The Minus Eighty-Degree Laboratory Freezer for ISS (MELFI) is a European-built experiment storage freezer for the International Space Station. It comprises four independent dewars, which can be set to operate at different temperatures. Currently temperatures of −80 °C, −26 °C, and +4 °C are used during in-orbit ISS operations. Both reagents and samples are stored in the freezer. As well as storage, the freezer is designed to transport samples to and from the ISS in a temperature-controlled environment. The total capacity of the unit is 300 litres.
History
The first MELFI unit, FU-1, was flown to the station in 2006 on Space Shuttle mission STS-121, installed in the Destiny Laboratory Module, and commissioned by Thomas Reiter.
The MELFI flight units were originally designed to be flown fully powered in the Multi-Purpose Logistics Module, permitting pre-made experiments to be flown to the station without contaminating or destroying any samples.
The plan was to cycle the three MELFI units between orbit and Earth.
The final MELFI unit was flown to the ISS on board Space Shuttle Discovery during the STS-131 mission in 2010.
MELFI description
Dewars are cylindrical, 75-liter vacuum-insulated containers that may hold samples of various sizes and forms. A number of extra dewars were also delivered with the unit at first. The cooling system for the MELFI is based on the Reverse Brayton Thermodynamic Cycle which uses nitrogen as a working fluid.
MELFI was developed by the European Space Agency. Two units have been supplied to NASA and one to the Japan Aerospace Exploration Agency (JAXA). In addition ground units for training, experiment preparation, and use in control experiments have been built.
- Weight: 730 kg (1609 pounds)
- Design lifetime: 10 years.
Additional cold storage
Additional cold storage and transportation options available are listed below:
- MERLIN (Microgravity Experiment Research Locker/ Incubator)
- GLACIER (General Laboratory Active Cryogenic ISS Experiment Refrigerator)
- Polar (Research Refrigerator for ISS)