In March 2004, the X-43 for the first time demonstrated a free flight of a scramjet-powered aircraft, reaching hypersonic speeds of Mach 6.8, or about 5,000 miles per hour, for 11 seconds.
In November of that year, an identical X-43A again set records, reaching remarkable hypersonic speeds above Mach 9.6, or about 6,800 mph.
August 15, 2012 12:02 PM PDT
Photo by: NASA
| Caption by: James Martin
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