Fact Sheet

Text Size

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.

Kennedy Space Center Gaseous Nitrogen Freezer (GN2)


Overview | Description | Applications | Operations | Results | Publications | Imagery

Facility Overview

This content was provided by David R. Cox, and is maintained in a database by the ISS Program Science Office.

Brief Facility Summary

The Kennedy Space Center Gaseous Nitrogen Freezer (GN2) is a double-middeck-locker replacement facility designed to provide a cryogenic preservation environment for experiment samples onboard the space shuttle and the International Space Station.

Facility Manager(s)

  • David R. Cox, Kennedy Space Center, Kennedy Space Center, FL, United States
  • Co-Facility Manager(s)

  • Charles D. Quincy, Kennedy Space Center, Kennedy Space Center, FL, United States
  • Facility Developer(s)

    Kennedy Space Center, Space Life Sciences Laboratory, Cape Canaveral, FL, United States
    Bionetics Corporation, Cape Canaveral, FL, United States

    Sponsoring Agency

    National Aeronautics and Space Administration (NASA)

    Expeditions Assigned


    Previous ISS Missions

    The Kennedy Space Center Gaseous Nitrogen Freezer (GN2) was used on STS-87, STS-95, and STS-111.

    ^ back to top

    Facility Description

    Facility Overview

    • The Kennedy Space Center Gaseous Nitrogen Freezer (GN2) is a passive freezer container (requires no power).

    • It is designed to hold samples at cryogenic temperatures (-196 C) for between 21 and 35 days, depending on the flight configuration and use scenario.

    • The GN2 can be used to transport frozen samples to and from orbit and is certified to fly on the International Space Station.


    The aluminum outer tank of the Kennedy Space Center Gaseous Nitrogen Freezer (GN2) houses an internal tank containing the absorbent material used to hold the gaseous nitrogen. The absorbent material is CAB-O-SIL TS-720, manufactured by Cabot Corporation. CAB-O-SIL TS-720 is a hydrophilic (it has a strong affinity for water) fumed silica whose surface has been rendered hydrophobic (it has little affinity for water) through treatment with a silicone fluid. The absorbent material is appropriately contained with cotton cloth. The CAB-O-SIL is insulated with a combination foil, molecular sieve, and palladin oxide getter. The insulation material is sealed between the outside tank and the inner tank. The freezer's outer dimensions are 14.5 in. in diameter and 19.0 in. in height.

    The sample area inside the internal tank can hold up to four cylinders 6.0 in. long and 3.7 in. in outer diameter. In addition, one of the freezer compartments will be filled preflight with an insert of the same absorbent material to increase the thermal mass of the system. The additional insert is wrapped with cotton cloth to contain any particulate.

    Quick disconnects are added to the freezer lid to allow for ease of use. The ladles containing the biological samples in the freezer are tethered to the external body pf the freezer via insulated wire. The freezer lid is stowed in a foam insert. The lid's quick-disconnect pin is tethered to the lid to prevent it from floating away. The gaseous nitrogen is held in the absorbent material by a vacuum and the insulation material. The freezer has a valve that ensures the integrity of the vacuum container. The total volume of liquid nitrogen when full is 6.5 L. The static evaporation rate of the unit is about 0.3 L/day. Depending on the flight configuration and use scenario, the GN2 can hold temperatures at approximately -196 C for between 21 and 35 days.

    ^ back to top


    Facility Operations

    The GN2 is a passive facility which provides access for crew interaction for removal and insertion of biological samples in microgravity.

    ^ back to top

    Results/More Information

    Information Pending

    ^ back to top


  • Operated on Space Shuttle
  • ^ back to top

    Results Publications

    ^ back to top

    Ground Based Results Publications

    ^ back to top

    ISS Patents

    ^ back to top

    Related Publications

    ^ back to top

    Related Websites
  • Life Science Services Contract
  • ^ back to top


    image The Kennedy Space Center Gaseous Nitrogen Freezer (GN2) with lid removed. Image courtesy of Kennedy Space Center.
    + View Larger Image

    Information provided by the investigation team to the ISS Program Scientist's Office.
    If updates are needed to the summary please contact JSC-ISS-Program-Science-Group. For other general questions regarding space station research and technology, please feel free to call our help line at 281-244-6187 or e-mail at JSC-ISS-Payloads-Helpline.