Robonaut 2

What it is

Robonaut 2, usually shortened to R2, is a humanoid robot developed jointly by NASA and General Motors under a cooperative agreement ^[1]. NASA describes it as a dexterous machine with human-like hands and arms, and the human-like shape is not decoration: R2 is able to use the same tools that crew members on the International Space Station use ^[1]. That saves designers from building a separate set of robot-only equipment. A hand that can grip a hand tool can pick up a wrench, hold a camera, or work a control that was designed for a person.

Getting ready for space

Hardware bound for orbit has to survive conditions that are hard to reproduce in a workshop. NASA says R2 underwent vibration, vacuum and radiation testing in preparation for its flight ^[1]. Vibration testing imitates the shaking of launch, vacuum testing the near-empty environment above the atmosphere, and radiation testing the charged particles that spacecraft encounter outside most of Earth's protective atmosphere. Passing such tests does not guarantee that a machine will work in orbit, but it removes the most obvious ways for it to fail.

Launch and arrival

R2 was launched to the International Space Station on 24 February 2011, with the aim of becoming a resident of the station rather than a short-term visitor ^[1]. It travelled on the STS-133 mission, which launched at 4:53:24 p.m. EST on February 24, 2011, with an 11-day mission duration ^[2]. Becoming a resident changes what a robot is for. A machine that stays aboard can be tested over months, adjusted, and used as a platform for repeated experiments rather than a single demonstration.

The first job

R2's primary job at first was to teach engineers how dexterous robots behave in space ^[2]. That is a research task rather than a maintenance one. Motors, joints and control software that work smoothly on the ground can behave differently when nothing has weight, and engineers needed measurements from a real dexterous robot in orbit before they could design the next one.

In 2014 a mobility platform with two new legs was added to let R2 manoeuvre inside the ISS ^[1]. A robot fixed to a single mounting point can only reach the workspace around that point; legs give it a way to move to different parts of the station.

Why it matters

NASA says the greatest future benefits of humanoid robots in space may be as assistants or stand-ins for astronauts during spacewalks ^[1]. Work outside a spacecraft is slow, physically demanding and exposes crew members to the hazards of the environment beyond the hull, so a machine that can use the same tools as a person is an attractive candidate to share that work or take the riskier part of it. R2 was built and flown as a step in that direction: a human-shaped robot sent to the station so that engineers could learn how such a machine actually behaves in orbit ^[1][2].