larly sensitive to spurious, out-of-band, and harmonic emissions from other services. A major effort to modernize and upgrade engineering standards for active services is desirable, especially with regard to out-of-band emissions. Modernization of these standards would be useful to other services as well as to radio astronomy. This is particularly the case with airborne and satellite transmitters because of the potential clear line of sight to the radio telescope and devices that do not require licensing.
In the past 30 years, radio astronomy studies have demonstrated the presence of ever-more-complex molecules in interstellar space. These discoveries have been one of the most fascinating and puzzling developments in the field. The complexity of the largest molecules already exceeds that of simple amino acids. It is anticipated that in the future, still-more-complex molecules, and possibly amino acids, will be found. The identification of complex molecules can be made only by detecting of a number of radio lines. Consequently, observations may be necessary either in or adjacent to bands allocated to other services. If unwanted emissions are minimized, observations adjacent to the bands of other services may be possible.