Ryan Nugent | California Polytechnic State University at San Luis Obispo (original) (raw)

Papers by Ryan Nugent

In the CubeSat industry, the demand for benign launch environments that can be predicted is conti... more In the CubeSat industry, the demand for benign launch environments that can be predicted is continuously increasing, but the current knowledge of CubeSat environments leaves a lot of CubeSat developers without accurate information regarding the environments that their CubeSats will experience. Due to the severe random vibration environments experienced on launch, the industry has already taken strides to provide isolation systems that significantly reduce these levels. While these systems are very successful at reducing loads, many of them are still difficult to accurately predict for any given random vibration specification. Additionally, the demand for larger, 12U CubeSats has increased, while 12U environments have remained relatively unexplored. NLAS isolated transmissibility is compared to the baseline, and an isolated 12U dispenser transmissibility is explored. Each dispenser modeled and correlated to test data to evaluate the efficacy of analysis for each system. Additionally, methods for predicting environments for a given input specification are reviewed and compared.

The space industry has found significant utility in short turnaround , small satellite missions. ... more The space industry has found significant utility in short turnaround , 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.

The Ionospheric Scintillation eXplorer (ISX) mission is a collaboration between SRI International... more 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. ...

AIAA SPACE 2008 Conference & Exposition, 2008

The development of the CubeSat standard, a picosatellite standard, has become a tool that encoura... more The development of the CubeSat standard, a picosatellite standard, has become a tool that encourages engineering collaboration, trains students with real-world satellite experience, and provides technology advancement in the aerospace industry. The Poly-Picosatellite Orbital Deployer (P-POD), in conjuction with the CubeSat standard, plays a key role in providing access to space for CubeSats. Developing satellites at the CubeSat level highlight the increasing opportunities for access to space while yielding quicker development times. The upcoming launches demonstrate the growing interest of universities, companies, and government organizations to develop CubeSats to perform valuable scientific experiments and missions. The educational benefits of CubeSat development are emphasized by providing an ideal training ground for future scientists and engineers.

Auxiliary payload accommodations often place CubeSats in unusual locations on the launch vehicle ... more Auxiliary payload accommodations often place CubeSats in unusual locations on the launch vehicle that result in severe dynamic environments. CubeSats and their payloads have recently become more sophisticated and thus, more sensitive to these harsh environments. This is even more relevant for larger CubeSats with very sophisticated but fragile instruments. Developers of this class of CubeSats desire low environmental loads that can be accurately predicted, in order to ensure mission success. One option is to reduce high dynamic loads through the implementation of isolation. Before looking at reducing these levels, it is important to understand the actual levels the CubeSat sees on launch, rather than just the levels input to the CubeSat dispenser. Primary spacecraft load sources are discussed and compared to load sources for auxiliary payloads. CubeSat payload levels for different dispensers are explored, including the transmissibility of a P-POD, an NLAS, and a CSD, both with and without isolation in order to examine the CubeSat levels and how they differ with different constraint mechanisms.

The initial creation of the P-POD was driven by the need for consistency and increased frequency ... more The initial creation of the P-POD was driven by the need for consistency and increased frequency in both pico-satellite development and access to space. The P- POD protects the launch vehicle and the primary payload as well as the CubeSats, and is compatible with many launch vehicles, making integration repeatable and cost-efficient. The P-POD can accommodate pico- satellites that meet the 1kg mass and 10 cubic centimeter dimensional CubeSat standard. Mass producing a stock deployment device creates reliability in flight heritage and decreases design, manufacturing and testing costs. The P-POD provides a framework for developers to design around, and enforces adherence to the CubeSat specification. In turn, the P-POD is designed with the capability to integrate onto multiple launch vehicles. The advantages of this system are most evident in creating flexibility for CubeSat developers to launch on multiple rockets as secondary payloads. Since most satellite manufacturers must coordin...

AIAA SPACE 2008 Conference & Exposition, 2008