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Table of Contents
Robotics
Processors
The processor is the robot equivalent of a brain. It controls, decides, directs, interprets programs and gives orders. Computers, memory chips and information systems are all examples of processors. When these devices are miniaturized, they are known as microprocessors.
To build accommodations in space, such as the Space Station, the human mind must perform enormous feats of imagination and logic. But today it no longer has to work alone. Super computers are there to do the most complex calculations and execute programs at high speed to control multiple robot systems. The latest robot systems are so tiny that they are practically invisible! Soon these nanomachines will make it possible to build microscopic factories and robots that can swim inside arteries to repair them! The increasingly small size and mass of computer interfaces is a huge advantage in outer space.
Sensors
Sensors are systems that enable robots to gather information from their immediate surroundings. There are several types of sensors: tactile (touch), sound, light and heat. The artificial vision system is a highly sophisticated version of this type of system.
Sensors closely resemble your senses. Indeed, your hands (which can touch and feel heat), your ears (which can hear sound), your eyes (which can see), and even your nose (which can smell) are all perfect examples of sensors.
Your senses pick up sensations and transmit them to your brain—your "processor". As you can see, humans tried to create robots in their image...to a certain extent!
Vision Systems
Much like the human eye, artificial vision systems gather optical signals. Unlike our eyes, however, they can "see" other parts of the electromagnetic spectrum, like microwave frequencies and infrared.
The Canadian Space Vision System is used aboard space shuttles and the International Space Station to supply real-time data on the position and orientation of objects in space. It’s so precise that it can tell if objects are moving forwards or backwards, or even rotating. It does this by using artificial visual cues, since in an environment like space there are no natural reference points to tell you which way is up.
Astronauts need the artificial vision system to help them operate the Canadarm2, since they cannot see it directly. In the Space Station, the module housing the Robotic Workstation used to operate the Canadarm2 has no windows. In any case, remember that once completed, the International Space Station will be as big as a football field. Even if the astronaut controlling the Canadarm2 looked out a window, he or she wouldn’t be able to see much!
Effectors
In the human body, effectors are the messengers that go into action whenever one of the senses (sensors) demands a response. In space robotics, effectors perform manual tasks requested by astronauts via control terminals.
The Canadarm2 has effectors called Latching End Effectors at each of its ends. These effectors enable it to move around the Station by gripping one of the numerous docking fixtures on the Station surface.
Click to enlarge
The Special Purpose Dextrous Manipulator (SPDM), a smaller dual-armed robot also of Canadian design, can be attached to the Canadarm2 via one of its effectors. The SPDM will become an effector in itself, since it will be used as a tool platform to assist astronauts or perform delicate maintenance and repair tasks.
It’s sort of like taking a pair of scissors (SPDM) in your hand (effector) and cutting a flower (task) while helping your father (astronaut) in the garden.
Transportation Systems
Moving from Place to Place
When you want to get from one room in the house to another, you can walk, crawl, jump or use any other number of ways to get to the other room. When building a robot, how it will be able to move from one spot to the next is an important factor. Some robots operate on wheels, like tractor wheels. Others make part of an assembly line, this means that the objects to be repaired or worked on, move on a conveyor belt while the robot remains fixed to one spot.
Since the International Space Station is as large as a football field, the people who designed Canadarm2 had to construct a robot that would be able to move around to the different parts of the Station with ease.
The Space Station is built around a main truss that is like the backbone of the Station. A mobile base, another part of Canada’s contribution to the Space Station, will be able to slide on rails along the truss. Once it is brought to the Station around 2003, this Mobile Base System will provide a movable work platform and storage facility for astronauts during space walks. Canadarm2 will sit on the top of the Mobile Base System.
Canadarm2 will be able to move along the Space Station on the Mobile Base System, but it is also capable of moving round without the base. Canadarm2 also has the ability to "walk" from place to place. Click here to learn about it!
Communication Systems
The future of communications lies in satellite technology. Satellite networks will one day provide an extremely low-cost alternative to existing cable, fibre-optic and cellular systems.
Once deployed, a satellite can transmit a wide range of signals—television, mobile telephone, multimedia, etc.—primarily using microwave technology.
Networks like the Internet have experienced phenomenal growth over the past few years. And this is only the beginning. As space technologies evolve, it will eventually become possible to communicate from anywhere on Earth, anytime, thanks, in large part, to satellite networks.
