Continuing the Long March to the Moon

It’s been a while since I’ve examined China’s lunar exploration program on this blog, so in light of several recent developments, I will re-examine China’s achievements and accomplishments to date, and from these observations, infer possible future directions. I have no inside source of information on China’s plans, though I am able to draw on my own and others’ expertise in this area to assess what the Chinese are developing, what their new hardware is capable of, their past accomplishments and their known aspirations.

The biggest news is the successful debut of the newest Chinese launch vehicle, the Long March 7. The new vehicle uses liquid oxygen-kerosene fuel (considered “safer” than the toxic, hypergolic fuels used by its predecessor, the Long March 2) in a medium lift class vehicle; it launches from the more southerly located Wenchang spaceport, which increases its effective payload capacity (due to the addition of lift-off velocity from Earth’s rotation, more pronounced nearer the equator). The Long March 7 can deliver about 13.5 metric tones to Low Earth Orbit, comparable to such medium-lift rockets as the Falcon 9 and Atlas 5. Thus, its likely future use in a human spaceflight program is for crew and cargo delivery to a LEO space station, a planned structure in space to be assembled in the next decade. From their station, the Chinese will obtain long-duration spaceflight experience, in addition to developing critical spacefaring skills, such as rendezvous, docking and extravehicular activity (spacewalks). The Long March 7 is not so much a new technical advancement as it is a modernization of an existing capability.

On a parallel track, China continues to develop a variety of robotic missions, with an emphasis on the Moon. Recent reports telling us that China plans to land at the lunar “south pole” are mistaken—what is actually planned is to land on the far side of the Moon, on the floor of the “South Pole-Aitken” (SPA) basin. This feature is an impact crater over 2,500 kilometers in diameter that spans nearly the entire southern far side hemisphere. The confusion comes from its name, derived from two unrelated geographic features (the south pole and the crater, Aitken), which span the approximate extent of the basin. This basin is of high scientific interest because it is the oldest and largest impact feature on the Moon, and both its time of formation and the mechanics of the impact that created it can tell us a great deal about the history and evolution of the Earth-Moon system.

For Chang’E 4 (which was the backup spacecraft for Chang’E 3), a radio relay satellite will be placed into a “halo” orbit around the Earth-Moon L-2 point (a point in space 60,000 km above the center of the far side). From this distant vantage, the relay satellite will be in constant radio communication with Earth, as well as with any spacecraft on the far side of the Moon—a region permanently shielded from contact with Earth. With this capability in place, Chang’E 4 will be launched in 2018 to land on the far side of the Moon. This lander will carry a rover to the surface, similar in size and capability to the Yutu rover flown on Chang’E 3 in 2013.

It’s not yet known exactly where the mission will attempt to land, but it’s unlikely to be at a polar site. The area around the south pole of the Moon is extremely mountainous and rugged, threatening clear lines of radio contact. The most desirable area for science is somewhere near the center of the South Pole-Aitken basin, a low-lying region of anomalous chemical and mineral composition. Operationally, to permit an unobstructed view of the relay satellite at L-2, the site needs to be at a mid- to low-latitude site near the center of the far side.

Although this is not a sample return mission, Chang’E 4 could make significant contributions to lunar science by conducting measurements of the surface properties of this basin, by providing ground truth for the multitude of remote sensing measurements of the Moon and by addressing questions about the composition of the lunar crust in this region. The experiments to be conducted on Chang’E 4 are similar in scope and type to those undertaken on the Chang’E 3 mission three years ago, which include chemical, mineralogical and morphological characterization of its landing site. Additionally, a low frequency radio astronomy experiment will be deployed. The proposed New Frontiers Moonrise mission (which plans to return a sample from this area) could also benefit from the results of Chang’E 4, either from a preliminary characterization of the basin floor or from data that would cause its team to re-select their landing site to increase the likelihood of sampling desired material (impact melt from the SPA impact).

The Chang’E 5 robotic mission currently is scheduled for launch in 2017 (this out-of-sequence chronology probably results from changing programmatic imperatives, some of which reflect China’s perceived national goals and security needs). The Chang’E 5 mission will return a sample of the lunar maria on the near side, probably from an area close to the landing site of their previous Chang’E 3 mission (although it would be more scientifically valuable if they chose a different site). This mission has a complex architecture, including a rendezvous in lunar orbit for the returned sample capsule; once this is accomplished, the Chinese will have demonstrated all of the technologies and procedures needed to send people to the Moon. That goal is clearly within the scope of China’s space program.

Assiduously described as being pursued for peaceful reasons, the purpose and meaning for China’s space program remain unclear. To fully appreciate their plans, one must examine a variety of Earth-orbital missions that test “anti-satellite” capabilities. The story of the Chinese 2007 ASAT space test is well known, but less attention has been paid to another ASAT test in 2014, in which an interceptor simulated a collision with a target by precisely intercepting its trajectory. Although the Chinese claimed that this was merely a test of tactical missile defense (non-orbital), the flight profile was clearly applicable to a future orbital interception. Even more significant is the flight of a small satellite on last month’s Long March 7 debut flight. The Aolong-1 (Roaming Dragon) satellite has an articulated robotic arm to grapple and handle other orbiting satellites, including “non-cooperative” ones. The claim is that Aolong-1 is intended to collect and safely remove orbital “space debris” but most of the hazard from such debris is from tiny fragments of exploded rocket stages and disaggregating satellites, not from fully functional, “non-cooperating” objects.

Though their intentions are often unspoken, the strategic direction and accomplished milestones of China’s space program speak eloquently on intent. China is developing (and in many cases, has already achieved) the capability for space dominance, not only in low Earth orbit, but also throughout cislunar space, the zone between Earth and Moon where virtually all our scientific, economic and security assets (satellites) reside. China has demonstrated a variety of capabilities, including launch on demand, interception of orbital targets, rendezvous and docking, terminal hazard avoidance and safe approach, long loiter in deep space with subsequent departure and operations, and now the physical manipulation of space assets by remotely controlled robotic means. Individually, these capabilities represent a variety of novel and useful skills, while collectively they pose a significant challenge to western powers that depend on space-based assets for their national security, as well as for the security of many other nations.

While the world welcomes China into the family of spacefaring powers to share the experience of discovery and the advancement of human knowledge, we must not be blind to the flip side of this coin—the serious security issues raised by the type and number of space missions China has conducted in the past decade, and have planned for the near future.

Our deepest concern should not be Chinese presence in cislunar space but our absence from it. By leaving the way clear for China to dominate the Moon and cislunar space, we’re relinquishing our vital space leadership role and condemning America’s space pursuits to an uncertain future. Though none of these capabilities are beyond our reach, we have little experience using them in real, operational situations. We need to pursue a sustainable space program, beginning in the arena of cislunar space. America must awake from this self-imposed slumber and dreams of Mars and direct its attention to the cislunar theater of space. By learning how to access and use lunar resources, we can protect vital satellite assets, while steadily and permanently advancing beyond LEO into the Solar System.

Paul D. Spudis | READ MORE

Paul D. Spudis (1952-2018) was a senior staff scientist at the Lunar and Planetary Institute in Houston, Texas, and a prolific author on the subject of the moon. His books include The Value of the Moon: How to Explore, Live, and Prosper in Space Using the Moon's Resources.