Cocooned inside an aluminium frame and foam blocks cut out to its shape, Robonaut 2 (R2) is heading to the International Space Station inside the Permanent Multipurpose Module in space shuttle Discovery’s payload bay as part of the STS-133 mission.
Once in place inside the station, R2, with its humanlike hands and arms and stereo vision, is expected to perform some of the repetitive or more mundane functions inside the orbiting laboratory to free astronauts for more complicated tasks and experiments. It could one day also go along on spacewalks.
Making sure the first humanoid robot to head into space still works when it gets there has been the focus of workers at Nasa’s Kennedy and Johnson space centres. Engineers and technicians with decades of experience among them packing for space have spent the last few months devising a plan to secure the 150-kg machine against the fierce vibrations and intense gravity forces during launch.
“I think back in May we realised we had a huge challenge on our hands,” said Michael Haddock, a mechanical engineer designing the procedures and other aspects of preparing R2 for launch, including careful crane operations inside the Space Station Processing Facility’s high bay.
Though it was fast-paced, intense work, the payoff of getting to help R2 into space added extra motivation for the engineers involved.
By spaceflight standards, planning for the packing effort moved quite quickly, particularly considering R2 is perhaps the heaviest payload to be taken into space inside a cargo module.
“The mass is what’s driving the crane operations, otherwise we’d be handling the robot by hand,” Haddock said. “But the robot itself weighs on the order of 151 kg and when it is installed in the structural launch enclosure, it will weigh over 227 kg.”
As they must when loading anything for spaceflight, the engineers designed the packaging so astronauts could easily remove R2 from its launch box, known by its acronym SLEEPR or Structural Launch Enclosure to Effectively Protect Robonaut.
“We were trying to do something very unique and very fast,” said Scott Higginbotham, payload manager for the STS-133 mission. “And we’ve got the best team in the world for dealing with things like that.”
There was talk of simply strapping the robot into the empty seat on the shuttle’s middeck, Higginbotham said, but R2 was too heavy for that. So the teams came up with a plan to fasten R2 to a base plate and use struts to support the back and shoulders. Then dense foam will provide more support, followed by an aluminium frame. A clamshell of foam tops off the package.
Assembling the packing precisely is important for R2 because a space shuttle accelerates to more than three times the force of gravity during its eight-minute climb into orbit.
“The team had to educate ourselves, learn the uniqueness of it as well as learn how to install it into the vehicle,” said Ken Koby, lead systems engineer for Boeing. “That’s what the team has basically been doing every day for the last three months, educating ourselves about Robonaut.”
Coincidentally, detailed analysis showed that R2’s best position to withstand the launch forces will be the same as the astronauts – facing toward the nose of the shuttle with the back taking all the weight.
“The orientation is just like the crew flies,” Koby said. “The crew will be facing straight up on their backs and Robonaut will be the same direction, obviously 9 m behind them in the module here.”
Although the robot is fundamentally a very complex machine full of state-of-the-art sensors and operated by phenomenally sophisticated software, it is its shape that stirs fascination. Designed by Nasa and General Motors as a robotic assistant for astronauts working in space, R2 looks like the upper torso of a sculpted bodybuilder and is topped with a helmeted head that includes two cameras to give it three-dimensional vision plus other sensors.
Its look has been compared to Star Wars bounty hunter Boba Fett, the endoskeleton from the Terminator films and the animated robot that plays football on Fox Sports.
“It’s rather intimidating at first sight because of its size, its physique and you can’t see its eyes,” Haddock said.
“From the moment you walk into the room and see R2, it’s everything you’d expect from a robot, from the gold-shield face to the thickness, the broadness of his shoulders,” Koby said. “It’s truly very science fiction-like, but it’s all fact in this case.”
It also has a pair of beefy arms and two hands, complete with four fingers and one thumb each, that can shake hands. Its programming is sensitive enough to respond to a handshake with the same amount of force as the person squeezing R2’s hands. In other words, it can hold a piece of equipment in space without crushing it.
“It really grabs people’s attention,” said Higginbotham. “It’s so incredibly cool. It can use the same tools and procedures as an astronaut.”
This Robonaut was not meant to fly at first. Instead, it was strictly a developmental model to be tested and perfected on the ground. However, it was adapted for flight and has tested well for launch. That is a bit of a theme for the STS-133 mission because the Permanent Multipurpose Module (PMM) that Discovery is taking to the station also was retrofitted to add more capabilities. The PMM was formerly a Multipurpose Logistics Module known as Leonardo and was built to stay in space for only short periods at a time. But its mission has changed and engineers built up its armour and added some interior features so it can be permanently attached to the station and used as more of a storage closet than the moving van first envisioned.
“Someone said this mission is anything but ordinary,” said Higginbotham, “and that is a fact.”
* Video: Meet Robonaut2, the next generation dexterous robot
* News: Nasa, GM take giant leap in robotic technology (8 February 2010)