Non-Deployable Miniaturized Quadslot Antenna for Cubesats

The combination of the structural panels of a 1U cubesat and their air gaps can form a quadslot antenna. This type of antenna eliminates the need for a deployment mechanism and reduces the risk of a disconnection from the satellite. The electrical field constructs in an air gap at the corner of two panels, and when all four panels are powered the antenna emits a semi-omnidirectional radiation pattern similar to a dipole. Unlike a dipole, it can radiate up to 5dB of gain instead of 2.15dB. Another benefit to this antenna is its ability to have sensors and or solar cells on the panels without interfering with the radiation pattern. This is because each panel serves two electrical purposes: increasing the electrical length to reduce frequency and providing space for miscellaneous electrical hardware. Overall, this type of antenna provides the same capability as an L-dipole or patch antenna without sacrificing space, increasing cost, or cumulating more risk. The design allows for a variety of flexibility in frequency, bandwidth, physical size, or construction. This was designed and developed at California Polytechnic State University

Leveraging the Success of the CubeSat Standard to Create a SmallSat Standard for ESPA Spacecraft

The space industry has found significant utility in short turn-around, small satellite missions. There has also been a significant increase in both rideshare and dedicated launch opportunities for small satellites around the world. Small satellites can be developed in much shorter timelines than the traditional, large spacecraft missions. In order to fully leverage the short-development time of small satellites, a standardized design approach is required. Following the success of the CubeSat Design Specification (CDS), it is clear that a standard set of specifications in a concise document allows developers to design their spacecraft without knowledge of their specific launch opportunity. A publicly available standard provides developers and launch vehicles with a set of common parameters for initial design and analyses. CubeSats have shown that a standardization approach is effective at getting missions to space quickly and inexpensively. As the small satellite industry continues to flourish, adapting to the new paradigm is crucial to widespread success

Damping And Vibrations Experiment (DAVE): On-Orbit Performance of a CubeSat Particle Damper

The Damping And Vibrations Experiment (DAVE) is a 1U CubeSat designed to study the performance of particle damping technology in the space environment. Particle dampers rely on the free movement and collision of particles and, as such, are influenced significantly by gravitational effects on Earth. Damper performance was characterized using a single degree of freedom cantilever beam experiment. Beams were equipped with particle dampers and then excited to produce a response at various input amplitudes and frequencies. The on-orbit response of the system was compared to a theoretical model of particle damping as well as ground and ZERO-G flight test data in order to ascertain the degree of non-linearity of the system

The LightSail 2 Solar Sailing Mission Summary

The LightSail 2 mission concluded a 3-year mission in November 2022, having successfully demonstrated controlled solar sailing in low-Earth orbit using a CubeSat platform. Flight data show that LightSail 2 successfully controlled its orientation relative to the Sun, with sustained periods of apogee raising and increasing orbital energy. The LightSail 2 solar sail was 5.6 m on a side and has a total deployed area of 32 m². Four independent triangular aluminized Mylar® sail sections 4.6 microns thick were Z-folded and stowed into four sail bays. The sail segments were deployed by four 4 m Triangular Retractable And Collapsible booms made of elgiloy. The booms were wound around a common spindle, with deployment driven by a Faulhaber motor containing Hall sensors. Attitude was controlled using a single-axis Sinclair Interplanetary momentum wheel and magnetic torque rods. During solar sailing operations, two 90 degree slews were performed each orbit to harness momentum from solar photons. The thrust from solar radiation pressure measurably reduced the rate of orbital decay, including an extended period of orbit raising. Two Planetary Society Cameras developed by the Aerospace Corporation were mounted at the tips of opposing solar panels, providing imaging for engineering evaluation and public engagement throughout mission operations. This paper provides a summary of the LightSail 2 mission implementation, including the flight system design and the pre-launch test program. LightSail 2 mission operations are described, including discussion of the ground system. Solar sailing performance is presented, and anomalies encountered during the mission are discussed. The Planetary Society\u27s decade-long LightSail program was entirely donor-funded, with over 50,000 contributors worldwide. With a total cost of about $7M for two flight missions, the LightSail program showed that solar sails can provide a cost-effective option for propulsion of CubeSat-class vehicles

The LightSail 2 Controlled Solar Sailing Demonstration Mission

The LightSail 2 mission is the culmination of a decade-long program sponsored by The Planetary Society to advance solar sailing technology. The objective of LightSail 2 is to demonstrate controlled solar sailing in Earth orbit using a CubeSat platform. The LightSail 2 attitude is controlled using a single-axis momentum wheel and magnetic torque rods. During solar sailing operations, two 90 degree slews are performed each orbit to harness momentum from solar photons. Flight data show that LightSail 2 is successfully controlling its orientation relative to the Sun, and the controlled thrust from solar radiation pressure is measurably reducing the rate of orbital decay. The Planetary Society declared LightSail 2 mission success on July 31, 2019. This paper provides an overview of the LightSail 2 mission implementation, including the design of the flight system and flight software, and the pre-launch testing program. A summary of LightSail 2 mission operations is provided, including a description of the ground system. Solar sailing performance is presented, and anomalies encountered during the mission are discussed. The flight team continues to refine solar sailing performance and conduct on-orbit imaging for engineering purposes and to engage public interest. The LightSail program is entirely donor-funded, with over 50,000 contributors around the globe

A Deeper Look into the Ionospheric Scintillation eXplorer (ISX): A Failure Analysis

The Ionospheric Scintillation eXplorer (ISX) mission is a collaboration between SRI International and Cal Poly. The ISX space weather investigation seeks to better understand the physics of naturally occurring Equatorial Spread F ionospheric irregularities by deploying a passive UHF radio scintillation receiver. Rocket Lab’s Electron-4 launch vehicle successfully placed ISX into a nearly sun synchronous orbit 500km above the surface of the Earth, however contact was never made with the spacecraft. Since this anomaly, Cal Poly has taken an extensive look into the possible failure causes on ISX, including a system level fault tree and additional testing with the engineering test unit. The primary takeaway from the failure analysis is the importance of testing beyond what is considered normal for CubeSats. The second main conclusion reinforces the important role that adequately documenting the spacecraft design, fabrication, and testing plays in performing a post hoc failure analysis. In addition to presenting analysis outcomes, this paper addresses both of these main takeaways

INSPIRE: Interplanetary NanoSpacecraft Pathfinder in Relevant Environment

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106507/1/AIAA2013-5323.pd

802.11 Denial-of-Service Attacks: Real Vulnerabilities and Practical Solutions

The convenience of 802.11-based wireless access networks has led to widespread deployment in the consumer, industrial and military sectors. However, this use is predicated on an implicit assumption of confidentiality and availability. While the security flaws in 802.11\u27s basic confidentially mechanisms have been widely publicized, the threats to network availability are far less widely appreciated. In fact, it has been suggested that 802.11 is highly susceptible to malicious denial-of-service (DoS) attacks targeting its management and media access protocols. This paper provides an experimental analysis of such 802.11-specific attacks - their practicality, their efficacy and potential low-overhead implementation changes to mitigate the underlying vulnerabilities

PolySat’s Next Generation Avionics Design

The CubeSat platform provides a unique challenge for flight software design due to the incredible size and power constraints. A number of tradeoffs must be made to balance effectiveness, fault tolerance, and cost. These basic requirements have been combined with the lessons learned from Cal Poly’s past 8-bit avionics system to design a significant revision based around a 32-bit microprocessor running Linux. This work analyzes both generations of avionics design, including a discussion of major design principles that are relevant to other CubeSat missions