A simple microwave power-transmission system has been proposed for maintaining the charge on spacecraft batteries immediately prior to launch. The basic concept of this system could also be applied to other systems (e.g., emergency equipment) that must be kept in a state of high readiness for rapid deployment, without need for cable connections that could impede or slow deployment.

Microwave Power Would Be Rectified to dc power, which would be used to charge batteries.

The umbilical cable that supplies power to a spacecraft on a launch pad must be disconnected at some prescribed time before launch. Once the disconnection is made, the spacecraft operates on battery power. The spacecraft must be launched before the battery discharges so much that the spacecraft could not be relied upon to function correctly. The launch must be canceled if the delay exceeds the allowable discharge time.

The proposed system would make it unnecessary to cancel a launch on account of battery discharge. The system (see figure) would function as follows: Immediately before the disconnection of the umbilical cable, a microwave source would be turned on. The microwave beam from this source would be aimed at the spacecraft through a microwave-transparent window on the fairing of the launch rocket. An antenna on the spacecraft would intercept the microwave beam. A rectifier-and-power-converter circuit connected to the antenna would convert the received microwave power to dc power, which would be used to charge the spacecraft batteries.

This work was done by Richard Rolnicki of Goddard Space Flight Center.

No further documentation is available. GSC-13784


NASA Tech Briefs Magazine

This article first appeared in the April, 2000 issue of NASA Tech Briefs Magazine.

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