NASA has modified its NASA Launch Services (NLS) II contract with Orbital Sciences Corporation of Dulles, Va., to add the Antares launch vehicle, formerly known as Taurus II, for future missions.

The NLS II on-ramp provision provides an opportunity annually for launch service providers not presently under NLS II contract to compete for future missions, and allows launch service providers already under contract to introduce launch vehicles not currently on their NLS II contracts, such as Antares.

NLS II contracts are multiple award, indefinite delivery/indefinite-quantity contracts with ordering periods through June 2020. The contracts provide for a minimum capability of delivering agency payloads weighing approximately 550 pounds or more to a minimum 124-mile-high circular orbit with a launch inclination of 28.5 degrees.

The launch service providers also may offer a range of vehicles to NASA to meet higher payload mass and orbit requirements.

These contracts support the goals and objectives of the agency's Science Mission Directorate, Human Exploration and Operations Mission Directorate, and Office of the Chief Technologist.

Under the contract, NASA also can provide launch services to other government agencies, such as the National Oceanic and Atmospheric Administration.

The Launch Services Program Office at NASA's Kennedy Space Center in Florida is responsible for program management.