SP-466 The Star Splitters
 
 

[11] PART TWO

THE STAR SPLITTERS

 

The telescope was christened the Star-Splitter
Because it didn't do a thing but split
A star in two or three the way you split
A globule of quicksilver in your hand
With one stroke of your finger in the middle.
It's a star splitter if there ever was one
And ought to do some good if splitting stars
'Sa thing to be compared with splitting wood.
 
Robert Frost, The Star-Splitter

 

3

THE ROAD TO HEAO

 

[13] The traditional image of an astronomer is a shy, pipe-smoking man, patient to a fault, who would rather spend his nights on a lonely mountain-top gazing at the stars than at home in bed. This caricature never did apply to more than a few astronomers, and it applies to fewer still in space astronomy. Successful space astronomers are at the same time scientists, managers, and entrepreneurs. They must understand nuclear physics as well as Einstein's theories and be familiar with the working of telescopes that are as complicated as a jet aircraft. They must direct the work of dozens of scientists, engineers, and technicians, and they must sell their ideas to funding agencies. They must be ready to wheel and deal if necessary to get space for their project on a satellite, and they must always be ingenious, for there is never enough time or money to do everything that should be done. Above all, they must be dreamers, for only a dreamer would undertake a project that will take a decade or more to come to fruition.

The idea of the High Energy Astrophysical Observatories, or HEAOs, was conceived in the 1960s. This decade, noted for its political turmoil, was also a turning point in the history of astronomy. It was one of those golden, exhilarating ages when discovery followed upon discovery: quasars, X-ray stars, gamma ray sources, pulsars, the cosmic microwave background radiation, all indicating the importance of high energy processes in the universe. It was also the time when the nation made and carried out a commitment to put a man on the Moon. Both these developments were crucial to the ultimate success of the HEAO program. On the one hand, the discoveries gave tremendous scientific impetus to high energy astronomy; on the other hand, the rapid development of the space program assured the technical capability necessary to put large space experiments in orbit.

In the early 1960s three different groups were moving along independent paths toward what would eventually become the HEAO program. There was the group at the Naval Research Laboratory (NRL). This group, under the leadership of Herbert Friedman, had been the first to detect X-ray emission from a cosmic source, the Sun. Using rocket-borne detectors, they had been studying the solar X-ray emission for over a decade and had made unsuccessful attempts to detect X-rays from sources outside the solar system. What was needed, Friedman felt, were larger detectors with better efficiency and larger area.

Of course, no one knew for sure just how efficient the detectors would have to be, since the properties of the X-ray sky beyond the solar system....

 


[
14]

Herbert Friedman.

Herbert Friedman.

 

....were a complete mystery. If all the stars were about the same strength as the Sun, then detectors thousands of times more efficient would be needed This would mean detectors with thousands of times more area than those currently in use, or an X-ray telescope which could focus many x-ray photons into a small area. The idea of a focusing X-ray telescope captured the imagination of two physicists in Cambridge, Massachusetts, Bruno Rossi of the Massachusetts institute of Technology (MIT) and Riccardo Giacconi of American Science and Engineering (AS&E). in parallel with a program to detect cosmic X-rays by more conventional techniques, they began their active advocacy of focusing X-ray telescopes.

In June 1962, the AS&E-MIT group flew a rocket experiment that succeeded in detecting the first X-ray source outside the solar system. Assuming that the source was from a nearby star, it implied the existence of an object emitting X-rays at a rate millions of times greater than the Sun. Only a few months after the public disclosure of this discovery, the NRL group was able to confirm the result and to report the existence of other sources. A...

 


Riccardo Giacconi.

Riccardo Giacconi.


[
15]

Early X-ray astronomy experiments used sounding rockets to carry X-ray detectors above the atmosphere for a few minutes.

Early X-ray astronomy experiments used sounding rockets to carry X-ray detectors above the atmosphere for a few minutes. Shown here is a two-stage Nike-Tomahawk rocket with a 12-inch diameter payload designed by the X-ray astronomy group at the Lawrence Radiation Laboratory for the purpose of studying the X-ray source Sco XR-1. The rocket was launched from Johnson Atoll, September 228, 1967. (Photo courtesy Fred Seward).

 

[16] ....rich new field of research had been opened. Because the sources were so strong, they could be studied with small conventional detectors aboard rockets or, in the case of sources that produced strong fluxes at high X-ray energies, from high flying balloons.

