All 2008 Content

Norwegian Student Satellite Program – HiNC Cube

Espen Oland et al. — Thu, 14 Aug 2008 12:15:00 PDT

The HiNCube project is a student satellite project where the students build a picosatellite that shall take pictures of the Earth. In this paper, an overview of the project is given from an organizational perspective with lessons learned from the process of initiating and performing a satellite project. None of the members in this student managed satellite project had any practical experience with satellite building when the project was initiated. This paper shows how the HiNCube project is implemented with lacking experience, but with many passionate students who are working hard to complete the satellite. The HiNCube project became member of the Norwegian Student Satellite Program in 2007 after a call for proposals of Norwegian Student Satellites. Through this program the project has gained valuable knowledge, contacts and assets which have been used to enhance the project.

Nanosatellite Attitude Control System for the Oculus: A Space-Based Imaging Platform for Space Situational Awareness

Mary Farmer et al. — Thu, 14 Aug 2008 12:00:00 PDT

Space situational awareness (SSA) with in-space imaging is one of the top priorities of the U.S. military. The Oculus is a low-cost test bed for nanosatellite in-space imaging technologies. The purpose of the Oculus is to (1) demonstrate vision-based attitude control for tracking resident space objects (RSOs), (2) provide in-space validation of two imaging devices, and (3) train future space-systems engineers through both undergraduate and graduate student research and development. One of the major challenges of creating a low-cost nanosat imaging test bed is the three-axis attitude control system. The Oculus' mission requires two types of attitude control: inertially referenced attitude control and visually referenced attitude control. The visually referenced attitude control, focused upon in this paper, requires precise RSO tracking where both a wide field-of-view imager and a narrow field-of-view imager are used to provide feedback for visual servoing of the spacecraft. Such precise attitude control is implemented using reaction wheels. This paper describes the control strategies used for Oculus' attitude control for visual servoing. Closed-loop performance is illustrated using a dynamic simulation of the spacecraft and a hardware-in-the-loop test bed utilizing a Stewart platform.

The Creation and Impact of Corporate Mentorship on Student-Led Satellite Projects

Bruce Davis et al. — Thu, 14 Aug 2008 11:45:00 PDT

Over the past year, strong relationships have developed between a team of students at the University of Colorado and industry mentors. These students, who are participating in the University Nanosat 5 Program, have found that professional mentorship is a critical part of the learning experience. It has resulted in an increased motivation to succeed, and a more comprehensive level of real-world thinking when designing satellites. The participating professionals also find the experience rewarding and go out of their way to accommodate student needs. At the corporate level, involvement with student projects provides company exposure to rising engineers, networking with other participating companies and in some cases flight heritage of products under development. This effort and support towards education promotes long-term growth for the aerospace industry. The University of Colorado team has planned from the beginning to pair each subsystem discipline with an industry mentor. As a result, over a dozen professionals are involved in the project. They provide the availability of testing facilities, confirmation of analytical results, and access to flight-rated hardware not commonly available to student teams. Most importantly, early and ongoing guidance by mentors helps students generate logical and realistic requirements; a process critical to mission success not always appreciated by young engineers. This paper describes the philosophy and implementation used by the University of Colorado student satellite team in establishing professional mentorships and presents the business perspective from a participating corporation. In addition, it proposes that this program-wide methodology can be beneficial to other university teams working in technical fields.

The FASTRAC Satellites: Software Implementation and Testing

Aaron Smith et al. — Thu, 14 Aug 2008 11:30:00 PDT

The Formation Autonomy Spacecraft with Thrust, Relnav, Attitude, and Crosslink (FASTRAC) project from the University of Texas at Austin has developed two nanosatellites as the winner of the University Nanosat-3 Competition. Both satellites have been manifested for a launch provided by the Space Test Program (STP) in December of 2009. The FASTRAC satellites will demonstrate the following enabling technologies for nanosatellites: (1) on-orbit real-time GPS relative navigation via real-time crosslink data exchange; (2) on-orbit real-time attitude determination using a single frequency, C/A-code, reprogrammable GPS receiver; (3) a micro-discharge plasma thruster; and (4) a distributed ground station network. In this paper, the design and testing of the FASTRAC command and data handling system (C&DH) is described. The C&DH system is divided into four subsystems, each controlled by one Atmel Atmega128 microcontroller: communications, electrical power, GPS, and thruster or IMU (depending on the satellite). The major functionality of the C&DH software is presented: automatic crosslink, dual uplink frequency support, user command capabilities, automatic beacon updates, automatic storage and retrieval of experimental data, and support for all mission phases. By using commercially available off the shelf components and leveraging freely availably software, it was possible to build and deliver two low-cost, fully functional satellites. The major hardware and software testing and debugging tools, including the Flatsat electronic test-bed and the FASTRAC GUI Debugging Program, are discussed. Finally, the challenges encountered during the design process and the lessons learned through the numerous design iterations are presented.

Today’s Students – Tomorrow’s Engineers: Jump-Starting the Transition from University to Industry

David Klumpar — Thu, 14 Aug 2008 11:15:00 PDT

Evidence suggests that the nationwide production of Science Technology, Engineering, and Mathematics graduates qualified for employment in the aerospace enterprise is insufficient to meet current and future demand. A unique program at the Space Science and Engineering Laboratory (SSEL) at Montana State University (MSU) has been training a new generation of engineers and scientists through direct hands-on immersion in small satellite design and development. This program jump-starts the college to workplace transition by intimately involving undergraduate (and graduate) students in the hands-on design, development, test, and flight and operations of space flight systems. The extracurricular program is based upon the formal academic curriculum of the University, yet furthers that traditional pedagogical goal by focusing on project-based workgroup learning to develop the specific individual and collaborative skills required to successfully develop space flight systems. Students progress through several tiers of a hands-on training pyramid, spiraling through the project development cycle multiple times with progressively more challenging projects. Project management, systems engineering, interdisciplinary project-based workgroup interactivity, along with configuration management, formal design reviews, peer reviews, and the full design, build, test, rebuild, retest, and fly cycle are the cornerstones on which individual space flight hardware projects build the required skills.

