The Canadian Space Agency ) was established by the Canadian Space Agency Act which received Royal Assent on May 10, 1990. The president of the agency is Walter Natynczyk who reports to the Minister of Industry. He was appointed as president on August 6, 2013.The headquarters of the CSA is located at the John H. Chapman Space Centre in Saint-Hubert, Quebec. The agency also has offices in Ottawa, Ontario, at the David Florida Laboratory , and small liaison offices in Washington, D.C.; Paris; Cape Canaveral, Florida; and Houston, Texas. Wikipedia.
Aghili F.,Canadian Space Agency
IEEE Transactions on Robotics | Year: 2012
Visually guided robotic capturing of a moving object often requires long-term prediction of the object motion not only for a smooth capture but because visual feedback may not be continually available, e.g., due to vision obstruction by the robotic arm, as well. This paper presents a combined prediction and motion-planning scheme for robotic capturing of a drifting and tumbling object with unknown dynamics using visual feedback. A Kalman filter estimates the states and a set of dynamics parameters of the object needed for long-term prediction of the motion from noisy measurements of a vision system. Subsequently, the estimated states, parameters, and predicted motion trajectories are used to plan the trajectory of the robots end-effector to intercept a grapple fixture on the object with zero relative velocity (to avoid impact) in an optimal way. The optimal trajectory minimizes a cost function, which is a weighted linear sum of travel time, distance, cosine of a line-of-sight angle (object alignment for robotic grasping), and a penalty function acting as a constraint on acceleration magnitude. Experiments are presented to demonstrate the robot-motion planning scheme for autonomous grasping of a tumbling satellite. Two robotics manipulators are employed: One arm drifts and tumbles the mockup of a satellite, and the other arm that is equipped with a robotic hand tries to capture a grapple fixture on the satellite using the visual guidance system. © 2012 IEEE.
Chen G.,Canadian Space Agency |
Qian S.-E.,Canadian Space Agency
IEEE Transactions on Geoscience and Remote Sensing | Year: 2011
In this paper, a new denoising method is proposed for hyperspectral data cubes that already have a reasonably good signal-to-noise ratio (SNR) (such as 600:1). Given this level of the SNR, the noise level of the data cubes is relatively low. The conventional image denoising methods are likely to remove the fine features of the data cubes during the denoising process. We propose to decorrelate the image information of hyperspectral data cubes from the noise by using principal component analysis (PCA) and removing the noise in the low-energy PCA output channels. The first PCA output channels contain a majority of the total energy of a data cube, and the rest PCA output channels contain a small amount of energy. It is believed that the low-energy channels also contain a large amount of noise. Removing noise in the low-energy PCA output channels will not harm the fine features of the data cubes. A 2-D bivariate wavelet thresholding method is used to remove the noise for low-energy PCA channels, and a 1-D dual-tree complex wavelet transform denoising method is used to remove the noise of the spectrum of each pixel of the data cube. Experimental results demonstrated that the proposed denoising method produces better denoising results than other denoising methods published in the literature. © 2006 IEEE.
Aghili F.,Canadian Space Agency |
Salerno A.,Canadian Space Agency
IEEE/ASME Transactions on Mechatronics | Year: 2013
This paper focuses on the integration of inertial measurement unit (IMU) with two real-time kinematic global positioning system (GPS) units in an adaptive Kalman filter (KF) for driftless estimation of a vehicles attitude and position in 3-D. The observability analysis reveals that 1) integration of a single GPS with IMU does not constitute an observable system; and 2) integration of two GPS units with IMU results in a locally observable system provided that the line connecting two GPS antennas is not parallel with the vector of the measured acceleration, i.e., the sum of inertial and gravitational accelerations. The latter case makes it possible to compensate the error in the estimated orientation due to gyro drift and its bias without needing additional instrument for absolute orientation measurements, e.g., magnetic compass. Moreover, in order to cope with the fact that GPS systems sometimes lose their signal and receive inaccurate position data, the self-tuning filter estimates the covariance matrix associated with the GPS measurement noise. This allows the KF to incorporate GPS measurements in the data fusion process heavily only when the information received by GPS becomes reliably available. Finally, test results obtained from a mobile robot moving across uneven terrain demonstrate driftless 3-D pose estimation. © 1996-2012 IEEE.
