WEEKLY HIGHLIGHTS FOR WEEK ENDING 5 SEPTEMBER 2003:
- Conditioning of the dewar to a superfluid state has begun. Conditioning is the process of taking liquid helium at a temperature of about 4 Kelvin to a colder state, known as superfluid, which will allow the helium to last throughout the duration of the mission. Getting the dewar 95% full of superfluid helium is a long, iterative process of repeated evacuations and fills.
- Currently, the dewar has successfully been taken to sub-atmospheric pressure, and the temperature has dropped below the normal boiling point of helium. The dewar is currently 76.5% full of helium, at a temperature of 2.11 Kelvin. Over the next two weeks, the dewar will be filled to 95% capacity, with a corresponding temperature drop to 1.65 Kelvin.
Photo: The GP-B Cryo group performing a sub-atmospheric transfer of liquid helium into the dewar's main tank.