submitted by Perry Edmundson
Small Planetary Rover Platform (SPRP)
This presentation will summarize ongoing work at Ontario Drive and Gear Ltd. (ODG) and its partners on development of lunar and planetary rover prototypes for the Canadian Space Agency, including the Lunar Rover Platform and Drivetrain Prototype (LRPDP) and Small Planetary Rover Platform (SPRP) for lunar and planetary surface analog testing, plus qualification to TRL 6 of a Lunar Rover Drivetrain Prototype (LRDP) under simultaneous exposure to thermal vacuum and lunar regolith simulant. A brief history of ODG's involvement in lunar rover prototype development will also be given, as well as examples of commercialization of technologies developed on these programs.
submitted by Sergei Dobrianski
Team Plan B's journey in the Google Lunar XPrize
While participating in the Google Lunar Xprize (GLXP), team Plan B – the only Canadian team in the international competition, has developed an array of technologies to help come closer to reaching their vision of using lunar regolith for 3D printing. The GLXP, at a high level, is an international competition to deliver a rover to the surface of the moon. Traverse 500m and stream HD data back to Earth. In the frame of the GLXP, Plan B utilizes their creativity above all to come up with new ways to deliver a rover to the moon at an economic price. The presentation will focus on some of the technologies Plan B developed and is currently developing. Technologies such as pulsar signals for navigation, comm systems, PIC real time queue OS ect.
Conceptual design of an early wildfire detection system using a low earth orbit nanosatellite constellation
Forest fires across Canada cost up to $500 million annually in detection, containment and cleanup as well as endanger the lives of thousands of people living in forest fire prone regions. In British Columbia alone the spread of wildfires cost a total of $297.9 million in 2014. Forest fire detection is still primarily reliant on reports submitted by the public, in 2014 50% of detected wildfires in BC where reported through the public, in Alberta public reporting accounted for 40%. Forest fire detection budgets are currently spent primarily on aerial and ground patrols, in Alberta where ground patrols and watch towers are the primary method of detection; approximately $3 million is spent on the operation and maintenance of forest fire watch towers.
The use of satellite data from MODIS and other sources do account for a large percent of detections in some provinces but suffer from low temporal resolution having days between images or low spatial resolution allowing for only large fires to be detected. Of the total 6312 detected forest fires In 2013 human activity accounted for 2691 while lightning strikes added up
to 1615. Despite the larger number of human activity caused forest fires only 63,043 hectares are attributed to them while lightning strikes generated 4,131,875 hectares. The comparison of burned area shows that the detection time of a wild fire makes a significant impact on final burnt area. If the detection time of lightning strike caused forest fires which are currently detected primarily through aerial patrols, ground patrols, or current generation satellites can be reduced to a similar time to that of human activity caused wildfires the affected area caused by them can be greatly reduced.
This paper proposes the design and use of a nano-satellite constellation in low earth orbit monitoring the short wave infrared spectrum for early wildfire detection. This system is intended to address the limitations of large satellites currently in use and reduce the overall cost of wildfire management in Canada by increasing response time and detection time of non-human
activity caused wildfires.
submitted by Kate Howells.
Crowdfunding for Space Exploration
The Planetary Society received international media attention in 2015 when a Kickstarter campaign to raise money for the LightSail spacecraft exceeded its goal of $200,000 USD within 48 hours. That campaign went on to raise over $1.25 million over its six week course, and broke records for the number of backers in a space-related crowdfunding campaign. Although this phenomenal success made headlines, it is not a standalone effort. The Planetary Society has been using crowdfunding to advance space exploration since the organization’s founding in 1980. Crowdfunded projects have encompassed education, communication, science, engineering and advocacy.
There is an urgent need to increase space education to inspire youth to explore university and career opportunities in space related fields. Canada has insufficient space systems events and competitions aimed at engaging junior and secondary school students.