Aghili F.,Canadian Space Agency
IEEE/ASME Transactions on Mechatronics | Year: 2013
The problem of self-tuning control of cooperative manipulators forming closed kinematic chain in the presence of inaccurate kinematics model is addressed in this paper. The kinematic parameters pertaining to the relative position/orientation uncertainties of the interconnected manipulators are updated online by two cascaded estimators in order to tune a cooperative controller for achieving accurate motion tracking with minimum-norm actuation force. This technique permits accurate calibration of the relative kinematics of the involved manipulators without needing high precision end-point sensing or force measurements, and hence, it is economically justified. Investigating the stability of the entire real-time estimator/controller system reveals that the convergence and stability of the adaptive control process can be ensured if 1) the direction of angular velocity vector does not remain constant over time, and 2) the initial kinematic parameter error is upper bounded by a scaler function of some known parameters. The adaptive controller is proved to be singularity-free even though the control law involves inverting the approximation of a matrix computed at the estimated parameters. Experimental results demonstrate the sensitivity of the tracking performance of the conventional inverse dynamic control scheme to kinematic inaccuracies, while the tracking error is significantly reduced by the self-tuning cooperative controller. © 1996-2012 IEEE.
Canadian Space Agency | Date: 2011-02-11
A method and system for creating a high spatial resolution image from a multidimensional imagery is disclosed. The technique exploits an intrinsic spatial distortion of the sensor that acquired the imagery and uses it as additional information to increase spatial resolution of the imagery. The method comprises obtaining a baseline image from the multidimensional imagery; deriving nm1 sub-pixel shifted images from the multidimensional imagery, where n and m are spatial resolution increase factors in x and y directions respectively, integers and greater than 1; organizing the baseline image and the nm1 sub-pixel shifted images from the multidimensional imagery; fusing the organized images using iterative back projection (IBP) to generate a high resolution image; and outputting the generated high resolution image.
Aghili F.,Canadian Space Agency
IEEE Transactions on Control Systems Technology | Year: 2011
The excitation currents of a brushless dc motor can be preshaped by an electronically controlled commutator based on position feedback so that the motor delivers ripple-free torque and simultaneously minimizes copper losses. However, at high rotor velocity, the commutator issues high frequency control signals which may not be precisely followed by the motor driver/amplifier due to its finite bandwidth. As a result, pulsation torque may appear at high velocities even though the commutator is calibrated to perfectly compensate the motor's position nonlinearity. This brief describes a modification to the commutation law based on Fourier coefficients in order to eliminate the velocity induce torque ripple. This is made possible by expressing the motor's current waveform as a function of not only the rotor angle but also the velocity and taking into account the amplifier dynamics model in the control design. A case study is appended that illustrates the proposed commutator nested inside a motion controller is able to eliminate the pulsation torque and velocity fluctuation at high velocities even if a low bandwidth amplifier is employed. © 2010 IEEE.
Aghili F.,Canadian Space Agency
IEEE Transactions on Power Electronics | Year: 2011
Fault tolerance is critical for servomotors used in high-risk applications, such as aerospace, robots, and military. These motors should be capable of continued functional operation, even if insulation failure or open-circuit of a winding occur. This paper presents a fault-tolerant (FT) torque controller for brushless dc (BLdc) motors that can maintain accurate torque production with minimum power dissipation, even if one of its phases fails. The distinct feature of the FT controller is that it is applicable to BLdc motors with any back-electromotive-force waveform. First, an observer estimates the phase voltages from a model based on Fourier coefficients of the motor waveform. The faulty phases are detected from the covariance of the estimation error. Subsequently, the phase currents of the remaining phases are optimally reshaped so that the motor accurately generates torque as requested while minimizing power loss subject to maximum current limitation of the current amplifiers. Experimental results illustrate the capability of the FT controller to achieve ripple-free torque performance during a phase failure at the expenses of increasing the mean and maximum power loss by 28% and 68% and decreasing the maximum motor torque by 49%. © 2006 IEEE.
