In the recent years, CubeSat’s are evolving from purely educational tools to a standard platform for technology demonstration and miniaturized scientific instrumentation. The use of COTS (Commercial-Off-The-Shelf) components aided the ongoing miniaturiza- tion of several technologies and demonstrated successfully. Furthermore advantages in this small satellite approach are due to their lesser development times and smaller sizes suitable for multiple CubeSat launches on a single launcher into their respective desig- nated orbits which is cost effective for Universities. These architectures not only promise the combination of both temporal resolution of GEO missions with spatial resolution of LEO missions, but also breaks the trade off in conventional Earth observation satel- lite designs. A thorough implementation of the firmware of vision payload of the Nano Satellite VELOX-I for the Earth observation and remote sensing purposes, in the near future with high scientific payoff is presented here. In course of implementation various case studies have been learned, current date CCSDS recommendations for image com- pression have been considered. Effect of key components such as power, memory and data transmission capability for small satellite remote sensing applications are discussed. Implementation of the core firmware of the payload and serial interface development in Java on Linux platform of Payload Processing Unit shall be able to inherit into the future VELOX missions. / <p>Validerat; 20121128 (global_studentproject_submitter)</p>

Yes / This paper is concerned with the effects on the network performance of moving parts of what is considered traditionally to belong to the ground segment to on board the satellite. Initially, an overview of geostationary satellite communication systems and payload technology is presented, followed by a description of the network architecture and protocols that are the basis of the simulation models. The results obtained from this testbed are presented before concluding with a discussion of the results obtained.

As more spacecraft reach more locations in the solar system, and with increasing residual capability of those spacecraft, an opportunity exists to improve scientific return at low cost to the satellite operator and minimal effect on its primary mission, regardless of the nature of that mission. The practicality of permanently attaching a small, mass-produced, non-deployable hitchhiker payload to modern spacecraft buses is investigated, and a case study of one such payload is presented. The Ancillary Scientific Instrument Attachment (ASIA) is a modified CubeSat bus that can be mass produced, independently tested, and delivered to spacecraft manufacturers with the design, analysis, integration, test, and software development already complete. All it requires are single-string power and data connections, and a location to mount the bus structure. The unit includes power regulation; data collection and storage; command processing; thermal control; and structural support. As many as five small scientific instruments can be included, all of which increase scientific value of the host spacecraft's primary mission without significantly interfering with that mission. Generally, ASIA would operate independently, with a minimum of interaction from the host spacecraft operations team; only routine data dumps for scientific return need be executed. Scientific data processing, distribution, and bus subsystem troubleshooting are offloaded to an independent facility. One possible scientific instrument loadout is described, designed to collect data about the space environment at any location in the solar system. Recommended forward steps for designing, testing, demonstrating, and implementing such a space-based system and its ground elements are presented. / Master of Science / Modern spacecraft (“buses”) are designed to provide basic services for one or more primary payloads. These services include electrical power, orientation control and orbit maintenance, radio communication with control centers and end-users on the ground, and structure to support the payload during launch. Spacecraft buses are often Commercial-Off-The-Shelf, built to include flexibility to support a wide variety of different payloads without extensive modification. The proposed Ancillary Scientific Instrument Attachment (ASIA) is a small, self-contained module that includes a variety of small, low-cost sensors. The unit can be mass-produced, independently assembled, and delivered to a spacecraft vendor as a low-priority, simple way to increase the scientific benefit of nearly any spacecraft that launches. It is a “hitchhiker” payload, acting as a self-contained add-on unit that, unlike CubeSats, is not deployed or released once in orbit; instead, it remains connected to the host spacecraft and relies on that spacecraft for power, radio, and attitude control services. All the unit requires are power and data connections from the host spacecraft, both of which are generally abundant on modern bus designs, and a location to mount it. Because of its low cost, ASIA units can be launched on multiple satellites to distribute development and operational costs while allowing for many measurements to be taken at different parts of Earth orbit simultaneously. A ground computer system will receive, process, and distribute the scientific results of the distributed units to the scientific community. The basic organization and technical characteristics of this concept are presented, including functions of the space unit, the corresponding ground system, and an example instrument loadout for sensing characteristics of the space environment throughout the solar system.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / For every space mission, there are challenges with the launch site/field operations process that are addressed too late in the development cycle. This potentially causes schedule delays, cost overruns, and adds risk to the mission success. This paper will discuss how a single interface, representing the payload at the launch site in all phases of development, will mitigate risk, and minimize or even alleviate potential problems later on. Experience has shown that a single interface between the project and the launch site allows for issues to be worked in a timely manner and bridges the gap between two diverse cultures.

