X-15 Research Results: Bibliography

X-15 Research Results

Bibliography

Aerodynamic Characteristics

Aerodynamic Heating

BANNER, R.D.; and KINSLER, M.R., "Status of X-15 Aerodynamic-Heating Studies," ARS Report No. 1629-61, 1961.
Summary of flight-test results to Mach 3.
REED, R.D.; and WATTS, J.D., "Skin and Structural Temperatures Measured on the X-15 Airplane During a Flight to a Mach Number of 3.3", NASA TM X-468, 1961.
Survey of the structural temperatures at a few selected locations and for specific conditions.

Drag Characteristics

SALTZMAN, E.J., "Preliminary Full-Scale Power-Off Drag of the X-15 Airplane for Mach Numbers from .7 to 3.l", NASA TM X-430, 1960.
Comparison of flight results with wind-tunnel tests and theory.
SALTZMAN, E.J., "Preliminary Base Pressures Obtained from the X-15 Airplane at Mach Numbers from 1.1 to 3.2", NASA TN D-1056, 1961.
Comparison of flight results with wind-tunnel tests, semiempirical estimates, and theory (base drag only).
HOPKINS, E.J.; FETTERMAN, D.E. JR.; and SALTZMAN, E.J., "Comparison of Full-Scale Lift and Drag Characteristics of the X-15 Airplane with Wind-Tunnel Results and Theory", NASA TM X-713, 1962.
Limited comparison to show deficiencies in theory and wind-tunnel techniques.
SALTZMAN, E.J., "Flight Base Pressure Coefficients Obtained from the X-15 Airplane for Mach Numbers to 6", NASA TN D-2420, 1964.
Survey of base drag characteristics and comparison with wind-tunnel measurements and with theory.

General Review

WALKER, H.J.; and WOLOWICZ, C.H., "Stability and Control Derivatives Characteristics of the X-15 Airplane", NASA TM X-714, 1962.
Brief review of pertinent aerodynamic characteristics as determined from flight tests.
YANCEY, R.B.; REDIESS, H.A.; and ROBINSON, G.H., "Aerodynamic-Derivative Characteristics of the X-15 Research Airplane as Determined from Flight Tests for Mach Numbers from .6 to 3.4", NASA TN D-1060, 1962.
Flight results and comparison with wind-tunnel data to Mach 3.4. Appendix presents data-reduction and analysis techniques for hypersonic speeds.

Pressure Forces

KEENER, E.R.; and PEMBO, C., "Aerodynamic Forces on Components of the X-15 Airplane", NASA TM X-712, 1962.
Limited measurements of the pressure forces to Mach 6.
KORDES, E.E.; and TANNER, C,S., "Preliminary Results of Boundary-Layer Noise Measured on the X-15 Airplane", Proceedings, 2nd Inter. Conference on Acoustical Fatigue, Dayton, April-May, 1964.
Measuring techniques and results from one flight to Mach 5.3.
PYLE, J.S., "Comparison of Flight Pressure Measurements with Wind-Tunnel Data and Theory for the Forward Fuselage of the X-15 Airplane at Mach Numbers from 0.8 to 6.0", NASA TN D-2241, 1964.
Flight measurements and theoretical calculations.

Background and History

WILLIAMS, W.C.; and DRAKE, H.M., "The Research Airplane - Past, Present, and Future", Aero. Eng. Review 17 (1): 36-41, Jan., 1958.
History and highlights of the joint Air Force-Navy-NACA Research Airplane Program through 1957.
WILLIAMS, W.C., "The Airplane as a Research Tool", IAS Report No. 59-79, presented at IAS 27th Annual Meeting, New York, Jan., 1959.
Discusses philosophy, techniques, and role of research aircraft as means for obtaining research information. Pre-X-15 flight tests.
"The Rocket Research Aircraft Program - 1946-1962", AFSC Historical Publications Series 62-110 V, Air Force Flight Test Center, 1962.
History, chronology, and description of the various research-airplane programs. Contains list of pilots who were active in these programs.
MARTIN, J.A., "The Record-Setting Research Airplanes", Aerospace Engineering 21 (12): 49-54, Dec., 1962.
A compilation of the unofficial records of the rocket airplanes through mid-1962.
"Thirty-Five Years of Winged Rocket Flight", The Thiokol Magazine, Thiokol Chemical Corp., 1963.
Brief review of rocket-airplane history from 1928 to 1963.
"X-15 Research Aircraft", System Package Program - System 653A, AeronauticaI Systems Division, Air Force Systems Command, 22 July, 1963.
Reviews management, logistics, and financial support for the X-15 program subsequent to 1963.
BECKER, J.V., "The X-15 Project", Astronautics and Aeronautics 2 (2): 52-61, Feb., 1964.
A history of the research activities leading to the design and development of the X-15.
DRAKE, H.M., "Aerodynainic Testing Using Special Aircraft", in Proceedings, Aerodynamic Testing Conference, Washington, March, 1964, American Institute of Aeronautics and Astronautics.
Discusses role of special test aircraft, including X-15, in the field of aeronautical research.

