The RD-180 Russian-produced American booster Atlas 5 is turned off for five seconds when a previously scheduled launch to the ISS cargo spacecraft Cygnus, made March 22, edition of Spaceflight Now with reference to the unnamed representative of the company United Launch Alliance (ULA) is a developer and manufacturer of the rocket.
The incident resulted in a pull and a speed stage of the first stage was lower than planned. ULA, the representative stressed that the Atlas 5 has had enough time to correct the situation and deliver Cygnus to the point of separation.
According to Spaceflight Now, United Launch Alliance working to identify causes of abnormal situations with the first step to take if necessary measures before the next run.
Centaur upper stage the block had to work a minute longer than planned, the newspaper notes SpaceNews with reference to telemetry data that shows NASA Television. Industry sources told the publication that it was probably done to compensate for premature deactivation of the first stage.
At a press conference held after the launch, ULA coordinator for cooperation with NASA Verne Thorpe suggested that additional work of the engine of the upper stage to fit in standard deviation calculations. “Before running calculations designed to show exactly when will occur an event, based on prior trajectory. Usually they are made for a few weeks before the start”, he said, noting that “nothing unusual” in that the specific conditions of each run cause the slight variations of design parameters.
The representative ULA Ling Hassan SpaceNews has confirmed that the first stage was six seconds shorter than planned, but did not say what caused it. She noted that despite the setbacks, the launch should be considered a success.
In a press release, ULA after the launch on March 22, information about abnormal operation of engines no.
The USA consider possibility of refusal of the Russian RD-180 engines used in the Atlas 5 missile production ULA, a joint venture of Boeing and Lockheed Martin. According to the Deputy head of the Ministry of defence of the USA Robert Wark, the RD-180 will have to use until at least 2022.
Аtlas 5 is one of the two main types of carrier rockets, which uses the Pentagon. At the end of 2015 ULA signed a contract for the purchase of another 20 RD-180. In early 2016 the Pentagon has awarded two contracts worth $162 million for the development of rocket engines, which should come to replace the Russian product.