One of Chris Hadfield’s key assignments during his first spacewalk was to install a UHF communication antenna underneath the U.S. Laboratory, Destiny. This antenna improves communications between the shuttle and the Station, as well as between the Station and astronauts on spacewalks.
Movement
Just as your arm is attached to your shoulder, Canadarm is permanently attached to the space shuttle. It can take hold of payloads like satellites and can either remove or insert them in the payload bay of the shuttle. It can also transport and support astronauts during spacewalks. Unlike this first generation robotic arm, Canadarm2 is not attached to the shuttle. Its home is the International Space Station. Initially, it will be attached to the Destiny module. Once Canada’s Mobile Base is delivered to the Station in 2002, Canadarm2 will sit on the base and be able to move from one end of the station to the other. It will even be able to detach itself from the Mobile Base and move end-over-end across the ISS like a giant inchworm.
Functions of Robots
Robots play a huge role in our lives, and it's getting bigger! There are thousands of possible applications of robotics, and lots more to explore. Robots are already used widely in harsh environments to reduce the risk to which humans are exposed. They are valued team members in assembly plants, on production lines...
Some jobs that are repetitive or very delicate and precise can be done by robots instead. Robots never complain, and never sleep or eat either!
There are almost as many functions for robots as there are robots! They help us in our daily lives, at work, in school... everywhere!
The space industry is another area that really counts on robotics. In fact, robots are useful for scientists who want to know more about other planets, the universe and themselves! Canadarm2 is one example. It will play a crucial role in building and maintaining the International Space Station, the largest orbiting laboratory ever built.
Canadarm2 is as important to the building of the International Space Station, as a construction crane is to building a skyscraper. Before the Space Station is completed, many shuttle missions over several years are required. The construction of the Station can be compared to the building of a cargo ship, at sea, with only a canoe to transport the equipment necessary to its construction. It will take at least 40 shuttle missions to deliver the different components of the ISS, just as it would take at least the same number of trips for the little canoe to build the ship at sea.
Thermodynamics – A Really Hot Topic!
The study of thermodynamics investigates the relationship between heat (thermal), and mechanical concepts (dynamics). Why is this relationship important when it comes to building, living and working in space? As you know, the Space Station completes one full orbit around the Earth every 90 minutes which means that it moves from full sunlight into total darkness every 45 minutes or 16 times per day. When it is in full sunlight the temperature outside the Station can reach almost 149 ºC. In complete darkness the temperature falls to approximately -126 ºC. Therefore, over the course of every 90 minutes the Station undergoes a temperature change of about 175 ºC.
To give you a better idea of what this means, think about the conditions under which materials expand and contract. Some materials, like those you might find on a bridge, expand during the winter when temperatures can reach -40 ºC to -60 ºC in some places across Canada. In the spring and summer months those same materials contract (shrink). The expansion and contraction of these materials happen over a long period of time. Even so, repairs need to be made quite often because the process of expansion and contraction is really hard on most materials and reduces their lifetime.
In space, temperatures not only vary drastically as a result of exposure to full light and total darkness, but the amount of heat generated at various point on the Space Station differ as well.
The amount of heat required to maintain the Station and the people inside is different depending on the location of each part of the Station. For example, outside the Station, the temperature of the materials used to build the long truss structure decreases as we move further and further away from the centre point of the Station (where the laboratory and habitation modules are located). This is because the greatest concentration of heat is produced around the astronaut living and working quarters.
A point that had to be considered while designing Canadarm2, which will roam the entire Station and experience the drastic changes in temperature, was thermal expansion—the ability of its materials to expand, contract and remain useful and function under these very harsh conditions.
Thermal expansion is due to the change in the relative space between the molecules in a material. Click here to see how molecules in the truss of the Space Station move as the temperature increases or decreases.
So now you know that thermal expansion means that most materials will expand or contract as the temperature changes. When the change in temperature is extreme, as it is the case in space, materials must be chosen carefully. If the wrong materials were used in designing Canadarm2, it could melt or become so brittle that it would crumble like an icicle! Not to worry though. Engineers at MD Robotics, one of the companies that worked on the development of Canadarm2 had a lot of experience building space robotic arms for Canada. In fact, they built the original Canadarm and it has completed more than 80 missions to space successfully!
