December 2, 2014NASA's Journey to Marshttp://mars.jpl.nasa.gov/msl/multimedia/images/?ImageID=6829NASA is developing the… https://www.rawpixel.com/image/9975908/photo-image-astronaut-moon-spaceFree Image from public domain licenseInterior of the 20-foot diameter vacuum tank at the NASA Lewis Research Center’s Electric Propulsion Laboratory.… https://www.rawpixel.com/image/441483/free-photo-image-nasa-interior-laboratoryFree Image from public domain license