Algorithms, calculators, and computers for celestial navigation

During the last 10 years, the use of hand-held calculators has become feasable for navigation problems. The prices of the calculators have dropped precipitously and miniturization has significantly increased the capabilities of the hand-held calculator. But more significantly, miniturization has resulted in full-scale personal computers which can be used for navigation. In 1976, Almanac for Computers was introduced and many versions of similar publications have followed. Unfortunately, the progress in software has not equaled the rapid advances in the hardware. Today, we are very close to the comletely automatic integrated navigation system which can provide digital and visual presentation of the craft's position. However, a realistic approach to navigation, which will include safety, reliability, and accuracy under all possible conditions of equipment and personnel problems and adverse actions, must be maintained.