NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., said May 22 that preparations are proceeding apace for a mid-June launch of the Nuclear Spectroscopic Telescope Array, or NuSTAR.

Scheduled to launch no earlier than June 13 from the Kwajalein Atoll in the Marshall Islands, the X-ray space telescope will launch from the belly of Dulles, Va.-based Orbital Sciences Corp.’s L-1011 aircraft aboard the company’s Pegasus rocket.

JPL said in a press release that technicians at Vandenberg Air Force Base in Central California are busy installing the rocket’s fairing around NuSTAR while another team is working to complete a flight computer software evaluation in time to support a flight readiness review scheduled for June 1.

If all goes according to plan, NuSTAR and its Pegasus rocket will be attached to the L-1011 June 2 and the aircraft will depart California June 5 and arrive the following day. Launch is targeted for June 13 at 11:30 a.m. EDT.

NuSTAR, a NASA Small Explorer mission led by the California Institute of Technology in Pasadena, has cost NASA about $160 million to date, according to agency budget documents. Its prime mission — scanning the sky in the high-energy X-ray band to hunt for hidden black holes — is expected to run through 2014.