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EXpedite the PRocessing of Experiments to Space Station Rack 2 - Active Rack Isolation System (EXPRESS_Rack_2A)
05.15.09
Scientists and payload developers can get more information on International Space Station research facilities by contacting the ISS Payloads Office or at 281-244-6187.

Overview | Description | Applications | Operations | Results | Publications | Images

Facility/Payload Overview

Brief Facility Summary

EXpedite the PRocessing of Experiments to Space Station Rack 2 ? Active Rack Isolation System (EXPRESS Rack-2A) is a modified EXPRESS Rack (ER) that house experiments aboard the International Space Station. The ARIS component of the ER reduces external vibration disturbances at selected experiment locations inside the ER, allowing the payloads to operate in an environment of greatly reduced vibrational disturbances.

Facility Manager(s)

  • Annette Sledd, Marshall Space Flight Center, Huntsville, AL

    • Co-Facility Manager(s)

    Information Pending

    Facility Developer

    Marshall Space Flight Center, Huntsville, AL and Boeing, Huntsville, AL

    Sponsoring Agency

    National Aeronautics and Space Administration (NASA)

    Expeditions Assigned

    |2|3|4|5|6|7|8|9|10|11|12|13|14|15|16|17|18|19|20|21|22|

    Previous ISS Missions

    Information Pending

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    Facility/Payload Description

    Facility Summary

    • The EXPRESS Rack - ARIS provides simple standard interfaces to accommodate up to ten small payloads and acts as a buffer between experiments on ISS that are sensitive to vibrations.


    • The ARIS system acts as a shock absorber on the EXPRESS Rack for delicate science experiments that could be damaged by normal disturbances of the ISS.

    Description

    International Space Station provides an orbital laboratory for conducting science experiments with minimal interference from the force of gravity. This research has the potential to impact the lives of people on Earth, as well as space explorers traveling far from Earth. By housing, supporting and transporting these experiments, the EXPRESS Rack 2A could play a key role in the development of better medicines, more powerful computer chips or lighter metals. Similarly, by reducing the time, complexity and expense historically associated with orbital research, the EXPRESS Rack 2A system helps universities and industry achieve these advances more quickly and for less money.

    The microgravity environment of the International Space Station (ISS) experiences tiny vibrations. These vibrations can be caused by crew exercise, on-board pumps and motors, and additional everyday activities, which can upset sensitive science experiments. The Active Rack Isolation System (ARIS) acts as a vibration absorber to help isolate and attenuate the disturbance. The EXPRESS Rack is a standardized payload rack system that transports, stores and supports experiments aboard ISS. When the ARIS system is installed on an EXPRESS Rack it attenuates vibratory disturbances at the rack level to support on orbit requirements for a microgravity environment. Attenuation is achieved by imparting reactive forces between the rack and module in response to sensed vibratory accelerations, thereby reducing disturbances to user payloads within the rack.

    The ARIS ISS Characterization Experiment (ARIS ICE) operated during Expeditions 2, 3 and 4 characterized the on orbit performance of EXPRESS Rack 2 ARIS. In addition to generating controlled disruptions on and off the rack, ARIS ICE enabled real-time monitoring of the on-orbit vibration isolation capabilities of various ARIS configurations. These tests allowed for the performance of microgravity sensitive experiments such as EXPPCS during Expeditions 2, 3 and 4 and ZCG on Expeditions 4, 5 and 6.

    EXPRESS Rack 2 - ARIS was launched to ISS during Expedition 2 on flight 6A (STS-100) in April 2001.

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    Operations

    Facility Operations

    International Space Station provides an orbital laboratory for conducting science experiments with minimal interference from the force of gravity. This research has the potential to impact the lives of people on Earth, as well as space explorers traveling far from Earth. By housing, supporting and transporting these experiments, the EXPRESS Rack 2A could play a key role in the development of better medicines, more powerful computer chips or lighter metals. Similarly, by reducing the time, complexity and expense historically associated with orbital research, the EXPRESS Rack 2A system helps universities and industry achieve these advances more quickly and for less money.

    The EXPRESS Rack was developed to provide Space Station accommodations for small subrack payloads. The EXPRESS Rack accepts Space Shuttle middeck locker-type payloads and International Subrack Interface Standard (ISIS) drawer payloads, allowing previously flown payloads an opportunity to transition to the International Space Station. The EXPRESS Rack provides power, data, command and control, video, water cooling, air cooling, vacuum exhaust, and nitrogen supply to payloads.

    Although it is primarily controlled from the ground, the ARIS system required crew interaction for installation in EXPRESS Rack 2A and to complete its activation and initial checkout phases. After installation, the ARIS system at any time can be commanded to Active Isolation mode, the mode in which it actively reduces external disturbances, with minimal crew time. Using laptop computer displays, the crew activates or deactivates ARIS hardware, performs pushrod alignment procedures or changes ARIS states of operation. The states of ARIS operations are:

    • Idle: ARIS does not attempt to control position or acceleration of the rack.

    • Hold: ARIS centers the rack and holds its position relative to the Space Station without actively reducing vibrations.

    • Active: ARIS senses and compensates for acceleration to maintain microgravity environment.

    • NOGO: ARIS is in an idle-like state and does not attempt to control position or acceleration. ARIS enters this state upon any error, or failure of the active built-in test that is part of the initialization sequence.

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    Results/More Information

    Information Pending

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    Availability

  • On-Board ISS

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    Related Web Sites

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    Publications

    Results Publications

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      Related Publications

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        Images

        imageNASA Image: ISS004-332-034 - Astronaut, Dan Bursch works at EXPRESS Rack 2 in the U.S. Lab during ISS Expedition 4.
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        imageNASA Image: ISS007E14214 - Express Rack 2 with protective ARIS netting in the Destiny laboratory module during ISS Expedition 7.
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        imageNASA Image: ISS006E27001 - View of EXPRESS Rack 2 in the U.S. Laboratory during ISS Expedition 6.
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        Information Provided and Updated by the ISS Program Scientist's Office
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