Cities in space: dream or reality?

Space cities are probably returning to the pages of science fiction books: this was the sad conclusion of the space cities panel held at the Icon Festival 2009. However, if it is possible to solve the technological problems and improve the efficiency of the launchers, it will be possible to speed up the projects

Avi Blizovsky, "Galileo"

"The main conclusion of the committee is that the manned flight program is on an unstable course," said Norman Augustin, who chaired a committee appointed by the US government to review the state of NASA's manned flights, in a report published in October 2009. "We say this due to the incompatibility between the vision of The program and the resources available for it". In the report, the members of the committee write that an additional budget of three billion dollars per year is urgently needed for NASA, otherwise it will be impossible to carry out any manned launches, or very few of them.

Even earlier, in August, the committee published a partial report. This report resonated among the participants of a panel that dealt with the future space cities, which took place at the Icon conference held every year at the Tel Aviv Cinematheque. This year the festival was marked by the city of the future, and the discussion dedicated to the topic was attended by Tal Inbar, chairman of the Israel Space Association and head of the Center for Space Research at the Fisher Institute for Strategic Air and Space Research, and Yoav Landesman, a space engineer in the aerospace industry.

"We'll stay with science fiction"

It was nice to cuddle up to the beautiful paintings published in the XNUMXs that showed space stations containing thousands of inhabitants if not more; and which were designed in a variety of types and shapes, for example a keech shape or a cylinder shape, and what they have in common is that they rotate to give some sense of weight to their occupants.

But Tal Inbar brought us back to today's reality, where there is not much news after a jubilee of space programs and over 40 years of manned flight. "The first flights were short - minutes, hours, and at most days," said Inbar.

"The technological challenges that had to be overcome in order to develop the ability to stay for long periods of weeks and months were great and were reflected in a series of space stations, the current one of which is the International Space Station. Basically, a space station is a bus-sized component that people board and are inside an enclosed space that keeps them alive with atmosphere, air conditioning, water and food. The record for a continuous stay of astronauts was recorded at the Soviet Mir space station. In all of history there were eight Soviet space stations and only one American station - Skylab."

The population of the human race in space today is at most 13 people (six Soyuz passengers and another seven shuttle crew members, with one of these docked at the station). This is a zero number compared to the optimistic visions we saw in the movies.

It was once thought that space stations should be built at the Lagrange points - fixed, stable areas in orbit between the Earth and the Moon, to which billions of people could be sent. The idea was to use space stations as a kind of insurance certificate for the survival of the human race against a disaster on Earth, such as a nuclear or biological war, the collision of a large asteroid, etc. Inbar estimates that if and when the Earth's population reaches 30-20 billion people, there will be no choice but to go outside and use the resources in space.
In the visions of the XNUMXs, there was talk of three main types of space colonies - a rotating cylinder several kilometers long, which would be placed between the Earth and the Moon, so that it would always see the sun. Large collectors will convert sunlight into available energy. Another form, less efficient in terms of volume utilization, is the form of a torus, in which a kind of artificial gravity can be created. The third shape envisioned by the creative space planners of the seventies based on the best human knowledge of physics, and which unfortunately still remain in the imagination, is that of a spherical space station. Tens and even hundreds of thousands of people are expected to live in each such colony.

One of the motivations for such a settlement, or at least for the desire to build buildings on a large scale, is energy - setting up a farm of solar collectors in space and converting the electricity into radio waves that will be transmitted to the earth to receiving stations.

The launch problem

Yoav Landsman described the field of launches and explained that in order to establish colonies in space, a completely different scale of launches into space would be needed. "If we want to build cities in space we will have to carry out dozens of launches a day and not one launch every few weeks. We are at the bottom of the gravity well and to get to the space station you have to invest a lot of energy."

However, in order to do this, the problem of the inefficiency of the existing launchers, which operate with an outdated method and whose cost to launch them into low orbit is 20 thousand dollars per kilogram, must be overcome. Landsman presented one of the most studied solutions: a magnetic cannon operating on an electric field. You put the desired charge into the cannon and install means on the charge to absorb the energy and turn it into movement, and give it momentum. In this way, most of the energy is saved and the launch costs can be greatly reduced.

However there are some problems. When we ask to lift heavy loads we will have to invest a lot of energy. A byproduct of the process will be heat, which can be overcome using superconductors. Another disadvantage is that due to the high accelerations - about a thousand G - it will be impossible to transport any cargo, certainly not humans.

