Blue Origin, Jeff Bezos' private aerospace company that wants to make space travel affordable and plans to make it happen by April 2019, test fired its most powerful rocket yet.

The engine dubbed BE-4 (Blue Engine 4) went through its first hot-fire test on Wednesday (28 October). The engine is powered by liquid oxygen and liquid methane and is the most powerful American-built rocket engine in several decades, notes a report by Popular Mechanics.

The BE-4 will reportedly be mated to the New Glenn heavy-lift rocket, but before that it could be first put to use to boost Vulcan, the flagship rocket from United Launch Alliance.

The company tweeted out a short clip of the rocket firing off at the testing grounds in West Texas. The rocket was tested at 50% for three seconds.

The company apparently started working on the engine in 2011, but details about its development came out only in 2014.

The BE-4 is reportedly the largest rocket engine developed and built entirely on private money. At sea level, the reusable engine puts out 550,000 pounds of thrust. This test plants Blue Origin's place in the heavy launch game, notes the report, adding that the engine could become the go-to rocket engine for both commercial and military heavy launch.

BE-4 is reportedly more powerful than SpaceX's biggest capacity engine — the Raptor. It is even bigger than the Space shuttle's main engines. Elon Musk's BFR, which is slated to take people to Mars and colonise it, will make use of Raptor engines. The BFR will also make Earth to Earth trips, making any point on the planet a 40-minute flight.

Apart from Musk and Bezos, Richard Branson's Virgin Galactic is also only six months away from its first spaceflight.

New Glenn will have two-stage and three-stage variants and the BE-4 will power both the first and second stages of the heavy lift rocket, which the company wants to launch by 2020. New Glenn stands at 270ft for the two-stage version and the three-stage version will be 313ft tall.