China pursues air-launched rockets

China is modifying its largest military transport aircraft to launch satellites into low-Earth orbit, according to Chinese media reports.

Quoting the head of rocket development at the China Academy of Launch Vehicle Technology, the English-language China Watch reported this week that deliveries of the Y-20 transport to the Chinese air force began last July. The heavy lift transport plane would carry a new generation of Chinese rockets initially capable of launching payloads weighing about 100 kilograms (about 220 pounds) to low-Earth orbit.

According to a China Daily report, Chinese designers plan to develop a larger air-launched rocket capable to boosting 200 kilograms to low-Earth orbit. The web site Defence Blog reported earlier this month that the China Academy of Launch Vehicle Technology is working with Ukrainian companies to co-develop an air-launched rocket.

The air-launched capability is similar to techniques long used in the west to deliver smaller payloads to orbit. The former Orbital Sciences Corp. (now Orbital ATK) developed a series of Pegasus rockets launched from a modified Lockheed L-1011 TriStar aircraft beginning in the early 1990s. In December, for example, a Pegasus XL rocket was used to launch eight weather microsatellites.

Solid-fuel rockets are stowed under the transport plane's fuselage until they are launched at altitudes of about 40,000 feet. The rocket ignites shortly after being released from the mother ship.

The Chinese Y-20 transport being deployed by the Chinese air force reportedly has a maximum takeoff weight of more than 200 metric tons and can accommodate rocket payloads of about 66 tons, Chinese media reported. Reports also quoted a researcher at the Chinese Academy of Engineering who claimed the Y-20 transport plane could eventually loft a 200-kilogram payload into a sun-synchronous orbit 435 miles above the earth.

Given the relatively small size of the Chinese satellites, it remains unclear how sophisticated the payloads would be and what military requirements they could meet.

The Y-20 heavy transport aircraft is described as China's version of the American C-17 transport. It is the largest Chinese military aircraft currently in production.  

China has reportedly been working on the air-launched rocket capability for more than a decade. China Aerospace Science and Technology Corp., the primary contractor for the Chinese space program, is spearheading development work on the air-launched rocket capability. The state-run enterprise has also developed most of China's frontline ballistic, anti-ship and cruise missiles as well as "tactical microsatellites," according to the web site GlobalSecurity.org.