NASA Rocket Launches Harvard Spectrometer

A Harvard spectrometer, designed to observe the sun closely by ultra-violet light from above its obscuring atmosphere, was successfully launched yesterday aboard an Aerobee rocket from the White Sands Proving Ground in New Mexico, by the National Aeronautics and Space Administration.

The launching, which has been delayed several times because of U.S. nuclear tests in space, was made to test the sensitivity and performance of the delicate instrument under the vibrations and temperature changes which occur during the rocket's flight.

At the height of the rocket's trajectory, the nose cone should have opened, the spectrometer glided out on a trunnion and spent five minutes scanning the dise of the sun. The spectrometer then should have folded back into the nose cone. Hopefully, the instrument will be recovered when the cone lands in New Mexico.

Some time next year, the instrument will orbit around the earth aboard an observatory satellite, OSO II, which will collect data on the sun and return it to Florida, where it will be processed and wired to Cambridge within the hour.

Two Modes of Operation

The Harvard spectrometer is designed to observe the solar flares in two ways. First, rather than recording ultra-violet light from the whole solar disc, it can concentrate on a small spot in the center. During this mode of operation, the spectrometer will record the intensity of radiation over the whole ultra-violet spectrum in about 27 minutes.

During its other mode of operation the "eye" of the spectrometer will scan the entire disc of the sun in alternating east-to-west and north-to-south motions.

The information recorded by the instrument will then be recorded and relayed to earth on command. Each complete scan will take about four-and-one-half minutes and should provide a crude ultra-violet picture of the whole sun.

During its scanning mode, the Harvard spectrometer can build up and store about 12 ultra-violet pictures of the whole sun each hour, recording the occurrence and spread of solar flares in every direction. However, it can scan only one wave-length at a time.

But when the instrument is fixed on the center of the sun, it can record intensities over the entire spectrum, providing more detailed information on how and where flares originate and move outward through the sun's atmosphere.