The European Space Agency (ESA) has launched an investigation into the Planetary Fourier Spectrometer (PFS) onboard the Mars Express orbiter.

Fred Jansen, the Mars Express mission manager at ESA told us: "The problem manifests itself as a failure in properly executing its initialisation sequence. If this is not successfully executed the instrument cannot do any measurements."

If we are reading this correctly, he means that they can't switch it on, so they can't do any science with it.

The PFS had been working perfectly, and had produced plenty of data on the composition and movement of the Martian atmosphere, until it developed its inexplicable problem a couple of months ago.

Team engineers have suggested that vibration effects from recent spacecraft activity - possibly the unfurling of the MARSIS radar booms - might be to blame, but nothing has been positively identified as being the cause of the trouble.

The investigation board will include experts from ESA, industry, and from ASI, the Italian space agency. ®