Space

Intermediate station

What to expect from the project of an international “base” in the near-moon orbit

Most recently it became known that the Russian astronaut can go to the moon in 2024. According to the plan, he will accompany the residential module of the future habitable station Lunar Orbital Platform-Gateway, which will rotate, as you might guess from the name, around the moon. And although this is not the first such project, today it is the most promising. In our material, we talk about why a station is needed at a satellite of the Earth, what it will look like, and also with what difficulties the researchers will face when flying.

Space powers today resemble a man who stands on the beach and can not decide to dive. As a result, we have been “trampling” for 40 years in low-Earth orbit, and when new manned expeditions are sent beyond it, it is still unclear. Hopes for active space exploration are given by the projects of creating an international base “halfway” from the Earth to the nearest heavenly body – the Moon.

Heads of space agencies unanimously agree that the next big goal of manned flights should be Mars. But such a task is too expensive and difficult to undertake for it “with kondachka.” It requires a lot of training and a lot of experience, so starting with a goal is not so risky, choosing something simpler.

Leaders in the exploration of outer space, the United States, over the past few decades have called such accessible targets several times – and changed them to new ones. The ambitious Constellation program with plans to return people to the moon was replaced by a flight to the asteroid, and then – a project of “catching” such an asteroid and its towing into the Moon’s orbit. In 2012, NASA discussed with Roscosmos the possibility of creating a joint habitable station at the point of Lagrange, where several space telescopes operate. But only recently the two powers have seriously started talking about taking a step in another direction and building a station on the Moon.

The epoch of “storm and onslaught”

Projects of near-moon orbital stations of various degrees of audacity were numerous. Back in the 60s Sergey Korolev proposed to create a certain insurance point, where the reserves intended for servicing interplanetary space complexes would be stored. One of the most developed projects appeared in 1971, when NASA considered a huge “Integrated plan for space exploration”, connected with the construction of ramified infrastructure far beyond the Earth. Stations in near-earth and geostationary orbits, interorbital tugs with nuclear reactors, fully reusable shuttles, and in the future bases on Mars and on the Moon … The near-moon base was planned as an almost ordinary part of this grandiose complex.

Under the project of North American Rockwell, the main module of the future station was to consist of a cylindrical structure measuring 18.5 × 8 meters (one and a half times wider and twice as long as Zarya, the basic module of today’s ISS). Divided by internal decks, it could accommodate cabins and laboratories, rest areas and storage facilities. To the main module, it was planned to attach approximately the same energy (with solar batteries of almost 1000 square meters), as well as an experimental module with a gateway and a repository for microsatellites. The additional components were also docked, so that the total mass of the entire lunar complex could reach 71.5 tons.

Deliver bulky station modules to the site could be superheavy Saturn V rockets, already then transporting people to the Moon, or Space Shuttle ships, which at that time were still at the stage of an early draft design. It was assumed that the station would be able to play the role of a control center for all elements of the lunar infrastructure, would become a base for manned expeditions to the satellite, provide support for research stations and robots on the surface, allow for rapid analysis of samples and launch of small research apparatuses.Similar ideas were expressed by Soviet scientists. In 1987, under the heading “Letter to the 21st Century” of the journal “Technique of Youth”, Vladislav Shevchenko, Doctor of Physical and Mathematical Sciences, wrote :

If we move the space station to a circumlunar orbit, it will become the focal point for the entire operation to develop this celestial body. From here, at the first stages preceding the construction of the lunar base, the control of the lunar rovers will be carried out, analyzes of rocks delivered from various regions of the Moon by automatic devices, biological and other experiments will be carried out here. 

But even then, after the completion of construction, the headquarters will not lose its importance. It will turn into a space moon landing. It can be assumed that from here in the distant future the ships wholly built on the Moon will flock to the planets of the Solar System.

Time to think

In our practical time, such projects look like a pure utopia, and modern proposals are much more modest. In accordance with the spirit of the times, the tasks of the prospective moon-center station must also change. They include assistance in choosing optimal, resource-rich and radiation-protected areas to accommodate the future base, as well as preventing the notorious asteroid threat. In fact, the Earth is visible to observers in the lunar orbit “from the side”, which theoretically allows us to track asteroids that approach us from the side of the Sun and may remain unnoticed by the ground instruments (as happened with the 20-meter asteroid that suddenly exploded over Chelyabinsk in February 2013).

