The Mars Exploration Rover (MER) folks that operate the Spirit and Opportunity robots on the red planet have gotten some bad news.

A directive has come from NASA Headquarters to take a 40 percent financial cut in their program - some $4 million in fiscal year 2008.

It all comes down to a financial stun gun for one of the rovers - both still busy at work doing science. Cost per year to run the Mars twins is $20 million per year.

Steve Squyres, the MER principal investigator at Cornell University, told me that the 40 percent cut is huge. “We’re rapidly coming to the conclusion that if we have to implement this cut, it’s going to mean essentially shutting off science activities for one of the vehicles.”

Safely shutting down a rover on a temporary basis is doable, Squyres said, a move that could save money but at the expense of science. “We’re going to go off and look at what our options are…but I feel confident that we have to essentially halt science operations on one of the two vehicles.”

While both robots are healthy and doing good science, it looks like the one to hibernate for the remainder of this fiscal year could be Spirit, Squyres suggested.

The MER group has also been told to expect an $8 million cut in fiscal year 2009. It would essentially be the same magnitude of cut. At that time, it is expected there would be two healthy rovers both able to move, drive and explore.

“We would have to make some very tough decisions about which one we would hibernate and which one we would keep active. That’s a situation I do not want to face…but that’s a future worry,” Squyres added.

For now, the message back to NASA Headquarters is that, if the MER team has to take the first cut, there is going to be an impact on science return…and in fiscal year 2009, it will be much more severe.

The two priceless assets on Mars continue to crank out good science, Squyres emphasized, and are in good health. Another concern sparked by the budget cut, along with keeping the rovers healthy, is keeping the MER team together and morale high, he said.

In an email just received, it also looks like the venerable NASA Mars orbiter, Odyssey, is on the cost-cutting table too.