TRW has demonstrated an increased-efficiency liquid apogee (LAE) engine designed to increase the payload and extend the on-orbit life of geostationary communications satellites.
The company has completed 25,000s of hot fire testing of a flight-like prototype of its TRS312, demonstrating a specific impulse (Isp) of 325s, 5-10s better than that now available.
LAEs are used for orbital insertion of large geoschynchronous satellites. Increased efficiency is expected to result in reduced propellant mass, as well as potentially lower launch costs, according to the company.
The higher efficiency is made possible by an iridium-coated rhenium thrust chamber able to withstand higher temperatures. The chamber is produced using a powder metallurgy process, which provides increased strength and reliability, according to TRW.
The initial version of the 110lb-thrust (0.49kN) TRS312 burns monomethylhydrazine and nitrogen tetroxide (NTO). The company plans to complete qualification of this engine early next year.
It is also planning a later version, burning hydrazine and NTO, with an increased Isp of 330s.
Source: Flight International