March 2010 could see the second suborbital ballistic flight to test materials survivability, sensors and avionics for the Hypersonic International Flight Research Experiment (HiFire) effort.

HiFire is to investigate technologies for high-speed weapons by conducting 10 flight tests at hypersonic re-entry and cruise conditions. The high-speed weapons are for global strike capabilities and HiFire is led by the US Air Force Research Laboratory (AFRL) and the Australian defence department's Defence Science and Technology Organisation (DSTO).

For the second flight, planned for 14 March, a two-stage Terrier Orion sounding rocket will send the 105kg (231lb), 2.5m (8.1ft)-long, conical-shaped experimental vehicle into a ballistic trajectory. Speed on re-entry is expected to reach Mach 7.2.

With a 50/50 cost share between its US and Australian partners, HiFire has a budget of $56 million in 2007 US dollars.

USAF HiFire programme manager Douglas Dolvin set out the flight roster at the 16th International Space Planes and Hypersonics Technologies and Systems conference in Bremen in October. "HiFire will expand our knowledge on thermal protection systems, sensors, guidance, navigation and control, as well as aerothermodynamics," he said.

The March flight is referred to as flight one, although it is the second as a "flight zero" has taken place. Launched in May 2009, flight zero ended when the payload broke up at about 81,700ft (25,000m). Based on the loss of radar signal and other factors, the cause of the break-up is thought to be a divergence from the planned trajectory due to an incorrect re-entry.

Another HiFire anomaly is that the remaining seven flights are not taking place in number order. Counting flight zero as the first, in March 2011 the third, fourth and sixth flights will take place and the eighth is in October of that year. The fifth, seventh and ninth launches are a year later in March 2012.

Australia's Woomera test range is the location for seven of the 10 flights, while the US military's Pacific Missile Range is being used for the third and seventh.

The third flight, called flight two, was to have taken place in October 2010 after an October 2009 critical design review. The review will now take place this December. A tenth flight, called 2A, will be at the White Sands Missile Range.

As well as the AFRL and DSTO, Boeing, the University of Queensland and the NASA hypersonics project office are all involved.

Source: Flight International