Cowgill and Professor Hismouth today showed me around the astronavigation room as I had expressed an interest in the intricacies of the skills involved.
The good ship 'Uncle' has its own sophisticated version of the sextant, an optical device used for centuries by sailors to measure angles between stars, the Sun and an Earth’s horizon.
The region of space we are traveling through, encompassed by the Moon’s orbit around Earth, is termed cislunar space. Finding a way across it is therefore called cislunar navigation. Apparently sighting on celestial objects is only one of a range of techniques that they bring to bear on the problem of guidance and navigation, skills that have had to be mastered to ensure that the 400,000 kilometres of space between Earth and the Moon are crossed in both directions accurately and safely. These skills required consummate finesse in the measurement of extremely subtle parameters, and mathematical competence to interpret the results correctly, as excessive errors could be utterly and lethally unforgiving.
I was somewhat surprised, therefore, that Professor Hismouth seemed somewhat inebriated!
Cowgill assures me that the Professor has explained to him that this is merely an undesirable physiological effect of space flight. His balance and orientation are disturbed, but this in no way effects his visual acuity or mental capacity.
Well, one hopes so - given the importance of his navigation tasks.