Extended mission for MER twins

摘要

Spirit and Opportunity - NASA's Mars Exploration Rovers (MER) - have been roving the planet Mars for more than 18 months, far exceeding their originally planned three month lifetime. Operations continued to go well and mission managers requested an 18 month mission extension. By June 2005 both MERs had passed the 500 sols (Martian day equivalent to 24 hours 39 minutes) milestone. Following on from the articles in Spaceflight in the October 2004 and March 2005 issues, this article covers the latest ups and downs of the Mars rovers.