So, yesterday I heard that a new startup in Texas was looking to build a launcher for small satellites. The company is named Firefly, and of course, a quick google search found mostly pics of Serenity and Mal Reynolds. But one thing caught my eye, was a reference to aerospike engines, which the company plans to use. That lead to the question, what the hell is an aerospike engine?
You’re familiar with a liquid fueled rocket engine, right? Let’s look at a typical engine. The is the RS-25, a derivative of the Shuttle Main Engine intended for the future SLS platform.
Pumps mix fuel and oxidizer in a combustion chamber that then flows out the bell. Simple enough.
Aerospike engines kinda turn the bell idea upside down. The flame exhaust goes outside of a wedge, and uses ambient air pressure to shape the plume.
Confused? So was I.
In spite of extensive testing and several developmental models, the aerospike has never flown to space. Whether Firefly Systems changes that remains to be seen.