Firefly Alpha represents a revolution in light satellite launch design. It’s the first vehicle in a scalable family of launchers specifically designed to address the needs of the light satellite (< 1,000kg) community. Featuring an aerospike engine and the lowest launch cost in its class, this all-composite launch vehicle is set to completely transform the entire industry.

When we first set out to design Firefly Alpha, we did so with one goal in mind: create the lowest cost vehicle with the highest performance possible. In order to achieve that, we designed a vehicle that is both innovative and simple. The results speak for themselves.

Payload / 400 kg (LEO, un-margined)
Propulsion: Stage 1
Engine / FRE-2
Propellant / LOx / methane
Cycle / Pressure-fed (autogenous)
Configuration / Plug cluster aerospike
Thrust (SL) / 90,000 lbf (400.3 kN)
lsp (vac) / 305 sec
Propulsion: Stage 2
Engine / FRE-1
Propellant / LOx / methane
Cycle / Pressure-fed (autogenous)
Configuration / Conventional bell
Thrust (vac) / 10,000 lbf (44.5 kN)
lsp (vac) / 335 sec
Stage 1 Diameter / 6 ft
Stage 2 Diameter / 5 ft
Materials / Carbon composite


Why use an Aerospike?

Conventional rockets all use a traditional bell nozzle. The nozzle represents lost weight from a payload point of view, but is necessary to direct thrust and ensure that the exhaust gas expands at the correct rate. However, this expansion velocity is dependent on the external air pressure, and for a rocket, that pressure is constantly changing. In other words, traditional bell nozzles are a compromise; while they are effective at optimizing thrust for a given external air pressure, they are less efficient at other points during the rocket's trajectory.

An aerospike tackles the problem the other way around: though not as efficient as a bell nozzle at a specific pressure, an aerospike uses aerodynamics to make it more efficient across the range of pressures in the rocket flight.

Propulsion Cycle

Although it has never been used before on an orbital launch vehicle, the attraction of methane - essentially natural gas - is undeniable. The fuel is readily available and clean burning when compared to a solid, kerosene or hybrid engine. It’s also easy to store, transport, and is inexpensive.

Moreover, many engines require an inert pressurant (typically helium) to drive the fuel and oxygen into the combustion chamber. This adds additional weight and cost to the vehicle. Firefly's engines are actually self-pressurized (AKA autogenously pressurized), so that the fuel itself is used to provide the working pressure for the engine. This simplifies the design and saves weight.

Better yet, the engine burns with a cool blue flame, just like your stove.

Structure & Design Philosophy

Great engineering does for a penny what any fool can do for a buck. In the quest to get to low earth orbit, cost is not just a factor; it’s the primary factor. Firefly Alpha is designed from the ground up, with efficiency and simplicity in mind.

Our first and second stage engines are essentially identical, simplifying manufacturing. Our first stage also contains ten identical engine cores, which facilitates mass production.

The all-carbon fiber design makes the structural mass supremely light, enabling the maximum payload capacity.

Payload Integration

We understand that launch challenges do not begin and end with the launch vehicle. Every stage of the process must be streamlined. A well-run integration process is a must in the small satellite launch business, since the proportionate costs of integration can be higher than with a larger spacecraft.

Download our Payload User's Guide to get a better understanding of our integration process.

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