Graham Warwick/LONG BEACH

Boeing-led joint venture Sea Launch and the company's Delta Launch Services business are drawing closer as Boeing prepares to introduce its Delta IV booster early next year.

When the Delta IV enters commercial service, Boeing will have two launchers, able to lift large communications satellites weighing up to 6,000kg (13,200lb) into geostationary transfer orbit. The company plans to market the two vehicles co-operatively, to provide customers with increased launch reliability and flexibility, says Sea Launch president Bill Trafton.

As a first step, the two operations have signed an agreement under which each will provide back-up launches for the other. "The customers have asked for it," says Delta Launch Services vice-president Dave Schweikle.

Sea Launch plans its next flight on 7 May, with a second attempt to launch XM Satellite Radio's XM-1 spacecraft. The first attempt was aborted earlier this year, seconds before lift-off of the Zenit-3SL three-stage booster. The venture will launch PanAmSat's Galaxy IIIC later this year and there are six flights planned for next year, including four for unannounced new customers, as part of its backlog of 16 firm launches.

Boeing, meanwhile, has agreed with its Russian and Ukrainian Sea Launch partners to market commercial launches on the land-based version of the Zenit booster (Flight International, 24-30 April). This two-stage vehicle, to be launched from Baikonur, will be aimed at the low Earth orbit market. The land-based vehicle will be added toSea Launch's portfolio and is likely to be marketed as a complement to Boeing's Delta II.

Four launches of the new Delta IV are planned for next year. Boeing is still negotiating with a commercial customer for the first flight in March. "If we don't reach an agreement, we'll fly a demonstration payload," says Schweikle. The second launch, in the second quarter, will be the first for the US Air Force of a DSCS III communications satellite. Space Systems/ Loral has purchased the third flight, in the third quarter, to launch Brazil's Estrela do Sul communications satellite. The fourth launch, in the fourth quarter, will be a USAF-funded demonstration flight of the Delta IV Heavy.

Boeing plans eight Delta II launches next year, but no flights of its new Delta III. The company has a backlog of five Delta III launches, all for New ICO, the first three of which have been pushed back from 2002 to 2003.

Schweikle says Boeing will build no more than 20 Delta III launchers. "Most satellites coming along are larger than the payload it was designed for," he admits. The Delta III can lift 3,800kg to geostationary transfer orbit.

Source: Flight International