U.S. Sailors participating in Riverine Combat Skills (RCS) course class 13-010 conduct a simulated patrol during the medical… https://www.rawpixel.com/image/8738899/photo-image-smokes-public-domain-gunsFree Image from public domain licenseSpace shuttle Endeavour glistens in the sun on Launch Pad 39A at NASA's Kennedy Space Center in Florida. Original from NASA.… https://www.rawpixel.com/image/441068/free-photo-image-space-shuttle-rocketFree Image from public domain license