MIT-LINCOLN LABORATORY EXPERIMENTS

Mr. ROBACK. Can you state briefly and specifically for the record what the MIT experiments are contributing to the Defense communications program. I gather it is mainly in the tactical field. Also, if you can, and you may submit this later, if you do not have it, what proportion of the defense budget for MIT is allocated to this effort, and to what extent, if any, this represents potential advances in the technology, that is, are these advances in the technology of circuitry, for example, as well as developing some tactical opportunities?

Mr. ROGERS. The part of the Lincoln Laboratory program that is addressed to the field of satellite communications research and development is not only monitored by the Air Force, it is funded by the Air Force, and I dare say they consider this to be one of the more important elements of their research and development activities in communciations.

Mr. ROBACK. There you mean the Air Force or Lincoln Laboratory? Mr. ROGERS. The Air Force. These Laboratory activities are funded by the U.S. Air Force. Not all of their activities at the Laboratory are so funded, but in this case that is the source of funds.

In general, they are charged with having sufficient general and broad knowledge of the needs of military communications that they can so shape their research and development programs as to address what, in their considered judgment, are the important technological problams, the solutions to which must be sought in the advancement of satellite communications technology.

Now, this is a very, very broad and basic area of investigation, and it covers analysis, it covers experimentation, it covers the satellites themselves, spacecraft, it covers surface terminals, it concerns itself with transmission techniques, with certain network studies; very, very broadly their interest is in advancing important areas of technology in satellite communications.

Their program goals are discussed with the Air Force on a semiannual basis. Their program is reviewed in some considerable detail by technical people from within the three services. The Air Force having the responsibility, it does conduct a formal review twice a year, and the Laboratory program is responsive to the general guidance, the general instructions, of the Air Force.

Now, when we come to specifics of programs there are two or three main areas which, to my knowledge, they are pursuing.

For some considerable time they have focused on the problem of trying to obtain more useful effective radiated power per pound in orbit, as it were, so they have worked very diligently on such matters as directive antennas; they have fabricated a few satellites. There are two of them in orbit now.

They have also addressed themselves to advancing the design of surface terminals, and they put together not only modifications to the surface terminals which were developed years ago as part of the then West Ford program, but they have also put together transportable terminals to demonstrate that, in fact, one could, with fairly modest surface terminal equipments, demonstrate very reliable low capacity circuits.

I have encouraged the Army and DCA and, I dare say, DCA has encouraged the Lincoln Laboratory through the Air Force-I have encouraged the services to pay a great deal more attention to the matter of reliability of surface equipment, and the Laboratory is spending some attention, spending time and attention on that area.

In the past year the Laboratory has worked closely first with elements of the Air Force, and then more broadly with the Army and the Navy as well, in the development of some initial experiments considered to be important in the beginnings of tactical satellite communications research and development.

The first-one of the first-satellites launched of the pair last. December is being used-has, in fact, already been used-to make certain propogation measurements between the satellite and an aircraft. The satellite-spacecraft which they are now fabricating, which we expect to be launched in the first half of the next calendar year, is one whose design has been worked out very carefully to accommodate, in proper fashion, the characteristics of certain airborne equipments, and the Air Force will conduct, as soon as that satellite is launched, certain initial air-ground and air-air experiments with that satellite.

I believe, also, that the Army and the Navy within the last 6 to 9 months also have obtained very detailed knowledge of that program, the characteristics of the satellite, and also will begin some early experiments with that satellite.

Beyond that I could, if you would like, have put together a more detailed statement.

Mr. ROBACK. I wish you would enlist the cooperation of the Laboratory and submit for the record an unclassified statement

Mr. ROGERS. Yes.

Mr. ROBACK (continuing). Of the activities which are relevant to the field of inquiry.

Mr. ROGERS. I would be pleased to do that.

Mr. ROBACK. Thank you very much.

(The information above-referred to is included in Air Force testimony at p. 195.)

SPACE NUCLEAR POWER APPLICATIONS

Mr. ROBACK. One of the aspects of this matter concerns the nuclear applications.