Design Features cmd Development

Air-Conditioning System

BOUMAN, C.P., "X-15's Cryogenic Cooling System is Simple and Lightweight", Space/Aeronautics, 36 (5), Part 1, 61-63, Nov., 1961.
Description of air-conditioning and pressurization system and development problems.

Escape System

HEGENWALD, J.F., JR.; MADDON, J.F.; and PENROD, P.R., "X-15 Research Aircraft Emergency Escape System", AGARD Report 243, 1959.
General review of the design, development, and test program for the stabilized ejection seat.

Flow-Direction Sensor

"Technical Description and Operating Instructions - NASA Flow-Direction and Pitot-Pressure Sensor", Nortronics Report 60-46, 1960.
Design features and operation of hypersonic angle-of-attack and yaw-angle sensor.

Hydraulic System

HOHMANN, C.J., "Designing a Hydraulic Pump for the X-15", Hydraulics & Pneumatics 15 (12): 75-77, Dec., 1962.
Description and specifications for the hydraulic pump.
CULLETON, R.J., "High Temperature and Vibration-Prime Parameters for X-15 Hydraulic Design", Hydraulics & Pneumatics 15 (12): 70-73, Dec., 1962.
Pertinent features of the system, fluid, seals, and unusual requirements.

Inertial System

"Handbook of Operating and Maintenance Instructions for the All Attitude Flight Data System", Sperry Pub. No. CA-33-0001, prepared for WADC USAF Contract AF33 (600)-35397 Proj.No. 1373, 1960.
Detailed description of theory, operation, and maintenance of the inertial-reference System.
JUDGE, JOHN F., "X-15 Flight Data System - A Precursor", Missiles and Rockets, Feb. 27, 1961, 42-44.
General description of functions and design of the inertial-reference system for attitude-angle and velocity measurement.

Reaction Jet Controls

MERRICK, G.B., "X-15 Controlled in Space by Reaction-Control Rocket System", SAE Journal, Aug., 1960, 38-41.
Description of system development, including flight simulation, of the reaction jet controls.

Rocket Engine

SEAMAN, R.W.; and SMITH, D.S., "Flight Rating Test Demonstration of the XLR-99-RM-1 Rocket Engine", ARS Paper 1409-60, 1960.
Discussion of requirements and demonstration program for the flight-rating of the XLR-99 engine.
BARTON, H.A.; and CRAMER, G.R., "Rocket Engines for Manned Vehicles", Missile Design & Development, Nov., 1960, 14-14, 46, 58.
Discussion of fail-safe and manned-flight considerations for XLR-99 engine.
LUPERI, M.J.; and TICK, S.J., "Vibration and Combustion Investigation of the LR-99 Engine", ARS Paper 1720-61, ARS Propellants, Combustion, and Liquid Rockets Conference, Palm Beach, 1961.
Description of combustion-insta:bility phenomena related to severe vibrations experienced with XLR-99 engine.
DAVIES, H., "The Design and Development of the Thiokol XLR-99 Rocket Engine for the X-15 Aircraft", Journal of the Royal Aeronautical Society 67 (626): 79-91, Feb., 1963.
Detailed description of engine design, performance, and test program.

Structure

SCHLEICHER, R.L., "Structural Design of the X-15", Journal of the Royal Aeronautical Society 67 (10): 618-636, Oct., 1963.
Thorough review of the design and test program for structural development.

Summary

MELLINGER, G.R., "Design and Operation of the X-15 Hypersonic Research Airplane", AGARD Report 288, Oct., 1960.
General description of airplane and systems.

