ADvanced Space Experiment Processor (ADSEP) - 01.09.14
Science Objectives for Everyone
ADvanced Space Experiment Processor (ADSEP) is a thermally controlled single-middeck-locker equivalent that accommodates up to three cassette-based experiments that can be independently operated. Its companion hardware consists of a collection of several experiment cassettes, each doubly or triply contained, that accommodate experiments in cell technology, model organisms, multiphase fluids, solution chemistry, separation science, microencapsulation, and crystal growth.
Science Results for Everyone
Techshot, Incorporated, Greenville, IN, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration
October 2008 - April 2009
Previous ISS Missions
ADSEP has flown on two space shuttle missions, STS-77 and STS-95.
- ADvanced Space Experiment Processor (ADSEP) can be used as a thermal carrier for a variety of experiments.
- ADSEP is applicable to any experiment that must be doubly or triply contained, requires thermal control and programmed operation, and involves fluid transfer or contact with fluids. ADSEP has been proven in space flight applications involving cell cultures, microbial experiments, biphasic extraction, protein and oligonucleotide crystal growth, and microencapsulation.
- Cell Culturing (CellCult) - Each cassette contains a single 50-ml rotating filtered bioreactor, a reservoir for fresh medium, two programmable peristaltic pumps, a waste reservoir, and up to six sample-collection or reagent containers connected by manifold to the reactor. Cultures can be operated in continuous perfusion, batch fed, static, or sampling mode. Both the removal of samples and the addition of additives to the reactor volume can be programmed or teleoperated. Aeration and humidity control are available. At least two of these may now be made available.
- Microorganisms and C. elegans (fluid processing cassette) - Each cassette contains a triple-containment system within which a combination of four pumps, eight valves, and twelve 30-ml bags can be combined in any way to transfer fluids among containers according to experiment requirements. This versatility affords, for example, up to nine serial transfers, four parallel three-container experiments, or six single-fluid-change experiments. Feeding and fixing of microbial or model-organism (e.g., insect or worm) cultures is a typical application. Internal events (starting and stopping flows) are controlled by the ADSEP computer. These cassettes are also designed to operate autonomously (without the ADSEP facility) by battery and manual programming using external toggle switches for which nearly 100 operations can be programmed. Four fluid processing cassettes are currently available.
- Microencapsulation - A process in which tiny particles or droplets are surrounded by a coating to produce small capsules with many useful properties. In its simplest form, a microcapsule is a small sphere with a uniform wall around it. The material inside is referred to as the core, internal phase, or fill, whereas the wall is sometimes called a shell, coating, or membrane. The reasons for microencapsulation are many. In some cases, the objective is not to isolate the core completely but to control the rate at which it leaves the microcapsule, as in the controlled release of drugs. The microgravity environment is optimal for the production of microcapsules, and an ADSEP cassette is available for this purpose.
- Biphasic Separation (BISEP) - Each cassette contains two pairs of rotating plates. Each pair of plates has 22 pairs of sample cavities. Normally, the sample cavities are kept separate from one another until activation. Upon activation, a half-step rotation of the plates brings opposing cavities and their fluid contents into contact with one another. This arrangement provides up to 44 shear cells, diffusion chambers, mixing cups, or fluid contactors per cassette. Inserts provide up to four membrane-based diffusion experiments per pair of cavities suitable for crystal growth experiments. Without dynamic control, up to 176 such experiments could be accommodated per BISEP cassette. Some plates provide magnetic stir bars for mixing experiments, including mixing-demixing studies. The speed and duration of mixing for each pair of plates is controlled by the ADSEP computer. Sample cavities may remain in contact or be half stepped to separate for sample return and recovery. At least three BISEP cassettes are currently available.
Using its half-stepped mode, ADSEP is capable of conducting up to 44 separate experiments in each cassette assembly. Biological samples are loaded (preflight) into cassettes that provide appropriate levels of containment. Processing module doors are opened with two thumb screws, allowing cassettes to be installed in, and removed from, each processing module on orbit. Cassettes interface with the processing module through a blind-mating power/data connector on the back side of the cassette. The maximum mass is 34 kg with a peak power requirement of 130 W. The ADSEP is launched with power. At launch it can contain as many as three cassettes that will need temperature control during ascent. Additional cassettes are launched in a stowage locker or another environmentally controlled facility (possibly frozen). The facility and its cassettes are transferred to the International Space Station, installed in an EXpedite the PRocessing of Experiments to Space Station (EXPRESS) rack, and checked out by a crewmember. With a small amount of crew assistance, the investigation is initiated from the ground.
The programmed timelines are followed and executed automatically or from the ground (normally), and crewmembers are notified when the cassette in a given compartment is to be replaced by a stowed cassette. All timelines include dynamic control of temperature.
In addition to data recorded during experiments, most investigators require the return of their processed samples. ADSEP cassettes return to Earth with or without the ADSEP facility, depending on user requirements and other requirements for sharing the ADSEP facility on subsequent increments. Operations
- The ADvanced Space Experiment Processor (ADSEP) can be installed anywhere a middeck locker will fit and can be operated from the ground or on orbit.
- An operating computer and three independent thermal zones constitute the facility. As many as three experiments in fully enclosed cassettes are operated simultaneously and independently, and cassettes can be changed at any time on orbit by a crewmember.
Ground Based Results Publications
ADSEP cassette. Image courtesy of Techshot, Incorporated.
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Payload Specialist John Glenn worked with Techshot's ADSEP hardware on board space shuttle Discovery on STS-95. Image courtesy of Techshot, Incorporated.
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