The big advantage of space robots is that they need neither food nor drink and can work in inhospitable conditions. More importantly, although expensive to design and produce, their loss is always preferable to an astronaut. In the edition of November 2004 ASTRA robots designed in the Space Research Laboratory of the Technical Center of ESA in the Netherlands attracted much attention.On Earth, robots often take repetitive tasks or when human health is jeopardized. They are used to assemble cars, deactivate bombs, weld pipes at the bottom of the sea and work in nuclear power plants, “says Gianfranco Visentin, Head of Automation Robotics Section at ESA ESTEC in the Netherlands.
“In the space even more attractive to use robots,” he emphasizes. “They can support or replace people to perform tasks that are too dangerous, difficult, repetitive, time-consuming or even impossible for astronauts. They can be quicker and more accurate people” jokingly adding, “They can work 24 hours a day and do not stop for lunch or sleep “.
What is a space robot?
In the space community can call any unmanned spacecraft, a robotic spacecraft, but Visentin prefers a more specific description: “A system having mobility and the ability to manipulate objects plus the flexibility to perform any combination of these tasks autonomously or by remote control.
“The objective of space robots is basically to perform an action in space such as position an instrument to take a measurement, collect a sample for examination, assemble a structure or even move around an astronaut.”
In no ways space robots are different from their brothers on Earth, they basically replace a human performing an action.
But those who are destined to space must meet some specific requirements:
– Resist a pitch. – Operate in difficult environmental conditions and often in very remote locations.
– Weighing as little as possible, as any burden, its release is very expensive.
– Consume less energy and have a long functional life.
– Operating independently.
– Be extremely reliable.
“To respond to these advanced technological challenges are very complex systems required,” says Visentin, “sounds like a big problem, but space gives us great opportunities to create robots that could not otherwise be made for use on Earth . “The biggest advantage is the almost zero gravity in outer space. This means that everything weighs much less than on Earth and even the heaviest object can be moved and raised with little effort, so a small robot can move objects enormous. ”
Types of robots :
The robot most commonly used in space missions is the rover (wanderers). This vehicle can move around the surface of another planet transporting scientific instruments. Usually both the vehicle and the instruments are operated autonomously. ESA, in collaboration with European industry, has developed the incredibly small micro-rover Nanokhod. Although only the size of a large book and weighing just 2 kg it can transport and position 1 kg. of instruments within a small radius around the “lander” (landing ship).
A larger robot has been developed to collect soil samples from other planets. The mini-rover MIRO-2 from 12 kg a robotic drill that can collect up to 10 samples from a depth of 2 m. It then returns to the lander where the samples can be analyzed by the scientific instruments on board.
A third mini-rover of 15 kg has been developed by ESA is powered entirely by solar energy. Solero mini-rover that uses miniature batteries to store electricity on board. It also has an innovative chassis. Its six wheels arranged on the vertices of a hexagon enable it to operate in very irregular terrain.
Robot designers often inspired by nature. A good example is the impressive Aramie / Scorpion developed by ESA. With his legs and the movement inspired by the animal is capable of operating in rugged terrain and dunes.
Another example is EUROBOT as big as a human being is designed to perform the tasks of an astronaut on the International Space Station. EUROBOT be able to climb the outside of the space station, attach itself to the rails like an astronaut and be tele-operated by the crew inside.
Nature also inspired the hopping robot. With just under 40 cm. high it can leap over obstacles up to six feet high, a feat impossible on Earth due to gravity but fairly easy to accomplish on the Moon or Mars.
Visentin emphasizes that research in the ESA is aimed specifically at space issues and are not interesting or profitable for terrestrial use and does not duplicate what is already available. “Whenever possible we re-use robotics technology used for applications on Earth, but some operations required for space exploration are of no use on Earth. For instance, nobody would want to make a robotic field biologist to explore the Earth, even with the most advanced technology the result would always be far below that of a real biologist, at least today. On Mars, however, is currently the only option. ”
The constraint of space.
The space raises many issues not faced by robots for use on Earth. The low pressure in the orbit leads to cold-weld metal parts together, atomic oxygen can react with almost any material and nullifies the cooling benefits of electronic transmission.
Radiation also differs from that encountered on Earth and in space, heavy particles make digital electronics misbehave or even burn. Thermal conditions are also extreme, with external temperatures ranging from more or less, 100 ° C.
Another characteristic of space missions is that robots have to operate far from their base. Radio signals to control and monitor them have to travel for a long time and this introduces communications delays that prevent tele-operation in real time or near real time. Space robots, therefore, must be able to work alone and solve any problems that occur while performing their tasks. The ESA’s space engineers have learned to cope with all these problems. Qualified design techniques, materials, hardware and electronics components are specifically designed to work reliably despite these effects.
“We continue research into new types of robots that can cope with the special conditions of space, go where humans can not and that will help astronauts manage the enormous amount of work on the International Space Station,” says Visentin.