Innovative space education has been realized around the world by the CSA, ESA, JAXA, NASA and private initiatives. These include the open source ArduSat allowing students to upload experiments to the on-board payload, FITSAT-1 with a bright LED array visible from Earth, and OPS-SAT providing a vast range of on-board hardware to evaluate use of powerful COTS components.
This paper proposes a hardware platform to encourage secondary school students to interact with a satellite in orbit, consisting of a satellite and a replica payload. The replica payload contains a microcontroller, and suite of sensors and actuators, that can be programmed by students for experimental missions. The payload is provided to students allowing them to develop and evaluate the hardware and their code interactively in the classroom. Experiments are then uploaded to an online queue that provides slots to operate the on orbit satellite payload. Students can track when the satellite, and their experiment, are overhead of their geographical location and make contact with the satellite visually through a telescope or using the Amateur Radio band to receive communication signals. The proposed program will be compared to those being operated in other countries.
submitted by Ron Vincent
The CanX-7 ADS-B Mission: Tracking Aircraft from Space
Automatic Dependent Surveillance - Broadcast (ADS-B) is an air traffic surveillance technology in which aircraft transmit position and identification. The development of space-based ADS-B will allow precise control of aircraft in areas, such as oceanic regions and high latitudes that are not covered by radar or ground-based ADS-B systems. The Royal Military College of Canada has developed a spaceborne ADS-B receiver that is scheduled to fly on the CanX-7 nanosatellite as a technology demonstrator. The payload will collect ADS-B data on 1090 MHz over the North Atlantic, which will then be compared to truth data provided by air traffic services. A detailed model of the 1090 MHz signal propagation has been developed at RMCC, and indicates that the power received at the satellite in low Earth orbit will be sufficient to successfully conduct the mis sion. Validation of the model, which could be used for the development of an operational ADS-B system, will be possible with the retrieval of data from the CanX-7 mission. Once sufficient data has been collected from the North Atlantic, ADS-B signals will be collected in higher density air traffic areas to study signal collisions. These efforts are topical with the announcements of ADS-B receivers being used as secondary payloads on the Iridium Next constellation.
submitted by Duarte Rondao
The paper will be presented by Cass Hussmann
Abstract:An Accurate, Inexpensive Attitude Determination and Control System for CubeSats
Attitude determination and pointing control in cube satellites has been a continuous challenge mainly due to volumetric constraints and lack of small attitude sensors. As a result, most CubeSat control designs are characterized by considerable attitude errors. This paper proposes an attitude determination and control system (ADCS) using low-cost sensors and actuators that allows for an attitude knowledge to less than 4 degrees and a pointing control to less than 1 degree.
For attitude determination (AD), the development and comparison of four quaternion-based algorithms from different families of estimators is performed using vector measurements from a sun sensor and magnetometer, and angular velocity measurements from MEMS gyroscopes. The first algorithm is the notable Multiplicative Extended Kalman Filter (MEKF) for quaternion and gyro bias estimation, implemented as a benchmark for the forthcoming methods. The second algorithm is called the Unscented Quaternion Estimator (USQUE), a new alternative to extended Kalman filtering which is based on a second-order approximation of the nonlinear satellite dynamics. Similarly to MEKF, USQUE is also designed to estimate the gyro bias parameters. The third algorithm belongs to the realm of Nonlinear Observers (NLOB). It exhibits global convergence, i.e. it can converge from any initial attitude guess. While not directly estimating it, this method adaptively compensates for gyro bias. The fourth algorithm, Adaptive Optimal REQUEST (AOPRQ), is based on least-squares fitting of the attitude quaternion to the vector measurements, featuring a process noise adaptive procedure that compensates for unknown gyro biases.
For attitude control (AC), a B-dot control law using magnetic torquers is implemented for the detumbling stage and a 3-axis controller using specially designed reaction wheels is employed for the nominal mission phase.
Simulations are performed in an environment for the ECOSat cube satellite: a nanosatellite designed by the University of Victoria student team who achieved first place in the 2014 Canadian Satellite Design Challenge (CSDC). These tests comparatively demonstrate the attainable performances of the four AD methods, allowing for the selection of the most adequate one for the ECOSat mission scenario based on the trade-off between accuracy and computational effort.
