Video: Russian cargo ship spinning

A Soyuz rocket poised to send two new crew members to the International Space Station rolled to its launch pad Tuesday at the Baikonur Cosmodrome in Kazakhstan.

President Trump called the International Space Station Monday for a videochat watched by thousands of school kids, congratulating commander Peggy Whitson on becoming America’s most experienced astronaut and jokingly promising to get Americans to Mars “during my first term or, at worst, during my second term.”

A commercial Northrop Grumman Cygnus supply ship berthed at the International Space Station fired its main engine for 50 seconds Tuesday in a test of the spacecraft’s ability to reboost, and possibly eventually deorbit, the massive research outpost.