Thats where Sierra comes in.
For over 25 years, NASA has depended on Sierra mass flow instruments and support for a variety of applications. Most recently, NASA decided to replace the outdated technology they were using to maintain positive space shuttle cargo door air flow on re-entry with Sierras model 780s mass flow meter.
Successfully installed, and later tested by a third party calibrator, the 780s has become a trusted part of NASAs arsenal of advanced technologies. See why here: http://www.sierrainstruments.com/chronicles/stories/mission.html.