To prepare the technology for a long term vacuum insulated dewar for the European Columbus attached laboratory a study was performed to evaluate adequate insulation methods.
Different insulation and design concepts were evaluated and the necessary technologies for a long term insulated dewar were developed, including the use of getter material.
A cylindrical test dewar of length 800 mm and diameter 450 mm, was manufactured and tested to demonstrate the feasibility of the selected technology.
The pressure evolution in the test dewar has been monitored for more than a year. The pressure dropped from 10-5 mbar to well below 10-6 mbar in the first year.
The intention is to continue the monitoring for at least 2 years.
The work was done under ESA-contract No. 9586/91/NL/FG.