In addition, the near-moon station is capable of becoming a control center for lunar drones, small lunar rovers or unmanned landing probes. The absence of signal delay will make it easy to transfer commands to them, make their device simpler and cheaper than traditional research probes that need great autonomy. Projects of such systems, controlled from orbit, are being developed now. Just as in April 2016, European astronauts, while remaining on the ISS, demonstrated control of a robotic rover on the Earth. However, many experts consider these modest projects unnecessary burden.In their opinion, the orbital station may be useful only for future visitors to the Moon, if it is possible to arrange production of fuel from local resources. The reserves of lunar ice found at the poles of the satellite make it possible to expect that in the future it will be possible to get water from it , as well as oxygen and hydrogen for fuel and respiration. In this case, the creation of a filling station on a circumlunar orbit will have a direct economic meaning.

However, while the extraction of oxygen and hydrogen from the lunar ice remains a matter of uncertain future, and it is probably easier to use them directly on the lunar surface. Even tracking of asteroids can be organized without the participation of a person, using automatic devices.

Lunar Orbit Station 1975 Concept

NASA / Marcus Lindroos

Rethinking the station

However, in favor of building a near-moon station, there is at least one “impenetrable” argument. Such a project can become a weighty answer to the question of what will happen to the manned space flight after the ISS, how and to what extent the vast experience of joint work accumulated over the years of its creation and operation will be used. The international station has been operating for almost 20 years, the end of its operation was designated in 2024 – it is possible that the terms will be extended to 2028, but sooner or later it will still have to be decommissioned. And then international cooperation can find a natural extension already in the lunar orbit. Work at the new station will save this experience and recruit a new manned expedition to Mars, which is necessary for the next stage.

In September 2017, NASA and Roskosmos signed an agreement on the intent to create a near-moon station Deep Space Gateway, later renamed the Lunar Orbital Platform-Gateway. Space agencies and their partners in the ISS have created a working group to discuss the implementation of this project. According to cosmonaut Oleg Kotov, the most detailed way to create a station on the polar high-elliptical orbit. The low orbit is not very profitable because of the need for constant corrections. The elliptical station will allow the station to hang for a long time on the spot, to relay signals to the Earth and to search for suitable places for the future base, including using remotely controlled probes.

At the beginning of the year a large meeting was held with the participation of about 300 specialists, where the main directions of work with the Lunar Orbital Platform-Gateway were discussed. It is assumed that this will be arelatively modest visited station of four small modules.

The Power Propulsion Element (PPE) will be the first to go to the Moon with a capacity of about 40 kilowatts, which will perform the key functions for the orbital base. Its development involved five companies: Boeing, Lockheed Martin, Orbital ATK , Sierra Nevada Corporation and Space Systems Loral. NASA will choose the final version as soon as companies demonstrate the working capacity of the proposed project – and it is possible that more than one contract will be entered into.It is expected that the launch will occur already in 2021-2022. PPE will carry the necessary elements in itself, necessary to provide the station with energy, correction of orbit and communication with the Earth and other spacecraft. In addition, the power plant may have a payload designed to measure the level of radiation and neutron detection, neurocognitive experiments and assess psychological health, plant cultivation and waste processing.

Next to the Earth satellite will be delivered a residential module (presumably, no later than 2025), where for at least 30 days can be a crew of four people. In an article for the American edition of Popular Mechanics, journalist Anatoly Zak reported that as a basis, the Russian RSC Energia suggests using a large 24-tonne scientific and energy module of the NEM, which is now being built for the ISS. However, to take it to the near-moon orbit, it will take an extra-heavy rocket, which has yet to be created – today NASA intends to use the American Space Launch System, the first flight of which will not happen until 2019.

On the other hand, last year NASA told that under the program NextSTEP six companies are also developing prototypes of a residential module (including Bigelow Aerospace, which is going to launch a private residential module to the Moon). There are all chances that one of them will be chosen for LOP-G, but we will not know about it until the second half of next year.

The third element of the future orbital station will be the logistics module. There will come cargoes that will extend the mission of the crew, there can also be scientific experiments and demonstration of technology. In addition, the module can potentially be used for commercial purposes – though, so far it is not clear how.And the last for the near-moon orbital base will go the airlock for the crews’ exit into outer space – Russia may receive a proposal for its construction .

The development and creation of the first modules for the creation of a near-moon station will cost $ 2.7 billion, with NASA planning to request the first 504 million from the US budget in the new year. Of these, 328 million will be spent for the energy module, and the remaining 176 million for the habitable module, as reported in the presentation of Mark Geier, NASA’s executive director for manned programs.

Secure room

The astronauts aboard the ISS receive a dose of radiation about 200 times greater than people on the surface of the Earth, covered by the atmosphere – every day it is about 1 millisievert. However, due to the fact that they retain an important element of radiation protection – the effect of the planet’s magnetic field extends far beyond the orbit of the space station – people can stay in orbit for up to 200 days without much risk. Near the Moon, this factor will cease to function – and whether people can live and work there, still a big question.

