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The effects of aerodynamic lift on the performance capability of a two stage space shuttle are discussed. The performance program uses three degrees of freedom to describe the trajectory of a point mass moving over the rotating earth. Two cases of ascent modes are described and compared. It is concluded that significant improvements in performance through the use of lift appear to be configuration dependent, and for this reason cannot be generalized for all spacecraft configurations.

The proliferation of papers published on various aspects of optimum space trajectories has made it desirable to produce a unified treatment of this subject that contains the major results of these papers. This monograph on optimal space trajectories is addressed to this goal. It includes chapters on space propulsion systems, the maximum principle, general theory of optimum rocket trajectories, trajectory optimization in field free space, trajectory optimization in an inverse square-field, linearized power-limited transfer in the vicinity of an elliptic orbit, optimum power-limited orbit transfer in strong gravity fields, linearized impulsive transfer in the vicinity of a circular orbit, optimum impulse transfer in an inverse square field, singular arcs, interplanetary trajectories, and combination propulsion.

NAS 1.60:1565 Digitized from IA1177308-04-0042 .

The author has developed a theory on optimal trajectories for air vehicles with variable wing areas and with conventional wings.   He applied a new theory of singular optimal solutions and obtained in many cases the optimal flight. The wing drag of a variable area wing does not depend on air speed and air density.   At first glance the results may seem strange, however, this is the case and this chapter will show how the new theory may be used.   The equations that follow enable computations of the optimal control and optimal trajectories of subsonic aircraft with pistons, jets, and rocket engines, supersonic aircraft, winged bombs with and without engines, hypersonic warheads, and missiles with wings.     The main idea of the research is to use the vehicle’s kinetic energy to increase the range of missiles and projectiles.     The author shows that the range of a ballistic warhead can be increased 3–4 times if an optimal wing is added to it, especially a wing with variable area. If we do not need increased range, the head mass of rockets can be increased. The range of large gun shells can also be increased 3–9 times. The range of an aircraft may be improved by 3–15% or more.    The results can be used for the design of aircraft, space ship, head of rockets, missiles, flying apparatus and shells for large guns.

There has been an increasing interest in on-orbit autonomous servicing and repair of satellites as well as controlled active debris removal (ADR) in the space industry recently. One of the most challenging tasks for servicing/repair as well as forADR is the rendezvous and docking with a non-cooperative tumbling resident space object (RSO). This paper presents apropellant optimal maneuver profile for a servicing spacecraft to perform proximity operations and eventually dock with a non-cooperative target. The strategy is to find an optimal trajectory which will guide the servicing spacecraft to approach the tumbling satellite such that the two vehicles will eventually have no relative motion. Therefore, a subsequent docking or capture operation can be safely performed. The research described here elaborates on the previous work that studied the minimum-control-effort for a 3-D docking to a tumbling object considering a full six-degree-of-freedom model of both chaser and target. The current work expands the scope by adding newset of linearized equations of motion that capture the effect of the J2 geopotential disturbance force.

The performance gains which are possible through the use of optimal trajectories for a particular space shuttle configuration are discussed. The spacecraft configurations and aerodynamic characteristics are described. Shuttle mission payload capability is examined with respect to the optimal orbit inclination for unconstrained, constrained, and nonlifting conditions. The effects of velocity loss and heating rate on the optimal ascent trajectory are investigated.

Optimal round trip space tug trajectories for earth escape missions