An international hypersonic flight planned to test scramjet fuel combustion at eight times the speed of sound will reach two major milestones next month.

To fly in October 2010 the hypersonic payload's critical design review and its two-stage launch vehicle's preliminary review will take place this October. The launch vehicle's critical review is in January.

In October 2010 the payload will be accelerated to Mach 5.5 by its two-stage launch vehicle and at 60,000ft (18,300m) the payload's shroud will drop away to enable air to enter an inlet that leads to the combustor.

The plan is to achieve at least 6s of combustion as the payload accelerates from M5.5 to more than M8. The military wants to study combustor performance as stable combustion is key for good propulsion performance.

To be launched from the US Navy's Pacific missile range facility it is the second of up to eight flights for the Hypersonic International Flight Research and Experimentation (HiFire) programme. HiFire flight one took place in May this year in Woomera, Australia.

The HiFire programme's partners include the AFRL propulsion and air vehicle directorate, Alliant Techsystems, the Australian Defense Science and Technology Organisation, Boeing and NASA's Langley Research Center. Originally the US/Australian hypersonic effort had planned 10 flights, but it now has up to eight.

Source: Flight International