Experiments

CLARK, W.M.; and MULDOON, H.A., "High Altitude Sky Luminance Measurement", Northrop Nortronics Paper presented at 9th National IRIS Symposium, Dallas, May, 1963.
Results of measurements for three X-15 flights, one of which attained 280 000-ft. altitude.
THOMAS, L.P., "The X-15 as a Zero-Gravity Test Facility", in Proceedings, Zero-Gravity Fluid Behavior Review and Planning Meeting, NASA, Washington, D.C., Oct., 1963.
Description of the X-15's capability for zero-gravity tests.
LARSON, T.J.; and MONTOYA, E.J., "Stratosphere and Mesosphere Density-Height Profiles Obtained with the X-15 Airplane", NASA TM X-56009, 1964.
Density-height profiles from 16 to 74 kilometers' altittide for six X-15 flights.

Flight Dynamics

Adaptive-Control System

BOSKOVIC, B.; COLE, G.H.; and MELLEN, D.L., "Advanced Flight Vehicle Self-Adaptive Flight Control System", WAIDD Tech. Report, 60-651, Part 1, Contract No. AF 33 (616)-6610, Project No. 8226, Task No. 10889, U.S. Air Force, 1960.
Description of design and operation of adaptive system.
BAILEY, A.J., JR., "Development and Flight Test of Adaptive Controls for the X-15", in Supersonic Transport Symposium, SETP Quarterly Rev. V (4): 3-23,1961.
General discussion of adaptive principle and development of X-15 system.
TAYLOR, L.W., JR.; and ADKINS, E.J., "Adaptive Flight Control Systems - Pro and Con", NASA TM X-56008,1964.
Description of development of, and operating experience with, the adaptive system.

Flight-Control System

HOLLADAY, W.L.; and HOFFMAN, D.P., "Systems Approach to Flight Controls", Astronautics 36-37, 74-80, May, 1962.
Systems-analysis techniques used during the developnient of the flight controls.
TAYLOR, L.W., JR.; and MERRICK, G.B., "X-15 Airplane Stability Augmentation System", NASA TN D-1157, 1962.
Highlights of the development and flight-testing of the control system.
TREMANT, R.A., "Operational Experiences and Characteristics of the X-15 Flight Control System", NASA TN D-1402, 1962.
Detailed description of control system: characteristics, operating problems, modifications, and reliability.

General Flight Characteristics

TAYLOR, L.W., JR., "Analysis of a Pilot-Airplane Lateral Instability Experienced with the X-15 Airplane", NASA TN D-1059, 1961.
Analytical techniques developed to explain roll-yaw coupling problem.
PETERSEN, F.S.; REDIESS, H.A.; and WEIL, J., "Lateral-Directional Control Characteristics of the X-15 Airplane", NASA TM X-726, 1962.
Detailed discussion of the roll-yaw coupling problem, and successful and unsuccessful solutions.
WHITE, R.M.; ROBINSON, G.H.; and MATRANGA, G.J., "Résumé of Handling Qualities of the X-15 Airplane", NASA TM X-715, 1962.
Highlights of exploratory-research phase of program. Discusses flight maneuvers from launch to landing.
HOLLEMAN, E.C.; and ADKINS, E.J., "Contributions of the X-15 Program to Lifting Entry Technology", AIAA Aerospace Sciences Meeting, New York, Jan., 1964.
Description of flight-control system and flight characteristics for powered flight, space-equivalent flight, and reentry.

Landing

GAINES, L.M.; and SURBER, T.E., "Prediction of Optimum Approach and Landing Techniques for Manned Reentry Gliders", IAS-ARS Joint Meeting, Los Angeles, June, 1961, Paper No. 61-115-1809.
Description of the interplay of various factors important to landing maneuver. Compares results from 15 landings with analytical techniques.
MATRANGA, G.J., "Analysis of X-15 Landing Approach and Flare Characteristics Determined from the First 30 Flights", NASA TN D-1057, 1961.
Discussion of conditions and problems encountered during the approach pattern and the flare to touchdown.
HOEY, R.G., "Horizontal Landing Techniques for Hypersonic Vehicles", AGARD Report No. 428, 1963.
Discussion of navigation phase to landing site, and description of factors important to favorable landing experience with the X-15.
JOHNSTON, E.W.; and GAINES, L.M., "Low-Speed Characteristics and Piloting Techniques of Landing the X-15 Research Airplane on Earth and Other Planets", in "Dynamics of Manned Lifting Planetary Entry", ed. by S.M. Scala, New York: John Wiley & Sons. Inc., 1963, pp. 668-700.
Discussion of X-15 landing techniques and of their potential application to landings on Venus and Mars.

