The Pentagon's far-out science arm is planning an April test flight for a prototype of a hypersonic weapon that – in theory – could cross the Pacific Ocean in under two hours.

In a solicitation issued late last week, Darpa said it was looking to charter a U.S.-flag vessel to help collect telemetry for the upcoming test of a Hypersonic Technology Vehicle-2 (HTV-2). According to the solicitation, an unpowered HTV-2 will be launched on a booster rocket from Vandenberg Air Force Base in California and glide to a target site in the Marshall Islands, sometime between April 20 and April 27.

It's the first public announcement of a flight test originally scheduled for 2009.

The flight test is part of the Falcon program, a Darpa-Air Force project to develop the tech that could lead to a reusable hypersonic vehicle that could take off and land like a plane. It would carry 12,000 pounds of payload over 9,000 nautical miles in less than two hours.

Falcon is related to another effort, dubbed Blackswift, that was supposed to lead to a test aircraft that could take off from a conventional runway, cruise at Mach 6 and land back on a runway. (The video embedded above is Darpa's computer-animated rendition of Blackswift, a.k.a. Lockheed Martin Skunk Works' Falcon HTV-3X hypersonic test vehicle.) However, Congress chopped Fiscal Year 2009 funds for the project, and Darpa decided not to move ahead with plans for the reusable spaceplane.

This upcoming test is supposed to demonstrate the thermal protection systems and aerodynamic controls of the HTV-2. If all goes according to plan, an HTV-2 will be launched by a Minotaur IV Lite rocket from Vandenberg, separate from the launch vehicle, then follow a hypersonic glide trajectory to an impact area in the ocean near Reagan Test Site at Kwajalein Atoll, where the Air Force also tests ICBM reentry vehicles.

According to the Darpa solicitation, the ship will be hired to transport, deploy and retrieve a set of nine impact-scoring rafts, as well as telemetry equipment that will help track the HTV-2 in its final seconds of flight.