First launch of the Lockheed Martin Atlas V is due this week, in what head of the development  programme John Karas describes as "the most important [launch] in the history of the Atlas".

With the downturn in the satellite and launcher industry, and increasing competition between the Atlas, Arianespace Ariane 5, and Boeing Delta launchers, Lockheed Martin considers the Atlas V flight on 21 August as crucial to its future in the launch business.

The flight will be the first of a launcher built under the US Air Force Evolved Expendable Launch Vehicle (EELV) programme. The Atlas V 400-series booster will fly an International Launch Services (ILS) mission, carrying the Eutelsat Hot Bird 6 communications satellite from launch pad 41 at Cape Canaveral.

It will be followed by Boeing's first Delta IV EELV launch in October, also carrying a Eutelsat satellite. Karas says it is a case of "he that launches first and successfully and often [having] an impact".

The US Air Force awarded Lockheed Martin and Boeing contracts worth a total of $3.03 billion in 1998 for the EELV programme to replace Atlas I and Il, Delta II and Titan IV boosters. Each received $500 million for engineering and manufacturing development, while Lockheed Martin was awarded $650 million for nine Atlas V launches, and Boeing $1.38 million for 19 Delta IV launches.

Lockheed Martin's EELV launches have since been cut to seven and Boeing's increased to 22.

Both vehicles are offered on the commercial market and will be the USA's launcher workhorses for several years, eventually completely replacing earlier models.

The Atlas V is based on the ILS-operated Atlas III series, which is powered by the Russian RD-180 liquid-oxygen/kerosene stage throttleable first engine. The newvehicle incorporates a strengthened first stage.

Like the Atlas III, the Atlas V will use one or two RL-10A Centaur second-stage engines. Atlas IIIA and IIIB models have already been launched.

There may be up to 19 Atlas V models, some with solid-rocket motors, which are capable of carrying payloads of up to 8,670kg (19,070lb) to geostationary transfer orbit (GTO) or 20,520kg to low-Earth orbit.

The Hot Bird 6 launcher will be a basic 401 model equipped with a single Centaur stage, no solid rocket boosters and a 4m (13.1ft)-wide fairing, with a 4,950kg to GTO capability.

The Atlas V is manifested to fly in 2003 as an EELV carrying a US Navy Geosat F/O 2 and a Wideband Gapfiller Satellite. Lockheed Martin has six commercial contracts for the launcher, including an Inmarsat 4 satellite and the Nimiq 1 satellite.

Source: Flight International