Mr. ROGERS. Excuse me, Mr. Roback, I have not, as memory serves me now, I have not been fully responsive to your earlier questions. You also asked for information about the funding level at the laboratory

Mr. ROBACK. This is an Air Force matter, and we can inquire of the Air Force on that.

Mr. ROGERS. That information is available.

Mr. ROBACK. I notice a statement by Dr. Edward C. Welsh, who is the executive secretary of the National Aeronautics and Space Council, who was quoted recently in an address before the Armed Forces Communications and Electronics Association meeting here in Washington. He is quoted as saying, among other things: "One of the major constraints on our space operations is the limited capability of

onboard electric power supplies. The present family of spacecraft have been designed around the use of solar cells, batteries, and fuel cells. These are not suited, however, for the high power, long-life requirements for planetary exploration of spacecraft. Also, broadcasting type communication satellites, in order to provide economical service, will need reliable, long-time power supplies of the order of 100 kilowatts or more. The development of nuclear supplies appears to be our only option in meeting this type of requirement.

Do you agree substantially with that statement?

Mr. ROGERS. Certainly with the parts of it with which I am professionally familiar, and that is the part addressed to the power required for broadcasting satellites.

Several times through the years I, as well as many other people, have, upon concluding calculations as to what is required for direct broadcasting from satellites at any reasonable altitude into television receivers, have concluded that to meet commercial broadcasting standards one would have to have very, very large effective radiated powers. If, at the same time, you wished to cover a very large fraction of the area of the earth's surface seen from orbit, you would have such a restriction on the antenna gain that you would, in fact, have to have a very large, real power output delivered to the antenna. I would not say that 100,000 watts is the amount of power necessarily required, but I do not think that it is in error by a factor of 10. Certainly, a very large amount of power would be required.

Mr. ROBACK. Would a large amount of power be required for a tactical satellite?

Mr. ROGERS. In my judgment, appreciably larger satellite effective radiated powers will be required for tactical purposes than for strategic purposes, yes.

Mr. ROBACK. What is your understanding of the problem, what is the main obstacle to further development of nuclear power supplies to such spacecraft?

Mr. ROGERS. The matter of reliable power has been an important consideration to us in the satellite repeater and spacecraft field since the beginning of serious attention to satellite development, and it continues today.

Fortunately, insofar as the IDCSP and, perhaps, even the ADCSP satellites are concerned, since the circuit capacity requirements are relatively modest we do believe that we can derive from solar cells the level of raw power that we need. I say perhaps on the ADCSP, and my reservation here relates simply to the fact that, since I do not know yet in quantitative detail what the Joint Staff will pass on in the form of a recommendation as to the system, I cannot attest as to whether or not the technology of spacecraft solar cells design is adequate.

Mr. HOLIFIELD. Mr. Rogers, as you know, I have an interest in this matter because

Mr. ROGERS. Yes.

Mr. HOLIFIELD (continuing). Of my membership on the Joint Com mittee on Atomic Energy, and we developed the so-called Transit. device which was launched in June of 1961, otherwise known as the SNAP-3. It was a small device, about like a grapefruit, and weighed

about 5 pounds, I think it was, and carried the equivalent of about 8,000 dry cell batteries in power. It has been transmitting now over 5 years, and in June 1966, why, we passed the fifth year mark of its transmission back to earth.

Then we worked very hard-that was an isotopic powerplant, as you know, and we worked very hard-to develop the SNAP-10A, and we had a very difficult time obtaining permission to launch both of these devices. There seemed to be a holding back on the part of the Defense Department and other people who were involved in allowing these devices to be tested, for one reason or another.

Finally, we tested the isotopic device and, as I said, it has gone far beyond its projected life of 5 years.

Then we, after a great struggle, we got up the SNAP-10A which was supposed to produce 500 watts. It actually produced about 600 watts, as I remember, and with very little changes it could have been brought up to 1,000 watts.

