Monday, September 7, 2009

Thoughts on Scary Messages


The last blog entry, Scary Messages, talked about the gap between NASA's planetary budget and its ambitions. The Decadal Survey has the job of deciding which missions and programs get funded. The current budget forecasts funds the Mars program at ~60% of historic levels and doesn't have the funds to fly the Jupiter Europa Orbiter (JEO).

In this blog entry, I want to explore some ideas to give a feeling for the types of solutions that might be available. I'm not trying to sell anyone on any particular plan -- my opinion counts for less than squat in this process. This is an exercise to explore the option space for educational purposes.

We'll start with the current projected budget. In the following chart, I average the projected spending on mission programs as presented in the FY10 budget proposal and then multiplied the figures by ten to get an estimated decadal spending amount (all figures are in millions):

At the rate of three Discovery missions per decade, each Discovery mission costs ~$817M. The two expected New Frontiers missions cost around $1.3B apiece. This figures are higher than the normally quoted $450M and $650 million per mission for these two programs. Those lower figures are the amounts that the Principle Investigators receive. On top of that, NASA has to buy a launch and pay for various kinds of overhead.

In all my options, I make three assumptions. First, the Discovery and New Frontiers programs will continue with target of three and two launches per decade, respectively. These are extremely popular programs with the scientific community, and I don't expect them to go away. Second, I assume that the Lunar Quest program does go away as a line item. I expect that all lunar programs at NASA will get de-emphasized now that it appears that NASA astronauts will not be returning to the moon anytime soon. In doing this, I make no statement about the worth of the missions in this line item. They may eventually be funded as Discovery or New Frontiers missions. The third assumption is that the budget available for the entire decade can be projected from the FY10 proposed funding plan.

The planned Mars funding buys what the current head of NASA's science program calls 60% of a Mars program (compared to funding levels of the previous decade). That comes at a time when the minimum cost of meaningful Mars missions seems to be moving to the $1B to $1.5B range, each. NASA plans to make up for this shortfall by pooling funds with ESA to create an international Mars program.

Option 1: Full Jupiter Europa Orbiter Funding

In this option, the Outer Planets line item, Lunar Quest line item, and part of the Mars line item go to fund JEO. (I'm ignoring the fact that Cassini operations are funded out of the Outer Planets line item. I presume it will still be funded, but lack the detailed budget numbers to subtract it. These are back of the envelope estimates!) The Mars program takes a 16% cut from its currently planned levels. there's no changes to the Discovery or New Frontiers programs. (Percentages in all cases refer to the percent of funding based on a run out of the current budget plan.)


Option 2: Enhance Discovery and New Frontiers Missions

I am sure that there are many interesting planetary missions that can be flown for $450M (the current PI funding for Discovery) or $650M (ditto for New Frontiers). However, many of the interesting planetary questions seem to require more money than then program can afford. This is especially true for the the New Frontiers program. A great many interesting missions seem to come in around the $1B mark: Venus landers, comet sample returns, Ganymede orbiter, high resolution mapper for Venus, to name but a few. In this option, Discovery missions (three per decade) are raised to $650M for PIs and New Frontiers missions (two per decade) become small flagship missions for $1B for PIs. (Although at $1B, these missions may be out of the class of what a PI can lead and may revert to a laboratory such as JPL or APL managing the missions.) Mars funding is held to the currently planned levels.

In this scenario, there would be funds for a small flagship mission to an outer planet destination, perhaps a Jovian icy moons observer or a Titan/Enceladus observer and relay for in situ Titan probes.

Option 3: Focus on Flagships

This option retains the enhanced funding for New Frontiers and the outer planets. The New Frontiers line funds two small Flagship missions ($1B equivalent PI funding to each) and funds the JEO mission (or two small flagship outer planet missions). These increases are paid for by reducing Mars funding to the equivalent of two small Flagship missions (with ESA as a partner, probably the equivalent of three small Flagships can be flown). The Discovery program is held to currently planned funding levels ($450M to PI per mission.)


Option 4: De-emphasize Mars

This option increases Discovery mission funding to $650M PI funding per mission, New Frontiers to $1B PI funding per mission, and funds the equivalent of JEO or to two small flagship missions to the outer planets. This option reduces Mars funding, with ESA contributions, to the equivalent of two small flagship missions.

Editorial Thoughts: Picking a favorite among these options is a personal choice of which solar system targets you favor. I'm personally torn between options two and four. I believe that we need to up the spending caps for Discovery and New Frontiers missions to address high priority science questions that just can't be answered within their current budgets. Whether or not you prefer option two or four depends on whether you find Mars or the outer planets more interesting. I switch preferences about every day.

I hope that you will submit your preferred alternatives either to the comments or e-mail them to me at vkane56[at]hotmail.com

Sunday, September 6, 2009

Scary Messages

I finally found the time to listen to Ed Weiler's talk in early July on the state of NASA's planetary budget (although the messages are similar for other parts of NASA's science budget except Earth monitoring). The key takeaways:

  • NASA's planetary budget has shrunk to approximately half of what it was at the end of the last Decadal Survey (~2003) that set mission priorities
  • NASA can now fund about 60% of its Mars program -- hence the joint program in definition with the European Space Agency
  • NASA cannot afford an outer planets flagship mission without cannibalizing some or all of the Mars program, the New Frontiers program, and/or the Discovery program
  • The loss of the low cost, small Delta 2 launcher will raise the cost of small missions by tens of millions of dollars and potentially a $100M
As a result of these pressures (and if anything, I see the planetary budgt shrinking in the future to fund the manned spaceflight program or to hold down deficits), the program that comes out of the current Decadal Survey may be quite different than the current program.

