FireFly Space Systems, a startup space-launch company based in Austin, Texas, has officially announced its first product — a small-satellite launcher called FireFly Alpha, designed to place 400 kilograms (880 pounds) into Low Earth Orbit.
Firefly Space Systems, which also maintains a facility in Hawthorne, California, was founded by veterans of the emerging commercial space industry. CEO Thomas Markusic formerly served as vice-president of propulsion at Virgin Galactic, senior Systems engineer at Blue Origin, and principle propulsion engineer and test-site director at SpaceX.
Firefly Space Systems, which completed a seed-funding round in January, seeks to “lower the prohibitively high costs of small satellite launches to Low Earth and Sun Synchronous Orbits with the goal of revolutionizing broadband data delivery and earth observation missions.” Firefly will offer small-satellite customers dedicated launches for $8-9 million, according to Markusic.
Firefly Alpha will be a two-stage, single-core rocket. (The artist’s concept shown above is presumably a follow-on version, with two strap-on boosters). In time, Firefly Space Systems intends to evolve its launchers into reusable systems. (See Firefly Space Systems To Pursue Reusable Launcher.)
The first stage, six feet in diameter, will be powered by a pressure-fed liquid-oxygen/methane rocket engine with 90,000-pounds thrust and a specific impulse of 305 seconds. Instead of a conventional bell nozzle, it will use an altitude-compensating aerospike nozzle. An illustration on the Firefly website appears to show an engine with eight combustion chambers.
The second stage, five feet in diameter, will be powered by a pressure-fed LOX/methane engine with a conventional nozzle. The second-stage engine will have thrust of 10,000 pounds and a specific impulse of 335 seconds.
The aerospike-engine concept has been around since the 1960’s but has never been used in an operational vehicle, mainly due to lack of development funding. Aerospike engines have been proposed as powerplants for many design concepts, especially single-stage-to-orbit (SSTO) vehicles.
NASA and Lockheed Martin attempted to develop a linear-aerospike engine for the ill-fated X-33 during the 1990’s. Firefly Alpha is using a more conventional, circular aerospike design. The linear aerospike is more technically challenging because engineers must deal with edge effects, which do no not occur with a symmetrical circular aerospike. (Almost all aerospike designs are circular for that reason. Lockheed’s linear-aerospike design was virtually unique.)