US manufacturer Aerojet informally unveiled a "brand new" rocket engine programme at the International Astronautical Congress in Naples, Italy in early October.

The new AJ-1-E6 dual-combustion chamber engine has been designed to have total thrust of 1 million pounds (4448kN). It is one of the engines bidding to power the two external boosters of later versions of the US Space Launch System (SLS) heavy lift rocket, with which NASA plans to launch astronauts on missions to the Moon, asteroids and eventually Mars.

Julie Van Kleeck, vice president of Aerojet's space and launch systems confirmed that a "risk reduction" demonstration contract under the NASA SLS programme was still under negotiation. "We are negotiating for a contract involving technology risk reduction for an engine of 1 mllion pounds thrust," says Van Kleek.

Van Kleek was careful to describe the AJ-1-E6 as "brand new engine." Often, 'new' rocket engines are derivative of existing designs.

Christopher Crumbly, manager of the NASA SLS Advanced Development Office, noted that the firm will be demonstrating the engine design's resistance to combustion instability, a pressure oscillation phenomenon that has dogged several liquid fuel engine designs.

Crumbly would not comment on the progress of the negotiations but he did note that the engine had been named AJ-1-E6 engine (previously dubbed AJ-1000 by informed analysts) after the scientific notation for one million pounds (i.e. one times ten to the power of six).

 SLS launch pad


The new engine is to use the highly efficient oxygen-rich staged-combustion cycle similar to that of the firm's smaller AJ-26 series, which is essentially a refurbished Russian NK-33 liquid oxygen(LOx)/kerosene-fuelled rocket engine designed for the Soviet Union's N-1 moon launch vehicle. Van Kleek noted that the new engine could also be used for other US launch vehicles.

Some US politicians have urged that USA should reduce its over-reliance on Russian designed LOx/kerosene rocket technology. For example, the United Launch Alliance Atlas V, one of the US standard launch vehicles, uses a licence-produced RD-180 Russian engine.

The announcment comes after three other SLS booster 'risk reduction' demonstration contracts were signed by NASA in early October with three teams: ATK for the construction and testing of the composite stucture, nozzle and avionics of its Advanced Solid Rocket Booster, Dynetics/Rocketdyne to demonstrate turbopump and gas generator hardware for its 1.8 million lb thrust F-1A engine derivative, and Northrop Grumman for in situ/autoclaveless manufacturing techniques concerned with composite fuel tanks.

Source: Flight International