Powered Flight

HOLLEMAN, E.C., "Piloting Performances During the Boost of the X-15 Airplane to High Altitude", NASA TN D-22893, 1964.
Discussion of piloting techniques utilized during flights to high altitudes.

Reaction Controls

JARVIS, C.R.; and ADKINS, E,J., "Operational Experience with X-15 Reaction Controls", SAE-ASME Air Transport and Space Meeting, New York, April, 1964, Paper 857G.
Brief review of the development and flight experience with the reaction jet controls.

Flight Research

B-52 and Launch

ALFORD, W.J.; and TAYLOR, R.T., "Aerodynamic Characteristics of the X-15/B-52 Combination", NASA Memo. 6-8-59L, 1959.
Analysis program, including wind-tunnel and dynamic-model tests, for the X-15 launching characteristics.
ADALPH, C.E.; ALLAVIE, J.E.; and BOCK, C.C., JR., "Flight Evaluation of the B-52 Carrier Airplane for the X-15", AFFTC TR 60-33, 1960.
Results of testing B-52-and-X-15 combination and the procedures used during typical launch mission.
MATRANGA, G.J., "Launch Characteristics of the X-15 Research Airplane as determined in Flight", NASA TN D-723, 1961.
Description of launch characteristics from analysis of first 16 airlaunch operations.

Dynamic Flight Simulation

CLARK, C.C.; and HARDY, J.D., "Preparing Man for Space Flight", Astronautics, Feb., 1959, 18-21, 88-90.
Description of the capabilities and potentialities of the centrifuge and its use as a flight simulator for the X-15 and future projects.
HARDY, J.D.; and CLARK, C.C., "The Development of Dynamic Flight Simulation", Aero/Space Engineering, 18 (6): 48-52, June, 1959.
Development of dynamic flight simulation and adaptation of the human centrifuge to closed-loop control for the X-15 program.
CLARK, C.C.; and WOODLING, C.H., "Centrifuge Simulation of the X-15 Research Aircraft", NADC-MA-5916, Aviation Medical Acceleration laboratory, Naval Air Development Center, 1959.
Detailed review of the procedures and tests performed during the X-15 centrifuge programs. Discusses restraint systems, cockpit instruments, control system, and pilot performance.
BERRY, D.T., "An Evaluation of a Variable Stability Airplane Simulation of the X-15", AFFTC-TR-61-42, 1961.
Description of an exploratory variable-stability-airplane simulation of the X-15 performed with a T-33 jet trainer.

Flight Operations Experience

ROW, P.V.; and FiSCHEL, J., "X-15 Flight-Test Experience", Astronautics and Aerospace Engineering 1 (5): 25-32, June, 1963.
Review of flight-test experience with emphasis on the operating problems and difficulties encountered.
MAHER, J.F.; OTTINGER, C.W.; and CAPASSO, V.N., "YLR99-RM-1 Rocket Engine Operating Experience in the X-15 Aircraft", NASA TN D-2391, 1964.
Review of flight-operating experience, problems, and maintenance requirements for the engine.

Flight Planning

JOHNSTON, E.W.; and JOHNSON, R.H., "Analysis of Sub-Orbital Vehicle Reentry Constraints", ARS Lifting Reentry Vehicles: Structures, Materials, and Design Conference, Palm Springs, April, 1961, NAA Report NA-61-167, 1961.
Discussion of reentry study as related to constraints from temperature, loads, angle of attack, and energy considerations.
HOEY, R.G., "Flight Planning and Conduct of the X-15 Envelope Expansion with Interim XLR-11 Rocket Engines", AFFTC TDR-62-73, 1962.
General summary for flights to Mach 3 and 135 000-ft. altitude. Discusses High Range facility, emergency lake facilities, and flight-control center.
HOEY, R.G.; and DAY, R.E., "Mission Planning and Operational Procedures for the X-15 Airplane", NASA TN D-1158, 1962.
Detailed review of the techniques used during the exploratory-research phase of the program.

