What Are the Different Types of Space Robots?

T. Broderick

There are a number of different types of robots and robotic machines at use in the space industry, but in general they can be broken into four main categories. Satellites are some of the best known and also the most used; these machines orbit the earth beaming signals and facilitate such things as real-time location services and globally available television programming. Rovers are car-like robots that are used primarily to explore and store data on foreign terrains, and are usually controlled remotely from space stations or hubs, either on earth or from ships in orbit. A number of probes and measurement tools can also fall within the “space robot” category, though these tend to be smaller and primarily focused on gathering a single sort of information, such as temperature, pressure, or wind speed. Finally there are a number of tools designed to help astronauts complete space missions. These can include things like cargo release tools, levers and machines for collection of specimens, and suit pressurization materials. In all cases, the main thing that distinguishes a space robot from an ordinary space machine is its ability to work independently. Most are controlled remotely, usually by computers, but many can also be programmed in advance, and they are often thought of as stand-ins for astronauts who, for various reasons, aren’t able to do the robots’ work themselves.

The man-made satellites orbiting the Earth qualify as space robots.
The man-made satellites orbiting the Earth qualify as space robots.


Orbital satellites typically make up the majority of space robots. These vary in size and purpose, but in most cases are machines designed to capture information from one part of the earth, then beam it and make it accessible elsewhere. They are usually owned and operated by a specific national government or space agency, but the information they beam out is usually accessible to anyone or anything with reading capabilities.

Canadarm is a fixture on the international space station.
Canadarm is a fixture on the international space station.

Some of the first satellites had a strictly military purpose, but most of those in orbit in modern times are used for the world's communication networks. Digital television and most broadcasting is handled by satellite, for instance. Others are dedicated to mapping, and their main role is to take, store, and relay images of the earth. Mapping satellites have a wide range of purposes including measuring changes on the earth's surface, surveying the weather, and even spying on other nations.

The Canadarm space robot, used on most U.S. space shuttles and stations, was developed with funding from the Canadian Space Agency.
The Canadarm space robot, used on most U.S. space shuttles and stations, was developed with funding from the Canadian Space Agency.


In contrast to satellites, which stay within and in fact usually depend on the earth’s orbital power to function, rovers typically travel beyond the earth’s orbit to land on and explore other planetary bodies such as the moon, Mars and Venus. These robots are rovers or stationary landers, and typically use airbags or retrorockets to land safely. After arrival, the robots use instrument packages to examine the soil and atmosphere.

For planets like Jupiter that have no solid surface, a different form of robot is necessary — and typically one that is able to send and receive transmissions quickly before being consumed and destroyed by the hostile environment. Jupiter-bound rovers typically use a parachute to slow their decent, then the robot transmits information back to Earth before being crushed by the planet's thickening atmosphere. Scientists back home usually find the cost worth the benefits, particularly if the rovers enable them to get important data to help them better understand the planet, what it’s made of, and hints as to how it might have been formed.

Probes and Measurement Tools

A similar class of robots explores the solar system without actually physically landing anywhere. These typically use cameras and a variety of instruments to measure conditions on other planets, moons, and the sun from some distance. Most of these use solar cells to power their instruments, but might also have to return periodically to a ship or space station hub for charging.

For probes that venture into deep space, radioisotope thermoelectric generators provide power. These generators typically use radioactive decay to produce decades’ worth of continuous electricity. Most scholars speculate that any robots launched to explore past the asteroid belt in the future will rely on this sort of technology.

Astronaut Assistance

Besides acting as explorers, space robots can also assist astronauts in manned spaceflight. One of the most notable examples is a device known as the Canadarm. Developed with funding from the Canadian Space Agency, the Canadarm became a permanent fixture on many American space shuttles and the international space station. With a human working a set of controls, the Canadarm — and other subsequent manipulators developed for use in outer space — moves within 6 degrees of freedom to transfer cargo, release satellites, and transport astronauts performing extravehicular activities to their work sites. It is all but certain that successors to the Canadarm will continue to be a part of future manned spaceflight, as will a range of other related and developing technologies.

Android, or humanoid, robots are designed to emulate the look, physique, and behavior of humans.
Android, or humanoid, robots are designed to emulate the look, physique, and behavior of humans.

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Discussion Comments


@miriam98 - Space exploration robots provide a wide variety of useful functions, whether they are operating solo or to assist other manned missions.

Personally I don’t think that we need to get to “sentient” robots anytime soon. The advantage robots have is that they don’t need oxygen and they don’t need water.

I would rather see more robotic missions to planets in our solar system rather than worrying about a manned mission to Mars or something like that. I simply don’t see the benefit of sending humans out into the far reaches of space, except perhaps maybe for the thrill that it produces. But that’s not enough of a reason in my opinion. Robots are safer and more efficient.


@David09 - Really the present state of the art is exciting enough on its own terms in my opinion. I remember teaching in elementary school at around the time the famous “Mars Rover” robot landed on Mars.

It moved about on the Martian surface and snapped photos of the landscape. It also used its robotic arms to gather samples and transmit the information back to planet Earth. The kids in my class were really excited about the Mars Rover and what it accomplished.


@hamje32 - I know what you mean by science fiction. I still think we are a long way from the Lost in Space robots that cry “danger, danger” and communicate with people in a truly intelligent manner.

We don’t have truly sentient beings. But we do have robots that can communicate basic information – and we certainly have computers that can beat chess masters at their own game. So I think we are getting close to robots that can truly function as human-like creations.


Space robots conjure up science fiction images. Honestly I never thought of something as mundane as orbiting satellites as being space robots. At first glance it would appear that they lack intelligence, but then again, maybe not.

Since their functions are to transmit and receive signals to and from the earth and gather information, I guess they really are robots in space. They don’t move on robot wheels but I think the basic intelligence – the brain if you will – is there.

It takes advanced computing algorithms to be able to do what satellites to; scan space and bring back meaningful information to planet earth.

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