can identify cooperating aircraft and provide pilots and traffic controllers with three-dimensional position fixes having greater accuracy and economy than available with current air traffic control radar systems.

Studies concentrating on traffic density, accuracy, and data transmission and processing needs during overland operations will be continued. We have also been cooperating with the U.S. Coast Guard in examining their need for satellite services, such as improved communications for surface vessels. These studies will provide an understanding of the degree to which satellite systems can meet maritime requirements.

This year, the National Oceanic and Atmospheric Administration requested NASA's assistance to determine the potential role of satellites in meeting needs for nationwide disaster warning. Hurricanes, earthquakes, tornadoes, forest fires, floods, epidemics, and transportation catastrophes have local and regional effects.

Timely warning might significantly reduce the costs to life and property. A satellite system appears feasible within this decade to relay warning data directly to inexpensive home receivers, routing messages to each of the 50 States or to smaller regions as appropriate. These are examples of the types of studies we undertake to determine the technology, the subsystems, and space systems which we should develop.

Mr. Chairman, I will now turn to a discussion of the principal spacecraft programs that we use. I am departing from the prepared text and will summarize each program briefly for the committee.

The first of our major programs is the applications technology satellites, or ATS program. This program, as the subcommittee is well aware, is dedicated to the development and flight test of technology for meteorology, navigation, tracking, and data relay, and educational television experiments.

In the case of satellites launched previously, ATS-1 and 3, we have offered the use of these satellites to the whole user community for experiments to demonstrate new applications after the initial objectives of the satellites were satisfied and, as you will see in the statement, a number of organizations have in fact participated in these experiments.

These include the State of Alaska, the Corporation for Public Broadcasting, and others. One particular use that I think is of interest to the subcommittee is covered in the statement on the bottom of page 53. This is the use of the satellites by NOAA which is a quasi-operational use of both ATS-1 and 3 in which NOAA receives data from the camera on each satellite at Wallops Island, Va.

This provides NOAA with a source of data from synchronous orbit which is useful for observation of short-term weather phenomena. We have a chart which depicts this use, and the outlines shown cover in general the areas of the earth which can be covered continuously by the pictures received from ATS-1 and 3.

Another experiment on ATS-5 which is of special interest was mentioned by Dr. Naugle in his testimony the other day. This is the L-band transponder on the ATS-5 satellite. I believe Dr. Naugle may have mentioned that we carried an experiment on the SS Manhattan on its trip through the Northwest Passage in the spring of 1970.

The results of tests between the Manhattan and ATS-5 were generally very good and this and other data confirmed the desirability of the use of the L-band for aeronautical and marine navigation and traffic control.

We had mentioned previously that experiments such as this experiment with the L-band transponder on ATS-5 enabled the Office of Telecommunications Policy to come out in January with their statement of air traffic control satellite policy which involves using L-band for air traffic control services.

In the interests of time, Mr. Chairman, I will move to the bottom of page 55 where we describe ATS F. & G., which is the major current mission of the communication programs. These spacecraft are shown on the next chart. This is a photograph of the full-scale model of the ATS-5 spacecraft.

It is considerably larger than the previous ATS spacecraft, weighing about 2,500 pounds. It will cary a 30-foot antenna into orbit and end of life power is indicated at 400 watts. It is to be launched by a Titan III-Ĉ. Fairchild-Hiller has the contract for the development of this satellite.

The objectives of these satellites are to space test a 30-foot diameter deployable antenna with good performance at frequencies up to 6 ghz.; point the antenna and spacecraft with an accuracy of 0.1 degree; space test precision attitude measuring technology; and provide a high gain steerable antenna at synchronous altitude for advanced space application concepts.

This large aperture antenna will be applicable to improved mass instruction broadcasting in developing areas as well as to tracking and communicating with lower altitude satellites and will also permit accurate measurements of surface sources of radio interference.

Both of these satellites will carry additional applications experiments which make use of the basic capability of the spacecraft. These experiments are described on pages 56 and 57 and again, in the interest of time, I do not plan to discuss those.

We will be happy to answer questions if the committee has any. I think I would like to move on, Mr. Chairman, if there are no questions, to the cooperative applications satellites, the next line item of the communications program.