Flight Simulation

DAY, R.E., "Training Aspects of the X-15 Program", Proceedings Report of a Working Group Conference: Panel on Psychology, Armed Forces-National Research Council Committee on Bioastronautics, Woods Hole, Aug., 1960, 5-14, 1961.
Simulation techniques as related to pilot training.
COOPER, N.R., "X-15 Flight Simulation Program", Aerospace Engineering, Vol. 20, Nov., 1961, 16-17, 71-77.
Detailed review of the various simulation programs conducted during the design and development program. Describes equipment and procedures.
HOLLEMAN, E.C.; and WILSON, W.S., "Flight-Simulator Requirements for High-Performance Aircraft Based on X-15 Experience", ASME Paper No. 63-AHGT-81, 1963.
Discussion of use of X-15 flight simulator during the research-flight phase of the program.

High Range

ARMSTRONG, N.A., "X-15 Operations: Electronics and the Pilot", Astronautics, May, 1960.
Description of High Range facility and ground-monitoring support for the X-15 program.

Research and Pilot Instrumentation

LARSON, T.J.; and WEBB, L.D., "Calibrations of Pressure-Type Airspeed-Altitude Systems of the X-15 Airplane from Subsonic to High Supersonic Speeds", NASA TN D-1724, 1963.
Flight data pertinent to pressure-measuring systems to Mach 4.
SANDERSON, K.C., "The X-15 Flight Test Instrumentation", 3rd International Flight Test Symposium, Buckinghamshire, Eng.; April, 1964.
Detailed review and description of research instrumentation and measuring techniques.
FISCHEL, J.; and WEBB, J.D., "Flight-Informational Sensors, Display, and Space Control of the X-15 Airplane for Atmospheric and Near-Space Flight Missions", NASA TN D-2407, 1964.
Description of conventional and unconventional sensing and pilot-display techniques utilized on the X-15.

Research Techniques

VIDEAN, E.N.; BANNER, R.D.; and SMITH, J.P., "The Application of Analog and Digital Computer Techniques in the X-15 Flight Research Program", Proceedings International Symposium on Analog and Digital Techniques Applied to Aeronautics, Liege, Sept., 1963.
Aerodynamic-heating and stability-analysis techniques used to monitor and predict flight conditions.

Man-Machine Integration

Bioastronautics and Pressure Suit

ROWEN, B., "Biomedical Monitoring of the X-15 Program", AFFTC-TN-61-4, 1961.
Summary of measurements for eight flights: heart rate, respiration rate, and body temperature.
ROWEN, B., "Bioastronautics Support of the X-15 Program", AFFTC-TDR-61-61, 1961.
Description of two versions of pressure suit, physiological instrumentation, and results from one flight to Mach 6.
BRATT, H.R.; and KURAMOTO, M.J., "Biomedical Flight Data Collection", ISA Journal, Oct., 1963, 57-62.
Development of biomedical measuring, telemetry techniques, and monitoring systems for the X-15 and future aerospace vehicles.

Mission Reliability

DRAKE, J.R., "The Pilot's Contribution to Mission Reliability on the X-15 Program", ARS Paper 1128-60, 1960.
Review of piloted-flight philosophy as applied to the X-15.
NAGEL, R.A., "X-15 Pilot-in-the-Loop and Redundant Emergency Systems Evaluation", AFFTC Tech. Doc. Report No. 62-20, 1962.
Detailed analysis of first 47 flights. Summarizes mission, system, and component reliabilities. Appendix summarizes flight record and attempted flights.

Pilot Display

WALKER, J.A., "Some Concepts of Pilot's Presentation", in SETP Quarterly Review, 4 (2): 90-96, Winter, 1959.
Discussion of X-15 pilot's display used in early flights.

