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A prototype packed bed convective dryer has been studied for use in an energy-efficient closed air-loop heat-pump drying system for astronaut cabin waste. This paper presents a transient continuum model for the heat and mass transfer between the air and wet ersatz trash in the cylindrical drying vessel. The model is based on conservation equations for energy and moisture applied to the air and solid phases and its formulation includes the unique waste characteristic of having both dry and wet solids. It incorporates heat and mass transfer coefficients for the system measured on an ersatz trash in the dryer vessel, and experimentally determined moisture sorption equilibrium relationship for the wet material. The resulting system of differential equations is solved by the finite-volume method as implemented by the commercial software COMSOL. The validated model will be used in the optimization of the entire closed-loop system consisting of dryer, condenser, and heat-recovery modules.

Orbital Technologies Corporation (ORBITEC) utilizes a variety of in-house testing capabilities (vibration, shock, acoustic loads, space vacuum, temperature cycling, humidity, burn-in, etc.) for qualification and screening of flight components. A lunar dust chamber was designed and constructed to include exposure to lunar regolith and dust simulants. A full factorial design of experiment (DOE) was used to investigate the failure modes of electric fans when exposed to airborne JSC-1AF lunar regolith simulant. This type of testing provides valuable insight into reliability predictions, planned maintenance of a system, and component design improvements to mitigate the effects of lunar dust. Incorporating lunar dust exposure testing at an early stage in the design process will help ensure proper system performance and reliability.

As space hardware continues to grow in complexity, the demands on crews expected to be able to operate and maintain this equipment continue to grow. In terms of the International Space Station, the demands on the crew have been further increased by the reduction in crew capacity from the originally planned seven members down to three. This situation has prompted the need to find new ways of training that can meet these demands. In particular, just-in-time training techniques promise to enable crew members to correctly execute procedures that they have never performed before on equipment that they are only marginally familiar with or perhaps have never even seen before. To enable crews to work with unfamiliar procedures or equipment, we believe that it is necessary to employ a highly visual approach to convey the complex spatial information that is often involved.

A common question for students to ask educators is “When am I ever going to use this?” An excellent way to answer that question is to demonstrate how interrelated many subjects are. At ORBITEC in Madison, WI, we are developing systems to help teachers demonstrate the exciting interrelationships of science, math and technology using activities related to growing plants in space. We are developing two portable plant growth systems that integrate multiple disciplines, enriching students’ classroom experiences. Each portable growth unit is based on similar principles. The Space Garden and Biomass Production Education System (BPES) are growth units for indoor use that utilize a bellows technology to create a greenhouse-like environment. The Space Garden is a personal growth unit that a student can use individually while the BPES will be 0.25 m2, allowing larger-scale experimentation. The Space Garden will be best used in classrooms of grades four through seven.

The design of reliable systems is especially important when they are intended for use on the International Space Station (ISS). Limits on crew time and the sensitive nature of experiments being performed require that the systems used to support those experiments have a very low probability of failure. The Plant Research Unit (PRU) has very strict reliability requirements and thus provides a good example of how the challenge of designing reliable systems can be met.

The International Space Station (ISS) presents unique challenges in the field of maintainability engineering. Due to limited training time on earth and crew time in space, systems must be designed for ease of operation and maintenance. The Plant Research Unit (PRU), an advanced plant growth facility, is required to operate on orbit with minimal crew interaction for maintenance. The PRU has been allotted one hour per increment for corrective maintenance, which consists of replacing Orbital Replacement Units (ORU) or incorporating workarounds. Designing highly maintainable systems is not possible without incorporating the principles of human factors engineering. The PRU has met the strict crew time requirements by combining those principles with maintainability engineering analysis techniques and then integrating them in the design process.

As spaceflight hardware becomes increasingly complex, ever greater demands are placed on astronauts’ training capacity. In addition, astronauts are being asked to conduct unplanned operations with minimal or no training, and long duration operations preclude the ability to thoroughly train before flight on many operations. This trend will be more pronounced as we approach remote operations on the moon and Mars in the Exploration era. In response, Orbital Technologies Corporation has developed an interactive and collaborative 3D simulation training solution for payloads and International Space Station systems. This portable web-based training system provides flexible, efficient and effective pre-flight, real-time and operational training support. Unlike virtual reality systems, this next generation simulation can also be used for remote or just-in-time procedural training between ground-based experts and astronauts in space due to its low file size and collaboration capability.

The wonder of space exploration is a sure way to catch the attention of students of all ages, and space biology is one of many sciences critical to understanding the spaceflight environment. Many systems used in the past for space-to-classroom biology activities have required extensive crew time and material resources, making space-linked education logistically and financially difficult. The new Education Payload Operations Kit C (EPO Kit C) aims to overcome obstacles to space-linked education and outreach by dramatically reducing the resources required for educational activities in plant space biology that have a true spaceflight component. EPO Kit C is expected to be flown from STS-118 to the International Space Station in June 2007. NASA and several other organizations are currently planning an outreach program to complement the flight of EPO Kit C.

As part of the PRU project a new plant lighting system has been developed. System design focused on light source development, chamber optical performance improvements and electronics optimization. Central to the lighting system performance is a high density LED Light Engine, enabling increased spectral diversity, higher irradiance levels, enhanced uniformity and improved efficiency. Chamber wall surface materials were tested to minimize the vertical irradiance gradient and improve planar uniformity. Total lighting system efficiency was improved through the use of switching converter LED drive circuitry. As an alternative to the LED light source, an advanced planar fluorescent lighting source has also been developed.