Now, that particular device we tested in the environment where it would have to function, and that was the argument. The argument was that we could test it on the ground just as well as we could test it up there. Well, we had two devices, identical. The one on the ground operated for over a year without any trouble at high power. The one launched operated for 43 days and then failed and, to the best of our scientific analysis, failed not because of any nuclear part but because the simple voltage regulator stuck or was faulty. So we felt that in getting this reactor-type auxiliary power device into the air, and getting it tested, we proved conclusively the complete feasibility of launching a cold reactor, starting it in space, far beyond the earth's atmosphere, and operating it successfully.

We do not consider the sticking of the voltage regulator, if that is what caused it, and that is what we think it was, was any derogation of the value of this device.

I am just wondering if enough attention has been paid to that. I am aware of the present capability of the solar cells and their limitation, and also the mechanical expanding devices which can fail, and I am also aware of their lack of capability either in periods of eclipse or when they are on the dark side of the moon.

I am just wondering if the Defense Department is pursuing this as strongly as they should in view of the fact that everyone agrees that as we move in the higher power requirements we are going to need something better than the solar source.

Mr. ROGERS. Mr. Holifield, insofar as the satellite communications area alone is concerned, I do know that at the time the decisions were made concerning the characteristics of the IDCSP we did then look at the question of nuclear sources for the power. We concluded at that time that considerations of schedule and cost and weight did not-all of these considerations weighted against, at that time, the selection of a nuclear source.

Since that time we have continued our interest in this, and I am positive that we will look again at the question of nuclear power sources for any advanced satellite. I am positive of that because I have already

Mr. HOLIFIELD. You believe that you are sound in relying on the solar cell source for the ADCSP?

Mr. ROGERS. There is one feature of a nuclear source which I consider to be very attractive, and that is it is relatively less vulnerable to physical attack than a solar cell.

Mr. HOLIFIELD. Meteorites, or man-made?

Mr. ROGERS. Either natural or man-made.

Now, that is an important argument in favor of a nuclear source. One will just have to weigh that advantage against whatever relative penalities one would have to pay in cost or weight, and at this point in time I could not say how such a weighing would work out.

But I do not know, I am quite sure, that this matter has been given consideration and will be given consideration by the Defense Communications Agency and the Air Force.

Mr. HOLIFIELD. We felt a little bit like we were not getting the support that we should have gotten in our committee on these programs. It seems quite clear to us that if eventually we are going to have any magnitude and duration of space exploration, we are going to have to move out of the cumbersome and vulnerable and inadequate area of solar cells and move into a continuing dependable source of power, and I recognize there is some weight problem at this time. But I think our scientists tell us that we are moving toward a solution of the weight problem.

I just wonder how your Department is keeping itself apprised of the capabilities of potential of nuclear isotopic or nuclear reactor types of power units to meet your future needs.

Mr. ROGERS. Within the Office of the Director of Defense Research and Engineering this responsibility, insofar as space applications is concerned, lies with Mr. Fink. He is a Deputy Director, as I am, and he, his office, has the primary responsibility for space technological matters, space technological matters under Dr. Foster.

Mr. HOLIFIELD. Does this happen to be Mr. Fink who used to be with General Electric?

Mr. ROGERS. Not to my knowledge. But he did appear in January with Dr. Foster and myself and testified before your committee.

Mr. HOLIFIELD. Yes.

Mr. ROGERS. Now, I have discussed the matter of nuclear power with his assistant, Mr. Kirk. Mr. Kirk has had conversations, I believe, with the Air Force on this general matter, and I am under the impression that, in fact, the Air Force is studying this area again today.

Mr. HOLIFIELD. Do you have confidence in the technical capability of the people on your staff-and I am saying this without any personal derogation because I am not personally acquainted with themdo you have confidence that you have men who are technically capable and also who are diligently watching this phase of power develop

ment?

Mr. ROGERS. I believe so, Mr. Holifield. I personally have on a number of occasions looked at that myself.

Mr. ROBACK. Better name those fellows so we will be able to put a finger on them.

Mr. ROGERS. All right. The man on my staff who has paid the most personal attention to this is Mr. Salton. Also, I have asked Admiral Boyle at DCA on two or three separate occasions to look