NASA said May 14 that it has added an additional configuration of the Space Exploration Technologies (SpaceX) Falcon 9 rocket to the NASA Launch Services 2 contract it awarded the Hawthorne, Calif.-based company last year.

The configuration, dubbed Falcon 9 v1.1, features an upgraded Merlin engine. Nine kerosene-fueled Merlin-1C engines power the Falcon 9’s first stage and a single Merlin engine powers the second stage. The upgraded engine, dubbed Merlin-1D, is expected to boost the rocket’s performance to 13 metric tons to low Earth orbit (LEO), up from the current 10- to 11-metric tons to LEO.