posted 08-25-2011 09:25 AM               

NASA And ATK Full-Scale Solid Rocket Motor Test Set For Sept. 8

NASA and Alliant Techsystems Inc. (ATK) will conduct a full-scale test of a five-segment, solid rocket motor at the ATK Aerospace Systems test facility in Promontory, Utah, at 2:05 p.m. MDT, Thursday, Sept. 8.

The static firing of the five-segment solid rocket motor, designated Development Motor-3 (DM-3), will last approximately two minutes. DM-3 is the third in a series of development motors and the most heavily instrumented solid rocket motor in NASA history, with a total of 37 test objectives measured through more than 970 instruments.

The DM-3 incorporates several performance-based improvements to the designs of the first two development motors. Additionally, the core of DM-3 will be heated to 90 degrees Fahrenheit for this full-duration firing to verify the motor's performance at high temperatures.

This test will continue to advance understanding of five-segment solid rocket motor performance and specifically assess performance at the highest end of the motor's accepted temperature range. Through development testing, the solid rocket motor will be certified to fly at ambient temperatures ranging from 40 to 90 degrees Fahrenheit.

The DM-3 test will follow wind constraint requirements different than past development motors. Two days before the test, ATK's public relations will notify registered media of a go/no-go decision. If no-go, the test will slip to the next day. Notification of a decision to proceed will be made via email, website and social media (Facebook and Twitter).

The solid rocket motor is managed by NASA's Marshall Space Flight Center in Huntsville, Ala. ATK Space Systems is the prime contractor.

posted 09-08-2011 03:31 PM               

NASA and ATK test five-segment solid rocket motor

(Video quality artifact of original live stream). Credit: ATK

During the test, DM-3's flame exited the motor at Mach 3 and burned for 125.6 seconds.

The gas temperature inside the chamber was about 5,630 degrees Fahrenheit.

The temperature of the flame escaping the nozzle approached 4,500 degrees F, approximately two-thirds the temperature of the Sun. At that temperature, steel does not just melt, it boils.

Following the test, the motor was sprayed with 2,300 gallons of water per minute until the cases are cooled from 1,000 F to 300 F. The quench systems sprayed 30,000 pounds of carbon dioxide gas into the nozzle exit cone to stop the burning.

posted 09-09-2011 12:49 AM               

ATK conducts 3rd successful test of next generation solid rocket motor

ATK today (Sept. 8, 2011) conducted a third successful ground test of the next-generation solid rocket motor. The successful test, known as Development Motor (DM-3), is an important milestone in further validating the rocket's potential use in heavy lift and commercial launch vehicles.

Initial test data indicate the motor performed as designed, producing approximately 3.6 million pounds of thrust, or 22 million horsepower, and burning for just over two minutes.

"This test is the third in a critical series of static tests to evolve and confirm the motor configuration while providing applicable technology maturation for next-generation systems," said Charlie Precourt, vice president and general manager, ATK Aerospace Systems, Space Launch Systems. "This milestone is another step towards completing our Critical Design Technical Interchange activity this fall."

The main test objectives from today's static motor firing were measuring the five-segment rocket's performance and verifying the performance of new materials in the motor joints at hot temperatures. Intentional flaws were introduced in the joint to allow hot gas to penetrate into part of the robust joint to verify joint performance.

DM-3 is the largest human-rated solid rocket motor built today, measuring 12 feet (36.5 m) in diameter and 154 feet (47 m) in length. The five segment motor is based on the space shuttle's four segment boosters, but it's been upgraded to incorporate modern technologies and materials that were not used on the shuttle booster. As a result it produces 30 percent more power than the four-segment motor while utilizing new materials that provide cost and weight savings.

Along with the motor development, ATK has been consolidating its facilities, workforce, and processes to further reduce the cost of producing the solid rocket motors. The five-segment motor was designed to maximize astronaut safety while providing the United States with an affordable and reliable launch capability for both crew and cargo missions.

"The data from these tests, along with information we have collected over the past three decades, confirms this is the most powerful solid rocket motor ever designed," said Precourt. "This performance makes the five-segment a great solution for heavy lift launch vehicles."