On November 1, China’s Chang’E 5 Test mission to the Moon safely returned to Earth. With this mission behind them, the Chinese have successfully completed all the steps needed to conduct lunar exploration—first by robotic spacecraft but eventually also with humans. Over a short six-year span, China has methodically conducted an incremental series of robotic missions to refine the skills they need to explore the Moon.
This architecture included two lunar orbiters—one was sent to impact the Moon, the other was commanded to leave lunar orbit for a trip to (and an extended loiter at) one of the Sun-Earth Lagrange points. Next, the Chang’E 3 lander (exceptionally large for its mission profile, with payload capacity of more than 1.5 metric tons) successfully soft-landed in Mare Imbrium. A small rover (Yutu) deployed onto the lunar surface, conducted a cursory surface exploration (apparently a much more ambitious traverse was planned, but mechanical failures cut that short). Which brings us to their latest successful mission. This one was flown to and around the Moon, with the capsule returned safely to the surface of the Earth—in effect, the mission sequence required for lunar sample return.
The only piece missing from their lunar mission architecture is rendezvous and docking in lunar orbit. Since the Chinese manned program has already done this multiple times in Earth orbit, odds are that they will be successful in applying this expertise to their lunar mission. The plan for the next mission (Chang’E 5) will be to conduct a robotic sample return mission sometime in 2017. The mission profile calls for a soft landing on the lunar surface, the collection of soil and rock samples, the ascent of the sample-return vehicle to orbit (where it will autonomously rendezvous with the Earth return stage), and then the firing of a rocket engine to leave lunar orbit and return to Earth.
The complexity of the Chang’E 5 mission profile is somewhat curious, since it would be much simpler to make a direct ascent from the lunar surface and head straight back to Earth (like the Soviet Luna sample return missions of the 1970s). The fact that China is adding the step of rendezvous and docking in lunar orbit is significant, as this step is a critical milestone for the certification of an architecture for human missions to the Moon. China’s choice of this mission profile for Chang’E 5 is a clear indication that they are planning such missions.
Although this mission series is a testament to China’s significant scientific and technical capability, another aspect must also be considered. To fully understand what this new space capability means, one must take a discerning look at Chang’E 2, launched in October 2010. Initially, this mission was simply another orbiter, an additional mapper added to the crowded lunar sky already being used by India’s Chandrayaan-1, the Japanese SELENE, and the American LRO spacecraft. Chang’E 2 mapped the Moon at higher resolution (10 m per pixel, as opposed to 100 m/pixel) and lower sun angles than its predecessor, Chang’E 1. Additionally, it carried a laser altimeter that produced a high-quality global topographic map of the Moon and a gamma-ray spectrometer to map surface elemental composition.
The lunar phase of Chang’E 2 was completed in nine months, with a departure from lunar orbit in June 2011. What happened next is significant. At the end of August 2011, the Chang’E 2 spacecraft was sent to Sun-Earth L-2, a stable libration point about 1,500,000 km from Earth. At this point, Earth and Sun remain fixed in space (relative to the spacecraft) and minimal fuel is needed to remain here (plans are to park the forthcoming James Webb Space Telescope here). After loitering at L-2 for about 8 months, Chang’E-2 departed in late April 2012 for an intercept and flyby of the asteroid Toutatis in December of that year. High-resolution images of Toutatis were obtained and the Chinese spacecraft entered solar orbit, where it remains to this day.
This mission sequence was highly complex and apparently completely successful. Although it accomplished a great deal scientifically, its operational significance is even greater. The ability to routinely move throughout and work in the volume of space between Earth and Moon (cislunar space) is key to both space permanence and space control. Space permanence means having vehicle assets on call in space for use as needed, as well as being able to position them at strategic spots where they can be reliably stored until required. Space control simply means the ability to provide space assets for national purposes when needed and to deny similar assets to an adversary if necessary. Both permanence and control are demonstrated by positioning satellites in cislunar space, lunar orbit, the L-points, and all parts of space in between.
These recent developments are serious but appear to have been largely overlooked in the west. I am not suggesting that China is taking hostile action in space nor am I suggesting that they intend to. But they are demonstrating that they have the ability to do so. We should always keep in mind that unlike NASA, the Chinese space program is run by their military (the People’s Liberation Army). Although we both have “dual use” technology (i.e., space capabilities that have both civilian and military use), the current focus of American scientific robotic exploration is on a variety of targets beyond cislunar space—asteroids, Mars and other planets. Our exploration of these objects is strictly for scientific (and peaceful) purposes.
It appears that while America continues to pursue the chimera of a human Mars mission at some future (but always unspecified) date, China is moving ahead with cislunar space dominance. They have systematically and carefully planned a logical pathway to the creation of a permanent space-faring capability. They have not yet achieved it, but looking at their progress to date, there is little doubt that they will. As virtually all of our space “applications” (i.e., communications, weather, remote sensing, GPS) assets are positioned in the various locales of cislunar space, we should be cognizant of evolving Chinese capabilities and intentions. Are we allowing ourselves to be outmaneuvered in space? Despite the happy talk of many in the space community, it remains a dangerous world.