Thursday, May 31, 2012

Let's Mine Asteroids

Martin Elvis has a blog post at (publishers of the journal Nature) arguing that mining near Earth asteroids will enable good science as well as be good economics.  I think his arguments are likely sound.  However, I suspect that the upfront investment is probably so substantial that the first profit is many decades away, but the scientific bonanza can come much earlier.  Take a read and form your own opinion: Let's mine asteroids — for science and profit

Friday, May 25, 2012

Planning the Next Steps to Mars

At the moment, I’m on vacation.  This means that I work only a couple of hours a day ( :> ), and I can’t listen in on major meetings that involve the future of planetary exploration.  The latter is a shame (well actually not, I’m having a good time) because a major review meeting is occurring this week to review NASA’s plans for astrobiology and planetary exploration (which frequently overlap).  The meeting is the first of the National Research Council’s Committee on Astrobiology and Planetary Science (CAPS) (for those of you who track review and advisory committees, CAPS merges two previous committees including the COMPLEX committee).  

Before I go into the news from the CAPS meeting, let me quickly update the status on ExoMars.  The European Space Agency (ESA) held a meeting to review its commitment to the project, which is still 350M Euros short on funding commitments.  Rather than make a decision now, ESA’s managers delayed the decision until later in June to allow time to develop funding solutions.  (See this Space Newsarticle.)

Three  good reports on of the meeting provide recaps of the key points relating to future planetary, and especially Mars exploration.  The first article on Space Policy Online provides information on the policy deliberations behind the cuts that NASA’s planetary exploration program faces this year.  I won’t try to summarize it here because the nuances count, but if you are interested in policy issues relating to planetary exploration, I encourage you to read the full article.  One key piece of information that I’ve not highlighted in my posts but highlighted in this article is that current U.S. law will require cuts of 7-8% in the budgets of federal agencies next January unless Congress and the President approve equivalent targeted dollar cuts.   As a result, the budget picture for planetary science today may be a high point. 

More interesting (to me at least) is a post at The Great Beyond blog (publishers of the journal Nature among others) giving an early look at the options being considered by the NASA study group planning a new robotic and human roadmap for exploring Mars.  The apex goal identified by the group is to have a human mission orbit Mars in 2033 and return samples collected by robotic missions on the surface. 

For missions between 2018 and 2033, the group has identified three potential roadmaps, one of which will presumably be the focus of its ultimate recommendation this August:

  • Implement the sample caching rover mission that had been planned as a joint mission with ESA for 2018.  This option would be most faithful to the goals outlined by the Decadal Survey to begin implementation of the three mission sequence to gather, send to Mars orbit, and then retrieve and deliver to Earth samples from the surface of Mars.
  • Expand our exploration of key sites that may have harbored life or conditions for life with surface missions to as many as three sites.  The most promising of these sites or the site to be explored by the Curiosity rover starting next summer presumably would be the site from which samples would eventually be returned
  • Drop sample return as a goal and instead implement a series of missions to explore Mars in general including the atmosphere and interior.

The roadmap team is also leaving open the possibility that the Curiosity rover in route to Mars will make a stunning discovery that will require revision of the roadmap.
The final roadmap proposal is expected to be delivered to NASA later this summer.

A second article on reports on the thoughts of Steven Squyres, Principal Investigator for the MER Spirit and Opportunity rovers currently on Mars and chairman for the recently completed Decadal Survey.  He gave his personal opinion on which roadmap options would fulfill the goals of the Decadal Survey.  Squyres said that a communications orbiter at Mars to support rovers to collect samples would support the goals of the Survey recommendations.  An orbiter focused on science or a lander that doesn’t lead to sample return would not meet the recommendations.  Interestingly, he said that a roadmap that first flew a Mars communications orbiter, then a mission to Europa, followed by Mars sample return missions would also fulfill the recommendations. 

Editorial Thoughts: I won’t dwell on the budget picture here except to say that US budget politics are a mess.  The ultimate planetary science budget may depend on how the election turns out this Fall.

I’m reluctant to speculate too much on the possible Mars pathways since all I have is a summary of the presentation and not the presentation itself, which may have also been kept vague at this point.  The first option, based on Decadal Survey estimates and planning for the joint mission with ESA, likely would cost more than $2B.  This requires substantial funding be available toward the end of the decade, which is at least two Presidents and several Congresses away.

The pathway that explores multiple sites could have several implementations.  The surface missions could be fixed landers like the Phoenix lander or smaller rovers that might be closer to the Opportunity rover than to the Curiosity rover on its way to Mars or the caching rover.