Spatial Building in Canada
To have a career in space does not necessarily mean to become an astronaut. Actually, the majority of careers take place here on the ground. For each astronaut who makes it to space, there are literally thousands of support people on the ground whose skills, knowledge and efforts, make each mission to space possible.
The space industry is a very broad and diverse field, involving participants ranging from a variety of science and engineering streams, to farming, manufacturing, and computer technology. One could even say that the space industry is really a combination of all these fields.
In Canada there are over 250 organisations that work in space technology and development. The Canadian Space Agency works in collaboration with several of these companies to develop spacecraft and space hardware, as well as to find terrestrial applications to space technologies. In fact, about 80% of the Canadian Space Agency’s annual budget is contracted out to Canadian companies, big and small.
Testing and Integration
Preparing Spacecrafts for the Ride of their Life: Testing and Integration
For nearly thirty years now, the David Florida Laboratory (DFL), the official testing facility for all Canadian Space Agency hardware, has tested space-bound elements to ensure they can survive the rigors of launch and the harsh environment of space. With testing facilities unique in Canada, the laboratory has worked on all of Canada’s major space projects from the first Anik communications satellite to the RADARSAT Earth Observation satellite.
Since the cost of launching a payload increases with every additional kilogram of weight, designers go out of their way to make space hardware that is as light as is feasible. Special materials are used in the construction of spacecraft to ensure that they are as durable and as lightweight as possible.
DFL is a very good facility for simulating the conditions of launch. It has several facilities for verifying the structural integrity of space hardware. For example, a large 18 000 kilogram (40 000 lb) force vibration exciter is used to simulate the launch, including the sudden jolt when a launch vehicle’s engines ignite.
This vibration exciter shakes the payload, like Canadarm2, with a force equal to that which would be experienced during a launch. A launch force feels a lot like a mini earthquake.
Can you imagine having a vibration exciter in your home? It would be worse than living next to a train track! You know how much the house shakes every time a freight train goes by. And, if the house is close enough to the train tracks, the dishes in the cupboards probably shake and some may even break! The vibration exciter at the DFL, is like this only more powerful and that is why they have placed it on its own foundation. If it were not the DFL building would crumble!
When the solid rocket boosters fire, a tremendous explosion results. Vibrations are transmitted through the shuttle’s structure to the payloads in the cargo bay, and can damage fragile hardware. Using a "vibration profile" of the Shuttle’s cargo bay, DFL uses several "shaker" devices to simulate the vibrations of launch, as well as those caused by the vehicle’s brute force effort to get through the atmosphere.
Payloads must also withstand the "g-forces" generated by the vehicle’s acceleration (these are the same forces that push the astronauts down in their seats and have them experience tremendous pressure on their upper torso. Astronauts often compare the pressure to an elephant sitting on their chest!) G-forces create a steady, continuous pressure until the engines shut down when the vehicle reaches orbit—whereupon everything onboard goes into "zero-g."
No vacancies!
No vacancies! The role of the builder and the keeper of the International Space Station is officially awarded to the new icon of Canadian space robotics technology, Canadarm2! Canada's star-builder is now attached to the International Space Station. Initial tests indicate that Canadarm2 is there to stay for the life of this, the largest orbiting laboratory ever built in space! So, let's wrap it up for this mission with a quick recap of moments that made history for Canada and the world!
Day 1: April 19
CSA Astronaut Chris Hadfield and the crew of Endeavour launch from Kennedy Space Center. It is a flawless, magnificent blast-off and Chris and the crew of STS-100 reach orbit in just 8 1/2 minutes.
Day 2: April 20
Canadarm and the Canadian Space Vision System are prepared for the first Canadian spacewalk. The crew inspects the payloads (Canadarm2, an Italian-built module called the MPLM and a UHF antenna), the spacesuits, tethers and tools to be used in each of the three spacewalks.
Day 3: April 21
The good ship Endeavour docks with the International Space Station, bringing the third Canadian to the largest floating laboratory in the history of the world! Chris doesn’t get to meet the Expedition 2 crew yet. The hatches between the shuttle and the Space Station are still closed. But the time has come to take step 2 in preparing the shuttle and its spacewalkers for their tasks the very next day. The air pressure in the shuttle is lowered from 14.7 pounds per square inch (psi) to 10.2 psi.
