X-15 Flight 188
| North American X-15A-2 with external tanks, before heat shield paint | |
| Mission type | Test flight, Record speed test | 
|---|---|
| Operator | USAF/NASA | 
| Range | 342.79 km (213 miles) | 
| Apogee | 58.4 kilometers (36.3 mi) | 
| Spacecraft properties | |
| Spacecraft | X-15-A2 | 
| Manufacturer | North American | 
| Crew | |
| Crew size | 1 | 
| Members | William J. Knight | 
| Start of mission | |
| Launch date | October 3, 1967 UTC | 
| End of mission | |
| Landing date | October 3, 1967 UTC | 
| Landing site | Rogers Dry Lake, Edwards | 
| William J. Knight with an X-15 | |
The North American X-15's Flight 188 on October 3, 1967, was a record-setting flight. William J. Knight took the X-15A-2 hypersonic rocket-powered aircraft to 102,100 feet (31,100 meters) over Mud Lake, Nevada when Flight 188 reached a record-setting top speed of 4,520 mph (7,270 km/h), Mach 6.70.