New NASA Rocket May Cost $500 Million per Launch: NASA is setting the bar at $500 million per launch for their new heavy launch vehicle the SLS (Space Launch System).
The vehicle is designed to take people to Mars and other destinations (including deep space). NASA believes it may be launched as often as once per year after 2023
Rather than using this as a replacement for the now-retired space shuttle program, this launch vehicle sets its sights higher than low-Earth orbit, leaving that to private companies.
The SLS will be capped with an Orion Mulit-Purpose Crew Vehicle, capable of sustaining a crew to destinations futher into space.
The NASA spokesperson warned that this was preliminary, and cost efficiencies will be more apparent when contracts are finalized and the launch schedule becomes more regular. Space.com also said, NASA is "aiming to launch the SLS-Orion combo two or three times per year eventually… That rate should be sufficient to take care of the agency's human spaceflight business beyond Earth orbit, and it will help keep costs down."