Pilot Viewpoints

CROSSFIELD, A.S.; and BLAIR, C., JR., "Always Another Dawn", Cleveland and New York, The World Publishing Co., 1960.
Pertinent to design and contractor demonstration flights.
WHITE, MAJ. R.M., "X-15 Program Status Report, Part I", and WALKER, J.A., "X-15 Program Status Report, Part II", in Proceedings Symposium "The Age of Omni-Sonic Flight", SETP Quarterly Review V (2): 145-152 (Part I) and 153-160 (Part 11), Winter, 1960.
Summary of program for flights to Mach 3.2.
WHITE, MAJ. R.M., "X-15 Operations in Pre-Lunar Studies", in Lectures in Aerospace Medicine, Brooks AFB, Jan., 1962, 191-210.
Summary of program for flights to Mach 6 and 217 000-ft. altitude.
PETERSEN, F.S., COMDR., USN, "Research Program Report - X-15", Naval Aviation News, 6- 10, May, 1962.
Summary of experience with the X-15 program.
WALKER, J.A., "The X-15 Program", in Proceedings IAS-NASA Meeting, St. Louis, April-May, 1962.
Highlights of program for flights to Mach 6 and altitudes to 200 000 ft.
RUSHWORTH, R.A., "Pilot Experience with the X-15 Airplane", in Proceedings 12th AGARD General Assembly, Paris, July, 1962, 117-123.
Air Force test pilot's view of the X-15 program.

Structural Loads

Aerothermoelastic Effects

KORDES, E.E.; REED, R.D.; and DAWDY, A.L., "Structural Heating Experiences on the X-15 Airplane", NASA TM X-711, 1962.
Highlights of structural-heating effects and problems up to Mach 6.
GARRICK, I.E., "A Survey of Aerothermoelasticity", Aerospace Engineering 22 (1): 140-147, Jan., 1963.
Summary of technical problem areas and interdisciplinary elements. Describes some considerations for the X-15.

Dynamic Loads Including Flutter

JORDAN, G.H.; MCLEOD, N.J.; and GUY, L.D., "Structural Dynamic Experiences of the X-15 Airplane", NASA TN D-1158, 1962.
Brief review of structural dynamic and flutter problems encountered during the development and flight-test program.
KORTES, E.E.; and NOLL, R.B., "Flight Flutter Results for Flat Rectangular Panels", NASA TN D-1058, 1962.
Brief review of X-15 panel-flutter phenomena. Presents semiempirical correlation parameters for flutter analysis.

Landing

MCKAY, J.M.; and SCOTT, B.J., "Landing-Gear Behavior During Touchdown and Runout for 17 Landings of the X-15 Research Airplane", NASA TM X-518, 1961.
Detailed analysis and review of landing-gear characteristics and dynamic-response problems for first 17 flights.
MCKAY, J.M.; and KORDES, E.E., "Landing Loads and Dynamics of the X-15 Airplane", NASA TM X-639, 1962.
Brief summary of landing-gear dynamics and loads.
NOLL, R.B.; JARVIS, C.R.; PEMBO, C.; LOCK, W.P.; and SCOTT, B.J., "Aerodynamic and Control-System Contributions to the X-15 Airplane Landing-Gear Loads", NASA TN D-2090, 1963.
Summary for 77 flights. Describes analytical techniques.
NOLL, R.B.; and HALASEY, R.L., "Theoretical Investigation of the Slideout Dynamics of a Vehicle Equipped with a Tricycle Skid-Type Landing-Gear System", NASA TN D-1828, 1963.
Comparison of flight-test data with calculated distance, lateral displacement, and effects of aerodynamic control.

Summary Papers

MELLINGER, G.R., "The X-15", Aerospace Engineering 20 (8): 12-13, 26-38, Aug., 1961.
A look at the development of the X-15 from the manufacturer's viewpoint.
WEIL, J., "Review of the X-15 Program", NASA TN D-1278, 1962.
Summary of the flight program (exploratory) to Mach 6 and 200 000-ft. altitude.
KORDES, E.E., "Experience with the X-15 Airplane in Relation to Problems of Reentry Vehicles", presented at 3rd Congress of the International Council of the Aeronautical Sciences, Stockholm, Aug.-Sept., 1962.
Discussion of panel flutter, landing dynamics, flight-control-system, aerodynamic and structural heating, and problems that developed through mid-1962.
ARMSTRONG, N.A.; WALKER, J.A.; PETERSEN, COMDR. F.S.; and WHITE, MAJ. R.M., "The X-15 Flight Program", in Proceedings 2nd National Conference on the Peaceful Uses of Space, Seattle, May, 1962, 263-271, 1962.
Pilots' views of the X-15 program.
TOLL, T.A., and FISCHEL, J., "The X-15 Project: Results and New Research", Astronautics and Aeronautics 2 (3): 20-28, March, 1964.
A research engineer's consideration of the results of the X-15 flight program.