Preparation for a Satellite

The first working example of cooperation between the Harvard College Observatory and the Smithsonian Astrophysical Observatory is being developed now on Garden Street through planning for the artificial space satellite.

A necessary precursor to space travel, this satellite is due to be launched next fall, and a large part of the project's success depends on the preliminary work being done at the two observatories.

The Smithsonian is organizing the optical plotting of the satellite's course, both by individuals with telescopes and binoculars and by special electronically operated cameras at set locations. This work will establish the sphere's orbit, thus setting the stage for obtaining and evaluating a wealth of scientific data from it.

Actually, there will be more than one satellite. The Department of Defense, operating through the Navy, will try to fire six, and then the Committee for the International Geophysical Year hopes to send up another six. Of course there is no guarantee that the spheres will get into an orbit, but "bugs" are likely to be ironed out as the tests progress, and it is hoped that at least six of the spheres will be put into flight.

The program was announced in July, 1955 by President Eisenhower as this country's major contribution to the International Geophysical Year, an oddly titled period that lasts from July 1, 1957 to December 31, 1958 and will include an unusual degree of international cooperation on scientific projects.

Although it has not yet been decided exactly what scientific equipment will be placed inside the spheres (about twice the size of a basketball), it is sure to return valuable information about the upper atmosphere, cosmic rays, dust-type meteors, ultraviolet rays, and the precise shape of the Earth.

Three-Stage Rocket

But first the satellite will have to get off the ground. It will be set into its orbit by a three-stage rocket, in which succeeding sections drop off as their energy is exhausted. The whole thing will weigh about ten tons, and the first stage will reach 40 miles and 4,000 miles per hour before dropping off. The next stage will carry it to 130 miles, and the final will put it into its orbit, ranging from 200 to 800 miles aloft and traveling at a speed of 18,000 miles per hour, or enough to revolve about the the earth in 100 minutes.

The satellite will be launched from Patrick Air Force Base at Point Canaveral, Florida, out over the Atlantic. While it might be easier to observe if fired due north, directly over the pole, inhabitants of Virginia or the Carolinas might be upset to find the earlier stages of the rocket dropping onto their front lawns. Fish, presumably, won't complain.

Around in 100 Minutes

The direction in which the satellite is fired (getting it aloft is known as Project Vanguard) will set it so that it passes over the earth every 100 minutes in rings which would not exceed the fortieth parallel either north or south. Thus it would go no further north than Philadelphia, although it could easily be seen from Cambridge under good observing conditions.

Once the sphere is aloft, the Smithsonian takes over, and the name for the project becomes Operation Moon watch. Groups of amateur astronomers across the country will be set to watch for the satellite at twilight and, if they detect it, will rush their findings to Cambridge. With a few of these determinations, high-speed computers will calculate the satellite's orbit, and the photographic stations will be ready to assume the major part of the observing program. The satellites will also be equipped with radio senders, but these may not function adequately at first.

The revolutions of the earth cause the satellite to pass directly over a different part on each circuit, and hence a great many observers must be ready for this tracking job. They will be together in groups, each watching only a small area of sky with a small instrument, and plotting the sphere's course against background stars.

The Moonwatch stations also become important in the last stages of a satellite's flight, when it begins to drop out of its orbit. If the density of the atmosphere were perfectly known, this orbit too could be figured out by the computing machines. But since it is not, data returned by the observers of the falling satellite will be used instead.

This satellite observation program forms the first effective use of the recent moving of the Smithsonian to Cambridge, where it can work jointly with Harvard. Fred L. Whipple and J. Allen Hynek, the two men ultimately responsible for the tracking program, hold joint appointments. Whipple, the Director of the Smithsonian, is Professor of Astronomy, while Hynek, the Associate Director in charge of the tracking program, is Visiting Professor of Astronomy. This is the sort of cooperation envisioned when, in May 1955, it was announced that the Smithsonian was moving its headquarters to Cambridge.Special MOONWATCH telescope provides a 12 1/2 degree field with impressive image brightness, and magnifies 55 times. The parts cost less than $20 and can be put together by a skilled amateur. The optical parts are war-surplus material and can be obtained from supply houses. Special teams equipped with these monoculars will watch for the satellite from locations scattered across the country, and report bach to Smithsonian headquarters in Cambridge when they spy it. Computing machines will use these findings to plot the sphere's orbit around the earth.