The timetable for Mars exploration in the coming decade has slipped badly in recent months. First came news that NASA’s Mars Science Laboratory (MSL), scheduled to launch in 2009, had been rescheduled for 2011. This was followed by the European Space Agency’s (ESA) announcement that its ExoMars lander, which has already slipped from 2013 to 2016, is now scheduled for 2018. And now we just learned that this year’s planned launch of Russia’s Phobos-Grunt mission, built to collect soil samples on the martian moon Phobos and return them to Earth, has been pushed back to 2011.

There is no arguing with the decisions to delay these missions. In each case it was the prudent and correct thing to do, since failure was all too likely if the mission handlers had tried to stick to their original schedules. Some risk of failure is unavoidable in space exploration, but today’s high costs, shrinking resources, and competing demands on public funds make it especially important to reduce the risk as much as possible before launch. This means much more testing — which takes time, is expensive, and almost always results in changes to the design.

Each of the mission delays had very different reasons and arose from very different situations. The American MSL builds on the extraordinary success of the Spirit and Opportunity rovers by introducing a larger, heavier and more-capable rover than anything tried before. This proved to be more challenging than expected as key components failed the rigorous testing regime. ExoMars is Europe’s first rover and first planetary lander, and it may have proved too ambitious as a first step. Russia viewed its Phobos-Grunt as a natural successor to the 1988 Phobos spacecraft and the ill-fated Mars ‘96 mission. It is also the only country to successfully complete a robotic sample-return mission from a planet, which is precisely what Phobos-Grunt is designed to do. But Russia has not had a truly successful planetary mission since the Soviet Union in the mid-1980s, and with this in mind the mission leaders opted to properly complete their testing rather than risk launch of a spacecraft not yet ready for flight.

What do we conclude from these delays? Are we biting off more than we can chew? Probably. But if we are to continue exploring, we cannot turn back from these missions. Each is in fact a scaled-down version of the long-desired Mars sample return mission (I led a mission development for this in the mid-1970s). And if our goal is a human mission to Mars, then a series of sample-return missions should (some say “must”) precede it. So while the current missions are big and ambitious, they are necessary steps in Mars exploration.

The lesson to learn is to plan better, to be more resilient and to provide more resources. NASA and ESA have recognized this, and one year ago they agreed to plan future large missions of exploration together. They are doing so now for ExoMars and for future U.S. missions to Mars and the outer planets. Russia should be brought into this international planning — its sample return experience could be very helpful in planning Mars missions. The Japanese, who are in the midst of a robotic surface sample return mission from an asteroid, should also be brought in. The complexity of today’s missions requires international planning and international resources.

We wring our hands about the mission delays. At the Planetary Society we are disappointed because Phobos-Grunt carries with it our LIFE (Living Interplanetary Flight Experiment) module, which is to contain the first living samples ever purposefully sent on an interplanetary voyage. But we must remember that exploration is never a smooth process but moves along in fits and starts, with huge failures as well as brilliant successes. Sometimes missions surpass their planned lifetime many times over, as is the case with Odyssey, Spirit, Opportunity, Cassini and Hayabusa; at other times they are subjected to unexpected long delays. In the end it is all worth it, because space exploration brings nations and people together in the search for answers to the great questions that unite us all: who we are, where do we come from, and might our future lie in space?


Louis Friedman is the executive director of the Planetary Society.

Louis Friedman is the co-founder and Executive Director Emeritus of The Planetary Society. Prior to that he was Manager of Advanced Programs and the post-Viking Mars Program at JPL.