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Aerodynamics of Trajectory Control for Re-Entry at Escape Speed

  • J. V. Becker
  • D. L. Baradell
  • E. B. Pritchard
Conference paper

Abstract

Aerodynamics of Trajectory Control for Re-Entry at Escape Speed. The problems of range control during re-entry of lifting manned vehicles are analyzed from the aerodynamic point of view. The ability to reach a given destination from the extremities of the entry corridor using wholly atmospheric modes of operation is found to require moderately higher lift/drag ratios than skip modes. However, the atmospheric cases do not suffer from the inherently sensitive guidance and control problems of the skip modes. An atmospheric technique is discussed whereby lateral and longitudinal range can be varied independently, using only roll control. For the longer re-entries the earth’s sphericity is found to have major influences on attainable lateral range and on the shape of the maneuver envelope.

Several types of re-entry vehicle capable of meeting the aerodynamic requirements for range control are discussed briefly. From a fixed-base simulator study for one of these vehicles it is concluded that the typical maneuvers required for range control can be performed satisfactorily by a human pilot with the aid of artificial damping.

Keywords

Range Control Lateral Range Trajectory Control Entry Angle Bank Angle 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notation

A

reference area

Cd

drag coefficient based on A

Cl

lift coefficient based on A

Cl1, Cl3

values of Cl at start and end of const. alt. maneuver (Fig. 4)

D

drag, component of resultant force along flight path

D1

drag at start of range-control maneuver

g

acceleration due to gravity at earth’s surface

G

resultant acceleration, \(D/\left( {W/g} \right)\sqrt {1 + {{\left( {L/D} \right)}^2}} \)

h

altitude

l

lateral range measured normal to initial entry plane

L

lift, component of resultant force normal to flight path

m

mass

q

dynamic pressure, ϱ V 2/2

re

mean radius of earth

R

range

ΔR

range overlap for steep and shallow entries

ΔRe. p.

longitudinal range between o-vershoot and undershoot entry point for a given perigee location (Fig. 8)

t

time

T

kinetic energy

V

velocity

\(V\sqrt {g{r_e}} \)

1

V at the end of initial pull-up and start of range-control maneuver

2, V̄3

values at start and end of constant q transition maneuver (defined on Fig. 4)

W

gross weight of vehicle

γ

path angle with respect to horizontal

γ0

re-entry path angle at 400,000 ft altitude

γ1

path angle at start of skip

λ

lateral displacement angle (Fig. 13)

ϱ

atmospheric density

ξ

heading angle (Fig. 13)

φ

roll angle (zero for unbanked vehicle)

φ1

roll angle at start of rangecontrol maneuver

Ψ

range angle (Fig. 13).

Zusammenfassung

Aerodynamik der Bahnkontrolle beim Eintauchen in die Atmosphäre mit Fluchtgeschwindigkeit. Die mit der Bahnkontrolle bemannter Raumfahrzeuge zusammenhängenden Probleme werden von der aerodynamischen Seite untersucht. Es wird eine Methode beschrieben, bei der Breiten- und Längenwinkel voneinander unabhängig verändert werden können, wobei nur Rollen des Fahrzeuges zugelassen wird. Für längere Eintauchbahnen muß die Kugelgestalt der Erde berücksichtigt werden.

Verschiedene Typen von Eintauchflugkörpern werden untersucht. Auf Grund von Untersuchungen an einem Simulator wird geschlossen, daß die beim Eintauchen nötigen Manöver in hinreichender Weise von einem menschlichen Piloten bewältigt werden können, wenn eine künstliche Dämpfung vorgesehen ist.

Résumé

Aérodynamique du contrôle de la trajectoire pour une rentrée à la vitesse de libération. Les buts du contrôle de la trajectoire sont, successivement, de réduire l’angle de rentrée à une faible valeur sans dépasser les limites de la décélération tolérable, d’éviter ou de contrôler un rebondissement hors de l’atmosphère et enfin, de contrôler longitudinalement et latéralement l’atterrissage dans la zone fixée. On décrit une façon d’opérer qui permet d’obtenir le contrôle du tangage et du lacet en agissant seulement sur la commande de roulis.

Les valeurs que doit prendre le rapport portance sur traînée du véhicule, pour réussir l’atterrissage dans la zone prescrite en commençant le pilotage à l’extrémité du corridor de rentrée, sont établies pour les diverses techniques de manoeuvre envisagées. Les dimensions de la zone d’atterrissage prédéterminée depuis de longues distances, supérieures au rayon de la terre, sont analysées en employant les équations de mouvement tridimensionnelles complètes, en coordonnées sphériques polaires. On trouve que les approximations communément employées pour obtenir le point d’impact du véhicule avec le sol sont très fausses si l’on part de longues distances.

Finalement, trois véhicules-type sont comparés pour leur comportement lors des manoeuvres de rentrée. On en conclut que dans beaucoup de cas, des rentrées pilotées peuvent être réussies sans même utiliser de systèmes artificiels amortissant les mouvements du véhicule autour de ses axes.

