Aerojet and Orbital Sciences, along with Aerojet's Russian partner, SNTK, have announced that a series of NK-33 rocket engine tests conducted in Samara, Russia were successfully completed in support of the development of Orbital's Taurus II space launch vehicle.

The purpose of the extended-time testing of the NK-33 engine, on which the AJ26 first-stage engine for the Taurus II rocket is based, was to demonstrate a 'hot-fire' duration equal to two times a normal Taurus II acceptance testing and launch profile duty cycle. Over the last two weeks, three tests were conducted by SNTK with a cumulative duration of more than 600 seconds.

These tests verified the significant technical margins on engine performance and durability required by Orbital's Taurus II development program.

GenCorp President and CEO and Aerojet President, Scott Seymour, said, "Completing the margin testing is a significant milestone in Aerojet's contract with Orbital. This success demonstrates the engine's robust design and its ability to operate at the power levels and duration times compatible with the Taurus II flight profile with additional performance margin."

"The success of the NK-33 engine tests in Russia is an important step forward in the development of the Taurus II rocket," said Ron Grabe, Orbital's Executive Vice President and General Manager of its Launch Systems Group.

"With the performance of the heritage engine now confirmed and well understood, we can move forward with confidence to configuration verification and acceptance testing of AJ26 engines at NASA's Stennis Space Center in Mississippi beginning in April."

Aerojet is the provider of the AJ26/NK-33 rocket engine for the first stage of the Taurus II launcher. The basic NK-33 engine was originally designed and produced in Russia for the Russian N1 lunar launch vehicle.

Aerojet subsequently purchased approximately 40 of the basic NK-33 engines in the mid-1990s and, under contract with Orbital, the company is currently modifying the engines specifically for the Taurus II launch vehicle.

Aerojet and Orbital are scheduled to begin ground testing of the AJ26 engine at NASA's Stennis Space Center in Mississippi in less than two months. The U.S.-based testing will validate the Taurus II specific engine configuration and continue to build on the extensive engine database that includes more than 17 years of development testing, encompassing approximately 1,500 engine-level tests totaling 194,000 seconds of firing duration.

After the design verification tests are completed at Stennis, regular production acceptance testing will be initiated, paving the way to the first flights of the Taurus II rocket in 2011.