The STARS-Me satellites entered the universe from the international space station ISS on 6 October 2018.
The engines of an H-IIB rocket roar loudly. It is September 22, 2018 and the rocket is coming off Japanese soil. Then he starts his five-day trip to the international space station ISS.
A special cargo is on board: satellites measuring 10 x 10 x 27 centimeters, connected by a 14-meter steel cable.
Two weeks later, the astronauts at ISS release the equipment into the universe through the airlock of the space station. The satellites orbit the earth at the same speed as the ISS, 27,724 km / h.
The STARS-Me satellites entered the universe from the international space station ISS on 6 October 2018.© JAXA / NASA
They slowly roll out the cable between them, causing them to fly apart. Now the construction is ready to carry out a groundbreaking mission: to run a spacecraft over the cable from satellite to satellite in a weightless state.
The experiment is a miniature version of a much larger project: a space elevator that will extend from Earth to 96,000 kilometers into space in 2050. From here, future space missions can be sent much further into space much cheaper and more easily than is currently the case.
Mini lift clears the way
The experiment, STARS-Me, was devised by researchers from the Obayashi construction company and the University of Shizuoka in Japan.
The lift boat, Miniature Space Elevator (MSE), moves between the satellites by means of a motor that is attached to the cable and moves with the help of friction. The vessel continuously transmits data about its position, condition and possible fluctuations in the cable via Bluetooth to one of the satellites, which it transmits to scientists on Earth. The project is filmed by a camera on every satellite.
The mini-lift must provide the researchers with important information about the load on the steel cable when moving between two satellites.
In the full-size space elevator, the cable must withstand enormous loads, because gravity will pull it to earth. The cable is also subjected to a force that wants to swing the upper part of the cable further into the room: the centrifugal force.
The space elevator will follow the rotation of the earth around its own axis, just like when you throw a rock around a rope. If the rope should break, the centrifugal force will cause the stone to fly away in a straight line. That force pulls the lift into the room.A lift between the earth and a counterweight follows the earth rotation in a geostationary orbit, and remains above the same point.
Space elevator must stand still above the equator
The lower floor of the space elevator becomes a floating platform above the equator. A cable runs from there, with a counterweight at the other end. The space station and the elevator cabin are located between the lift and the counterweight.
The entire lift must follow the earth rotation in a so-called geostationary orbit. From the face of the earth it will seem as if the lift is standing still, but in reality it moves through space as fast as the earth revolves around itself: at 1674.4 km / h.
The centrifugal force of the earth rotation swings the elevator away. As soon as its center of gravity is at least 35,786 kilometers high, the centrifugal force cancels the gravity of the earth, so that the cable is tight; otherwise the elevator would fall to earth.Show more Show less
It will also become apparent how the vessel and cable react to each other, so that the researchers can make the final lift cabins work as well as possible.
For example, double capsules hanging on either side of the cable and forming each other's counterweight can prevent the cable from swinging. Another option is to build capsules that sit securely around the cable. This results in a more stable construction, but the number of capsules will be limited to one.
Material gives lift to life again
The idea of a lift from the earth to space has been on the rise since the end of the 19th century, but for almost 100 years it seemed unrealistic, because there was a lack of strong materials to build the lift cable.
However, in the early 1990s, researchers made nanocarbon tubes from uninterrupted chains of very strongly bonded carbon atoms. Thanks to that structure, nanocarbon tubes are the strongest material that is known, and the invention breathed new life into research into the space elevator.
However, the researchers have not yet been able to produce enough of it; according to Obayashi, the lift needs a cable of 7000 tons.
Researchers from Shizuoka University and the Obayashi company built the STARS-Me satellites to test the space elevator. You can see the satellites in front of the table.© JAXA
The researchers also do not know which method is best for building the lift. Obayashi has plans whereby the first phase until 2032 involves the construction of a floating station at sea near the equator plus
20 tons of cable that rises like a very thin tower.
In the next 18 years, climbing capsules must walk more than 500 times to the top of the tower to add new segments of cable, until it goes 96,000 kilometers into space.
The space lift needs 12,500 kilos of counterweight for a stable construction.
The International Space Elevator Consortium (ISEC), an alliance of researchers and engineers supported by, among others, Microsoft, wants to build a space elevator from space.
First, rockets bring a station to a geostationary orbit. From there, the cable is built downwards and upwards, so that the lift does not tilt. When the cable is anchored to the ground, more cables can be added so that the lift can transport even more goods.
Elevator presses the price
If the space elevator becomes a reality, it will be a much cheaper form of transport to space than rockets.
The latter usually consist of 90 percent fuel, 5 percent hull and only 5 percent useful cargo in the form of, for example, astronauts and satellites. The lift can work on solar energy, so there is much more room for goods.
According to Obayashi, a lift can transport 30 passengers in 7.5 days and at 200 km / h to a space station 35,000 kilometers from the earth.
In 2014, the International Academy of Astronautics published a calculation that the price per kilo of cargo brought from Earth to a space station can fall from around 17,500 to less than 500 euros thanks to the lift.
Lift is a springboard for space missions1 / 3
The satellite test must lead to a full-size space elevator that can transport cargo to a space station at least 35,000 kilometers above the earth. From there, missions can go further into the universe for a shot.© Adrian Mann
There may also be other stops along the cable other than the main station. In this way, satellites can be sent around the earth in a lower orbit from their own platform, which can immediately meet the ever-increasing demand for satellite launches.
In November 2018, it was calculated that some 330 satellites would depart every year until 2027 - three times as many as in the last ten years.
A platform above the main station can take advantage of the fact that, thanks to the rotation of the earth, the capsules accelerate as they walk up the cable. As a result, they move further into space, and from this outpost of the Earth into the universe, missions can explore the solar system.