Due to U.S. Government export control requirements, International Launch Services (ILS) is limited to sharing only public domain information regarding the July 5, 1999 Proton launch failure investigation.
Following is an English translation of an exclusive interview given to Izvestia on July 27 by Anatoli Kiselev, Director General of Khrunichev State Research and Production Space Center (Khrunichev), regarding the investigation surrounding the July 5, 1999 scheduled launch of a Proton launch vehicle carrying the Raduga spacecraft from the Baikonur Cosmodrome in Kazakhstan. Click here for the full Izvestia interview in Russian.
"The cause of the failure has been established. A fire started in the number three engine of the second stage. The fire was started by a stray aluminum particle in a seam between the cover and the apparatus as a result of a defect in a weld. Such stray particles may enter the apparatus from the fueling equipment through personnel neglect or can be blown in by a turbo pump. The engines were designed by Khimavotmatika Design Bureau and are being manufactured at Voronezh Mechanical Engineering Works.
Tuesday morning [July 27] we expect our Subcommission to come back from Voronezh. They were there to investigate the fifth "control" engine, which remained on the ground. Their findings would add a last touch to the Commission¿s deliberations. In the Commission¿s conclusions, it is stated that we will upgrade the turbopump design and install a filter that is to protect us from fire which can be caused by an spurious strays [particles]. We are not entirely happy with the fueling equipment as well. We were planning to perform all these upgrades in 2000 anyway, but this failure presses us to do it earlier than we expected.
An important thing is that this failure is of a singular manufacturing nature. The failure has not lowered our estimate of Proton reliability beyond the reference level. We have always said that we might lose as many as four launch vehicles out of 100 [i.e., achieve 96 percent reliability]. In reality, however, we are losing even less.
On July 28, we are to hold a meeting with Lockheed Martin to consider a U.S. satellite for Intersputnik. Our American partners do not question Proton performance. Through the end of this year, we may launch another four Western spacecraft. On July 29, Klebanov [Ilya Klebanov, Deputy Russian Prime Minister], Koptiev [Yuri Koptiev, Head of the Russian Space Agency] and myself are leaving for Kazakhstan to discuss the timeframe when the Kazakh Government is going to be ready to abolish the moratorium on Proton launches."
Following is the sequence of events leading up to the launch failure, as provided by our Russian partners at Khrunichev.
The first 277 seconds of the flight were nominal. The first stage and the fairing separated faultlessly, and the dynamic loads were within the average statistical range.
At 277 seconds into the flight (111 km altitude, about 50 seconds before the planned separation of the second and third stages), the second stage engine failed, destroying itself, along with elements of the rear section of the stage and the bottom of the second stage fuel tank.
This is confirmed by the instantaneous cessation of all the telemetry channels from the second stage. The third stage and upper stage telemetry data continued, allowing the restoration of the course of events subsequent to the 277 second point in flight.
At 277.35 seconds, a depressurization of the fuel tank occurred, accompanied by discharge of the fuel component.
At 277.50 seconds, a depressurization of the oxidizer tank occurred, accompanied by escape of the oxidizer.
The drop of pressure in the tanks was accompanied by an impulse of increased longitudinal acceleration and by lateral disturbances.
The mated configuration of the second stage remains, the completely fueled and intact third stage, and the Breeze M upper stage with the Raduga spacecraft continued to follow a ballistic trajectory.
As the third and upper stages are the heaviest, the vehicle was oriented with the spacecraft ahead upon reentry.
At an altitude of approximately 30 km, the vehicle experienced an [aerodynamic] impact of considerable dynamic and heat loads, causing its destruction.
While the debris impact points lay along the vehicle trajectory, they fell some kilometers short of the expected landing point as they dispersed when they were destroyed in the atmosphere.
The analysis of available telemetry information has led to the following conclusions:
The Breeze M upper stage successfully went through maximum acoustic, static and vibration loads. All of the systems of the upper stage, including its control systems, continued their normal operation, even after failure occurred.
The new nose fairing especially designed for the Breeze M upper stage was flawlessly jettisoned at the planned time.
The actual loads at the spacecraft interface during critical events (i.e., liftoff and first stage burnout) were lower than the average statistical values of the loads registered during launches of a Proton vehicle with the Block DM upper stage.
Up to 277 seconds into the flight, no deviation from normal behavior of the Proton launch vehicle or its systems was recorded.
While definitive conclusions will be drawn upon completion of the failure investigation by the Russian State Commission, the Proton launch failure appears to have been caused by the destruction of the turbopump unit of Engine #3.
Following are additional updates from ILS on the progress of the failure investigation.
While all Proton launches remain on hold pending the outcome of the July 5, 1999 Proton launch failure investigation, ILS is engaged in ongoing efforts to ensure that return to launch dates remain as close as possible to those dates contracted by our customers.
ILS has also established an independent Failure Review Oversight Board on the Proton failure. Details concerning the makeup of the board, as well as the timing of its findings, will be released as soon as our U.S. Government license to engage in technical discussions with Khrunichev regarding the failure is approved.
In the meantime, ILS has been advised that release of the Russian State Commission preliminary report has been delayed until the first or second week of August. The availability of this report is contingent upon its release into the public domain or our license approval.
ILS remains committed to sharing updates on the progress of the failure investigation with our customers as soon as new developments occur.