The robustness of the AC algorithms is also evaluated. The results demonstrate that an accurate ADCS for CubeSats is obtainable on a restricted budget, without resorting to high precision optical sensor suites.
submitted by Ricardo Gomes
Development of a reliable and low cost miniaturized Reaction Wheel System for CubeSat applications
Generally the attitude control systems of CubeSats use magnetorquers as the main attitude control component and these have a full range of control at polar orbits, becoming less effective at lower inclination orbits. They also suffer from reduced pointing accuracy when compared to reaction wheels. Recent advances in CubeSat missions are demanding faster and more accurate pointing systems. These requirements can only be achieved by using reaction wheels for attitude control purposes. The paper presents the design and development of a Reaction Wheel System (RWS) with a total mass of approximately 200 grams and a minimum service life of two years, which takes into account worst-case launch conditions for real world rockets. The proposed design features will enable a new classes of missions currently difficult to achieve. The optimal design, reliability analysis, and construction of a miniaturized reaction wheel prototype using a commercial off-the-shelf brushless DC (BLDC) motor is presented. This RWS is designed for the ECoSat-III, the Enhanced Communications Satellite, currently under development at the University of Victoria, which has won the first place in the Canadian Satellite Design Challenge (CSDC).
The hardware design is described, with emphasis on the disk-rim flywheel. Its mass is minimized subject to constraints on the required moment of inertia, flywheel thickness and type of material used. The analytical theory of a rotating disk of uniform thickness and density is applied to the disk and the rim as a simplified model to compute the radial and tangential stresses and the radial displacement. A comparative analysis between the results obtained by the analytical model and the ones obtained by ANSYS Workbench software has validated the chosen method for flywheel's design. The required torque and the maximum external disturbance torque at which the satellite will be subject are presented. The dynamics simulation of the RWS has shown non-neglectable systemic torque disturbances, which were taken into consideration in the controller's design and verified through experiments.
Finally, a fully functional prototype, which satisfies all the constrains and requirements, is presented as well as all the conducting tests that demonstrates the effectiveness and the reliability of the RWS to be integrated on ECoSat.
submitted by Guilherme Reis
A Novel Application of Maglev Graphite for Attitude Control of CubeSats
Attitude control and determination system of small satellites must be precise, fast and accurate for applications such as camera pointing for earth or celestial observation or communication using precision pointing of an antenna using the least energy possible. Current attitude control systems required fuel and a considerable amount of power, and can sometimes be hindered by mechanical systems failure. Here, a novel attitude control system is proposed using the diamagnetic characteristics of magnetic levitating pyrolytic graphite in the Earth’s magnetic field. Diamagnetic materials are used to stabilize magnetic levitation, however, these materials can self-levitate when subjected to a static magnetic field. Furthermore, the diamagnetic properties of pyrolytic graphite depend on temperature. Using this characteristic, it is possible for the gra phite to generate a torque by simply heating small sections of it. On this paper, this phenomenon is studied and analyzed and its applications are discussed. In particular, the ECOSat cubesat, currently being developed by the University of Victoria, will carry a payload experiment specifically designed to explore and validate this phenomena in space. This payload will have various experiments, one of which will be composed of a plate of pyrolytic graphite that, under the influence of the Earth’s magnetic field, will produce a torque when a small section of it is heated using a semiconductor infrared laser. With several of this small lasers, several points of the graphite can be irradiated thus creating a torque along the required direction. The exposure time can be used to influence the maximum temperature change on the graphite plate and thus controlling the magnitude of the torque created.
This thermal effect on the diamagnetic properties of pyrolytic graphite has never been fully explored, nor applied for satellite attitude control of small satellites.
Index terms: Optical control, attitude control, diamagnetism, pyrolytic graphite, magnetic actuator, laser, magnetic field.