![X-43a hypersonic scramjet test vehicle flying](http://static.sciencelearn.org.nz/images/images/000/000/418/full/X43a2_nasa_scramjet.jpg?1674164291)
The X-43a hypersonic scramjet test vehicle flew at Mach 9.8. It was 3 metres long and was accelerated by a Pegasus rocket to Mach 5 before release to be accelerated by its scramjet engine to Mach 9.8 (over 12 144 km/h).
The X-43a hypersonic scramjet test vehicle flew at Mach 9.8. It was 3 metres long and was accelerated by a Pegasus rocket to Mach 5 before release to be accelerated by its scramjet engine to Mach 9.8 (over 12 144 km/h).