A robotic relic of the Space Age is going up for auction with the bids expected to reach US$80,000. Looking like C3PO's down-at-heel cousin, the Power Driven Articulated Dummy (PDAD) was developed for NASA in the 1960s by the IIT Research Institute in Chicago and was designed to test spacesuits. The sale is part of R R Auction's Elite 100 Auction in Cambridge, Massachusetts, later this month.

Even at the best of times, pressure suits are unpleasant things to wear. When inflated, it's not easy to move in one, and in some of the early ones, almost impossible. The first pressure suits were designed for high-altitude bomber crews and their purpose was to keep the crew alive in case the cabin suddenly depressurized. Since these were emergency suits for people in seats, there was no need for the suits to allow for more than the most basic of movements.

That was fine for the very first US manned orbital missions where the Mercury astronauts spent the whole flight sitting in a can, but the subsequent Gemini missions required the astronauts to be able to leave the spacecraft to practice spacewalks, and Apollo would see them walking and working on the surface of the moon, so something better was needed.

This meant developing new spacesuits, which meant a lot of testing. Unfortunately, pressure suits aren't like coveralls. They're complex pieces of engineering. A human can provide qualitative information about how (un)comfortable a suit is, but cannot gauge the forces involved with the precision and accuracy that an an engineer needs. In addition, testing pressure suits with volunteers can be grueling, unpleasant and even painful.

Running from May 22, 1963, through July 31, 1965, the PDAD project's goal was to build a robotic stand-in for the human pressure suit wearer, which could provide the data that the engineers needed. It would have to be able to fit inside the suit, have adjustable parts to fit different sized suits, and move like a human being.

The result was a 230-lb (104-kg) robot that that could simulate 35 motions and had torque sensors at each joint to measure the forces generated by the suit. The PDAD could swivel its hips, raise and lower its arms and legs, shrug its shoulders, clench its fists, and shake hands. However, it could not balance or walk, so it spent its time hanging on a frame.

The PDAD was controlled by an operator and powered externally using electrics and hydraulics to save space. The limbs and torso were adjustable, so the robot's height could be shifted from 65 to 74 in (165 to 188 cm), so it could correspond to 95 percent of adult American army males of the 1960s. Meanwhile, the mechanics and the nylon-tube circulatory system were sealed in a removable aluminum skin and the glassfiber head. To give it a distinctly odd touch, the robot was fitted with a neoprene suit and boots.

Despite over two-years of development and the construction of two robots costing US$175,000 the PDAD system was never put into service. The problem was that the hydraulics that the robot depended on leaked oil, which is one of the reasons for the neoprene suit, and the engineers could never lick the problem. In the end, the project was defunded. One of the robots went to the Smithsonian's National Air and Space Museum and the other went to the University of Maryland, from which it was later bought as surplus.

The one for sale has seen better days. After half a century, it has lost a forearm, the wiring is damaged, and is generally scuffed, dented, and dinged. But it's still a very quirky piece of Space Age history.

The Elite 100 Auction runs from September 15 to September 25.

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