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Home | Update | LATEST ISSUE | Gallery | FR Profile | Datafiles | FR 2/98 250TH DELTA LAUNCHED by Wolfdietrich Hoeveler When on 10 November, 1997, a Delta II took off from Vandenberg AFB, California, it was the 250th launch of this rocket type, for which its manufacturer had claimed a 100-percent reliability at the beginning of the nineties. The Delta's history reaches back into the fifties when McDonnell Douglas modified the Thor medium-range missile into a Thor-Delta for the launch of satellites. On 1 May, 1960, this rocket was used the first time to carry a satellite into space. However, the mission of Thor-Delta with Echo I failed. In August of that year, the launch of Echo IA was successful. Since then, the Delta has become the workhorse of NASA and the US Air Force. The Delta was used up until the beginning of the eighties. After the Space Shuttle had become operational, the Delta production ceased. Following the tragic Challenger disaster, the production was started again after President Reagan had suspended the transport of commercial satellites with the Shuttle. Beginning in 1989, McDonnell Douglas produced the new Delta II. A first contract asked for 20 rockets. This allowed McDonnell Douglas to commercially market this launch rocket. Since then, Delta II was modernized and its performance improved. Today's system is able to carry satellites weighing up to 1,8 tons into a geostationary transfer-orbit, and up to 5,1-ton payloads into low earth orbits. The first stage is powered by a Rocketdyne-R-27A engine, generating 1052 kN thrust in high altitudes. The engine can be supplemented by three, four, or nine solid-fuel boosters, the so called Strap-on Solid Rocket Motors (SSRM) with the GEM system (Graphite Epoxy Motor) by Alliant Techsystems. The second stage is fitted with an Aerojet-AJ10-118 motor and the third is powered by a Star 48. Delta III is the newest version of the Delta rocket family. It was developed with company funds and is supposed to fly for the first time in 1998. Delta III will be able to carry payloads up to 3,8 tons into a geostationary orbit and up to 8,3 tons in low earth orbits. The main engine, the boosters and further parts of the avionics were taken from the Delta II. With Delta IV, Boeing is competing for the US Air Force tender for a new launcher that is supposed to be able to carry payloads between 2,1 and 14,9 tons into a geostationary orbit. With a price of 12000 US dollars per pound of payload, Delta IV is cheaper than its predecessors. The first testflight is scheduled for 2001. From page 45 of FLUG REVUE 2/97 Home | Update | LATEST ISSUE | Gallery | FR Profile | Datafiles | FR 2/98 Copyright 1998 by Motor-Presse Stuttgart. All rights reserved. Last updated January 9, 1998 FLUG REVUE, Ubierstr. 83, 53173 Bonn, Germany