The last option, to explore Mars as a planetary system, could have a range of orbiters or landed missions like the proposed Insight geophysical station. 

Based on past prioritization of goals, the order of the options listed above may represent the ranking the scientific community would give to these options.  However, this order may also reflect the ranking by cost, or at least for need for peak funding.  (Most of the costs of missions usually occur in the last two years before launch, requiring a large peak funding rate in those years.)  If budgets become tighter than currently planned, then the second two options may better fit actual funding resources.

Squyres comments on flying a mission to Europa before starting the sequence of missions to return samples from Mars is intriguing…

Sunday, May 20, 2012

And the Discovery Nominees Are ...

If NASA holds to it's previously discussed schedule, we should know in a month or two which of the three proposals it is considering will be its next Discovery program mission.  This program funds low cost ($425M for the spacecraft, instruments, and operations and analysis; NASA picks up other costs such as launch vehicle) missions throughout the solar system.  

Below, I've reproduced slides that summarize each of the current candidates from a presentation given by Jim Adams, Deputy Director for NASA's Planetary Science Division a year ago.  (Readers with good memories may remember these slides from a post last May.)  At the end of this post, I also provide links to my own summaries of the proposals, which typically include links to more detailed write ups.

These proposals were the three that NASA's reviewers selected as having the best science return among the 27 proposals submitted.  As a result, determining which has the greatest science potential is a like deciding whether apples, oranges, or pomegranates are the better fruit -- it depends on individual preferences.  For the final selection, NASA will emphasize analyses of the feasibility of each proposal in terms of its technical risk and likelihood of remaining within budget.  It's possible that the eventual winner will be the only one that passed the technical and financial review.  (According to press reports, the European Space Agency's recent selection of the JUICE Jovian system mission over two other missions was because it had the lowest technical risk and lowest price tag.  All three missions promised excellent scientific return.)

Editorial ThoughtsThe program has been spectacularly successful with ten past missions ranging from Mercury to the asteroid belt and just a single failure.  (See the Discovery home page for a full list of the missions that have flown.)  Unfortunately, in the President's latest budget proposal, the rate of Discovery missions per decade will drop to around one every 4.5 years compared to the Decadal Survey's recommendation for a mission every two years.  Given this program's past success and the high quality of the current finalists (and the presumed high quality of the missions that just missed the finalist cut), I think this proposed is unwise.  If Congress chooses to increase NASA's Planetary Science program's budget above the President's proposal, I believe that the Discovery and its sister New Frontiers programs deserve to receive additional funding to allow more frequent flights.  The House bill would do this while the Senate bill does not.  The final budget may not be known until the end of the year.

In the meantime, it's hard to predict which mission is likely to be selected.  The Mars Insight mission is likely low risk since it reuses the Phoenix mission's design and incorporates mature instruments.  The Comet Hopper (CHopper) proposers likely have to convince reviewers that they can implement the complex mission mission operations of repeated landings within the budget.  The Titan Mare Explorer (TiME) proposers likely have to convince reviewers that an outer planets mission to a hostile environment (the lakes on Titan are frigid) can be done within the budget cap.  However, the proposers for all three missions are highly experienced, and they will have had a laser focus on resolving these issues.

If all three are judged to be low risk and financially feasible, then NASA will have a tough choice.  The Insight mission would provide continuance for NASA's Mars exploration program between the 2003 MAVEN mission and the next mission in 2018 or 2020.  The CHopper mission would be NASA's first to rendezvous with and land on a comet for extended observations. And the TiME mission would continue NASA's outer planet exploration beyond the missions already in flight.  In this situation, the TiME mission may have an advantage given that it must be selected in this competition to launch in time to be able to land on the northern lakes of Titan and still communicate directly to Earth.  The other two missions could be flown following future Discovery competitions (although CHopper likely would have to fly to a different comet).

As for my preference, I'm greedy.  I want to see all three eventually fly; hence my desire to see the highest flight rate possible for the Discovery program.


Mission summaries from a presentation by Jim Adams, Deputy Director for NASA's Planetary Science Division.  Double click on the images to read the full slides.  You can see the full presentation here.

Previous posts with more details:

Wednesday, May 16, 2012

CHopper Comet Hopper Discovery Proposal

CHopper spacecraft design from 2009 presentation

I like to think that I’m reasonably good with a web search, but sometimes I get skunked.  I’ve had several posts on two of the current Discovery mission finalists, the Titan TiME lake probe and the Martian InSight geophysics mission.  I’ve wanted to do a post on the third candidate, the Chopper Comet Hopper proposal.  (I do send emails, but given the competitive nature of these proposals, often get either a polite refusal or no response.)  So, today I’m going with limited information based on a presentation that’s almost three years old (and I don’t have the link anymore, sorry).  Some of what I write today is likely to be out of date.

