularly.

I’ll start my new series of posts with a report of the key issues raised at this week’s OPAG meeting.  Next post will describe an upcoming planetary mission.


While predicting the future is always a risky business, I’ve been seeing clues that NASA and the planetary science community are moving towards a new way of constructing mission portfolios.  The cause of the move is familiar to anyone who follows this blog or space news in general: NASA’s budget for planetary exploration has shrunk each year for the last several years.  Good news in future years may be flat budgets, and further cuts are quite possible.  The planetary science program is caught between political forces that want to reduce the overall government budget and NASA’s own priorities that put this program fairly far down the list.  (Higher up according to news reports: Operating the International Space Station, developing the next human spaceflight system, completing the James Webb Space Telescope (JWST), and the Earth science program.)

For the last two days, I’ve listened to portions of the Outer Planet Analysis Group’s (OPAG) meeting.   This is one of several groups of scientists that meet once to twice a year to review NASA’s plans for their corner of the solar system.  OPAG’s members fear that they are witnessing and end of an era.  After the Juno Jupiter mission and the Cassini Saturn missions end within months of each other in 2017, NASA has no plans for future missions to the outer solar system.  While the concepts for a mission to Europa keep getting better, there’s no way to fit these $2 billion missions into any foreseeable budget. 

The meeting participants had long discussions about how hard it is to fit an outer planet mission into the Discovery program.  Reaching Jupiter typically takes five years and Saturn seven years, at a cost of around $5-7 million per year in mission operations.  Subtract that from a mission budget of $425-500M, and it’s hard to have a science return that competes with missions that take months or a year or two to reach their targets.  (Rendezvous missions to comets and non-near Earth asteroids face a similar problem.)  

Hopes for a new outer planets mission that would fly in the next decade rest on the results of the single Discovery and single New Frontiers competitions likely to occur later this decade.  The competition from other destinations will be stiff.  New Frontiers competitions are limited to a preselected list of missions, and the only outer planets candidate will be a Saturn atmospheric probe mission.  (The rest of the list includes a comet sample return, a lunar sample return, a mission to the Trojan asteroids, and a Venus lander.  For the competition after that, an Io and a lunar geophysical mission are planned to be added.)

During the OPAG meeting, there was considerable talk about how to expand the list of outer planet candidate missions.  The approved list came from the Decadal Survey performed earlier this decade.  Here, the politics of the Survey put the outer planet community at a disadvantage.  They only had so many missions they could propose for consideration, and two of those were for very large (>$4B) Flagship missions to Jupiter-Europa and Saturn-Titan and a third was for a more modest ($2B) Uranus orbiter.  These missions were considered when it appeared that NASA’s future budgets would support at least two Flagship missions, in additions to a new Discovery mission every two years and a New Frontiers mission every five years.  Now it looks like Discovery missions will come every five years and New Frontiers missions every seven years.

Several times, the talk at the OPAG meeting returned to how the community would have looked harder at New Frontiers-class missions to the Jupiter system, Titan, and Uranus if they could have foreseen the new budget realities.

In the new budget reality, Flagship missions seem to be out; Discovery missions put large parts of the solar system at a competitive disadvantage; and many of the outer planet community’s highest priority targets aren’t on the New Frontiers list.  A NASA official at the OPAG meeting referred to the recently announced $1.5B 2020 Mars rover as New Frontiers class.  Historically, anything over $1B has been considered a Flagship mission, but the intent seems clear.  While the budget cap may be flexible, New Frontiers-class missions are the new big mission class.

In the 2020’s, the situation may not be much better.  NASA recently put out a request to industry for information on future launch upper stages for planetary missions for “the potential for a Mars mission every two years along with an additional science mission every three to five years beginning in the 2017 time frame,” (Note: I’d prefer a 50-50 split between missions to Mars and the rest of the solar system.)

The budget squeeze on Flagship missions isn’t unique to NASA’s planetary science community.  The recently completed heliophysics Decadal Survey called for a focus on more frequent smaller missions en lieu of future large missions.  The astronomy and astrophysics community has planned on a Flagship mission to study dark matter and search for exoplanets to follow JWST.  NASA now is wondering if that is politically possible and has commissioned a study to examine a new Probe-class program of ~$1B missions for this community.

If something around $1B is the new cap for missions, then NASA’s mission classes will come to resemble those of the European Space Agency (ESA).  ESA structures its science program into Large- (~$1.2 B) and Medium-class (~$625 M) missions and into a separate Mars program where each individual mission falls into similar price ranges.  (There’s also a Small-class program that is ~$50M.)  ESA and NASA account for mission costs differently, so the Large- and Medium-class missions are roughly equivalent to planned budgets for the New Frontiers and Discovery programs respectively.   NASA’s science budget is expected to be larger than ESA’s, so the United States should fly more missions, but they would be of a similar scope to those of Europe.

If this change comes to pass, then several good Flagship mission concepts will not fly, at least in the coming decade or two.  But there are a plethora of good ideas for missions in the lower price ranges.  However, the planetary community in its Decadal Survey still counted on Flagship missions, so the list of missions that were considered for the New Frontiers may not represent the best pool to pick from in the coming decade.  (This varies by community.  For comet, asteroids, and the moon, no Flagship missions were considered.  For the outer planets, Mars, and Venus, Flagship missions were assumed.)

The OPAG members spent considerable time talking about whether to ask NASA to add outer planet candidates to the list for the next New Frontiers competition expected later this decade.  The consensus at the end of the meeting seemed to be that this was likely to be politically awkward – should the list be re-opened for all other communities, too?   

Congress requires a mid-term assessment of decadal surveys, which would come around 2016 for the planetary community.  That seems to me a good time to review and possibly expand the list of New Frontiers missions.  That likely would be too late for the next New Frontiers selection but would be well before the first selection in the 2020s.

In the meantime, the OPAG members were discussing whether to ask NASA to raise the cost cap for outer planet Discovery proposals by ~$5M for each year that would be spent in transit to the destination.  In the past, NASA has offered to raise budget caps for proposals using selected new technologies.  If the flight-time adjustment were extended to all proposals so that proposals for comets and asteroids could also benefit, this seems fair to me.  Without a change similar to this, hope for a continued NASA presence in the outer solar system after 2017 rests on the results of the fiercely competitive New Frontiers competitions planned to occur every seven years or so.