These and other maneuvers will be routine in space operations. Let us look at the phases of a future space flight which one day will be commonplace. For the sake of illustration, let us assume that an astronaut is planning to inspect one of our unmanned communications satellites which malfunctioned before being injected into its operating orbit. The satellite is in a 300-nautical-mile circular parking orbit at 60° inclination. A manned spacecraft launched from Canaveral will be limited to a maximum orbital inclination of about 52° by the imposed launch azimuth restrictions. Thus, after being put into a 100nautical-mile circular parking orbit, a Hohmann transfer is used to reach the 300-nautical-mile altitude with a dogleg maneuver at apogee to change orbit plane from 52° to 60°. (Note that plane changes are always made at

Figure 6. Inspection maneuvers

energy or AV requirement.) Figure 4 shows the relative position of the two spacecraft at rendezvous, the astronaut then initiating the closing maneuver as illustrated. The nearrange closing maneuver, as shown in Figure 5, brings the astronaut within inspection range. Finally, the payoff phase of the operation is performed. The astronaut maneuvers his spacecraft around the satellite, using his sensors to determine the cause of the malfunction. This maneuver is shown in Figure 6.

Other aspects of the operation that have to be calculated are left for the reader.

(1) How do you determine the "launch window" for this inspection?

(2) How long must the astronaut remain in orbit before he can initiate his re-entry and land at Edwards?

(3) Assuming his spacecraft has a lift/drag of .30, what is his "footprint"?

TO HELP in finding the answers, a bibliography is given. References 12 and 17 will be particularly useful. One suggestion is made: In trying to visualize space maneuvers, have a globe handy. The wall map of the air operations planner is an unsatisfactory tool for the space operations planner.

The Air Force has several programs to educate space planners and operators. The Aerospace Research Test Pilot School at Edwards is training our X-20 astronauts. The Air Force Institute of Technology gives formal education up to the doctorate level for scien

tists. Air University conducts the Aerospace Operations Course of the Warfare Systems School. The output of these schools is quite limited.

If you want to be among the pioneers of space planning and operations, you should do as the air pioneers did over a half-century ago -take the initiative to understand the new environment and the principles on which operations in it are based. By preparing yourself, you wil not be lost in the Land of AV, but ready for space.

Hq Air Force Systems Command

Bibliography

1. American Astronautical Society. Advances in the Astronautical Sciences, Vol. 6, Proceedings of the Sixth Annual Meeting, New York City, 18-21 January 1960. New York: Macmillan, 1961.

2. Benson, O., Jr., and Strughold, H., (ed.) Physics and Medicine of the Atmosphere and Space. New York: John Wiley & Sons, 1960.

3. Brouwer, D., and Clements, G. Methods of Celestial Mechanics, New York: Academic Press, 1961.

4. California, University of, Engineering and Physical Sciences Extension. Space Technology. Berkeley: University of California, March 1958; New York: John Wiley & Sons, 1959.

5. Duncan, Robert Clifton. Dynamics of Atmospheric Entry. New York: McGraw-Hill, 1962.

6. Ehricke, K. A. Space Flight. Vol. 1, "Environment and Celestial Mechanics." Princeton: Van Nostrand, 1960.

7. Helvey, T. C. Space Trajectories. New York: Academic Press, 1960.

8. Herrick, S. Astrodynamics. Princeton: Van Nostrand, 1961.

9. Jenson, Jorgen. Design Guide to Orbital Flight. New York: McGraw-Hill, 1962.

10. Koelle, Heinz Hermann. Handbook of Astronautical Engineering. New York: McGraw-Hill, 1961.

11. Macko, S. Satellite Tracking. New York: John F. Rider, 1962. 12. Markey, Winston R. The Mechanics of Inertial Position and Heading Indication. New York: John Wiley & Sons, 1961.

13. Ordway, Frederick I., Gardener, James P., Sharpe, Mitchell R., Jr., Wakeford, Ronald C. Applied Astronautics: An Introduction to Space Flight. Englewood Cliffs, N. J.: Prentice-Hall, 1963.

14. Stearns, Edward V. B. Navigation and Guidance in Space. Englewood Cliffs, N. J.: Prentice-Hall, 1963.

15. Thomson, William Tyrrell. Introduction to Space Dynamics. New York: John Wiley & Sons, 1961.

16. USAF Academy, Astronautics. Elements of Free Flight Trajectories. (Instructional text only.)

17. White, J. F. Flight Performance Handbook for Powered Flight Operations. New York: John Wiley & Sons, 1962. 18. Wolff, Edward A. Spacecraft Technology. Washington, D.C.: Spartan Books, 1962.

W

ITH A history spanning barely more than a decade, the record compiled by the Republic of Viet Nam Air Force (VNAF) belies its tender age. In terms of combat sorties flown, numbers of enemy soldiers killed, and quantities of supplies destroyed, this 12-year-old organization has more than proved its worth in battle.