We’ve now seen several comets up close, and have learned that each has a diverse surface that invites a mission to rove across the surface to investigate each of the landforms.  Comets have too little gravity hold a traditional rover on the surface (a major problem of landing on a comet is staying on it – the Rosetta mission’s Philae lander will use harpoons to anchor itself).  The CHopper  mission would use the low gravity as an advantage.  It would gently settle on the surface multiple times at different locations on the comet.  In between landings, the spacecraft would observe the comet from a distance, mapping the surface and watching the change in activity as the comet approaches perihelion at a distance just outside the Earth’s orbit.

The mission would carry an imager and an infrared spectrometer to map the shape and composition of the surface.  An ion/neutral mass spectrometer would measure the composition of the gases around the surface and presumably on the surface (the three year old presentation showed an extendable platform that would place the mass spectrometer in contact with the surface).   The instrument list includes panoramic cameras, presumably to take images on the surface.  The instrument manifest also includes a heating experiment, which is suggestive of several possible measurements of different sophistication.

The CHopper mission would combine remote observations of its target comet for almost two years with measurements from several locations on the surface.

The CHopper mission combines the roles of both a comet orbiter and a lander.  Within the Discovery mission budget (~$425M), the instrument list is necessarily limited.  The CHopper spacecraft would carry fewer remote sensing instruments than the Flagship-class European Rosetta comet orbiter and fewer instruments for studying the surface composition than the Philae rover.   However, CHopper would conduct a substantial portion of the science of Rosetta at a second comet and add the unique capability to conduct science at multiple locations on the surface.

The target comet for the mission would be 46P/Wirtanen, a small (1.2 km radius) body with an orbital period of 5.4 years.  This comet was the initial target for the Rosetta mission before it switched to a second comet, 67P/Churyumov–Gerasimenko.  46P/Wirtanen is similar in size to comet 103P/Hartley where NASA’s EPOXI mission (using the Deep Impact spacecraft) observed a heterogeneous surface and jets with different compositions. 

CHopper's target comet, 46P/Wirtanen, is believed to be similar in size to comet 103P/Hartley, which was imaged during a flyby in the EPOXI mission

Mission launch would be in 2015 with the rendezvous with 46P/Wirtanen in 2022.  Approximately 2.5 years of science observations would follow to observe the comet from near aphelion to perihelion.

The CHopper mission would be enabled by NASA new plutonium-based Advianced Stirling Radioisotopic Generators that are ready for their first flight test.  Solar arrays large enough to provide sufficient energy at 46P/Wirtanen would preclude landing on the comet.

Joseph Veverka of Cornell University gave an excellent talk at last Fall’s American Geophysical Union conference on the heterogeneity of the surface for comet Tempel 1. 

Editorial Thoughts: I find the concept of CHopper to be exciting, and I’ve been disappointed that the project team has chosen to keep the details close to the chest (but I understand the competitive pressures).   The science promises to be first rate and I think the images from different locations on the surface of an active comet would be spectacular.


Sunday, May 13, 2012

Updates: The Good, the bad, and the ugly

Note: An earlier version of this report used a graph from the wrong report.  This version corrects that error and expands on the issues facing NASA's Earth Science program.

Lots of news in the past week, so let’s get started.

The Good

NASA’s Mars Program Planning Group provided an update to the Planetary Sciences Subcommitte, a group of leading scientists that advises NASA on its plans.  The MPPG group was formed to develop a new Mars exploration plan that (1) fits within the reduced budgets for planetary exploration projected by the President’s budget and (2) merges the goals of scientific exploration with the goals of preparing for eventual manned missions in the 2030s.  The group’s chairman revealed almost no details of what the group is considering, but did list the criteria by which the program will be evaluated.  The list is long, here I’ll reproduce the top three Figures of Merit (FOM) (you can read the full list on slide 7):

  • FOM-1: Degree to which the program advances overarching scientific goals/ objectives of Mars exploration as stated in NRC Decadal Survey and within the MEPAG Goals document, including provision of surface samples from Mars to Earth laboratories
  • FOM-2: Degree to which the program advances knowledge and capabilities required to enable eventual human exploration of the Mars “system” (orbit, moons, surface), on a time-frame consistent with the President’s challenge (2030’s)
  • FOM-3: Degree to which the program infuses technology developed via Agency-level investments to reduce risk and increase capabilities for robotic scientific and eventual human-based exploration
The eventual science goal is to enable the return of samples to Earth no later than 2033, possibly by a manned mission that orbits Mars without landing (to demonstrate long duration flight capabilities without the difficulties of landing on and launching from the surface of Mars). 

