The TR-107 was a developmental rocket engine designed in 2002 by Northrop Grumman for the NASA and DoD-funded Space Launch Initiative (SLI).
[1] [2] The TR-107 was developed by TRW following the successful conclusion of the development program for the TR-106 engine, a similar throttleable engine of about half the thrust burning LOX/LH2 instead of LOX / RP-1.
Tom Mueller, then VP of Propulsion Development at Northrop, was project manager for both the TR-106 and TR-107 engines.
In 2002, Mueller co-founded SpaceX with Elon Musk and became the VP of propulsion[3] after cancellation of the SLI program.
[citation needed] Northrop Grumman development of the TR-107 engine permitted consideration for potential use on next-generation launch and space transportation systems.