Parlor Tricks for Space

Have you noticed that there are several reassembling robots in the news and on the web? Discover Magazine highlights ckBot, a Rubiks Cube looking robot from the U Penn, that can reconfigure after being kicked apart. A self healing chair on U-tube a chair can break apart and reassembly itself. These may seem like parlor tricks, but they are really laying a foundation for a larger problem related to space exploration.

The key to making space exploration more affordable is reducing the cost of getting objects into space. Many scientists are testing the theory of launching several small objects and then assembling them in earth’s orbit to create a larger vehicle, station, or satellite. This is the premise behind the International Space Station, which is assembled by Astronauts. To make this theory cost effective, the vehicles must be assembled autonomously, which is why these small reassembling robots are so important. These projects can lead to great understanding for docking robots in space.

The Orbital Express program highlights the difficultly of assembling vehicles while orbiting the earth and without human interaction. This government funded program made a failed attempt at docking two satellites with a robotic arm. A failure in the navigation system caused the two robots to hit each other and bounce away.

There are several reasons for this project's failure that are common to all space operations. The remote distance of scientist and hardware creates problems. Also, the space environment itself creates challenges. Space has low gravity which makes holding two objects close together difficult because they tend to float away. Also, because of no atmosphere, surfaces that face the sun become extremely hot and surfaces in shadow are extremely cold. This can make material warp and can make connecting to interfaces difficult or impossible.

Add these space factors to the challenges of coordinating a group of robots and the task becomes even more difficult. Controlling a group of robots to work together autonomously is called swarm robotics. Swarm robotics has challenges of its own, which include getting robots to communicate with each other, knowing where one robots is relative to another, and determining mating locations. These reassembling robots are really solving the problem of swarm robots.

The information learned from these reassembling robots can be help space application. Think of a reassembly robot that can operate in a desert location. How different is that from operating on the moon? Two flying robots that become one is a very similar operation as docking two satellites. These reassembly robots are giving scientists better understanding of docking robot swarms, without the expense of sensing things into space. So next time you laugh at these parlor tricks, think again!