Q&A with Michel Denis, ExoMars flight director

A rocket-transporting railroad car ferried a Proton rocket to its launch pad Friday at the Baikonur Cosmodrome in Kazakhstan for final checkouts and testing before the vehicle’s scheduled June 21 liftoff with the Russian-German Spektr-RG X-ray telescope.

Engineers suspect a piece of foreign object debris may be intermittently stalling a motor needed to place the Curiosity Mars rover’s drill bit onto rocks, and the robot’s ground team is assessing the source of the potential contamination.

NASA’s Perseverance rover will depart Cape Canaveral Thursday on a $2.7 billion mission to Mars, carrying with it the first interplanetary aircraft, sophisticated instruments to search for signs of ancient life, and drill to core samples for eventual return to Earth.