Before any then-and-now comparison of facts and figures, let us look for a moment at how the VNAF has traveled the often-bumpy road of expansion from an original force of less than 300 men to today's manpower total of something over 6000.

Just as the U.S. Air Force first flew as an arm of the U.S. Army, so it was with the VNAF. Organized by the French in 1950 to supplement the French Air Force in the battle for Indochina, its original name was the Air Department of the Joint General Staff. Not until 1956 did it become a separate operating arm of the Vietnamese Department of National Defense.

During its infancy the air unit was composed of an observation squadron, a liaison squadron, and a headquarters agency. For observation missions the French-built Morane-Saulnier-500 was used, while the liaison squadron fulfilled its requirements with several MS-500's, two C-47's, and a pair of C-45's. The latter unit was based at Saigon's municipal airport, Tan Son Nhut. The obser vation squadron split its forces between Nha Trang, on the coast of the South China Sea, and Saigon. In 1954 a light combat squadron was added to the inventory and equipped with 16 twin engine Marcel Dassault-312 light bombers, giving VNAF its first real combat arm. All previous mis sions had been in the realm of combat support since VNAF pilots flew only liaison and observation missions, leaving the actual fighter strikes to th B-26's and F-8F's of the French Air Force.

Concurrent with the establishment of th VNAF was the beginning of a program to trai

crews for it. The initial group of pilot trainees, 11 in number, reported to Nha Trang Air Base in December 1951. Just as in America, the eager cadets divided their days between long classroom sessions in aerodynamics, navigation, and military studies and occasional airborne instruction in the sturdy MS-500. All the teaching was done by French instructors in the language of their homeland.

Following graduation of the 11 pilots in October 1952, some were integrated into French aerial units in the Hanoi area, while others joined the newly established VNAF units. The Air Training Center at Nha Trang began training observers the same month the first class of pilots was graduated, and this group of six candidates won their wings in April 1953. VNAF students who were destined to become bomber or transport pilots received about two months of schooling in light airplanes in France, then went to Morocco for a year to sharpen their skills in the North American T-6. They returned to France for more training in the MD-312 until they sailed to Viet Nam four months later, ready to master C-45, C-47, or MD-312 cockpit duties.

The Geneva conference in July 1954 produced the armistice which ended the eight-year battle between the French and the Viet Minh. This agreement also divided the country in half at the 17th parallel and marked the beginning of the decline of French influence in the Republic of Viet Nam. From that date forward French fighting forces

Editor's Note

Progress Report

USAF tactical air experts work side by side with their Vietnamese officer and airman counterparts in molding the Viet Nam Air Force to the tactical air concepts and doctrines for COIN operations. The VNAF that has developed exemplifies the principle of central control of all tactical air power in the theater. It is integrated into a tactical air control system and operates its own Joint Air Operations Center. Fast becoming a deadly-effective tactical air force, the VNAF is officially credited with more than one-third of all Viet Cong casualties. Its combat sorties have increased from 250 a month in early 1962 to almost 1500 a month in April 1963.

were gradually withdrawn, and the four-year-old Vietnamese Air Force had to assume an increasingly important role in the country's fight against the Communist guerrillas, who remained behind after the signing of the Geneva accords. The last French Air Force personnel departed in 1956.

As a result of the withdrawal of the French Air Force, 1956 was a busy year for the VNAF. In January Tan Son Nhut and Bien Hoa Air Bases were activated, and the liaison squadron at Nha Trang was moved to Tan Son Nhut to provide better service to the headquarters located there. Bien Hoa, 17 miles to the northeast, became the home of the 1st Fighter Squadron and the Air Depot. The latter, which came into being in April, provided maintenance and supply support for the entire VNAF.

To provide communications and navigation aids, the Air Traffic Center was also established that spring, as was the Air Medical Center. In June the 1st Fighter Squadron received 25 F-8F Bearcat fighters, and the 1st Air Transport Group accepted 32 C-47 transports from Military Assistance Program sources. The forerunner of today's Joint Air Operations Center was activated at Tan Son Nhut in July, with the title of Air Operations Center. Major Tran Van Ho was selected as first commander of the newly renamed VNAF.

After the momentous growth of VNAF in 1956 activities leveled off as the VNAF continued its fight to drive the insurgents from their hiding places in the jungles and rice paddies. It was only in the fall of 1961 that another buildup of any significance occurred in the Vietnamese air arm as a result of the American decision to offer increased assistance to the Vietnamese republic. When the French armed forces personnel left the country, the United States began sending military advisers to this wartorn Southeast Asia land. The number of these advisers, however, remained quite small until the fall of 1961, when the U.S. advisory complement began to grow rapidly to meet the increasing challenge of Communist domination in the small republic.

In January 1962 records show that the VNAF flew a total of 251 combat sorties with their one squadron of AD-6 fighters. In startling contrast is the April 1963 figure for combat missions, which

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