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References

  1. 1.
    D. R. Chapman, An Analysis of the Corridor and Guidance Requirements for Supercircular Entry into Planetary Atmospheres. NASA TR R-55 (1959).Google Scholar
  2. 2.
    L. Lees, et al., Use of Aerodynamic Lift During Entry into the Earth’s Atmosphere. ARS Journal 29, No. 9 (1959).Google Scholar
  3. 3.
    Mac C. Adams, Recent Advances in Ablation. ARS Journal 29, No. 9 (1959).Google Scholar
  4. 4.
    F. C. Grant, Importance of the Variation of Drag with Lift in Minimization of Satellite Entry Acceleration. NASA TN D-120 (Oct. 1959).Google Scholar
  5. 5.
    L. Broglio, Similar Solutions in Re-Entry Lifting Trajectories. Univ. of Rome, SIARgraph No. 54 (Dec. 1959).Google Scholar
  6. 6.
    K. Wang and L. Ting, Analytic Solutions of Planar Re-Entry Trajectories with Lift and Drag. Polytechnic Institute of Brooklyn (PIBAL) Rep. No. 601 (April 1960).Google Scholar
  7. 7.
    F. C. Grant, Analysis of Low-Acceleration Lifting Entry from Escape Speed. NASA TND-249 (June 1960).Google Scholar
  8. 8.
    J. D. C. Crisp and P. Feitis, The Thermal Response of Heat-Sink Re-Entry Vehicles. PIBAL Rep. No. 576 (Juli 1960).Google Scholar
  9. 9.
    F. C. Grant, Modulated Entry. NASA TN D-452 (Aug. 1960).Google Scholar
  10. 10.
    E. F. Styer, A Parametric Examination of Re-Entry Vehicle Size and Shape for Return at Escape Velocity. Paper presented at Third Annual Meeting, American Astronautical Society, Seattle, Washington, Aug. 8–11, 1960.Google Scholar
  11. 11.
    O. A. Kelly Jr., Parametric Study of a Manned Space Entry Vehicle. Aero-Space Engng. 19, No. 10 (1960).Google Scholar
  12. 12.
    B. A. Galman, Direct Re-Entry at Escape Velocity. Paper presented at Third Annual Meeting, American Astronautical Society, Seattle, Washington, Aug. 8–11, 1960.Google Scholar
  13. 13.
    R. Teague, Flight Mechanics of Re-Entry After Circumlunar Flight by Means of Various Lifting Techniques. NASA-George C. Marshall Space Flight Center, MNN-M-Aero-4–60 (Sept. 15, 1960).Google Scholar
  14. 14.
    R. B. Hildebrand, Manned Re-Entry at Supersatellite Speeds. IAS Rep. No. 60–83 (Sept. 1960).Google Scholar
  15. 15.
    R. A. Minzner, et al., ARDC Model Atmosphere, 1959 Geophysics Research Directorate, ARDC, U. S. Air Force (1959).Google Scholar
  16. 16.
    J. E. Hays, et al., Analytical Study of Drag Brake Control System for Hypersonic Vehicles. Wright Air Develop. Div., U. S. Air Force Tech. Rep. 60–267 (Jan. 1960).Google Scholar
  17. 17.
    J. V. Becker, Heating Penalty Associated with Modulated Entry into Earth’s Atmosphere. ARS Journal 30, No. 5 (1960).Google Scholar
  18. 18.
    A. E. Bryson, et al., Determination of the Lift or Drag Program that Minimizes Re-Entry Heating with Acceleration or Range Constraints Using a Steepest Descent Computation Procedure. IAS Paper, New York Meeting, Jan. 23 – 25, 1961.Google Scholar
  19. 19.
    R. C. Wingrove and R. E. Coate, Piloted Simulator Tests of a Guidance System which Can Continuously Predict Landing Point of a Low L/D Vehicle During Atmospheric Re-Entry. NASA TN D-787.Google Scholar
  20. 20.
    R. E. Slye, An Analytical Method for Studying the Lateral Motion of Atmosphere Entry Vehicles. NASA TN D-325, Sept. 1960.Google Scholar
  21. 21.
    D. S. Mandell, A Study of the Maneuvering Performance of Lifting Re-Entry Vehicles. Paper presented at ARS 15th Annual Meeting, Washington, D. C., Dec. 5–8, 1960.Google Scholar
  22. 22.
    A. L. Friedlander and D. P. Harry III, Requirements of Trajectory Convective Impulses During the Approach Phase of an Interplanetary Mission. NASA TN D-255, 1960.Google Scholar
  23. 23.
    H. Multhopp, Design of Hypersonic Aircraft. Aero-Space Engng. 20, No. 2 (1961).Google Scholar
  24. 24.
    J. M. Eggleston, et al., Fixed-Base Simulator Study of a Pilot’s Ability to Control a Winged Satellite Vehicle During High-Drag Variable-Lift Entries. NASA TN D-228, April 1960.Google Scholar
  25. 25.
    Mac C. Adams, A Look at the Heat Transfer Problem at Super-Satellite Speeds. Paper presented at ARS 15th Annual Meeting, Washington, D. C., Dec. 5–8, 1960.Google Scholar
  26. 26.
    M. J. Brunner, The Aerodynamic and Radiant Heat Input to Space Vehicles which Re-Enter at Satellite and Escape Velocity. Paper presented at ARS 15th Annual Meeting, Washington, D. C., Dec. 5–8, 1960.Google Scholar
  27. 27.
    H. J. Allen, Problems in Atmospheric Entry from Parabolic Orbits. Paper presented at Conference on Aeronautical and Space Engineering, Nagoya, Japan, Nov. 8–9, 1960.Google Scholar
  28. 28.
    W. H. Stillwell and H. M. Drake, Simulator Studies of Jet Reaction Controls for Use at High Altitudes. NACA RM H58G18a, 1958.Google Scholar
  29. 29.
    G. W. Freeman, Reaction Controls for Re-entry Vehicles. Paper presented at Third Annual Meeting, American Astronautical Society, Seattle, Washington, Aug. 8–11, 1960.Google Scholar

Copyright information

© Springer-Verlag Wien 1962

Authors and Affiliations

  • J. V. Becker
    • 1
  • D. L. Baradell
    • 2
  • E. B. Pritchard
    • 2
  1. 1.Aero-Physics DivisionNASA-Langley Research CenterLangley FieldUSA
  2. 2.NASA-Langley Research CenterLangley FieldUSA

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