Missile launches, large space boosters register solid performances

By Clyde Carr, Robert Black and Joseph Majdalani|December 2017

The Solid Rockets Technical Committee works to advance the art, science and engineering of solid rocket propulsion and to foster dissemination of new knowledge in this field.

Solid rocket motor propulsion achieved notable milestones this year in the U.S. and European defense and space industries..In February, the U.S. Navy launched four unarmed Trident 2 D5 ballistic missiles as part of the Follow-on Commander’s Evaluation Test program. Aerojet Rocketdyne and Orbital ATK provided propulsion with integration through Lockheed Martin.

To demonstrate battle readiness of its high-speed defense weaponry, the Missile Defense Agency flew numerous interceptor systems. For example, the Aegis SM-3 Block 2A flew in February using Aerojet Rocketdyne boosters and Divert and Attitude Control System, or DACS, to collect performance data. The Ground-based Midcourse Defense interceptor, Orbital ATK’s Orbital boost vehicle, tracked and destroyed an intercontinental ballistic missile-class target in May. Similarly, in June, Raytheon’s SM-6 Block 1A interceptor completed its final land-based test by destroying a subsonic target in southern New Mexico. In July, the Terminal High Altitude Area Defense system with an Aerojet Rocketdyne booster and DACS intercepted and destroyed an Orbital ATK air-launched target in a real combat scenario over the Pacific.

NASA’s Space Launch System continued testing of its launch abort system. At Orbital ATK in June, the reduced-thrust abort motor was fired and readied for qualification. The corresponding three-valve Attitude Control Motor HT-11 test in May helped verify new hardware and related analyses. Meanwhile, at Aerojet Rocketdyne, the jettison motor completed its third development test. In emergencies, the launch abort system operates by firing the launch abort motor and attitude control motor followed by the jettison motor to prepare the crew module for a safe landing. In October 2016, Aerojet Rocketdyne also static-tested a Blue Origin crew capsule escape solid rocket motor.

Over the year, six Atlas 5 vehicles, powered by AJ-60A strap-on boosters and Orbital ATK retro separation motors, were launched. The Atlas 5 missions included the Cygnus cargo spacecraft to the International Space Station in April and five communications payloads launched into orbit from January through October. Other flights included a Delta 4 with four Orbital ATK Graphite-Epoxy Motor strap-on boosters in March and a Maxus-9 July launch from Sweden using an Orbital ATK Castor 4B first-stage motor. Furthermore, Orbital ATK’s all-solid Minotaur 4 and C launch vehicles (Peacekeeper-derived) placed military and commercial satellites into orbit in August and October.

From a tactical perspective, Lockheed Martin delivered the 2,000th Joint Air-to-Surface Standoff Missile to the Air Force and continued its lethality enhancement flight demonstrations. Aerojet Rocketdyne delivered the 2,500th Patriot Advanced Capability Cost Reduction Initiative tactical missile and the 500,000th PAC-3 attitude control motor used to maneuver the Patriot missile. Aerojet Rocketdyne’s Army Tactical Missile System motor propelled Lockheed Martin’s long-range surface-to-surface guided ATACMS rocket in six consecutive flight tests from November 2016 through May 2017.

Overseas, the European VEGA launch vehicle saw its 10th operational launch, delivering an Israeli optical satellite and the Venus Earth observation satellite. The VEGA employed three Avio Spazio solid rocket motors: P80, Zefiro 23 and Zefiro 9. The Ariane 5 launch vehicle achieved its 95th flight using two boosters from Europropulsion. In related news, the P120C SRM development for VEGA-C and Ariane 6 launch vehicles continued. The first filament wound case was manufactured and shipped for inert casting in September. The P120C has a 3.4-m outer diameter motor and contains 142 tons of propellant. So far, the ArianeGroup has finalized the nozzle design and manufactured the nozzle parts. The first P120C static firing is expected in March 2018.

Contributor: Agostino Neri