United Launch Alliance (ULA) has gotten its Delta 2 medium-lift rocket back on NASA’s list of approved launch vehicles and, according to a senior executive with the Denver-based company, hopes to capture business from the agency’s Earth sciences division.

“The customer’s really NASA’s Earth science directorate,” George Sowers, ULA vice president of business development, said in an Oct. 6 interview. “It’s the near- to mid-term Earth science missions that would be the prospects — things that are going into low Earth-orbit out of Vandenberg Air Force Base in California.”

The space agency announced Sept. 30 that the Delta 2 had been added to the NASA Launch Services (NLS) 2 contract. NLS 2 is a 10-year indefinite-quantity, indefinite-delivery contract that allows NASA to order up to 70 rocket launches. The agency can spend a cumulative total of up to $15 billion for these launches.

ULA would not disclose the per-launch price range for the Delta 2, which over the years has been among the most reliable rockets in the U.S. fleet. The vehicle is out of production, but ULA, a Boeing-Lockheed Martin joint venture, has five unsold Delta 2 rockets in its inventory.

James Norman, director of launch services at NASA headquarters in Washington, said in an Oct. 7 email that the agency “does not publicly release the prices on our NLS 2 contracts.”

Delta 2 was not on NLS 2 when the agency unveiled the rocket purchasing vehicle in September 2010. However, NLS 2 contains an onramp provision that allows NASA to add vehicles to the contract.

Chris Chavez, a ULA spokesman, said that under the NLS 2 contract, “we only will be launching from Vandenberg. The Vandenberg pad was never modified to support the heavy configuration, but we can launch all other [Delta 2] configurations from Vandenberg.

Chavez said it was “still possible” to launch a Delta 2 from Cape Canaveral Air Force Station in Florida, but that the NLS 2 contract does not provide for that option. In its last mission from the Cape, which took place Sept. 10, the Delta 2 launched NASA’s Gravity Recovery and Interior Laboratory (GRAIL) Moon-mapping spacecraft.