Resources: Ed Weiler's presentation and Q&A before the Decadal Survey committee

Friday, September 4, 2009

Titan Mare Explorer Abstract

Since the links to the abstract for this poster keep breaking, I'm posting the abstract here.

Title Titan Mare Explorer (time): A Discovery Mission To A Titan Sea
Author Block Ellen R. Stofan1, J. Lunine2, R. Lorenz3, O. Aharonson4, E. Bierhaus5, B. Clark6, R. Kirk7, B. Kantsiper3, B. Morse3
1Proxemy Research, 2University of Arizona, 3APL, 4California Institute of Technology, 5Lockheed Martin, 6Space Science Institute, 7USGS.
Abstract The discovery of lakes and seas in Titan’s high latitudes confirmed the expectation that liquid hydrocarbons exist on the surface of the haze-shrouded moon. The lakes and seas fill through drainage of subsurface runoff and/or intersection with the subsurface alkanofer, providing the first evidence for an active condensable-liquid hydrological cycle on another planetary body. The unique nature of Titan’s methane cycle, along with the prebiotic chemistry and implications for habitability, make the lakes and seas of the highest scientific priority for in situ investigation.
The Titan Mare Explorer mission is an ASRG (Advanced Stirling Radioisotope Generator)-powered mission to a sea on Titan. The mission would be the first exploration of a planetary sea beyond Earth, would demonstrate the ASRG both in deep space and a non-terrestrial atmosphere environment, and pioneer low-cost outer planet missions. The scientific objectives of the mission are to: determine the chemistry of a Titan sea to constrain Titan’s methane cycle; determine the depth of a Titan sea; characterize physical properties of liquids; determine how the local meteorology over the seas ties to the global cycling of methane; and analyze the morphology of sea surfaces, and if possible, shorelines, in order to constrain the kinetics of liquids and better understand the origin and evolution of Titan lakes and seas. The focused scientific goals, combined with the new ASRG technology and the unique mission design, allows for a new class of mission at much lower cost than previous outer planet exploration has required.

Titan Mare Explorer

The link to the abstract in my previous post appears to have broken. I've republished the entry with links that work correctly on my computer. If the active links don't work, you can try pasting the following in:

http://www.abstractsonline.com/plan/ViewAbstract.aspx?mID=2337&sKey=f5a63250-0cc1-4d95-9940-1a071b9728c8&cKey=e963b6e7-aa12-43f8-88c4-3a4504e092f4


Please let me know if the links break again either in comments or in e-mail to vkane56[at]hotmail.com.

Wednesday, September 2, 2009

Titan Mare Explorer (TiME)

As I've mentioned in past blog entries, NASA is funding a series of studies of Discovery missions that could make use of the newly developed ASRG plutonium power supplies. One of the most intriguing has been the Titan Mare Explorer (led by Ellen Stofan), which would put a probe on the surface of one of the lakes of Titan. Public information on the proposed mission has been scanty, but an abstract for the upcoming Division of Planetary Sciences meeting provides a few hints (and I'll add a couple of tidbits I've picked up).

From the abstract, "The scientific objectives of the mission are to: determine the chemistry of a Titan sea to constrain Titan’s methane cycle; determine the depth of a Titan sea; characterize physical properties of liquids; determine how the local meteorology over the seas ties to the global cycling of methane; and analyze the morphology of sea surfaces, and if possible, shorelines, in order to constrain the kinetics of liquids and better understand the origin and evolution of Titan lakes and seas."

I've heard through the grapevine that the instrument suite would be limited (as befits a ~$450M mission) to a mass spectrometer, a meteorology and physical properties experiment (probably several instruments in a package), and a descent and surface camera. This may compare favorably with the instrument package that was proposed for the lake lander in the Titan Saturn System Mission flagship proposal -- it's hard to tell without detailed listings of the proposed instruments. One key instrument that I haven't heard of for the proposed Discovery mission would be a gas chromatograph, which would enable detection of complex molecules. The TSSM lake lander had a combined mass spectrometer/gas chromatograph while I've heard of only a mass spectrometer for the proposed Discovery mission. It isn't clear if the gas chromatograph has been dropped, or just isn't listed.

The Discovery proposal calls for, as I understand it, six months of observations as the probe floats on the lake surface with a possible mission extension of several more months. Depending on how far the probe travels on the surface of the lake, this might allow depth measurements along a significant transect and might even bring the probe to a shore.

Editorial Thoughts: This is an exciting mission proposal. I'd love to see images from the surface of an alien ocean. The measurements of the lake composition would greatly advance our understanding of Titan chemistry.

However, there are some caveats to keep in mind. Data relay would be direct to Earth. Think of tens to hundreds of bits per second, most likely. We are unlikely to get great panoramas of photos. Think postage stamp images. Secondly, Titan is a cold place place (to put it mildly). Designing a probe that can reliably survive months on a Discovery budget may prove to be optimistic. Remember that one of the areas of technology development proposed to enable future Titan landers is technology to survive and operate in the frigid climate.

Still, I like this proposal, and hope that it is feasible in a Discovery budget.

Resources: Titan Mare Explorer abstract