Meanwhile, improvements in experimental techniques and the availability of small satellites had made possible significant advances in the study of cosmic rays. Observations of the relative abundance in the cosmic rays of the different nuclei and their isotopes and the discovery of an electron component in cosmic rays cast certain theories for the origin of cosmic rays in grave doubt. For example, high energy electrons should lose most of their energy in about ten million years. This makes it doubtful that these electrons were produced more than ten million light years away. Similar arguments concerning the abundance of heavy nuclei and certain isotopes of lighter nuclei restricted the possible theories of the origin and propagation of these high energy particles. Here too was a field ripe for development. One of the leaders in the field was Frank McDonald of the Goddard Space Flight Center in Greenbelt, Maryland. Frank McDonald thought the time was right to push for a large cosmic ray experiment aboard a large satellite.

To better understand how the progress down the paths blazed by Friedman, Giacconi, and McDonald eventually led to the HEAOs, let us look briefly at the way a new space mission gets started. It takes more than just a good idea, or even a great idea. It takes intense political groundwork on at least three levels.

First, there is the grass roots level, the scientific community. You must convince your peers that yours is a good idea, one that they will support both as a group and individually in committees on which they serve. This you must do by publicizing and promoting your idea in print and in person, at general meetings of such groups as the American Astronomical Society, the American Physical Society, the International Astronomical Union, and the American Association for the Advancement of Science, and before scientific advisory committees, such as the Astronomy Missions Board of NASA and the Space Science Board of the National Academy of Sciences.

Second, you must marshal! support within NASA. NASA Headquarters must agree that yours is a project more worthy of support than other, competing projects. It was here that the scientists found two staunch allies who would play key roles in ensuring the success of the HEAO program. They were Richard Halpern, who would become NASA program manager for the project, and Jesse Mitchell, who was at the time the director of the Physics and Astronomy Division at NASA. Also, since all large projects must be managed by NASA, one of the NASA centers, at Huntsville, Alabama, or Greenbelt, Maryland, for example, must be willing to devote a portion of their manpower to the project.

 


[
17]

High flying balloons carried gamma ray and cosmic ray detectors to altitudes over 100000 feet.

High flying balloons carried gamma ray and cosmic ray detectors to altitudes over 100000 feet. Shown here is the launch of MlT's High Energy X-ray (15-120 kiloelectron volts) Balloon Observatory from Australia on October 15, 1970. The 34 million cubic foot balloon carried the Observatory to an altitude of about 145 000 feet. After 10 hours of observing, the Observatory parachuted back to Earth (the parachute is visible in the picture behind the group of people). The flight became a historic one: the first slowly rotating X-ray pulsar designated GX 1 + 4 was discovered; its period was measured to be about 2.3 minutes. (Photo courtesy of Professor Walter H. C. Lewin)

 

Finally, Congress and the Administration must approve the funds for the project. This means that when the time comes, as it always does, to cut the budget, your project must survive. This step of the process connects back to the first stage. A staffer in the Office of Management and Budget, for example, will pick up the phone and call some eminent scientist when he has a question about a proposed space science project. If this scientist has been convinced by your early work in the hustings, you're in good shape. If not, you're in trouble.

In order for your project to fly, you must succeed at all three levels. If you fail at any one, you lose. In the words of the folk song, you must "know your song well before you start singing."

The road to the HEAO project led in the summer of 1965 to Woods Hole, Massachusetts. After the discoveries of the early 1960s, the scientific community began to take notice of high energy astrophysics as a field with great promise. Accordingly, the Space Science Board of the National.....

 


[
18]

Frank B. McDonald

.

Richard E. Halpern

.

Frank B. McDonald

Richard E. Halpern

 

Academy of Sciences convened a summer study group that included panels on X-ray, gamma ray, and cosmic ray astronomy. From this meeting emerged a consensus among cosmic ray physicists such as McDonald, who needed heavy payloads, X-ray astronomers such as Friedman, who were interested in extremely large area X-ray detectors, and X-ray astronomers such as Giacconi, who hoped to use X-ray telescopes. These groups agreed that a large but inexpensive spacecraft could do the job. They envisioned a series of identical and relatively inexpensive spacecraft-built from leftover Apollo program hardware, for example-that could carry out the two basic types of missions: one that performs a general survey of the sky, and one that points a telescope at particular objects and studies them in detail.

After Woods Hole, the high energy astronomers went back to work, flying rockets and balloons, improving techniques, and pushing back the frontiers in a field that was attracting a growing number of talented researchers. In the meantime they continued to champion the idea of a series of large spacecrafts in letters to NASA officials, in meetings, and to the scientific community at large. It became less and less difficult to convince the scientific community of the importance of high energy astronomy as the discoveries kept coming in. The detection by the NRL group of X-rays from....

 


[
19]

Jesse Mitchell

.

Alois Schardt

.

