Air force seeks development of fly-back launcher enabling heavier payloads to be placed into orbit at lower cost
The US Air Force has taken a major step in its responsive spacelift strategy, calling on industry to begin designing a next-generation, flyback booster that can launch from 4.5t (10,000lb) to more than 18t into low-Earth orbit (LEO).
The plan is significantly more ambitious than the Falcon small launch vehicle programme sponsored by the Defense Advanced Research Projects Agency (DARPA), which seeks to lift only a 450kg payload into LEO.
The so-called Affordable Responsive Spacelift (ARES) programme proposes a $200 million effort to develop a family of hybrid, three-stage-to-orbit launch vehicles. At the programme's heart is a new, reusable suborbital launcher that can release two expendable upper stages carrying the payload. ARES must be ready to launch within 24-48h and reduce launch costs by one-third to one-sixth compared with existing boosters.
The programme will move into sharper focus next month. The USAF's Space and Missile Systems Center (SMC) plans to award multiple contracts in May to initiate design studies for the new ARES family, followed 18 months later with follow-on contracts to develop a subscale demonstrator that can be prepared for launch by 2010.
A notional USAF design concept envisages a winged flyback vehicle. It would be propelled to an altitude of about 200,000ft (61,000m), achieving speeds in excess of Mach 6, where the two upper stages would be released on an orbital trajectory. The booster then begins an autonomously guided return trip, aided by onboard jet engines and active control surfaces.
SMC says the booster's propulsion and guidance will rely on already mature technologies, with system integration posing the biggest development challenge. Industry views USAF's cost projections for the $200 million development phase as a major risk driver, with the actual costs of developing a new reusable launch vehicle predicted to be hundreds of millions of dollars higher.
Source: Flight International