In society, personal load carriage systems (backpacks) are commonly used to transport loads by foot, however, they have also been implicated in causing injuries. The aim of this study was to develop a model for load carriage which could be used to determine safety limits in humans. To start, a number of experiments were conducted to determine the appropriateness of using pressure mapping technology to measure peak and mean pressures acting on humans during load carriage limits. Tests of accuracy and repeatability were performed using three common pressure mapping technologies: capacitance, piezoresistive and resistive ink. Pressure mapping was tested statically and dynamically on a human-like flat surface, as well as on human shoulder-shaped model. Error was found to be ≥ 20% on static flat and curved surfaces and it rose to 36-51% under dynamic conditions. Since pressure mapping would require significant modifications before it could be used to study human load carriage, a psychophysical approach was used instead. For this approach, an epidemiological study of pain was conducted based on 48 subjects who used multiple backpack designs to complete occupationally relevant tasks. As a result, pain trends and new methods of data analysis were identified that had potential use on human trials. In a final study, pain mapping, quantification of pain intensity, and physiological/motor testing were conducted on humans performing endurance exercise with light to heavy payloads. Results showed that all subjects were able to exercise with a 15-35 kg payload for 45 minutes and with a 50 kg payload for 30 minutes, without stopping. As well, pain was found to be highest in the anterior acromial (shoulder) region, particularly for the 50 kg payload (mean peak pain = 3.4/10). Based on these findings, two models were proposed: an assertive model and a conservative model to allow prediction of human load carriage limits for endurance exercise. / Thesis (Ph.D, Rehabilitation Science) -- Queen's University, 2007-10-06 15:33:31.933

Unmanned helicopters in recent years have gained much attention due to their potential in both civil as well as military applications. Helicopter is an inherently unstable system. As a result there is a growing need of developing a control structure that allows the helicopter to perform various applications while remaining stable throughout the flight. This thesis presents developments of a robust controller for the vertical channel of an unmanned helicopter while carrying and dropping a payload. In addition, a simulation platform is developed in Simulink that uses a nonlinear six degree of freedom helicopter model. Quantitative Feedback Theory, a frequency domain technique, is used to design a controller that meets specific performance criteria when uncertainties associated with different payload weights exist in the system. The controller performance is examined in simulation for an Xcell 60 helicopter for effective lifting and dropping of up to 10 lb payload. The performance is then compared with a traditional Proportional-Integral-Derivative controller. Further, the effect of actuator dynamics on the controller performance is also evaluated. Finally, a controller that is robust in minimizing the effect of actuator dynamics and the payload drop while keeping the helicopter stable in flight is designed.

Helicopters have been used in applications where they need to carry a slung load for years. More recently, unmanned (UAV) helicopters are being used to deliver supplies to military units on the ground in theaters of war. This thesis presents a helicopter slung vehicle used to carry the payload and furthermore, provide a means of actuation for the payload. This provides more control authority to the system and may ultimately allow a helicopter to fly higher with a longer tether. The vehicle designed in this thesis was designed for use with 100kg class helicopters, such as the Yamaha RMAX operated by the Virginia Tech Unmanned Systems Lab. Each system on the vehicle was custom designed — including the propulsion system, wall detection / localization system, and controller. Three shrouded propellers provided thruster actuation. A scanning laser range finder and inertial measurement unit (IMU) were used to provide localization. A first attempt at a linear full state feedback controller with a complementary filter was used to control the vehicle. All of the systems were tested individually for functionality. The shrouded propellers met their design goals and were capable of producing .7lbf of thrust each. The wall detection system was able to detect walls and windows reliably and with repeatability. Results from the controller however were less than ideal, as it was only able to control yaw in an oscillatory motion, most likely due to model deficiencies. A reaction wheel was used to control yaw of the vehicle with more success. / Master of Science

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / To support the processing of International Space Station (ISS) Payloads, the Kennedy Space Center (KSC) had the need to develop specialized test and validation equipment to quickly identify interface problems between the payload or experiment under test and the communication and telemetry downlink systems. To meet this need, the Payload Data Analyzer (PDA) System was developed by the Data Systems Technology Division (DSTD) of NASA’s Goddard Space Flight Center (GSFC) to provide a suite of troubleshooting tools and data snapshot features allowing for diagnosis and validation of payload interfaces. The PDA System, in conjunction with the Payload Data Generator (PDG) System, allow for a full set of programmable payload validation tools which can quickly be deployed to solve crucial interface problems. This paper describes the architecture and tools built in the PDA which help facilitate Space Station Payload Processing.

This thesis developed a Rudder Augmented Trajectory Correction (RATC) method for small unmanned aerial vehicles. The goal of this type of controller is to minimize the lateral image errors of body-fixed non-gimbaled cameras. This is achieved through both aggressive trajectory following and elimination of the roll angle present in current aileron only trajectory correction autopilots. The analytical derivation of the rudder augmented trajectory correction controller is presented. Using estimated aerodynamic derivatives of the Aerosonde UAV, RATC, produced a stable and controllable system. This control algorithm was integrated into the AggieAir Minion-class UAV using the Paparazzi open source autopilot. Flight results are presented that show significant reduction in the roll angle present during trajectory correction. This is shown using both inertial measurement nit sensor data as well as payload imagery collected over a selected region of interest. The conclusion of this thesis is that the RATC algorithm is a viable solution to minimize lateral image errors for body-fixed cameras in realm of aerial surveying.

High altitude balloons are an effective, inexpensive and readily available conduit for conducting near space and low Reynolds number experimentation. Experiments are being developed that will use high altitude balloons as carriers for near space and low Reynolds test vehicles. The first step in developing this capability is to create a system that is able to log collected data and track and control a high altitude balloon payload. It is also beneficial that this system be flexible enough to accept different sensor types, communication methods and connection and release linkages. By combining the flexibility of microcontroller biased circuitry and the availability of commercial off the shelf products an economical design solution to this problem has been be achieved. Analysis of this system has been performed and the design has been fabricated, tested and specially modified to withstand the extreme conditions of high altitude flight.