Jeffrey LewisStreak

STP-R1 is a DARPA satellite called Streak.

Space.com has the details.

Air Force launch officials say it will take about nine minutes for the Minotaur to haul the STP-R1 mission to the desired orbit tonight. The satellite, dubbed Streak by its operator, will test technologies for the Defense Advanced Research Projects Agency.

“Streak is a technology demonstrator whose objective is to demonstrate rapid response, short mission life, low Earth orbit space technologies and gather information about the low Earth orbit environment,” a DARPA spokesperson said.

Information released by DARPA indicates Streak is fitted with two instruments—an ion gauge and an atomic oxygen sensor.

“The vehicle will characterize the orbital regime, demonstrate operational feasibility from a command and control standpoint and also from a platform perspective for future DoD missions,” the spokesperson added.

General Dynamics C4 Systems/Spectrum Astro Space Systems built the craft in Gilbert, Arizona.

DARPA is the Defense Department organization whose mission is “to maintain the technological superiority of the U.S. military and prevent technological surprise from harming our national security by sponsoring revolutionary, high-payoff research that bridges the gap between fundamental discoveries and their military use.”

The Santa Barbara News Press has more (subscription only).

Update: Photographs of the launch are available from Jeff Gortatowsky and Jim Scotti.