Using oxygen from the air itself, a NASA experimental jet propelled itself past Mach 7 in the atmosphere above the Pacific Ocean this weekend. The small automated X-43A Hyper-X [ http://www.dfrc.nasa.gov/Gallery/Photo/X-43A/HTML/index.html ] craft was dropped from a huge converted B-52 [ http://www.af.mil/factsheets/factsheet.asp?fsID=83 ] bomber and then accelerated by a standard Pegasus rocket [ http://spaceplace.jpl.nasa.gov/galex/pegasus.html ]. At Mach 7, seven times the speed of sound [ http://www.grc.nasa.gov/WWW/K-12/airplane/sound.html ], the X-43A separated and the novel scramjet [ http://www.aviation-history.com/engines/ramjet.htm ] kicked in. Atmospheric oxygen [ http://pearl1.lanl.gov/periodic/elements/8.html ] was then scooped up, combined with onboard hydrogen [ http://pearl1.lanl.gov/periodic/elements/1.html ], and combusted in flight to propel the X-43A [ http://www.dfrc.nasa.gov/Newsroom/ResearchUpdate/X43A/index.html ] to record air speeds during maneuvers [ http://www.nasa.gov/missions/research/x43_suc.html ] over the next 10 seconds. Engines of ramjet [ http://www.grc.nasa.gov/WWW/K-12/airplane/ramjet.html ] design have been suggested as a satellite launch method without heavy fuel tanks and even romanticized for interstellar space travel [ http://www.bbc.co.uk/dna/h2g2/alabaster/A600436 ]. The previously acknowledged air-speed record [ http://www.aerospaceweb.org/question/performance/q0023.shtml ] for jet-powered flight was Mach 3.3 for the decommissioned SR-71 [ http://www.sr-71.org/ ]. Re-entering space rockets can start as high as Mach 36 before the atmosphere decelerates them. The X-43A [ http://www.nasa.gov/missions/research/x43-main.html ], depicted in the artist's illustration above [ http://www.dfrc.nasa.gov/Gallery/Photo/X-43A/Small/index.html ], might well propel itself past Mach 10 in future tests.