High-Sensitivity Fast-Response Laser Detection Systems

Electrooptical systems exist which can make use of the available bandwidth and directivity at optical frequencies without utilizing the coherence aspects of lasers. Development of a sensitive, very highspeed (microwave response) photoelectric detector which can function as a high-gain microwave amplifier and mixer is described. Sysyems are described for radar, communications, and reconnaissance purposes. Basic noise considerations are shown. CW and FM-CW optical range and range rate tracking systems are described in which the required detection bandwidth is not a direct function of the range resolution, allowing highly accurate range and range rate determination at low signal levels. Communication systems utilizing noncoherent carriers, microwave subcarriers, and the dynamic crossed field electron multiplier as the detector-amplifier-mixer are described.     

Missions to the asteroid anteros and the space of true anomalies

Three opportunities for missions to rendezvous ballistically with the Earth-crossing asteroid Anteros are studied to illustrate the requirements for a trip to a near-Earth minor planet. The rationale, sample payload, spacecraft requirements and trajectory characteristics of these opportunities are typical of a rendezvous mission to an accessible near-Earth object. Round trip ballistic trajectories to return small samples of the asteroid with launch dates between 1985 and 2000 are also presented. Contours of minimum total ΔV drawn in the space of launch and arrival true anomalies, given the designation Prime Rib curves, are introduced as a useful tool for mission design.