News Article | March 1, 2017
The Hubble Space Telescope, the first major optical telescope ever hurled into space, broke down a lot. Since its launch in 1990, NASA has organized five separate missions to service the Hubble—and it was doable, even though the telescope is 300 miles away from Earth. In the final servicing mission in 2009, the Space Shuttle Atlantis carried four astronauts to the observatory for a 12-day mission, when they replaced old batteries and equipment, while adding two new instruments to expand the capabilities of the Hubble, which is still going strong. After its big brother, the James Webb Space Telescope (JWST), launches in 2018, those sorts of fixes-on-the-fly won't be possible. Once the gigantic telescope—which is so big it can't fit inside any of NASA's rockets, and instead has to be folded up like origami to blossom once in space—is at its destination a million miles away, it's gone. If it breaks, it's done. And that would be a shame. Hubble redefined the way we see the universe around us, and JWST—a partnership between NASA, the European Space Agency and the Canadian Space Agency—will be Hubble on steroids. Astrophysicist Amber Straughn, who serves as the deputy project manager for the JWST Science Communications, is in Waterloo, Ontario to give an update on the telescope. Her talk from the Perimeter Institute for Theoretical Physics can be watched here: Excitement has only grown in the past week, with the announcement of a seven-planet system around a star called TRAPPIST-1, 39 light years away. The planets orbiting the star appear to be Earth-sized and rocky; some could even be habitable, so scientists want to find out more. Because TRAPPIST-1 emits light in infrared, the telescope will be perfect for observing it. JWST will be able to study the thin atmospheres of cold planets that are dominated by carbon-based gases (like the planets of TRAPPIST-1). It'll check for water vapor, oxygen, methane, and other signs of habitability. It's taken so long to build and test the telescope because NASA wants to get it right: the $8-billion price tag and million miles are unforgiving. For the last 10 years, the observatory's parts have been put through their paces, one by one. They've now entered the most important on-Earth phase: being tested as a package under simulation of brutal launch and space conditions. "We really have to make sure we get things right on the ground," said Straughn, who is based at NASA's Goddard Space Flight Center in Maryland. Researchers are subjecting the telescope to punishing sub-zero temperatures, blasting it with sound, and banging it around to mimic its launch and deep-space solitude. "Webb is designed to answer the biggest questions in astronomy today that Hubble just can't quite answer," she told me in a phone interview before her public lecture, adding that the JWST will be one hundred times more powerful than Hubble. Beyond learning more about exoplanets like those in the TRAPPIST-1 system, "we hope to be able to see some of the first galaxies that lit up the universe right after the Big Bang," she said. That's 13.5 billion years ago, at least in theory. "Of course, they've never been able to actually observe that part of space because, though the Hubble has seen quite far, it's never gone that far," she explained. Hubble is an optical telescope, while these first galaxies are red-shifted so far that their light falls into the infrared part of the spectrum. To observe them, NASA needs an infrared observatory—the JWST. After the Hubble telescope launched in 1990, scientists started talking about the next big telescope. By 2000, a machine with JWST's abilities had been selected as the priority for astronomy, Straughn explained. Aside from being an infrared observatory, the JWST has two main differences from Hubble. The first is its size: Webb's mirrors are six-and-a-half times as big as Hubble's—the primary mirror is made of 18 individual segments—while the telescope itself is the width of a tennis court (that's the size of its massive Sun shield) and more than three stories tall. Aside from the mirror and Sun shield, the JWST is comprised of science instruments (cameras and detectors to collect data) and a "spacecraft bus" where the controls and electronics lie. While Hubble orbits the Earth, the JWST will be about a million miles away, orbiting the Sun along with the Earth. This spot is called the second Lagrange point, a "gravitationally semi-stable point." In other words, Straughn said, it's a pretty good place to park. The current environmental testing is taking place at Goddard. They've just finished vibrational testing, Straughn said. "That's where we basically shake it, to simulate the stresses it will encounter during launch." The next test, after vibration, is acoustic testing—when they put the telescope in a giant acoustics chamber and blast the JWST parts with loud noise to mimic the sound of the launch rocket. Each mirror has been through a series of cryogenics (low-temperature) tests and other examinations, to make sure it will survive the rigors of deep space. Now, the mirrors and instruments are being put together and tested as a package, Straughn said. After vibration and acoustic exams will be center of curvature tests, where scientists basically measure that the mirror hasn't been hurt by the testing. Then the pieces will be shipped—via C-5 aircrafts, the largest military planes available—to the NASA Johnson Space Center in Houston, Texas, where the gigantic thermal vacuum chambers (same ones used to test the Apollo-era spacecrafts) will run a full, end-to-end optical test at really cold temperatures. They'll then move the mirrors and instruments to Northrop Grumman, a massive aerospace contractor in California, where everything will be put together with the Sun shield and spacecraft bus. Then, more testing. Read More: This Hubble Video Shoots You to the Center of the Galaxy After that, the JWST will be transported to a launch pad in French Guiana to embark on its final journey: on an Ariane 5 rocket, to a point in space that's far, far away. According to Straughn, scientists haven't decided what they should look at first when they get there. But among the JWST's priorities will be the universe's earliest galaxies, along with distant planets, and objects in our own solar system. The JWST is designed to last at least five years, but the it'll carry enough fuel for a 10-year mission. "We have all these questions that we plan to answer, but the most exciting thing is what we haven't thought of yet," she said. "That's what always happens when we build a big, ambitious observatory like this. We discover things that we never dreamed of." Get six of our favorite Motherboard stories every day by signing up for our newsletter.