A second method is a laser propulsion system, which is divided into two sub-methods, with what they have in common is that the propulsion system is on the ground, and no fuel is needed to raise it into space. The idea is to use a powerful focused laser, such as the one operating in the Nautilus missile defense system, or a laser that detects intercontinental missiles. The laser beam fires and hits the lower layer of the spacecraft coated with a solid propellant, which turns into plasma and in the process releases the energy and raises the spacecraft. In the second method, the solid propellant is replaced by gas in the spaceship's tank. In any case, the disadvantages are the unavailability of a suitable laser as well as the need for cooling systems.

Another method for raising cargo and people into space is the space elevator, which today is still stuck in the phase of searching for the materials to build the cable. Today there is talk of using carbon nanotubes, of which only a few centimeters have been created so far, and even then it is not certain that the 70 thousand kilometer long cable will not collapse under the weight.

"Today, the vast majority of flights into space are controlled by government bodies that have no interest in investing in space, unless it brings a military benefit. We hardly talk about flights of individual humans, and even when commercial flights take off to provide a route or even a route around the earth, it will still be a luxury that only a few will be able to afford. I don't think we will see cities built in space in our time. We will stay with science fiction," concluded Landesman.

The panel was concluded by Tomer Krauthammer, an industrial designer who designed products for a weekend without gravity as part of a final project for a product design degree at the Holon Institute of Technology.

A number of companies compete for the space tourism market: Virgin Galactic is in the stages of building a space port, has successfully performed test flights and is selling tickets for flights outside the atmosphere; Mark Newson designs an extra-atmospheric spacecraft for the European company Astrium.

Several companies are planning to build hotels in space - Bigelow Aerospace is developing the BA 330 module, and even launched a test model; Also planned to operate starting in 2012 is a Galactic Suite company's modular hotel.
A hotel in space must be warm, expensive and luxurious, inviting and pleasant; experience as free as possible; Simple, no learning curve. For the purpose of planning the products for the gravity-free weekend, one must take into account the handling of the problems of life on the track; and take advantage of the lack of gravity as much as possible. However the design must be connected to the ground: the products have to survive several years into the future; reference to room service, repair and replacement; Use of existing materials and technologies. Krauthammer decided to focus on the sleeping area, with an emphasis on a double personal room

Krauthammer got the inspiration for the construction of the products from yachts due to the similarity in the size of the facility, since the structure is closed and isolated moving in an environment hostile to humans; A similar ratio of administrative operation areas versus public spaces, similar size ratios of personal versus public space and even seasickness. And similarly to Licht, in a space hotel it is advisable to keep the technology to a minimum and use diverse materials and classic styles.

The products were designed according to the specifications of the space hotel based on the BA330 module of the Bigelow Aerospace company, intended for 2-10 guests and 1 to 2 staff members and containing a public space, a central corridor and a personal room for guests, including personal services.

Of course, it is necessary to take into account the lack of significant gravity since the hotel is in "free fall" in a designated orbit around the earth and therefore, objects float unless they are anchored. However, despite the "weightlessness" the mass still plays an important role.

Lack of gravity disrupts the sense of direction, creates seasickness and sleep problems. The movement is done by pulling and pushing with the hands, anchoring with the feet; Similar to diving or climbing. Some action is needed just to stay put. Therefore, it is necessary to ensure an even distribution of outposts. Certain points require special attention (corridors, doors, in front of cabinets and windows...)

One of the objects that Krauthammer designed was the bed, and the considerations were, among other things, the need for anchoring and pressure on the body, the psychological and physical need for pressure on the head, orientation considerations, posture considerations and a sense of security, no need for ergonomic support, and consideration of the problems caused when trying to perform sexual contact in a lack of gravity ( but we will not elaborate on that). The solution - a connecting bed.

The bed includes a variety of grip points and is attached to the mattress using electromagnets. The blanket, pillows and scarf-like components contain metallic components that will stick to the magnet. The bed also contains a shock and vibration reduction mechanism, the ability to control attachment, heating, mattress hardness, room lighting; Storage under the bed and the possibility of simple cleaning, convenient bed linen change. Krauthammer also designed the outposts and the room's lighting. Now all that remains is to convince the manufacturer of the space hotel to adopt this design.

To be sure, cities in space will not be established in the coming years, but even those few who will spend a weekend in orbit around the Earth deserve to enjoy themselves.

The article was published in the December 2009 issue of Galileo