Thermal design for space systems is an iterative process that balances the temperature requirements for all mission
phases with the available resources. Secondary payloads often have to be designed for a wide range of conditions
available on various launch platforms, without the benefit of additional resources such as power or thermal shielding.
This paper will discuss the thermal design, analysis, and thermal vacuum testing of a small satellite payload that was
initially intended for launch from the US Space Shuttle and eventually launched on the EELV Heavy demonstration in
Payloads delivered to orbit by expendable launch vehicles experience high levels of vibration. This vibration can cause component failures, or more frequently, lead to extra weight that would otherwise be useful for added functions on orbit. Vibration isolation systems have been flown to protect various components as well as entire spacecraft, dramatically reducing launch loads and saving costs in redesign and tests. Future spacecraft and components may benefit from further load reduction through the use of higher performance active isolation systems. These active systems are capable of introducing compliance in selected axes, while maintaining required rigidity in others. They can also produce excellent isolation without large amplification. Passive and active vibration isolation systems were developed for the Vibro Acoustic Launch Protection Experiment (VALPE) and flew aboard sounding rockets. The paper describes the design and development of the isolation systems, actuation and isolation architectures and control strategies. Integration of two flight experiments is summarized. Ground test results are presented for passive and active systems. Results of the experiments are provided, and recommendations for active vibration isolation are offered.
The cost of performing any mission on orbit is a strong function of the cost of getting the mass into orbit and the mass of a spacecraft is driven by the launch loads that the components must be deigned to survive. Additionally, these design loads vary between launch vehicles so if circumstances arise that require a change in launch vehicle significant time and money can be spent in modifying and testing to meet different requirements. Technologies that reduce both the vibration and acoustic environments during launch have the potential to both reduce the design load levels, and eventually equalize them between boosters. To this end the Air Force Research Laboratory, Space Vehicles Directorate in cooperation with the Space Test Program, Boeing SVS, CSA Engineering, and Delta Velocity have been investigating methods to decrease the acoustic and vibration loads induced on payloads by the launch environment and demonstrating them on a sounding rocket launch. The Vibro-Acoustic Launch Protection Experiment (VALPE) mission included an acoustically designed Chamber-Core skin, two passive/active vibration isolation experiments, a passive/active acoustic damping experiment, and an energy recovery experiment integrated onto a Terrier-Improved Orion sounding rocket and launched from NASA Wallops Island. A description of the overall mission, experiments, and general results from the flight test are discussed.
Experiments demonstrating several vibro-acoustic mitigation technologies will be tested on the Vibro-Acoustic Launch Protection Experiment 2 (VALPE-2) aboard a Terrier-Improved Orion sounding rocket slated for launch from Wallops Island Flight Facility in May 2003. Flight data collected in November 2002 from a nearly identical launch (VALPE-1) is being used to characterize the fairing environment and design the prototype hardware for the second flight. This paper discusses the various experiments that will be tested on the VALPE-2 flight, and presents some of the measured results and lessons learned from the first flight.
Determining the hazards from debris-generating events is a design and safety consideration for a number of space systems, both currently operating and planned. To meet these and other requirements, the United States Air Force (USAF) Phillips Laboratory (PL) Space Debris Research Program has developed a simulation software package called the Debris Analysis Workstation (DAW). This software provides an analysis capability for assessing a wide variety of debris hazards. DAW integrates several component debris analysis models and data visualization tools into a single analysis platform that meets the needs for Department of Defense space debris analysis, and is both user friendly and modular. This allows for studies to be performed expeditiously by analysts who are not debris experts. The current version of DAW includes models for spacecraft breakup, debris orbital lifetime, collision hazard risk assessment, and collision dispersion, as well as a satellite catalog database manager, a drag inclusive propagator, a graphical user interface, and data visualization routines. Together they provide capabilities to conduct several types of analyses, ranging from range safety assessments to satellite constellation risk assessment. Work is progressing to add new capabilities with the incorporation of additional models and improved designs. The existing tools are in their initial integrated form, but the 'glue' that will ultimately bring them together into an integrated system is an object oriented language layer scheduled to be added soon. Other candidate component models under consideration for incorporation include additional orbital propagators, error estimation routines, other dispersion models, and other breakup models. At present, DAW resides on a SUN<SUP>R</SUP> workstation, although future versions could be tailored for other platforms, depending on the need.