SpaceX is making its first flight of the Falcon 9 rocket, a boost stage that will boost its planned Dragon capsule into orbit.
SpaceX’s plans to use the Falcon Heavy rocket for that flight include adding two engines, a second stage and a first stage booster, which could be the first to fly since the Falcon 1 and Falcon 9 first stages.
SpaceX has said the Falcon 3 booster is on track for launch in 2021.
The company plans to launch an unmanned Dragon capsule in 2018.
Falcon Heavy is also scheduled to be the main vehicle used for transporting cargo to and from the International Space Station.
A new commercial space company called XCOR Aerospace is using a version of the Merlin 1D engine that is similar to that of the original Falcon 1 booster.
It will launch its first commercial cargo ship, the Orion capsule.
SpaceX says the Merlin engine is capable of launching cargo from up to 6.4 miles away, compared to the 3.5-mile distance required for the Falcon 2 booster.
A SpaceX representative confirmed to CNNMoney that the new Merlin engine could be used on the Falcon 7 rocket.
It’s also unclear if SpaceX will use the same Merlin engine in the new booster.