NASA Phase II SBIR Contract Final Report

Under NASA Phase II SBIR funding, Goembel Instruments has built, tested and delivered a flight-worthy Spacecraft Charge Monitor (SCM).

There are many innovations incorporated in the instrument we have delivered to NASA. The SCM includes patented charged-particle optics that will revolutionize charged particle detection in space. In fact the patented large-geometric-factor optics of the SCM delivered to NASA make it the only flight-qualified spectrometer capable of collecting laboratory quality spectra. Its ability to collect laboratory quality spectra will enable it to determine spacecraft charge in a powerful new way. Existing methods of charge monitoring are inaccurate and require bulky, expensive, unreliable instruments. The SCM is lightweight, accurate, easily deployed and inexpensive. Furthermore, the SCM's patented optics will allow it to measure charge in seconds rather than the minutes required by instruments with traditional optics. The SCM flight-prototype delivered to NASA is the distillation of nearly ten years of research and development by Goembel Instruments.

Numerous tests performed on the SCM prove that we have delivered a rugged, fully functional flight-qualified Spacecraft Charge Monitor. It has passed vibration tests to 14.5 Gs, six thermal vacuum cycles between -24 and +61°C, and advanced functional test by an independent NASA laboratory. Its 'technology readiness' has been proven as well as it can be without trials in space.

Most importantly, there is a clear need for the SCM. Electrostatic charging can damage spacecraft, cause instrument biases that limit the accuracy of scientific measurements, and can even pose a direct hazard to personnel during extravehicular activity. NASA, the Air Force and others need the inexpensive, compact, reliable, easily deployed Spacecraft Charge Monitor. The SCM could be particularly useful on the International Space Station where charging is life threatening. The SCM is needed on spacecraft that carry scientific plasma analyzers as well. No other instrument can compete with the SCM in size, mass, and efficiency at determining floating potential in the solar wind or in low Earth orbit. There is a need for the SCM on lunar missions, where the SCM could determine charge on the lunar surface (yes, charging might be a problem there). Almost any mission that uses ion propulsion (such as planned missions to Mars) would benefit from the Spacecraft Charge Monitor.

The 650gram, 2 Watt SCM delivered to NASA is ready for flight.