The second half of February brings news on the proposed sum of NASA's budget for 2013 fiscal year. Even though President Obama hasn't made the request yet, it is already known that the planetary program will suffer serious cuts. Last week it was announced that the agency was withdrawing from joint American-European project ExoMars. While the public wonders about what is in store next, world space agencies are discussing the future prospects of planetary exploration.

While NASA's participation in the ExoMars project is doubtful, ESA authorities began negotiations with Russian space agency Roscosmos on possible Russian participation in the mission.

The initial aim was to replace American Atlas V rocket launcher with Russian rockets. Back in 2011 no results, either positive or negative, of the negotiations were reported. Meanwhile, the Phobos-Grunt tragedy and overall uncertainties of the Russian planetary program complicate the situation even further.

Earlier, in 2002 European INTEGRAL X-ray observatory was launched by Proton rocket, with Russian scientists getting 25% of observation time in return. However, the scheme would not be effective with the ExoMars project, since the most important part of the expedition is its tools that will determine the set of experiments on Mars. Therefore, current negotiations would inevitably be about Russian participation in scientific payload.

As the Russian Mars program is rather tentative, a joint program might turn out to be a good decision, since Russian scientists will get a good chance to study Mars after more than 20 years of waiting. However, there is still a question of Phobos-Grunt reiteration, and that's when costs matter. Can Bolivar, or rather Russian space budget (and space industry as well), cover double expenses, is a question to be considered very carefully.

Most likely, the Jupiter project will be postponed accordingly. As there is no NASA Europa orbiter that would map the surface of Europa, Russian initial plan to land on this Jovian satellite seems too adventurous. If ESA decides to go on with its new JUICE mission to study Ganymede and Callisto with occasional fly-bys of Europa, Russia may have to shift to less interesting, but better studied Ganymede.

Both of the projects are to undergo close scrutiny in the near future, as the Phobos-Grunt loss caused the Russian planetary program to be revised. NASA's decision to withdraw from the project may play a crucial part in this revision. Stay tuned.

The news of space budget cuts in the U.S. did not come out of the blue. Rather, it was expected that some space projects would be inevitably sacrificed. But that it would hit the most successful part of American space program became a very unpleasant surprise to many, outside the U.S. as well.

Although plans to withdraw from the ExoMars project were more or less openly discussed in the autumn of 2011, the officials decided to wait until the 2013 budget proposal is announced.

The American planetary program might be cut down by $300 million, with $200 million taken away from the Mars program. Thus, the whole program will be $1200 million instead of the current $1500 million, with a possible reduction down to 1 billion in 2017.

The current Mars program is $581.7 million. Official statements will be made Monday, as NASA administrator Charles Bolden holds briefing for reporters about the agency's 2013 fiscal year budget.

This cut will most likely affect the ExoMars project, which already has a long and rather uncertain history. Originally initiated as a solely ESA project, it became a joint ESA-NASA expedition with two launches in 2016 (a Trace Gas Orbiter to study Martian atmosphere) and in 2018 (at first, two rovers were planned, but then due to cost only one remained).

Thus, the only Martian project except for now-flying Mars Science Laboratory is MAVEN orbiter to study Martian atmosphere, ionosphere, and their interactions with solar wind (to be launched in 2013). No further rovers and, apparently, no sample return missions, which could have followed a successful accomplishment of the ExoMars project, are planned.

However, the decision to cut the Mars program was qualified as 'irrational' by Ed Weiler, former head of NASA's science mission, who resigned in September 2011. In his opinion, the Mars program is 'one of the crown jewels of NASA'.

By the way, last year also faced NASA's withdraw from Europa Jupiter Science Mission (EJSM), also presumably a joint ESA-NASA project with Japanese and possible Russian participation. ESA is currently re-evaluating the feasibility and the overall scenario of the mission, now rechristened JUICE.