Tuesday, October 5, 2010

The end of lifetime tenure on spacecraft missions


Michael Carroll's concept of the Europa-Jupiter System Mission which proposes to implement a partially revolving science team.

One of my mentors and a friend at the University of Arizona is a professor named Bob Brown. In his earlier days, Bob worked with Voyager and was best known as the originator of a concept known as the solid state greenhouse effect. This concept would later be applied to Neptune's moon Triton and indirectly to the sublimation spiders on Mars. In 1989, as voyager was winding down, Bob was selected as an instrument Principal Investigator for the VIMS (Visual and Infrared Mapping Spectrometer) instrument on Cassini and has worked on that mission ever since. Currently, Cassini is funded through 2017 which will bring Bob close to retirement. Now Bob has also worked on other projects, but Voyager and Cassini have dominated his professional life.

It was originally intended for Cassini to have what we in the Mars program know of as a Participating Scientist program. Basically, this is a program whereby younger scientists who were perhaps not well-known enough to make it onto the main science team through the black art of mission team selection, could join the mission later on, after launch. But unfortunately the participating scientist program never happened. In this respect Cassini is far from unique. Phoenix also was forced to cancel its participating scientist program for monetary reasons.

Still, there is a big difference in giving lifetime tenure to science team members when a mission is expected to last 90 sols or even 152 sols, as Phoenix did, and giving lifetime tenure to science team members on a mission which could last 10, 20 or 30 years. This is something that NASA headquarters has realized, and to their credit, once it became clear that the MER rovers were going to far outlive their expected 90-sol missions, they held a participating scientist selection program that allowed new blood onto the mission, and helped the careers of many young scientists.

Now NASA hopes to apply this model to a future flagship mission. Today, Curt Neibur, project scientist for the EJSM (Europa-Jupiter System Mission) project announced a science team concept for the mission which is nothing short of revolutionary. While instrument P.I.'s and their Co-I's would maintain science team status throughout selection and all phases of the mission (projected to last from early 2011 through 2029), much of the science team would be hired on 3-5 year contracts as investigation scientists. These people would roll-on and roll-off the mission providing their expertise for a limmited time only.

This approach makes a great deal of sense. For instance, currently the project scientist needs to try to anticipate all the different expertise which will be required, and hire everyone at the start. As a result, some science team members do relatively little until after launch when their expertise is required. Other unanticipated needs may end up unfilled by a full science-team member. By having the option to change the make-up of the team over time, it becomes possible to use your resources more efficiently. You have the flexibility to hire those science team members who can be most useful in any particular phase at the time when their expertise is most needed, and not have to carry them through the entire project.

Additionally, this gives a way of getting more people involved with the mission, especially younger career people, who might have had great difficulty in breaking into a mission previously. By cycling through these science team members, perhaps as many as 6 generations worth with a mission like EJSM, you can expand the base of those who have intimate knowledge of the data sets to be gathered. That means better science return, as more people in the science community at large will have direct knowledge of how to process and interpret the recieved data. This contrasts markedly from the current situation where many of the researchers operating out of the PDS have had no direct contact with the team, instruments or spacecraft which gathered the data that they are interpreting.

The rub here is how to reward these rolled-off science team members in order to make the program attractive to them. Many questioners were concerned that in the early years, investigation scientist positions would be undesirable. Those who would be selected would be giving up significant time to get hardware ready for flight; time which might be better spent publishing or advancing their careers. Furthermore, given the large number of scientists who would cycle through, the cachet to working on the mission in that capacity would be reduced. As Curt has said before, operations experience on a NASA mission which has ended may be edifying, but a potential academic employer will not regard it as a plus. More potentially problematic is determining which investigation scientists get inside the data embargo once the science phase of the mission begins.

Therein lies an interesting potential consequence of this change. Once a large part of the community begins cycling through a mission during its lifetime, it may become more difficult to justify a 6 to 12-month embargo. As I've commented before, this embargo is one of the main motivators of researchers who work on missions. It allows you justify the calculus of giving up your time in the short term for long-term gains in a professional context. Without that embargo, mission participation may become less attractive to those looking to aggressively advance their careers.

These are complex problems without simple answers, we're just going to have to try a few things and see what ends up working. But one thing is clear, if a major mission, such as EJSM finds that lifetime tenure for science team members is not justifiable, then this is likely a practice that is on its way out. So, while it may not be possible for future researchers to follow the kind of path that Bob has had the opportunity to take, the process of spacecraft mission participation could be opened up to much wider segment of the community. I think that's something to be very pleased with.

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