Norwegian Student Satellite Program - ANSAT

Torbjørn Houge et al. — Thu, 14 Aug 2008 11:00:00 PDT

This paper deals with the Norwegian Student Satellite Program (ANSAT), and will give a brief account of NCUBE and a description of the subsequent program. In 2002, four educational institutions started to work on a joint project of developing the first Norwegian student satellite. The project was expanded to include two almost identical satellites with launch-opportunities together with other pico satellites. In 2006, The Norwegian Center for Space-related Education (NAROM), Andøya Rocket Range (ARR) and the Norwegian Space Centre (NSC) decided to initiate a Norwegian Student Satellite Program as a subsequent program to the NCUBE projects with the development and launch of three to four cubesats. This program started in August 2006, and was originally a competition-based program where the educational institutions in Norway had to compete to participate in the program. This was to ensure that the institutions and its students were doing their utmost to complete a working satellite, and to make sure that the best possible project was chosen. After the first round in late 2006 where only two institutions were competing for participation the program underwent a change in criteria for participation. The program is now recruiting contractors to build the satellite systems.

TJ3Sat – Unique Challenges of Building a Small Satellite within a High School Environment

Carlos Niederstrasser et al. — Thu, 14 Aug 2008 10:45:00 PDT

In 2006 Thomas Jefferson High School for Science and Technology (TJHSST) and Orbital Sciences Corporation announced a new initiative to have students from TJHSST design and build the first ever high-school satellite. Leveraging the large body of prior work done in the CubeSat community, and under the mentorship of Orbital Sciences engineers, TJHSST students are in the design phase of their new CubeSat dubbed TJ3Sat. The TJ3Sat payload consists of a digital voice synthesizer that will be accessible to the general amateur radio community. The launch of TJ3Sat is currently scheduled for mid 2009. Unlike most other student satellite programs, the TJ3Sat project has unique challenges by virtue of being a high school satellite. These challenges include organizational obstacles, resource constraints, and the absence of similar programs to draw experiences from. A high school usually does not have the required knowledge base to support a satellite program of any kind. To overcome these obstacles, the TJ3Sat program established a unique collaboration an industry partner to provide resources and real-world mentors.

Advanced Antenna Design for a NASA Small Satellite Mission

Jason Lohn et al. — Thu, 14 Aug 2008 10:15:00 PDT

Current methods of designing and optimizing antennas by hand are time and labor intensive, limit complexity, and require significant expertise and experience. Evolutionary design techniques can overcome these limitations by searching the design space and automatically finding effective solutions that would not ordinarily be found. In recent years, evolutionary algorithms have shown great promise in finding practical solutions in large, complex design spaces. We present our work in using evolutionary algorithms to automatically design X-band antennas for a NASA small satellite mission called Space Technology 5 (ST5). The highest performing antennas produced were fabricated and tests showed they outperformed a traditionally-designed antenna produced by the antenna contractor for the mission. Subsequent changes to the spacecraft orbit resulted in a change in requirements for the spacecraft antenna. By adjusting our algorithm we were able to rapidly re-evolve a new set of requirements-compliant antennas in less than a month. One of these new antenna designs was built, tested and approved for deployment on the three ST5 spacecraft, which were successfully launched into space on March 22, 2006. Our three evolved antennas performed flawlessly during the three-month mission. These evolved antennas are the first computer-evolved antenna designs to be deployed for any application and are the first computer-evolved hardware in space.

Tunable Microstrip Bandpass Filters Based on Planar Split Ring Resonators

Alper Genc et al. — Thu, 14 Aug 2008 10:00:00 PDT

A tunable bandpass microstrip filter based on varactor loaded Split Ring Resonators (SRRs) is presented. The filter is designed such a way that it has one transmission zero at the right hand side of the passband. Silicon tuning diode, of which capacitance is controlled by DC bias voltage, is used as the varactor element and it is placed between two concentric split rings of SRR to tune SRR’s resonance frequency. Single module of the tuning filter is designed and simulated using Momentum 2006C software. The size of the SRR is chosen to have passband located at 2.8 GHz. And, it is fabricated on Rogers RO4003 high frequency laminate.

Thermal Management Integration Using Plug-and Play Variable Emissivity Devices

Kenneth Shannon III et al. — Thu, 14 Aug 2008 10:30:00 PDT

The performance of mission-critical components and systems within spacecraft and satellites requires the ability to control the local thermal environment. Under conditions of relatively constant component and system loading, this would involve radiative dissipation of both internally and externally generated heat loads and altering thermal balances to provide heating where necessary. As the local thermal load changes with component use, the need arises to alter the heat transfer rates and dissipation within the spacecraft. It is also desirable to be able to evaluate, reconfigure or repair space-based thermal control systems using only ground station commands. These needs can be met using a Plug-and-Play variable emittance control system where operational analysis and reconfiguration is accomplished via an improved Universal Serial Bus (USB) or space-wire controlled architecture. This paper presents a modular, USB/space-wire-driven thermal control system using a solid state thin-film infrared variable emittance device (EclipseVED™) from Eclipse Energy Systems, Inc. The paper discusses critical issues including connectivity, device control scale-up for the advancement of an integrated variable emittance system, comparison of device weight to other variable emittance systems, the capacity to replace or repair devices in-flight, the survivability of the system in space and the importance of individual device control.