Mr. KARTH. I would like you to complete your statement on the entire communications portion of the budget and then we will see whether or not the committee has questions.

Mr. JOHNSON. Very good. In the cooperative applications satellites area of our program we have two active programs. The first, CAS-A, is a cooperative program with France intended to obtain scientific data on wind speed and direction, air temperature and air pressure at 45,000 feet altitude and to develop and demonstrate satellite and balloon technology for range and range-rate measurements to locate balloon position. The CAS-A satellite, being developed and funded by France, is proceeding well toward a launch from Wallops Island in the third quarter of 1971. NASA's contribution consists of the Scout launch and technical and scientific consultation.

The second cooperative project, CAS-C, is an outgrowth of an earlier, cooperative, scientific project with the Government of Canada, the international satellites for ionospheric studies (ISIS) program.

The success of ISIS led to the substitution of a communications technology satellite for the last of the projected ISIS spacecraft.

We have worked with the Canadian Department of Communications (CDC) during 1970 to define the experiment payload. The Government of Canada has approved the program, and expects to fund about 80 percent of the total program costs.

This satellite will advance the state of the art in spacecraft and related ground-based technologies relevant to broadcasting, remote area communications, and other satellite systems. It will include the development and flight test of communications experiments at 12 and 15 ghz. and technology and user experiments of importance to both countries.

NASA in this case will develop and test a 200-watt superefficiency 12 GHz transmitter tube. The tube development, and its associated power-conditioning equipment, the launch vehicle, and spacecraft environmental tests will be funded by NASA, while Canada will be responsible for the balance of the experiments, spacecraft design, fabrication, integration, and systems testing.

The Canadian experiments will include an unfurlable lightweight solar array of over 1-kilowatt capacity, liquid metal sliprings, electricpropulsion stationkeeping thrusters, and an accurate stabilization system for satellites with flexible appendages.

The next section in the statement covers mission studies for future technology flight programs.

I will summarize this very briefly and leave it to the committee to read portions of this statement. These mission studies have included such studies as those we are doing for the ATS-H class to follow F and G which we are considering for a possible first launch in 1976 and 1977.

A spacecraft such as this would be able to develop the space technology necessary for things like the biomedical communications network mentioned earlier.

It will also allow us to move heavily into the higher frequency band such as the 11.7 to 12.2 GHz band and provide information for tradeoff between ground station costs and satellite transmitter costs.

One area of advanced study of particular interest to us and I believe to the subcommittee are those advance mission studies of small standardized spacecraft which could be dedicated to quick, economical flight test of single experiments in order to overcome the 4-year leadtime experienced between selection and flight on an observatory class satellite.

These small applications technology satellites (SATS) would be Scout- and Delta-class spacecraft having standardized designs and specified experiment interfaces. Our goal is to be able to accept experiment hardware, integrate it with a spacecraft, and launch within approximately 6 months of flight go-ahead.

This area also includes the advanced applications flight experiment (AAFE) program which provides us with an inventory of designed experiments from which we can select flight payloads either for ATS or SATS missions.

Finally, we are conducting tracking and data relay satellite studies in concert with NASA's Office of Tracking and Data Acquisition and in coordination with DOD.

Moving on to air traffic control satellites on page 62 of the statement, the Office of Telecommunications Policy in late 1970 reviewed the projected requirements for aircraft communications, navigation, and air traffic control and considered the capability of existing technology and space flight systems to meet these requirements.

On January 7 that office issued a statement of Government policy on satellite telecommunications for international civil aviation operations, committing our Nation to a new satellite application in aeronautical and maritime communications and traffic control.

That policy statement recognized the primary responsibility of the Department of Transportation (DOT) to establish the preoperational and operational systems to serve the airlines and NASA's role to support DOT as required and to conduct general research and development activities in this area.

In the middle of page 63 we discuss a program called the radio interference and propagation program, or RIPP. It is very small but it is very important. This program was started by the Office of Telecommunications Management (OTM) in the late 1960's.