The chairman of the group did state (see this Space News article) that the earliest Mars mission under the new program would be in 2018, but budgets would constrain a mission for that launch date to an orbiter or a simple lander.  If the first mission is in 2020, then the mission could be a rover.  [Editorial note: The presentation states that the scientific community would like a future rover mission to find and cache samples.  A rover mission would maintain NASA’s expertise in Mars entry, descent, and landing.  However, an orbiter may be necessary to provide a communications link, monitor atmospheric conditions for future landers, and image potential landing sites.  A difficult tradeoff since funding an orbiter in 2018 may delay an eventual rover mission past 2020.]

The good news here is that science appears to be a key driver of the new program with an eventual sample return as a key priority.

The Bad: Part 1

Did my last post on Congress’ response to the President’s budget proposal with significant increases in planetary science funding (compared to the President’s proposal) seem optimistic?  This past week, the Administration gave its response (specifically to the House’s budget) and threatened a veto:

“The Administration strongly opposes the level of funding provided for the commercial crew program, which is $330 million below the FY 2013 Budget request, as well as restrictive report language that would eliminate competition in the program. This would increase the time the United States will be required to rely solely on foreign providers to transport American astronauts to and from the space station. While the Administration appreciates the overall funding level provided to NASA, the bill provides some NASA programs with unnecessary increases at the expense of other important initiatives.”

One of the major programs getting an increase would be the planetary program.  However, NASA’s planetary science budget is a small piece of a much larger disagreement between the two political parties that I suspect may not be resolved until after November’s election and we know who will be running the various branches of government.  (SpaceNews provides a good summary of the immediate disagreements on the House spending bill.)

The Bad: Part 2 (and may become an Ugly)

Space News reports that Europe’s support for the ExoMars 2016 and 2018 missions with Russia are hanging by a thread with continuation a 50-50% proposition.  One concern is the whether there is time to implement the 2016 mission, but a larger concern appears to be the need for Europe to find an addition 350M Euros beyond the 850M Euros already committed.  The Space News article lists possible sources for additional funding so there is still hope despite the financial crises in Europe.

The Ugly

All of NASA’s science programs are guided by Decadal Surveys issued approximately every ten years.  At the five year mark, an outside group of scientists issues a mid-term review of progress towards achieving the decadal review.  The mid-term report for the Earth Science’s program was recently released and the news isn’t good.  The number of instruments available to observe the Earth and its changing climate, surface and oceans is expected to drop dramatically by 2020.

The following text from the report's executive summary states the problem and the issues that led up to it.  

"Finding: The nation’s Earth observing system is beginning a rapid decline in capability as long running missions end and key new missions are delayed, lost, or canceled. 

"However, for several reasons, the Committee on Assessment of NASA’s Earth Science Program found that the survey vision is being realized at a far slower pace than was recommended. Although NASA accepted and began implementing the survey’s recommendations, the required budget assumed by the survey was not achieved, greatly slowing implementation of the recommended program. Launch failures, delays, changes in scope, and cost estimate growth have further hampered the program. In addition, the National Oceanic and Atmospheric Administration (NOAA) has made significant reductions in scope to the nation’s future operational environmental satellite series, omitting observational capabilities assumed by the decadal survey to be part of NOAA’s future capability and failing to implement the three new missions recommended for NOAA implementation by the survey...

"Thus, despite recent and notable successes, ... the nation’s Earth observing capability from space is beginning to wane as older missions fail and are not replaced with sufficient cadence to prevent an overall net decline. The committee found that the number of NASA and NOAA Earth observing instruments in space is likely to decline to as little as 25 percent of the current number by 2020.  This precipitous decline in the quantity of Earth science and applications observations from space undertaken by the United States reinforces the conclusion in the decadal survey and its predecessor, the 2005 interim report (NRC, 2005), which declared that the U.S. system of environmental satellites is at risk of collapse. The committee found that a rapid decline in capability is now beginning and that the needs for both investment and careful stewardship of the U.S. Earth observations enterprise are more certain and more urgent now than they were 5 years ago."

I use the data from several instruments aboard NASA's Earth Science missions and I understand how important this data is to measuring and then analyzing the state of our planet.  The studies I and my colleagues conduct simply would be impossible without the investments made over the past decades.  I strongly support increased investment in missions to explore our home world.  (Full Disclosure: NASA’s Earth Science program funds a portion of my research, and I depend on data from several instruments for my research.)