China has been bolstering its satellite systems and plans to keep on doing just that, causing concerns for U.S. military officials.

"China has developed a large constellation of imaging and remote sensing satellites," the Pentagon’s recent annual report to Congress on China notes. "These satellites can support military objectives by providing situational awareness of foreign military force deployments, critical infrastructure, and targets of political significance."

The coming year will see an even greater reliance on space sensors.

"China plans to continue to increase its on-orbit constellation with the launch of 100 satellites through 2015," the Pentagon reports. "The future launches will include imaging, remote sensing, navigation, communication, and scientific satellites, as well as manned spacecraft."

China’s burgeoning forays into space are causing concerns for the U.S. officials, another recent Congressional Research Service (CRS) report says. The Pentagon and other space-related agencies worry about collisions in the crowded orbits and Chinese anti-satellite weapons.

China has conducted 18 Yaogan remote sensing satellite launches since 2006, the Pentagon’s China report points out. Yaogan satellites conduct scientific experiments, carry out surveys on land resources, estimate crop yield, and support natural disaster reduction and prevention.

China launched the Gaofen-1 satellite in April 2013, the Pentagon says. Gaofen is one of 16 programs announced by the State Council for its national scientific and technology programs. "Gaofen will become the main civilian Earth observation project, combining the use of satellites, aircraft, and even stratosphere balloons, with at least 14 satellites set to launch by 2020," the Pentagon reports.

Gaofen-2 is expected to launch this year.

The Kuaizhou, or "quick vessel," imagery satellite was launched on Sept. 25, 2013, the Pentagon reports, adding, "Kuaizhou-1 was built by the Harbin Institute of Technology and is projected to be used for emergency data monitoring and imaging under the control of the Chinese Academy of Sciences’ National Remote Sensing Center."

China has also launched two Tianhui satellites designed to conduct scientific experiments and support land resource surveys and territory mapping with a stereoscopic imaging payload, the Pentagon says.

China has three Huanjing disaster monitoring satellites currently on orbit, the third of which was launched in November 2012, the Pentagon says.

China also employs the Ziyuan series of satellites, which are used for Earth resources, cartography, surveying, and monitoring, the Pentagon says. The country also operates the Haiyang ocean monitoring constellation and Fengyun weather satellites in low Earth and geosynchronous orbits.