“Please fasten your seat belts and secure all loose objects,” said the cabin speaker suddenly. “Forty degree slope approaching.” Two marker posts with winking lights had appeared on the horizon, and the bus was steering between them. Floyd had barely adjusted his straps when the vehicle sl...
In addition, the aperture size was constrained by a trade-off between mass, volume and signal to noise ratio (which is linked to the maximum allowable image smear coming from the spacecraft ground-track motion) resulting in an F-number of between 6 and 7. The long-lead time for manufactur...