WASHINGTON — Sierra Nevada Corp.’s Space Systems division will build an experimental space environment monitoring satellite for the U.S. Department of Defense under a contract announced Oct. 14 by the company.

The STPSat-5 spacecraft will carry four government-supplied payloads designed to characterize the space environment and is slated for a late-2016 launch to low Earth orbit aboard an unspecified rocket, Sierra Nevada said.

Louisville, Colorado-based Sierra Nevada Space Systems said the contract was competitively awarded but did not divulge its value. The Air Force did not respond by press time to a request for the contract value.

The STPSat-5 satellite platform will leverage infrastructure and design practices from the SN-100 platform, which Sierra Nevada is supplying for the second-generation Orbcomm asset-monitoring satellite constellation, according to John Roth, vice president of Sierra Nevada Space Systems. STPSat-5 will be about two-thirds the size of the Orbcomm satellites, six of which were launched in July, with 11 more undergoing final preparations for launch, Sierra Nevada said.

STPSat-5 is the latest in a series of experimental satellites funded by the Defense Department’s Space Test Program, a long-running activity that finds rides to orbit for promising experiments and technologies developed within the Pentagon. The program is managed by the Air Force Space and Missile Systems Center and based at Kirtland Air Force Base, New Mexico.

Warren Ferster is the Editor-in-Chief of SpaceNews and is responsible for all the news and editorial coverage in the weekly newspaper, the spacenews.com Web site and variety of specialty publications such as show dailies. He manages a staff of seven reporters...