Day 4: April 22
The day for which we’ve all been waiting has finally come! The payload bays are finally opened and the Canadarm, the grandfather of Canadian space robotics, lifts the transport cradle for Canadarm2 out of the payload bay and attaches it to the Station. Our own Canadian Space Agency Astronaut Col. Chris Hadfield then leaves the safety of the space shuttle, climbs onto the end of the Canadarm, his feet tethered firmly to its end, and uses great strength and skill to unbolt the 8 megabolts and 32 smaller bolts. At the end of the spacewalk, Canadarm2 is given the command to raise its booms and park itself next to the Destiny module until the next day and the next set of challenges!
Day 5: April 23
The hatch between the space shuttle and the International Space Station are opened and CSA Astronaut Col. Chris Hadfield visits the Station for the very first time since docking to the Station two days before. Canadarm2 is commanded to reach out and grasp a Power Data Grapple Fixture on the Destiny module, effectively requiring it to walk off its shipping cradle. This successful act commits the new icon of Canadian space robotics to its lifelong tasks of building and maintaining the International Space Station. There is no turning back now!
Day 6: April 24
CSA Astronaut Chris Hadfield doubles as an-out-of-this-world electrician as he and NASA Astronaut Scott Parazynski rewire the Power Data Grapple Fixture, the power source for the arm.
Day 7: April 25
Today’s activities, including the first Canadian handshake in space between the Station’s new robotic arm and the shuttle’s arm, are postponed until flight controllers can determine what happened with the Command and Control Computer on board the International Space Station, which stopped functioning last night.
Day 8: April 26
The main result of yesterday’s computer problem was the loss of communication and data transfer between the Space Station Flight Control Room and the Station. Luckily however, communication was possible through Endeavour, allowing the crew and flight controllers to talk to one another.
A third spacewalk was first scheduled to complete any unfinished tasks. However, Chris and Scott, our two spacewalkers, did such a fantastic job that this third spacewalk is not required. Today, the astronauts and cosmonauts aboard Endeavour will continue to reload the Raffaello logistics module with unneeded station equipment and supplies for return to Earth.
Day 9: April 27
The ten crewmembers were told late yesterday that they would be spending some bonus time together, after mission managers requested an additional day to Endeavour’s mission. The shuttle should remain docked to the Station until Sunday with a landing on Tuesday.
Today, the Station and shuttle crews will continue to concentrate on the transfer of supplies and equipment from the Station to the shuttle. Chris Hadfield and Commander Kent Rominger are also going to be talking with Canadian students later on this morning.
Day 10: April 28
With all the delays encountered during this mission due to computer difficulties the moment we’ve been looking forward to is finally at hand. Today’s the day for the first Canadian robotic handshake in space!
Canadarm2 struts its stuff as it removes its shipping cradle from the Destiny Module, transports it toward the payload bay of the space shuttle and hands the pallet to the space shuttle arm Canadarm.
Day 11: April 29
Yesterday’s Canadian "handshake in space" occurred at 5:02 p.m. as Canadarm2–operated by Expedition Two crew member Susan Helms–transferred its launch cradle over to Canadarm, with Canadian Space Agency Astronaut Chris Hadfield at the controls. The successful exchange of the pallet was the last remaining objective of the mission to be accomplished.
The Expedition Two astronauts and the crew of STS-100 say goodbye today, ending an eight-day stay aboard the ISS. The hatches between the two spacecraft close and Endeavour undocks from the International Space Station. Canadarm2 will be powered up so that the Expedition crew can view the undocking via the robot arm’s cameras.
Day 12: April 30
With a gentle push from springs in the docking module, Endeavour backed slowly away from the International Space Station at 12:34 p.m. CDT yesterday.
Today is spent transforming spacecraft Endeavour back into a vehicle that will be capable of landing on Earth. All of the shuttle’s systems are checked to make sure that they are all in working order.
Day 13: May 1
Today, Space Shuttle Endeavour streaked out of the sky and performed the 103rd successful landing. The crew of STS-100 along with Canadian Space Agency Astronaut Chris Hadfield are back on Earth, and it’s safe to say that their achievements on this mission were really out-of-this-world!
