What does JWST mean to Mars?

Some of the best images of Mars obtained using the Hubble Space Telescope. JWST could give us methane maps of the planet that approach this spatial resolution, but what are the costs for planetary science?

For those who thought that PSD's (NASA Planetary Science Directorate) budget woes came to a close along with the debt-ceiling increase, the bad news just keeps rolling in. Let's take a few minutes and analyze what consequences the recent dealings with the James Webb Space Telescope (JWST) will have on our exploration of Mars.


As many of you know, JWST is running vastly over budget. With $3.5 b already spent, the project requires additional funding of at least $4.5 b by 2018 to come to fruition. Compare this to early budget estimates for JWST of just $1 b for the whole thing. The draft of the 2012 US Budget had a solution to this problem. All funding for JWST was zeroed out, those funds were removed from NASA's overall budget, and it was recommended that the project be cancelled.

Astronomers everywhere and much of the NASA-supported R&A community cried fowl. Letter writing campaigns followed, including one spearheaded by the AAS, a professional society to which I belong. In response to the outpouring of community support, NASA decided that JWST would not, in fact, be cancelled - far from it. Instead the project was to be declared an agency priority. That means that Astrophysics would not be asked to shoulder the burden alone; the cost would be shared across all NASA programs.

That has, in turn, set off the latest budget fight within the agency as detailed here and here. As noted by vk, and as witnessed by readers of the Planetary Exploration Newsletter, one of the most strongly worded replies to this proposition came in an editorial letter signed by 14 prominent members of the planetary science community. You can read the full text of the letter here, but the most important part of the text is:

We individually and together reject the premise that JWST must be
restored at all costs... Without additional funds to NASA, JWST should not be restored unless and until an open science community assessment is made of the value of what will be gained and what will be lost across the entire NASA science portfolio. - PEN, vol 5 no. 40, Sept 8, 2011

As you will recall, PSD is still grappling with the fallout from the president's initial 2012 budget request which reduced the total planetary science funding for the next ten years by of order $5 b, which is somewhere between a quarter and a third of the planning window used for the decadal survey that was released in March.

This has already had consequences for the ongoing Mars program. Starting in April, re-negotiations began between ESA and NASA on the previously planned Exo-Mars/MAX-C joint landers. Then in June, as reported by vk over at Future Planets, NASA was unable to commit to its portion of the Mars Trace Gas Orbiter (TGO). As a result, ESA put all contracts related to TGO on hold pending a second deadline of September 15 for NASA to produce commitment documents.

What additional pain can be expected from a redistribution of the funds required for JWST? Well, if the cost is spread evenly across all directorates, PSD's share would be somewhere close to 8% or about $360 million over the next six years. But based upon how NASA's budget was cut in the spring, PSD's share could be much higher. One quick and painful way to close that additional gap would be to eliminate NASA support for TGO, estimated to amount to $500 million.

This would be a terrible loss for the Mars community, especially those of us who study the atmosphere. Most significantly, it will mean that methane mapping of the planet will have to be postponed. The discovery of this compound in the martian atmosphere is one of the most exciting developments of the last decade. Further, knowledge of the distribution of this gas would go a long way towards understanding the ability of Mars to harbour life in the current era.

It would also mean that, not including MAVEN, no new orbiters would reach Mars before at least 2020, putting into question whether the 2018 combined lander could take advantage of rapid data transmission through the DSN via an orbital satellite relay. By the time of arrival, MRO will have been in orbit for twelve years and Mars Global Surveyor lasted for only nine (MAVEN, with orbital insertion set to occur in 2014 will be younger, but should have a reduced lifetime due to a very low orbital periapsis).

It is unlikely that this cascade will end with Mars. Programatic balance is a priority for the Agency and the removal of major Martian missions could result in the field for discovery or new frontiers selections being tilted more heavily towards Mars then would have been the case otherwise.

Amid all this doom and gloom, is there some silver lining for Planetary Science? Perhaps so. While the resolution of the main camera will not beat Hubble by much (0.034 arc seconds instead of 0.043 arc seconds) the infrared capabilities will aid significantly with spectroscopy and spectral mapping. For instance, the Mumma et al (2009) methane discovery using the IRTF had very large bin sizes and the measurement was close to the signal-to-noise limit. JWST could follow up with high resolution spectroscopy (at resolutions that being to approach Hubble's main camera) and better SNR.