4 December 2008
Mike Griffin started the press conference, and got right down to business announcing the launch delay and indicating that the actuators as well as other technical problems are responsible. He said that aiming for 2009 would involve too much risk, and so the launch had to be slipped two years. Ideally, it would only slip a few months, but the way that travel between Earth and Mars works means that launch opportunities only occur every 26 months.
Ed Weiler spoke next, explaining that the project was given milestones to reach to stay on schedule, but yesterday there was unanimous support for a launch slip. The risk of rushing to launch was deemed to be too great. “We don’t think we’ll have to cancel any programs, but there may be delays. The impacts will come from mars first, but if there is not enough it may affect other planetary programs.”
Third was Doug McCuistion, speaking about the complexity of the mission and emphasizing that MSL is really three spacecraft: a cruise stage, the “sky crane” and the rover itself. Each alone is as complicated as a discovery-class mission. And all three are mostly assembled.
The two main categories of technical issues are development and testing. There have been development delays in the actuator electronics as well as problems with the actuator themselves. The sample handling system especially needs to be extremely well tested. For comparison, the majority of Phoenix development time was testing, and it payed off with a very successful mission.
The slip to 2011 will cost about $400 million due to extended mission duration and launch vehicle. Mars will pay back other programs and no cancellations are expected.
Charles Elachi, director of JPL spoke last. He repeatedly emphasized that “Mars is very unforgiving.” He said that the vast majority of the hardware is completed. By pushing for the 2009 launch, JPL was better able to find the problems which need to be dealt with.
Why does it cost $400 million if most things are built?
Testing, assembly, launch prep requires a lot of people, plus this means two more years of operations. Elachi emphasized tests will continue, the rover is not going to be shelved for two years.
If you had to pick out one thing, the actuators have poorly understood actuator behavior at Mars temps. Not going to gamble on launch.
Landing site selection will stay on schedule, and they see no reason to open that process up again.
There was a question about the possibility of adding or changing the instruments, and it was emphatically said that NASA is not going to start adding even more complexity and cost by tacking on newer instruments. The focus is on testing and understanding the current system.
Ed Weiler also mentioned something very interesting: NASA and ESA are now working on putting together a joint Mars exploration architecture, and future missions will be joint missions.
More detail on the technical issues, particularly actuators: They are essentially a motor in a gear box, and they do basically everything on the rover. They move the wheels, the arm, the drills, the sample handling, the mast. They are crucial to the mission. Without actuators you “basically have a metric ton of junk on the surface of Mars.” The ones on MSL are much more complicated than MER due to the larger size.
What is the new launch window? October – December 2011, specific dates have not been determined, and will vary slightly based on landing site.
Did anyone ever consider canceling MSL?
No. To cancel, have to think that project is going badly in a technical sense, but this project is basically built and “when you’re doing things that haven’t been done before, you are likely to encounter difficulties… The fact that we’re having troubles is not a surprise and not a cause for cancellation.” Hubble, COBE, most missions have these sorts of problems. “Some of the things of which we are most proud are missions where we have had far more trouble than MSL.”
But aren’t the goals of Hubble broader and more diverse?
MSL‘s purpose is to search for habitability and life. Griffin: “This is one of the fundamental questions of our age. If that doesn’t qualify as broad and diverse, then I don’t know what to tell you.”
Doug McCuistion said that the goals of MSL are the goals of the broader planetary community in the decadal survey, so pitting Mars against the rest of planetary science is inappropriate.
Weiler said that any sample return mission will probably be in the mid 2020s, but said that that’s a “realistic” date with a “realistic” budget. He also said that it is going to have to be an international effort.
The Phoenix team is advising the MSL team on how to deal with samples.
Is ExoMars officially a joint mission now? There’s definitely a possibility and NASA is open to it and welcomes it.
Emily Lakdawalla asked whether the plutonium will have decayed in the two year delay. Answer was that only 5% will have decayed so it shouldn’t affect operations.
What about a 2010 launch, park in solar orbit and then go to Mars? It turns out that that doesn’t help much. The system was not designed for such a long cruise stage. Also, a plutonium power source coming around and passing by earth takes a lot of safety testing and therefore cost, and in the end it doesn’t save much money.
Why does NASA keep going overbudget? Griffin’s answer was essentially that we’re doing things that have never been done, and that extra costs are inevitable. There is no good way to estimate the cost for projects like this because you don’t know what the problems will be. He said that we need to judge the worth of the work based on the results, not based on our ability to project costs. The best thing to do is put in place better independent cost estimates and follow those. But you have to have already started working on the mission to get accurate estimates.
What are the scientific costs of this delay? The Mars timeline will have to be modified. Probably will have to delay a major planetary mission.
It would do no good to provide extra funding for missions from the beginning, because then you would have a self fulfilling prophecy.
Stay tuned later for my thoughts on all of this, and take a look at my initial post about it.