Carroll C. Dailey

.

Jesse Mitchell

Alois Schardt

Carroll C. Dailey

 

....the galaxy M87 showed that the reach of X-ray astronomy extended beyond the galaxy. Gamma ray sources were discovered, and the nuclei of very heavy elements were detected in cosmic rays.

In 1967 NASA established the Astronomy Missions Board to assist in an advisory capacity in the planning of astronomical experiments in space. This board was composed of 18 members of the scientific community with a wide diversity of interests and experience. The Chairman was Leo Goldberg, at that time Director of the Harvard College Observatory. On the board were Friedman and three other scientists who were actively involved in high energy astronomy: William Kraushaar of the University of Wisconsin, Laurence Peterson of the University of California, San Diego, and [20] John Simpson of the University of Chicago. Assisting the board were 31 other scientists who served on panels that studied the various subdisciplines of astronomy, such as X- and gamma ray astronomy, optical astronomy, etc. After months of study, during which the board heard presentations from supporters of various competing missions, including Dick Halpern speaking on behalf of the HEAO concept, it recommended a greatly expanded program in high energy astronomy that would include as a top priority a series of large experiments, weighing from 1000 to 5000 kilograms, and would be launched by a Centaur or Titan III-C rocket.

The endorsement by the Astronomy Missions Board was crucial. It showed that a broad spectrum of scientists approved of the HEAO concept. Funds were appropriated for a feasibility study of the HEAO concept within NASA, and Dick Halpern became program manager. He quickly went to work establishing the basic ground rules and policies, putting together a skeleton organization, and in general building a strong case for the program in government circles. Assisting him in this effort were Alois Schardt, then Chief of the Particles and Fields Division of NASA, and Frank McDonald at Goddard.

Schardt and McDonald put together a cosmic ray astrophysics committee to investigate the feasibility of putting very large cosmic ray and gamma ray experiments on satellites. Their original idea was to stack the experiments up in a nested fashion, launch them with a Titan-C, and scatter the experiments in orbit. Schardt and McDonald took this idea to Goddard Space Flight Center, which had traditionally handled space science experiments. However, Goddard was heavily occupied with space applications programs at the time, so it turned down the HEAO project. McDonald and Schardt then went to Marshall Space Flight Center in Huntsville, Alabama. At that time Marshall was primarily a rocket building center, under the direction of Werner von Braun. However, von Braun and his associates, including Ernst Stuhlinger, realized that the peak effort of the Apollo program was about over as far as rocket building was concerned. So, when McDonald and Schardt made their presentation to Stuhlinger, they had a receptive audience. Stuhlinger liked their ideas and set up a panel, including McDonald, Schardt, Carroll Dailey, Tom Parnell, Jim Downey, and Gerry Fishman, to study the concept in more detail. Dailey and his colleagues at Marshall showed that the multiple deployment idea would not work. They came up with a workable alternative, a spacecraft that was essentially a large boxcar weighing about 12 000 kilograms.

Then Frank McDonald and Carroll Dailey put together what McDonald termed a "dog and pony show" to promote the HEAO concept. They took their show to the various advisory boards. Thanks in large part to this work and the efforts of Halpern and Mitchell at Headquarters, NASA accepted the HEAO concept. In early 1970 NASA issued an Announcement of Opportunity (AO) for proposals for experiments to be [21] flown on one of a series of High Energy Astronomy Observatory missions. The huge number of proposals received confirmed the conviction of HEAD's advocates that the program had strong support in the scientific community. Out of the proposals, four missions were formulated. The first mission would carry four X-ray experiments, two gamma ray experiments, and two cosmic ray experiments. The second mission would carry two X-ray experiments, two gamma ray experiments, and three cosmic ray experiments. The third mission would carry an array of focusing X-ray telescopes and the fourth mission would carry a group of cosmic ray experiments. Thanks to the advance work by McDonald, Dailey, Halpern, and many other scientists and engineers, the HEAO program was approved by Congress, and funding for the first two missions began in July 1971. Albert Opp of NASA Headquarters, who had been involved with the advocacy of HEAO since 1970, was named program scientist. Fred Speer was named program manager at Marshall Space Flight Center. TRW was selected as the industrial contractor for the spacecrafts. Design studies on the spacecraft and the instruments began. Six years after the Woods Hole summer study, HEAO was finally being transformed from a vision into a reality. Things went smoothly until January 2, 1973.

When Dick Halpern came to work after New Year's Day, he received a phone call. The message: work on the HEAO project was to be suspended immediately. Recalls Halpern: "After living and breathing HEAO for three years, the shock was too much. I was sick to my stomach. Literally."


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