News Article | February 16, 2017
Canada is a resource-rich country, but one mining executive in Sudbury, Ontario thinks we should take our mining efforts off Earth. He's petitioning the government to start taking this seriously, and has an idea about an obscure part of the Canadian tax code that could even help fund it. "Space mining is going to happen whether Canada wants it to or not," Dale Boucher, CEO of Deltion Innovations Ltd, told Motherboard in a phone interview. He thinks Canada should get in on the action before the field becomes too crowded. Although no one has successfully mined an asteroid yet, these space rocks are believed to be rich in valuable minerals like gold and platinum. And retrieving them is looking increasingly possible. The NASA OSIRIS-REx probe is getting an up-close-and-personal look at asteroids called Trojans—space rocks that could exist in a gravitationally stable location along Earth's orbit. If they're indeed there, they would be prime targets for future space mining efforts. Asteroid mining could one day be a multi-billion dollar economy. The tiny European nation of Luxembourg has invested in companies like Deep Space Industries and Planetary Resources, which have begun the march towards one day exploiting potentially huge amount of minerals and water found in near-Earth asteroids, Mars, and the Moon. I called the Canadian Space Agency to find out where we stand. They referred me to a 2016 interview from the agency's Gilles Leclerc, who told the Canadian Institute of Mining, Metallurgy and Petroleum's CIM Magazine that space-based resource extraction will play a significant role in the future. "Whoever is going to be first to exploit space resources is really going to have an advantage," he said. Boucher, the Sudbury executive, is no stranger to the industry. His mining-related robotics company was awarded $700,000 to develop a tool that can be used in many kinds of environments. PROMPT, or Percussive and Rotary Multi-Purpose Tool, is designed for tasks like drilling for scientific samples or affixing a solar panel to the surface of the Moon. I asked Boucher why he thinks Canada needs to invest in this. "Space agencies around the world have collectively determined that future missions must rely on the availability of local resources [for] support," he said. That means we'll need to retrieve materials for fuel or building structures from other bodies, instead of bringing them with us from Earth. As a way to support asteroid mining efforts in this country, Boucher points to the flow-through share. Called "Canada's quirky tax innovation" by The Financial Post, the incentive allows Canadians to invest in companies looking to find new natural resources. Read More: How to Start an Asteroid Mining Company Without a Mine By working a pretty clever tax trick, flow-through shares shift expenses of exploration from the mining company to their investors to use against their own incomes. Ideally, everyone benefits: the company's expensive initial steps are financed, and investors get lower tax bills. Boucher believes the incentive could kickstart off-planet industries in Canada. "[Flow through shares] were what really created that huge mining exploration industry in Canada," he argued. Even with friendly tax policies, Boucher recognized that, at the end of the day, it's political willpower that would drive the creation of Canada's off-planet resource industry. "Everything starts in Ottawa," he said. "The starting point is [for Canadians] to send an email to their MP or call their office and simply pose a question: what are you doing about space mining?" Get six of our favorite Motherboard stories every day by signing up for our newsletter.
News Article | February 24, 2017
Inside NASA's Goddard Space Flight Center in Greenbelt, Maryland the James Webb Space Telescope team completed the environmental portion of vibration testing and prepared for the acoustic test on the telescope. Engineers and technicians pushed the telescope (wrapped in a clean tent) through a large set of insulated steel doors nearly a foot thick into the Acoustic Test Chamber, where the telescope will be exposed to the earsplitting noise (and resulting vibration) of launch. These photos show the telescope outside (left) and inside (right) the acoustics chamber. The James Webb Space Telescope is the scientific successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency. For more information about the Webb telescope visit: http://www. or http://www.