Tim Furniss/LONDON
Boeing's first Delta III commercial booster exploded on its maiden flight about 70s after launch from Cape Canaveral, Florida, on 26 August. The Hughes PanAmSat Galaxy X satellite was lost in the $277 million failure.
Boeing said that the Delta III began to malfunction at T+55s when it started to roll abnormally, followed during the next 10s by pitch and yaw oscillations. The vehicle's self-destruct system is thought to have operated at T+70s, also triggering a destruct signal from the ground 5s later. Despite that, part of the booster appeared to plummet intact into the Atlantic Ocean 11km (6 miles) downrange, exploding on impact.
Video coverage of the final moments of the flight at about 16km altitude show a ball of fire and five intact "dots", indicating five of the booster's Alliant Techsystems graphite-epoxy solid rocket boosters, and a secondary fireball and debris which may have been a malfunctioning sixth booster. The incident occurred about 10s before the first six strap-on boosters - which are ignited at launch - were to be jettisoned, allowing three others to ignite in flight before being discarded at T+159s. Boeing says that it is too early to tell what caused the accident. An official investigation has been ordered.
The Delta III is a radically uprated model of the Delta II, including a larger diameter first stage fuel tank, a new cryogenic upper stage, larger strap-on boosters and a large composite payload fairing. The launcher - which provides more than double the geostationary transfer orbit launch capability of the Delta II, to 3,810kg - is manifested for 17 commercial launches.
The Delta failure follows the explosion after launch from Cape Canaveral of a US Air Force Lockheed Martin Titan 4A on 12 August in a $1 billion loss of the booster and an electronic intelligence satellite.
As records show that almost one-third of all maiden flights of new boosters fail, the wisdom of the decision to carry a fully fledged commercial satellite on the Delta III has been called into question by observers.
PanAmSat lost the Galaxy IV satellite in orbit in May and experienced the partial loss of Galaxy VII systems in June. The company will continue to provide services that were to have been provided by the new launch by retaining the Galaxy IX and SBS 5 satellites at their orbital stations.
Source: Flight International
