definitely be used for intact collection of particles impacting at less than 

 6 km/sec. The lowest impact velocity on an orbiting collector is 3 km/sec. 

 Collectors of this type that do not contain hydrogen, carbon, nitrogen, or 

 oxygen and hence will not contaminate samples, will have to be developed. The 

 development of soft collection substrates involves dust accelerators and actual 

 flight exposures. In the long term, it is hoped that electromagnetic decelerators 

 can be developed so that meteoroids can be collected, ideally, with no heating 

 at all. Near-term work in this area will be to develop a prototype design and to 

 conduct a feasibility study. 



6.2.2 Orbital Parameter Measurement 



An electronic technique to measure the impact velocity and direction of par- 

 ticles was used on Pioneers 8 and 9 and on the LEAM experiment placed on the 

 Moon during Apollo 17. Other techniques have been suggested and investigated 

 in at least a casual way. It is critical for the future of meteoroid collection in 

 Earth orbit to fully develop at least one approach that can be used with a prac- 

 tical system for the collection of 10- to 250-^m particles. The speed and impact 

 angle should be measured to an accuracy of a few percent so that the orbits of 

 collected samples can be determined with sufficient accuracy. There appear to 

 be no technological hurdles to achieving this accuracy, and the development will 

 probably be more of an adaptation and refinement of existing techniques. 



6.2.3 Laboratory Analyses 



The collectable cosmic dust samples will be small and techniques for their 

 analysis must be refined. As examples, isotopic, mass spectrometric, gas chro- 

 matographic, and spectroscopic analyses are possible for samples this small, 

 but techniques to do so have not been adequately developed. Laboratory tech- 

 niques that could be refined for this study include mass spectrometry, gas chro- 

 matography, Auger spectroscopy, microESCA (Electron Spectroscopy for Chem- 

 ical Analysis), Secondary Ion Mass Spectrometry (SIMS) microprobe, and a 

 variety of other techniques, including energy-loss spectroscopy. Developments of 

 such microanalytical techniques would also be of considerable value for the 

 analysis of meteorites, interplanetary dust, and samples returned from comets 

 and Mars. 



6.2.4 Flight Exposures 



Development and implementation of the new generation of orbital dust col- 

 lectors will require several types of long-exposure flight opportunities. For the 

 development of techniques, a square meter exposed for several months to a year 



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