To do this, Orbital plans to buy new rockets from an unknown supplier, Reuters reports. These vehicles will deliver the company's Cygnus cargo spacecraft to the ISS for one or two missions in 2015. Then in 2016, Orbital hopes to introduce a new-and-improved version of the Antares, which will include an upgrade to the rocket's propulsion systems (and a lack of AJ-26 engines). The company claims these changes will somehow consolidate their remaining five launches into four, and they will come at no increased cost to NASA, since an update to the Antares engines had already been planned for 2017. The plan will also puts Orbital on track to complete its CRS contract by 2016.