Europe is uncertain whether its ambitious Mercury probe can reach the planet

An artist's rendering of the BepiColombo mission, a joint ESA/JAXA project, which will take two spacecraft to the harsh environment of Mercury. (credit: ESA)

This week the European Space Agency posted a slightly ominous note regarding its BepiColombo spacecraft, which consists of two orbiters bound for Mercury.

The online news release cited a "glitch" with the spacecraft that is impairing its ability to generate thrust. The problem was first noted on April 26, when the spacecraft's primary propulsion system was scheduled to undertake an orbital maneuver. Not enough electrical power was delivered to the solar-electric propulsion system at the time.

According to the space agency, a team involving its own engineers and those of its industrial partners began working on the issue. By May 7 they had made some progress, restoring the spacecraft's thrust to about 90 percent of its original level. But this is not full thrust, and the root cause of the problem is still poorly understood.