By Yoav Landsman in collaboration with Catrina Melograna
We have much to gain by making the Moon humankind’s next destination. We can practice living and working on another world, operate autonomous machines from great distances, and utilize the natural local resources. It is a natural step on our way to explore the entire solar system more effectively.
A reasonable expectation is that lunar missions, governmental and commercial, will reach the Moon this decade, and will grow in number quickly. Thus, to avoid future conflicts, or at least to mitigate them, some rules of conduct must be agreed upon.
One of many important issues in this context is lunar space debris. More lunar missions mean more objects orbiting the Moon. Because of the lack of atmosphere on the Moon, objects that fall from orbit will end up crashing onto the lunar surface rather than burning up. And due to the inherent instability of low lunar orbits, objects will fall to the surface in a matter of days or weeks, not years. This will inevitably expose the lunar surface and our assets there, human and robotic, to potential major damage and destruction. It is an unacceptable threat to humans, infrastructure, and heritage sites.
Another consequence of the expected Moon rush is contamination and environmental damage. We should not be willing to haphazardly litter the lunar surface with debris and chemicals from the moment we get there. We have already indiscriminately crashed dozens of spacecraft on the Moon, including launch vehicle upper stages and of course landers. Our situation here on Earth should serve as a warning not to treat other worlds as we have carelessly treated ours.
Let’s examine two types of orbital debris. First is uncontrolled debris, such as a failed orbiter, a spacecraft that has run out of propellant, or a spacecraft with no propulsion system at all (e.g. a cubesat deployed in orbit). As opposed to falling space debris on Earth, the impact timing may be estimated with more precision on the Moon, so the impact location may be limited to a specific region.
The second type is controllable debris; an orbiter at the end of its life that can be moved. Responsible operators use the orbiter’s remaining propellant to deorbit and crash at a planned time and location. This may pose little to no threat to others, but it still pollutes and disturbs the surface.
Recognizing the significant consequences of failing to address and plan for lunar debris, we must enact a policy to protect humans and assets on the lunar surface. This policy should refer to and define the two types of orbital lunar debris mentioned above. To address uncontrolled debris, the policy should require lunar operators of failed or lost spacecraft to instantly communicate with all surface operators to alert them of the imminent danger. The communication method to support the alert needs to be designed as an integral part of this policy. Not only will this method be helpful for uncontrolled debris, but may also aid in preparing for natural hazards (e.g. meteor impact ejecta).
Second, for controllable orbiters, the policy should require operators to perform a proper disposal process. In addition, it should establish one or more designated disposal sites to minimize and organize surface pollution. The sites should be located near the equator to enable access from every orbit, while also being far from areas of major interest, heritage sites or scarce resources. Additionally, the disposed spacecraft may one day be useful, and having them all in one place may be an unexpected benefit.
Additionally, there might be a case to completely prohibit non-propelled lunar orbiters, unless they can be collected in orbit by some measures. For comparison, we don’t allow uncontrolled ultra-fast objects to fly above inhabited areas on Earth.
The Moon’s sky will soon be crowded, and the surface will inevitably follow. It is our responsibility as lunar enthusiasts, mission designers, explorers and pioneers, to anticipate the risks we create in the new frontier, and to confront them before we reach a point where we cannot undo the damage done. It is also our responsibility to ensure the sustainable use of the Moon for all humans and generations to come.
Yoav Landsman is an Israeli space engineer and entrepreneur, an expert in systems engineering and spacecraft operations. His last job was the senior systems engineer at SpaceIL and the deputy mission director of the Beresheet lunar lander, which has reached the Moon last April. Yoav holds academic degrees in both science and engineering, and is an alumnus of the International Space University. He is well known in Israel for his work in science outreach and education, and for his passion for space. Currently he is working on a new space startup called “Moonscape”, a commercial cis-lunar business.
This blog post originally appeared on LinkedIn and is republished with the kind permission of the author. You can access the original here.