Here’s a bit of interesting information: it appears that NASA officials had known for several years that old Soviet-era rocket engines are very unreliable, that they could crack (which they did repeatedly), leak fuel and in this way become a source of imminent danger for entire launch missions. And, eventually, that danger became a fact along with the catastrophic failure of an Antares commercial rocket just several brief moments after the rocket liftoff from the launch pad.
According to an article written by Melody Petersen from Los Angeles Times, this fact is clearly indicated by the U.S. government documents. These documents show that as early as 2008 a NASA committee investigating safety and reliability issues issued a warning stating the “substantial” risk associated with the use or practically obsolete launch vehicles.
The government documents cited sayings from top official from Orbital Sciences, the NASA’s contracted rocket building company, who criticized “fundamental flaw in the materials” used to produce these engines. There is no wonder such danger was present – the Soviet engines were built back in sixties and seventies, and definitely not every machine is capable of surviving several decades of storage, especially considering stringent requirements of rocket launch missions.
“They were never designed to be in storage that long”, said the Orbital Sciences manager Ken Eberly. Currently there is no official release stating exactly for how many years did the engines stay in the storage before the October launch.
The first stage of Antares rocket (the same as the one that exploded during the launch) is powered by two Aerojet Rocketdyne AJ-26 engines. The AJ-26 engine was first developed over 40 years ago as an NK-33 engine, manufactured by the Kuztensov Design Bureau of the former Soviet Union. All four launch attempts failed, and the program was ultimately canceled before the NK-33’s could be used. It seems that a sufficiently large batch of those engines has been manufactured, because they had not been dismantled and were stored in a warehouse for nearly 30 years. Then Aerojet purchased and imported dozens of these engines, refurbished them, renamed them to AJ-26, but the underlying technology and materials remained the same.
The Orbital rocket explosion raised many questions concerning the oversight of the program which was from the start intended to increase the reliability and safety of modern rocket vehicles while also saving a great deal of money. And, according to the article, the poor-reliability facts were known quite before the NASA awarded the Orbital Sciences with a 1.9-billion USD deal.
Of course in many cases it is much cheaper to use existing engine (but older and of questionable performance though). Some repairs should fix all the matters, shouldn’t they? (and that was the strategy employed to develop an innovative spacecraft!) And repairs were certainly attempted: an X-ray imaging was used to detect cracks, which were patched later using welding equipment.
Now some more facts: it appears that NASA officials knew before October explosion that the repair of old engines did not go as planned. Well, it’s not a 100% financial loss for Orbital Sciences, as under the NASA’s contract conditions 80 percent of the launch cost is awarded to the builder even if the rocket explodes. And, as both organizations new about the potential danger, it is very likely that the responsibility regarding the accident will be shared in some form with the U.S. government.
Now the private rocket building company plans to switch all of the subsequent developments to newly manufactured Russian engines. Most certainly, these engines will be used in six remaining cargo launches under the existing agreement with NASA.
Written by Alius Noreika