In 1969 the Office of Telecommunications Management asked NASA to manage RIPP and turned over to our use a relatively small sum of money which had been provided to OTM. These funds have been supplemented by NASA. This program will help develop the technical position on which to base the U.S. position to be presented to the World Administrative Radio Conference, or WARC, in 1971.

This is a conference which will convene in June in Geneva to look at the total worldwide frequency distribution problems which are extremely important both to the United States and other countries.

Mr. KARTH. Mr. Chairman?

The CHAIRMAN. I am very interested in this navigational satellite that you are going to do with DOT. How far along are you in the development of this now?

Mr. JOHNSON. Mr. Chairman, we have conducted experiments with our applications technology satellites which have proven the technical capability of launching and operating air traffic control satellites for control of aircraft over ocean areas.

The Office of Telecommunications Policy stated that the Department of Transportation would have the responsibility for preoperational and operational systems and requested that DOT together with NASA look at the possibility of providing these systems through commercial

sources.

The situation right now is that we are in discussions with DOT serving as a technical advisor to the Department of Transportation to look at the question of whether these services should in fact be provided through commercial sources or whether it would be better to use governmental sources of satellites.

The CHAIRMAN. What refinement do you think you can get with these when it comes to the positioning of a plane or a ship?

Mr. JOHNSON. I would like to ask Mr. Jaffe to provide you some numbers on that if I may, Mr. Chairman.

The CHAIRMAN. Mr. Jaffe, you can furnish it for the record if you want to. If you have something right off the top of your head, you can tell us now.

Mr. JAFFE. The accuracy we are looking for, Mr. Chairman, for aircraft navigational purposes is about 1 mile. This is what is required

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over ocean areas to reduce the separation standards of aircraft flying, let us say, the North Atlantic route.

The CHAIRMAN. That is a little better than the boys who flew in the Doyle flight. Only two planes got through. About 11 were never heard of again. One fellow had the captain of the ship as a pilot and this fellow who got through landed on Kaui and to tell you the trouble he had, the elevation and making computations when he shot the sun-apparently the others didn't quite make it so we have made a little progress in this field.

Thank you, Mr. Chairman.

Mr. KARTH. Thank you, Mr. Chairman.

Mr. JOHNSON. The aims of the RIPP program are specifically to determine whether communications satellite systems and terrestrial systems can continue to share the same frequency bands as the numbers of both increase, to determine the conditions for such sharing, determine the influence of weather on space and ground systems interference, and determine the utility of frequencies above 10 GHz for satellite services.

The knowledge gained from this will be important to us in providing technical consultation to other technical agencies such as the recent FCC request to NASA for an evaluation of the recent filings for the domestic communications satellite system.

I would like to discuss briefly the geodetic satellite program which in the statement begins on page 66. The two near-term goals of NASA's geodetic satellite program are management of the national geodetic satellite program (NGSP) and development of the advanced technology needed to measure time variations in the gravity field of the earth.

NGSP was established in 1964 as a joint program undertaken by NASA, DOD, and Department of Commerce with NASA having overall management responsibility. The objectives of this program are to provide a precise and accurate geometric description of the earth's surface and a refined mathematical description of the earth's gravitational field.

NASA uses both active and passive satellites to achieve the NGSP objectives. Two active geodetic satellites, GEOS 1 and 2, were successfully launched in 1965 and 1968. All systems aboard GÉOS 2, now in its fourth year of operation, are still functioning. During 1970, more than 140 stations of the U.S. Air Force, NASA, U.S. Navy, and France used GEOS 2.

I will provide the rest for the record and turn to page 68 for the summary.

Mr. KARTH. Mr. Johnson, without objection, the whole statement which you would otherwise have made from Dr. Naugle's prepared text will be inserted in the record at this point.

(The statement follows:)

COMMUNICATIONS PROGRAMS

I will now turn to the applications program and begin with a discussion of Communications where my principal topic will be the status of the Applications Technology Satellites (ATS F&G) and the Air Traffic Control Satellites.

The objectives of our Communications Programs are to develop the concepts and demonstrate the technology required for more effective and efficient telecommunication systems. There are two paths through which we evolve our Communications Programs. Both are based on the needs of society for services.