NASA’s twin Mars Exploration Rovers, Spirit and Opportunity, landed on Mars in January, 2004 after a six month journey. Initially intended to last 92 days, both rovers exceeded expectations, with Spirit lasting six years and Opportunity exploring the Red Planet for nearly 15 years. The LEGO Company built a full scale model in 2002 based on an image provided by NASA. The model has the proper size and shape, with all instruments, components, and structures represented to scale, though a few small details are not perfectly accurate because the rover design changed slightly during development. The model weighs 290 lbs./ 130 kg, while the actual rover weighs 410 lbs./ 185 kg. It is made of approximately 90,000 LEGO elements and required 650 man-hours to construct in a three month process by the LEGO master builder team.