Don Harrison, a Google executive and longtime SpaceX director, has stepped down from the role on the rocketmaker's board of directors. SpaceX said his departure, announced Friday, was effective immediately.

Harrison, the president of global partnerships and corporate development at Google, joined the SpaceX board in 2015, overseeing an investment that grew to $75.2 billion by the end of the third quarter.

His departure comes as the SpaceX board weighs a possible merger with Chief Executive Elon Musk's electric-vehicle maker Tesla. Both companies faced selloffs this week following the mid-term elections.