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BOEING DEVELOPS DELTA IV

The Delta was originally developed out of a requirement by NASA for a launch vehicle which would transport payloads of up to 200kg into low Earth orbit. The design was to be based on a combination of the Thor intermediate-range ballistic missile as its first stage and the modified upper stages of the Vanguard.

Having thus evolved from the earlier Thor Able and Thor Able Star versions, the Thor Delta version was developed at McDonnell Douglas Astronautics Co. (MDD) at the end of the 1950s / beginning of the 1960s, and in the DM-19 version it was successfully launched for the first time on 12 August 1960, carrying the communications satellite Echo 1A into space.

Altogether 186 of the first generation were launched, the last one on 12 June 1990 with the Indian earth satellite Insat 1D. Only 12 of these launches went wrong, which is an extremely good record. However, production of the Delta was terminated in 1981 after 24 years in service on the orders of the American president who wanted to switch to the new Space Shuttle transport system to perform all future commercial and military satellite launch operations.

The Challenger catastrophe on 28 January 1986 put a stop to these plans. Conventional rockets were given a second chance and, with the assistance of the US Air Force, the new Delta II generation was developed under the Medium Launch Vehicle (MLV) programme at McDonnell Douglas. By November 2000, ninety-three of these rockets had delivered their payloads into orbit, with only one failed launch, a testimony to the excellent reliability of the series.

But in the meantime the squeeze was on both at NASA and at the US Air Force Space Command. In the wake of the collapse of the Soviet Union and its satellite states, the politicians were now asking for greater effectiveness but at reduced cost. Whereas in the era of the Cold War all one had had to do was present a convincing case that something was in the interests of national security and billions of funding would be forthcoming, today these institutions lose out when manufacturers and suppliers undercut a cost framework that has been set.

The new frugal approach led at the beginning of the 1990s to the Evolved Expendable Launch Vehicle (EELV) programme which the Air Force initiated in order to be able to implement future launches more cheaply with the Delta (MDD) and Atlas and Titan (Lockheed Martin) launch systems. In November 1996 the initial phase of the EELV programme, Low Cost Concept Validation, (LCCV), under which the Boeing Company, the Lockheed Martin Corporation, McDonnell Douglas Aerospace and Alliant Techsystems each received $30 million to submit appropriate cost reduction studies, was successfully completed.

During the second phase, the 17-month long Pre-Engineering and Manufacturing Development phase which lasted to 1998, Boeing, now owner of the Delta family, and Lockheed were each awarded $60 million contracts to refine their system concepts and complete their draft designs. In the meantime the third phase, which entails Development Agreements and Initial Launch Services (ILS) contracts, has already begun. Under these, Lockheed and Boeing have until 2006 to complete engineering and manufacturing development (EMD) of the launch vehicles, launch pads, satellite interfaces and support infrastructure, as well as to demonstrate the reliability of their designs via two system launches.

In view of the increasing trend towards larger satellites and the higher take-off weights this implies, MDD in a separate initiative launched a new project to develop the Delta III launch vehicle, which in its basic configuration is similar to the Delta II 7925 (the 7 stands for the type Delta II standard, the 9 for the number of boosters, the 2 for the default two stages and the 5 for the third stage PAM-D). On the other hand, in the Delta III 8930 the 8 stands for the Delta III, the 9 in turn for the number of boosters and the 30 for the new third stage with the new RL-10B-2 Pratt & Whitney engine, whose nozzle is supplied by the French space company SEP.

The second stage was also a new development, with a diameter of 4m. At its lower end it holds the fuel tank for the first stage, in the middle is the RL-10 with the tanks for liquid hydrogen and liquid oxygen and, above this, the payload fairing. In this configuration the rocket, at 41.1m, is only very slightly longer than its predecessor but, with its wider diameter towards the top, it seems a lot bulkier. But above all its payload capacity has now significantly increased.

On 26 August 1998 and 4 May 1999, the Delta III also carried out the two required qualification launches, but both ended in disaster: on the first flight the rocket had to be blown up due to hydraulics problems, as a result of which the communications satellite Galaxy 10 was lost, while on the second mission the combustion chamber for the upper stage tore, so that the Orion 3 satellite was not placed in the correct orbit.

Under the original EELV tender terms these two incidents would have meant Boeing was in breach of its contract; however, in the previous months the terms had been modified several times, since Lockheed was also reporting technical problems. Moreover it had become apparent that the timescale for the demanding work had been set far too tightly. The new variants of the old Delta and their rival Atlas were far more complicated than the Air Force officials had assumed. Nevertheless the causes of the second Delta failure were found to include defective quality control and errors in the production process at Pratt & Whitney, so that it was no longer Boeing's engineers who were to blame.

So Boeing got a third chance, which it used on 23 August 2000. For all those involved, it was a weight off their minds when the telemetry reported that the DM-F3 simulated satellite had been successfully launched. It had been necessary to launch a simulated payload because Boeing's marketing people had not yet succeeded in finding a new customer for the apparently unreliable vehicle. Although originally the transport of a telecommunications satellite for the ICO company had been agreed at extremely favourable conditions, the company was forced to file for bankruptcy before the contract could be signed.

In the meantime, around two years behind schedule, Delta III was finally certified and has also clocked up 18 orders. Eleven of these, however, are from within the company, now that Boeing has taken over the satellite manufacturer Hughes. Whether the company can really make any money with the new rocket lies in the hands of the stars, given the programme slippage.

For Delta III was to have been the link between Delta II and Delta IV, which also uses the RL-10 engine in the third stage. It now seems likely that Delta III and IV will be operated in parallel for a certain period, and that this will only cause additional costs. Only Delta IV is really intended to transport both medium and heavy payloads and, as such, is the only one capable of satisfying the EELV requirements.

Its maiden flight is planned for 2001, and if this is a success, Boeing can expect 19 follow-on orders worth $1.38 billion between then and 2006. Thus Boeing is in a tight spot.

From page 42 of FLUG REVUE 3/2001