the unwound road

This morning’s launch of the shuttle Endeavour also launched the career of a new astronaut: Dextre.

The Dextre manipulator (or Special Purpose Dexterous Manipulator), a sophisticated dual-armed robot, is part of Canada’s contribution to the International Space Station (ISS). Designed for servicing the Station, Dextre can remove and replace small components on the Station’s exterior that require precise handling.

Like a mechanic in space, Dextre can pivot at the waist, and its shoulders support two identical arms with seven offset joints that allow for great freedom of movement. It is equipped with lights, video equipment, a stowage platform, and four robotic tools.

At the end of each arm is an orbital replacement unit/tool changeout mechanism, or OTCM-parallel jaws that hold a payload or tool with a vice-like grip. For fine manipulation tasks, Dextre has a unique technology: precise sensing of the forces and torque in its grip with automatic compensation to ensure the payload glides smoothly into its mounting fixture. To grab objects, each OTCM has a retractable motorized socket wrench to turn bolts and mate or detach mechanisms, as well as a camera and lights for close-up viewing. A retractable umbilical connector can provide power, data, and video connection feed-through to payloads.

The cargo bay of Shuttle Endeavour with the Canadian robot Dextre and the pressurized component of Kibo, the Japanese Experiment Module.

Dextre can accomplish tasks that require high precision and a gentle touch such as removing and replacing Station components, opening and closing covers, and deploying or retracting mechanisms. Some of the many tasks Dextre will perform include installing and removing small payloads such as batteries, power switching units, and computers, as well as manipulating, installing, and removing scientific experiments.

A typical task for Dextre would be to replace a depleted battery (100 kg) and engage all the connectors. This involves bolting and unbolting, as well as millimetre-level positioning accuracy for aligning and inserting the new battery.

Like the Canadarm2 and the Mobile Base System, Dextre can be controlled from a workstation inside the space station or by controllers on the ground in mission control centres in Houston, Texas and at Canadian Space Agency headquarters in Longueuil, Quebec. Its five cameras, including two pan/tilt cameras below its rotating torso, provide operators with multiple views of the work area.

Dextre, Canadarm2 and the Mobile Base System form a robotic system called the Mobile Servicing System (MSS). The MSS is built for the Canadian Space Agency by the Canadian company MD Robotics.

(Information and illustrations: Canadian Space Agency)

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The signs of urban decay are there for those who have the eyes to read them: leaking water and sewage systems, roadways deteriorating under the weight of too much traffic and buildings crumbling from smog and acid-rain, rotating black-outs and a strained electric grid, problems with water contamination and garbage disposal. Will the aging infrastructure that holds together our cities with a fragile network of wires and roads and pipes be sufficient for this century, let alone the next one?

I’m not talking about whether these things are fixable. All it takes to keep things running is a lot of money and perhaps some improvements in materials, such as replacing ashphalt pavement with concrete, or cast iron pipes with pvc plastic. But all this work is merely maintaining the status quo — how are we planning for the cities of the future?

The lead story on the WorldChanging website suggests that many cities in the developed world have racked up huge “infrastructure deficits” — backlogs of needed work on existing systems, as well as demand for new systems — and quotes a U.S. study which estimates that it would cost $1.6 trillion dollars to bring everything up to date. “Most of the infrastructure we use today was designed a century ago: some of it is based on ideas that go back to the Roman Empire,” says writer Alex Steffen.

“Essentially all of it was designed for a world without climate change, resource scarcity or any proper understanding of the value of ecosystem services. In other words, most of the systems upon which we depend are not only in a state of critical disrepair, they’re out-dated and even out of touch with the realities of our century.”

The article suggests five new ways to prepare our urban spaces for the future:

1. Adaptive and creative re-use - making the best use of what’s there
2. Whole-system missions - taking into account the impact of systems on society and nature as a whole
3. Resilience and survivability - the social and infrastructure net needs to be sustainable and be able to cope with whatever climate changes or epidemics the future holds
4. Distribution - efficient movement of water, power and other services
5. Wild ideas - creative thinking can change the world

As an example of creative thinking, Steffen points to the design which won one of the Regional Prizes in the History Channel’s “City of the Future” competition. The design by San Francisco architects IwamotoScott takes the city and transforms it using creative ideas like a “hydronet”. The description by Geoff Manaugh on the Bldg Blog sounds like a science-fiction fantasy:

“The project reimagines the entire San Francisco peninsula in the year 2108 A.D., having been overlain, if not completely replaced by, a kind of prosthetic hydrological landscape – complete with underground rivers of algae which will be cultivated as a source of hydrogen for fuel…. Architecturally speaking, the city will sprout a whole series of new structures, including multi-angled fog harvesting machines, tendril-like towers along the waterfront, subterranean transport tunnels, and biologically active reservoirs buried beneath the streets.”

My imagination is really caught by this concept of a truly living city, imagined as a whole system, not just a series of bits and pieces put together all “higgeldy piggeldy”. And like good science fiction, everything imagined here seems not too far from the realm of possibility. Would you like to live in this city? Check out this and other concepts, and vote for your future here.

For more images, check out IwamotoScott’s photoset here.

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