Mini International Space Station orbiting the Moon
Mini International Space Station orbiting the Moon
At the end of January 2016, the Russian news agency RIA Novosti published unexpected information. She said the US, Russian and European space agencies are negotiating forms of their future cooperation after the completion of the International Space Station (ISS) program, which is expected to take place around 2028.
It turned out that a preliminary agreement was quickly reached that after a large station in Earth orbit, the next joint project would be a station, much smaller in size, but moving a thousand times further - around the Moon.
Consequences of ARM and Constellation
Of course, the most diverse concepts of lunar bases - both surface, low-orbit, and high-orbit - have arisen in recent decades about once every two years. They were varied in scale - from small ones, allowing a crew of two or three people to stay for several months, requiring the transportation of literally everything that is necessary for life from Earth, to huge complexes, almost self-sufficient cities with a population of many thousands. residents. They had one thing in common - lack of funds.
A decade ago, for a brief moment, the American plan to return to the Moon, known as Constellation, seemed to have some chance, but it too fell victim to both lack of resources and political unwillingness. In 2013, NASA proposed a project called ARM (Asteroid Redirect Mission), later renamed ARU (Asteroid Retrieval and, Utilization), an ambitious program to deliver to our planet and explore a boulder from the surface of one of the asteroids. The mission was to be multi-stage.
At the first stage, it had to be sent to one of the planets of the NEO group (Near-Earth Objects), i.e. near Earth, an ARRM (Asteroid Retrieval Robotic Mission) craft equipped with an advanced ion propulsion system was scheduled to take off from Earth in December 2021 and land on the surface of an undetermined object in less than two years. With the help of special anchors, it was supposed to hook a boulder with a diameter of about 4 m (its mass will be up to 20 tons), and then wrap it in a tight cover. It would take off towards Earth but not land on Earth for two important reasons. Firstly, there is no such a large ship capable of carrying such a heavy object, and secondly, I did not want to come into contact with the earth's atmosphere.
In this situation, a project was created to bring the catch to a specific high retrograde orbit (DRO, Distant Retrograde Orbit) in 2025. It is highly stable, which will not allow it to fall too quickly to the moon. The cargo will be tested in two ways - by automatic probes and by people brought in by the Orion ships, the only remnant of the Constellation program. And the AGC, canceled in April 2017, could be implemented in the lunar base? Two key components - one material, that is, the ion engine, and one intangible, the GCI orbit.
What orbit, what rockets?
The decision-makers faced a key question: in what orbit should the station follow, dubbed DSG (Deep Space Gateway). If humans were to go to the surface of the Moon in the future, it would be obvious to choose a low orbit, about a hundred kilometers, but if the station were indeed also a stopover on the way to the libration of the Earth-Moon system of points or asteroids, it would have to be placed in a highly elliptical orbit , which would give a lot of energy profit.
As a result, the second option was chosen, which was supported by a large number of goals that could be achieved in this way. However, this was not a classical DRO orbit, but NRHO (Near Rectilinear Halo Orbit) - an open, quasi-stable orbit passing near different points of the gravitational equilibrium of the Earth and the Moon. Another key issue would have been the choice of launch vehicle, were it not for the fact that it did not exist at the time. In this situation, the bet on the SLS (Space Launch System), a super-rocket created under the auspices of NASA to explore the depths of the solar system, was obvious, since the commissioning date for its simplest version was the nearest - then it was installed at the end of 2018.
Of course, there were two more rockets in reserve - Falcon Heavy from SpaceX and New Glenn-3S from Blue Origin, but they had two drawbacks - a lower carrying capacity and the fact that at that time they also existed only on paper (currently Falcon Heavy after a successful debut, the launch of the New Glenn rocket is scheduled for 2021). Even such large rockets, capable of delivering 65 tons of payload to low Earth orbit, will be able to deliver a mass of only 10 tons to the Moon region. This became the limit for the mass of individual elements, since naturally the DSG had to be a modular structure. In the original version, it was assumed that it would be five modules - drive and power supply, two residential, gateway and logistics, which after unloading will serve as a laboratory.
Since other ISS participants also showed significant interest in the DRG, i.e. Japan and Canada, it became apparent that the manipulator would be supplied by Canada, which specializes in space robotics, and Japan offered a closed-loop habitat. In addition, Russia said that after the commissioning of the manned Federation spacecraft, some of them could be sent to the new station. The concept of a small unmanned lander, capable of delivering from the surface of the Silver Globe from several tens to several tens of kilograms of samples, was jointly promised by ESA, CSA and JAXA. Long-term plans were to add another, larger habitat at the end of the XNUMXs, and a little later, a propulsion stage that could direct the complex on a trajectory leading to other targets.
