Tim Furniss/LONDON

A key marker in the development of the ILS International Launch Services Atlas III takes place this month when a prototype booster stage with a Russian-based RD-180 engine will be test fired at NASA's Marshall Space Flight Center in Alabama. In early 1999 the Atlas III is planned to become the first US launcher to fly under Russian power - as the Atlas IIIA - carrying a Loral communications satellite.

The RD-180 - the world's highest-performance liquid oxygen/kerosene rocket engine and a version of the powerplant that powered the strap-on stages of the Energia heavylift booster - has already been test fired for 9,000s (the equivalent of 48 Atlas launches) by NPO Energomash at Kimky, in Russia. Energomash is working on a joint RD-180 programme - called RD Amross - with Pratt & Whitney of Palm Beach, Florida, under a contract from Lockheed Martin to build 101 engines.

US/Russian company ILS, of San Diego, California, has introduced another Atlas III booster to its commercial fleet. Called the Atlas IIIB, it will make its maiden flight in 2000 and will be able to carry a payload of 4,500kg into geostationary transfer orbit (GTO).

This compares with the 4,055kg of the IIIA; the 4,615kg of its ILS sister booster, the Proton K; and the 4,670kg into GTO performance of the Ariane 44L - Arianespace's most powerful booster until the Ariane 5 is declared operational, possibly later this year.


ILS (comprising Lockheed Martin Commercial Launch Services and the US company's LKEI joint venture with Russia's Khrunichev and Energia) and Arianespace will face increasing competition over the next year, with the introduction of the Boeing Delta III and Boeing-led Sea Launch venture, as the launch market heats up - with the help not only of Russian technology, but the buying power of the US Air Force.

The Russian Proton K is marketed by ILS, which will introduce a new Proton M to increase GTO performance to 5,500kg. The US Air Force's Evolved Expendable Launch Vehicle (EELV) contracts, to be awarded to both Boeing and Lockheed Martin in June, will create new commercial launchers. Lockheed Martin's EELV proposal is based on the Atlas III core stage, and Boeing's Delta IV partially on its Delta III, but with a new Rocketdyne first stage engine.

The Atlas IIIA was originally called the Atlas IIAR, while the Atlas IIIB is a new design, replacing the original Atlas IIARS, the IIAR with four solid strap-on boosters, as used on the current Atlas IIAS. The Atlas IIA and the IIAS are powered by Boeing Rocketdyne core stage MA-5As. ILS has retired the Atlas I and II from its fleet.

The first stages of the current Atlas IIA and IIAS versions are basically the original Atlas intercontinental ballistic missile, which - in various forms with upper stages - has flown almost 550 missions in 40 years. All but two of the ILS Atlas versions fly with a Centaur upper stage equipped with two RL-10 cryogenic engines. The exceptions are the IIIA, which will use one RL-10A, and the IIIB, which will fly with a stretched Centaur with two RL-10As. The Atlas IIIs require 15,000 fewer parts.

Atlas launches are from two pads at Launch Complex 36 at Cape Canaveral, Florida (for GTO launches), and a new pad, Complex 2E, at Vandenberg AFB, California (for polar orbit launches). The Vandenberg pad has its debut, launching the NASA Earth Observing System AM 1 polar orbiter in December.

Source: Flight International