At the end of 2016, China released a paper describing the nation’s very successful year in space, including an outline of their upcoming and future plans and intentions. Though well underway, China’s space accomplishments and stated plans continue to fly over the heads of many who continue to dismissively call Chinese lunar efforts “pointless.” While China continues to collect data from their 2013 Chang’E 3 lunar lander, this new report discusses two new Chang’E missions to the Moon—a lander/rover to be sent to the far side and another lander to collect samples of the lunar surface’s near side.
Why does China see value in a mission to the far side of the Moon? And why seek and return lunar samples when there are already ~380 kilograms of lunar material returned by the Apollo and Luna missions (not to mention an additional ~140 kg of meteorites of lunar origin)? China’s lunar exploration program serves many objectives—only some are scientific. The People’s Liberation Army (PLA) runs China’s space program and science is secondary to other goals of their missions. So a better question to ask is, what purpose do these missions serve from a national strategic perspective?
In the last decade, China has conducted a series of space missions designed to demonstrate and master freedom of access and movement throughout the volume of space between Earth and Moon (known as cislunar space). This region is home to many different classes of satellites, particularly in the high orbits of MEO (e.g., the GPS constellation) and GEO (e.g., communications and broadcasting, and weather observations). These vital space assets are worth billions of dollars and are difficult to replace, requiring long lead times to design, fabricate and launch replacements if one goes bad or is disabled. In addition to all the commercial assets, our national defense and that of our allies is critically dependent upon satellites in all regions of cislunar space—from low Earth orbit to highly elliptical orbits with apogees beyond GEO. Satellites residing in these higher orbits are difficult to reach with launches from Earth, but relatively easy to approach at distances from Earth using assets positioned in various locations throughout cislunar space.
China’s robotic lunar program provides a case study in how to systematically acquire routine cislunar capability. Their initial missions, orbiters Chang’E-1 and Chang’E -2, were designed to globally map the Moon and collect scientific information. These missions have taught China’s engineers how to operate and maneuver spacecraft in deep space (lunar distances) and conduct routine and specialized in-space operations. As I have written previously, the flight of Chang’E-2 was particularly instructive as to their intentions: After mapping the Moon for a year, the spacecraft flew to Earth-Moon L-2, a point 60,000 kilometers above the center of the far side of the Moon (significant to China’s future lunar missions). Loitering at this locality for eight months, Chang’E-2 was then sent on a flyby of the Moon and then on to fly by the near-Earth asteroid Toutatis. Thus, in one mission, China demonstrated and practiced presence, proximity operations, loiter and interception, all critical skills for the military use of space.
China’s Chang’E-4 mission, scheduled to launch in 2018 (their 2017 mission is listed as Change’E-5), is designed to soft-land on the far side of the Moon and deliver a surface rover (probably a copy of the rover landed on the near side by the Chang’E-3 mission in 2013) to measure surface chemical and mineral composition, the morphology of the surface, and other physical properties. In addition, the lander will probably deploy a demonstration experiment to observe the low frequency radio sky from the far side, a location permanently shielded from the radio noise generated by the Earth’s ionosphere. Such an experiment will have the goal of evaluating the facility of such observations for future larger installations on the far side of the Moon.
The far side of the Moon is important for the study of the Moon as a planet. From orbit, we have found that the enormous South Pole-Aitken basin (an impact crater over 2,500 km across) exposes the deepest parts of the lunar crust. This feature is the oldest crater on the Moon, having formed early in the history of the Solar System. Determining its age and compositional effects is a key question, not only for lunar science but also for the history and processes of planetary evolution in general. Although we need samples of this feature to definitively answer these questions, surface in situ measurement of properties at a known location can provide important “ground truth” for data obtained from orbit. Obtaining the first direct measurements of the surface of the far side, as well as getting our first look at the low-frequency radio sky—key to understanding the early history of the universe—is potentially breakthrough science.
The return of samples of the near side by the Chang’E-5 mission this year will be another milestone. Although we do not yet know where this spacecraft will land, indications are that it will probably be in the same region of the Moon where Chang’E-3 previously landed, i.e., the northwest area of the near side, somewhere around or in Mare Imbrium. Samples of relatively young mare basalt lavas will help explain the more recent stages of the volcanic history of the Moon, for which there is currently little direct information (except from lunar meteorites, for which we have no geological context).
But scientific considerations for both of these missions are secondary to their strategic operational value. Together, their successful execution completes China’s mastery of cislunar spaceflight. Landing on the Moon, collecting a sample, and returning it to Earth constitute all the required phases of a human lunar mission. The Chang’E lander is relatively large (capable of landing 1,200 kg on the lunar surface), roughly one-quarter the capacity of the Apollo Lunar Module (4,600 kg)—and much larger than necessary to land the 140 kg Yutu rover. All steps—landing, rendezvous in orbit and Earth return—will be demonstrated on this mission. Coupled with the development of new launch vehicles (including the forthcoming Long March 9, capable of sending 130 tones to low earth orbit, i.e., Saturn V-class), China will have the capability to send human and large cargo missions to the lunar surface within the next 5-7 years.
The far side mission of Chang’E-4 also provides new operational capabilities. Because it is not possible to communicate directly with spacecraft on the far side of the Moon from the Earth, control and operation of the Chang’E-4 lander and rover will use a relay satellite positioned in a “halo orbit” around the distant L-2 point over the far side. This mode of operations will extend Chinese experience in operations and control in deep space beyond LEO, allowing them to move and operate spacecraft at any point in cislunar space. Such capability has serious national security implications.
The concept of concealing true intentions in space by using science as a “cover story” has a long and venerable history. China’s upcoming missions to the Moon, in addition to seeking unique and interesting scientific information, are immensely significant operationally. The lunar science community welcomes these missions, but in this euphoria, those concerned with the broader arena of national interests should not lose sight of the fact that China’s dedicated move into cislunar space is driven by their military needs and ambitions, not by science. These missions are part of China’s long-term, deliberate strategy designed to obtain control of cislunar space. While the missions are not inherently bellicose, we would be foolish to ignore the obvious national security implications of such capabilities.
“Pointless?” Not to China, and certainly not to those who understand the uses and value of cislunar space.