America’s X-37B vs. China’s Shenlong: Top space planes and their shadowy role in orbital war

X-37B

A space plane is a reusable spacefaring craft that can maneuver in space independently and also fly and glide within Earth’s atmosphere. They are sent into space via a detachable rocket booster, and contain a cargo bay to deploy satellites and other objects for use and experimentation.

After completing their mission, they independently return to Earth’s atmosphere, land at a designated landing site on their own power, and prepare for their next mission. The most well-known space planes are the American Space Shuttle and the Soviet Buran. But in contrast to the Space Shuttle, the X-37B is owned and operated by the military.

The X-37B’s origin begins in 1999, when the civilian space agency NASA awarded Boeing a contract to develop a small unmanned spacecraft capable of fitting inside the Space Shuttle. What they created was a small space plane measuring approximately 30 feet long and with a wingspan of 15 feet — roughly one-fourth the size of the now-retired Space Shuttle.

It also contains a cargo bay measuring about 7 feet by 4 feet, which, in addition to housing satellites and other space cargo also holds a solar panel enabling the space plane to recharge. Boeing says the plane’s avionics automate its descent from orbit and landing.

In 2004, before a working prototype had even been built, the project was transferred to the US Defense Department, specifically the Defense Advanced Research Projects Agency. Glide tests on the first testing prototypes (known as the X-37A), began in 2005, with the first fully successful free glide occurring in 2006.

That same year, the project was transferred from DARPA to the United States Air Force Space Command, which then built another model, the X-37B. Also known as the Orbital Test Vehicle (OTV), two X-37Bs have been built.

They have flown seven flights so far, with each being longer than the previous one. Though most of the details of the flights and their results remain classified, some information has been released to the public.

Shenlong

Named after the most important dragon god in Chinese mythology and first revealed in 2007, the Shenlong is thought to be a direct Chinese response to the X-37B.

The program is surrounded in such extreme secrecy that there are no known images of the space plane in its current form. Images of what is believed to be a Shenlong test prototype mounted under the fuselage of an H-6 strategic bomber in 2007 indicate that the craft is likely to be similar in appearance to the X-37B.

Though its specific capabilities remain classified, it is known that, like the X-37B, the Shenlong is unmanned, that it is deployed via a rocket, that it is capable of adjusting its position and maneuvering in space, and that it can carry and deploy satellites and other space objects.

Perhaps the most impressive thing about the Shenlong is the speed of its development. Though the exact start date is unknown, academic models of a Chinese space plane were reported as far back as 2000.

Years of modelling, wind tunnel testing, and prototype test fights via deployment from H-6 bombers followed, and in 2011, the Shenlong reportedly made its first suborbital flight.

On September 4, 2020, the Shenlong made its first orbital flight, which lasted two days and saw it release an object into orbit before returning to China on its own power. A second orbital flight began on August 4, 2022, and lasted nine months.

Satellite threat

Given the immense secrecy of the crafts and what is known about their capabilities, it’s easy to understand speculation that the two space planes could be orbiting weapons platforms.

The very fact that the US Department of Defense is in charge of the X-37B instead of NASA confirms that the US government believes that there is a military application for the space plane. Similarly, the fact that the Chinese government has been so silent on the Shenlong’s activities despite its penchant for boasting about its other space accomplishments may be a tacit indication that there is more to the Shenlong than the ‘peaceful use of space.’

One of the most impactful possible uses of the space planes is as anti-satellite assets. Both have deployed satellites from their cargo bays, and the Shenlong’s proximity operations may be training runs for attacks on hostile satellites in orbit.

Proximity operations are murky. They could be dress rehearsals for disrupting or eavesdropping on an enemy’s satellite, just as they could be drills for missions to refuel and repair one of the country’s own satellites.

Satellites are among the most important assets for any first-rate military, as they are essential for secure communications, navigation, and intelligence gathering via orbital imaging and communication intercepts. They are even sometimes used to guide smart munitions to hostile targets as well.

Neutralizing an enemy’s satellites would be one of the most important objectives in any potential conflict between the world’s foremost military powers. China, the US, India, and Russia have each demonstrated a capability to destroy satellites in orbit with anti-satellite missiles, but each of those tests resulted in the creation of large debris fields in orbit that took sometimes took years to disappear. Such debris fields could also pose a very severe threat to friendly satellites as well. China’s anti-satellite missile test in 2007 triggered a space debris cloud that was an inspiration for the blockbuster film “Gravity.”

Having a way to neutralize or even capture satellites, then, could be a better alternative. Tapping into enemy satellites to eavesdrop or shut down their data streams and communications could also serve as a better alternative, and may also be possible with the assistance of space plane (similar to the tapping of underwater cables by submarines).

With the militarization of space seemingly fast becoming reality and with China’s space program demonstrating that it can tow away satellites, it is likely that space planes will only become more important in the years ahead.

Benjamin Brimelow is a freelance journalist covering international military and defense issues. He holds a master’s degree in Global Affairs with a concentration in international security from the Fletcher School of Law and Diplomacy. His work has appeared in Business Insider and the Modern War Institute at West Point.