“If the planet Earth is presented as a spaceship, then it has two means of protection from radiation,” explained Vyacheslav Shurshakov, head of the laboratory for radiation monitoring during space missions of the Institute of Biomedical Problems of the Russian Academy of Sciences. – The first is the Earth’s atmosphere, it screens, approximately like a 10-meter layer of water. The second is the magnetosphere. “

On the other hand, the effect of the magnetosphere is not always positive: its lines form radiation belts, a kind of “pockets” where high-energy cosmic particles accumulate, dangerous both for humans and for electronics. Usually they do not intersect with the ISS, but there are special zones, for example the South Atlantic Anomaly, where the height of the inner belt can “hang” up to 200 kilometers above the surface, which creates danger for the crew of the station.

“It turns out that the role of the magnetic field is twofold. On the one hand, it protects, and on the other hand – creates zones of increased radiation. Therefore, the dose of hazardous radiation that is on the circumlunar, that in a near-earth orbit will be approximately the same, “- says Vyacheslav Shurshakov.

Similar experiments are being conducted in Moscow, at the Institute of Medical and Biological Problems of the Russian Academy of Sciences. So, in November 2017, the SIRIUS-17 experiment was conducted , aimed at studying the effect of the spacecraft’s isolation and limited space on the crew’s psychological and physiological state during the 17-day simulation of the flight to the moon (the experiment was daily told about in the collective blog ).

In addition, in IBMP conducted experiments to simulate conditions of weightlessness with the help of “dry immersion” – volunteers for a certain number of days lie in special baths with water that does not come into contact with their bodies. During these experiments, doctors receive a lot of valuable information without significant costs associated with sending cosmonauts and special equipment into space.

Another isolation experiment simulating a four-month flight to the Moon is plannedfor IBMP for the first quarter of 2018. The crew will consist of three men and three women who will have to complete a full cycle of operations: launching and flying to the moon, docking with the orbital station (the equivalent of the Deep Space Gateway project), monitoring the lunar surface, landing on the moon and leaving two or three crew members on its surface, return to the orbital station and return to Earth.

Against this background, the main problem for visitors to the future near-moon station may be outbreaks on the Sun. They are accompanied by the emission of powerful and fast particle flows. Outside the magnetosphere, they can be deadly (largely due to the fact that rapid irradiation is more dangerous than slow accumulation of radiation), but they can be saved by simply hiding behind a suitable screen. Even very powerful screens will not be effective against galactic cosmic rays – heavy ions of very high energies that fall into the vicinity of the Earth from interstellar space. However, in the near-Earth space from them, it is difficult to defend themselves, since high-energy particles are almost not retained by the magnetosphere.Therefore, an anti-radiation shelter should become an obligatory element of the future near-moon station, and the role of screens can be played, for example, by tanks with water and fuel located along the skin of the protected module. Modern means of observing the Sun make it possible to notice the approach of such a flow in time – and to wait it out in a hiding place. Nevertheless, the creation of additional designs a priori leads to an increase in the weight of the station, which will complicate its output into orbit.

Attempt at writing

Of course, such a large-scale and unusual mission as the Lunar Orbital Platform-Gateway can not be started without preparation. Still, it’s one thing to send people on short expeditions, and the other is long-term work in the lunar orbit. That is why before the launch of the station it is planned to conduct at least two preparatory studies. Their plan was also presented in the presentation of Mark Geier on May 1.

In the first trial mission will take part the ship “Orion” and the SLS missile. First, it will take the spacecraft into a near-earth orbit. On its board there will be 13 couscous – very small research satellites that will travel together with the “Orion” to the Moon. The ship will make a loop around it along an elongated elliptical trajectory, while the cufts will only stay a little in the “gravitational domains” of the satellite and go to the heliocentric orbit.

After completing one full turn, Orion will return to Earth and land somewhere in the ocean. The total distance that the spacecraft will overcome will be about two million kilometers, and it will take 25.5 days. The test flight will, first of all, test the technology and test how the spaceship feels in space.In the second mission, Orion will leave with the crew. Probably, therefore the ship will not make full turns around the Moon, and the flight itself will last almost three times less than the first one. In total, the astronauts will spend next to the Earth’s satellite for four days, and then return home.

In general, the technical and medical problems associated with the construction and operation of the near-moon station are solvable, especially taking into account the speed of technology progress. The project can become an important stage in the development of manned space travel, an intermediate step from the ISS to the creation of permanent bases on the Moon and visiting Mars. It remains to be hoped that the participants will not be hindered by more significant difficulties – the economy and politics, and also that the project budget will not grow, as it happened with “James Webb”.

 

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