ARCA Space Corporation has announced its linear aerospike engine is ready to start ground tests as the company moves towards installing the engine in its Demonstrator 3 rocket. Designed to power the world’s first operational Single-Stage-To-Orbit (SSTO) satellite launcher, the engine took only 60 days to complete from when fabrication began.

Over the past 60 years, space launches have become pretty routine. The first stage ignites, the rocket lifts slowly and majestically from the launch pad before picking up speed and vanishing into the blue. Minutes later, the first stage shuts down and separates from the upper stages, which ignite and burn in turn until the payload is delivered into orbit.

This approach was adopted not only because it provides enough fuel to lift the payload while conserving weight, but also because the first-stage engines, which work best at sea level, are very inefficient at higher altitudes or in space, so different engines need to be employed for each stage of flight.