YM COLUMN ARCHIVE

October 15, 2008

NASA sticks to large scale Martian mission

Due to serial delays of development and budget overruns, it was expected unavoidable to postpone or cancel the large scale Martian mission of MSL (Mars Science Laboratory) to search the possibility of lives and habitability of human beings on Mars. According to the resolution of the review meeting on the mission held last Friday, however, NASA is very much willing to stick to the possibility of launching Martian mission in autumn of 2009. It simply states that appropriation of the additional budget and how to fund the project are up to the US congress.

Ed Weiler responsible for space science department of NASA said, “It’s easy to say postpone or cancel but we have already invested 1.9 billion dollars in this project and this is the most highly sophisticated space science. We can never so easily give up flagship mission of Mars exploration.” Because of the relative positioning of Earth and Mars, launch window to Mars comes once in every two years. The next window opens from Sept. 15 to Oct. 15 next year. If to target this window, it will naturally take more money, which may need due deliberation.

Funding of the project is either up to the approval by congress of the additional budget or appropriation of the money from some other NASA’s programs. What NASA should do, to begin with, is to review the whole budget on Mars, and if reviewing does not work out the necessary expenses, the next to do is to thoroughly examine the entire planetary exploration programs of NASA. As I introduced in this column before, the future Martian projects are scheduled for Martian climate mission “MAVEN” and also the internationally collaborated mission of bringing back samples from Mars around 2020. In order to make money for MSL, the idea was proposed to terminate the ongoing operations of “Spirits” and “Opportunity” that are still working on the Martian surface over the extended schedule, but this proposal was turned down.

The efforts to calculate how much more money is needed precisely is now hurriedly under way at JPL (Jet Propulsion Laboratory) that is a main player of the mission. If to miss window next year, the next comes at the end of 2011. With many unsolved problems both of hardware and software, JPL as a leader and engineering staffs of other institutions are seriously working hard. What is technically most difficult at the moment is the actuator to drive robot arms and to rotate wheels of rover. The actuator should never be dealt in a perfunctory manner because it is used for moving the samples collected on the surface by the drill and rover working for excavation.

There are many kinds of actuator and some of them is made from six hundred parts so that even with budget approval, it will be hardly predictable if process of works will be technically in time or not. Since the intensity of titanium alloy gears inside actuator is not strong enough, its replacing work by stainless steel is now going at some company in New York, of which new products are to arrive at JPL at Pasadena in California in November this year.

JPL seems to have various other problems with such as software needed for radar system used at landing on Mars; heat rejection, newly replaced in November last year, of the capsule at time of entering Martian atmosphere, and also malfunction in testing parachute to open at landing on Mars. In order to solve all these difficulties, JPL is working hard around the clock night and day. As far as I know, however, JPL seems to have a foreseeable prospect to come through all these difficulties except actuator so that the final key of success will all depend upon the test by JPL to begin from the end of November.

The US uses two ways of landing on Mars to soften the shock: one is opposing jet and the other is air-bag cushion. MSL is four times as heavy as Spirits or Opportunity to weigh one ton so that they now use new methodology of combining the above, of which operational results are gathering attention. At any rate, NASA administrator Griffin is to meet with the project leader in January next year to make a final decision on this matter. Let us be looking forward to the final achievement of JPL and related parties how they are going to solve all those technical problems for the conference with Administrator Griffin.

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I welcome your opinions on this column to the following E-mail address.
matogawa@planetary.or.jp