Advanced technology oscillator for small spacecraft

A small, low-mass, ultrastable oscillator with excellent frequency stability (1×10^-13 at 100 s) is being developed for use in small spacecraft. The very nature of a small spacecraft places a very high premium on mass, size, and power of all instruments. Therefore, the primary task of this design was to reduce by 50% the mass and size of a flight-proven ultrastable oscillator design without seriously degrading the oscillator´s frequency stability or immunity to environmental stress-a very challenging design problem. The mass of key components of an oscillator fabricated to test new design ideas was reduced by over 78%. A series of tests, including vibration testing, met or exceeded our expectations. On the basis of the results of the vibration tests, a vibration isolation system will not be used for this oscillator. A second thrust of this development is to optimize the oscillator electronics. Phase noise has been improved by 6 dBc to -159 dBc 1 kHz from the carrier. An oscillator configured to permit easy circuit changes is being used for this work. With the data and knowledge gained from this development, the probability of fulfilling the design goals are very high