Aerospace Engineering Commons^™

Propulsive Capability Of A Reel-In Tether With Safe Separation Between Payload And Orbiter, Jay H. Rothhaupt

Theses and Dissertations

This study investigates the use of a massless reel-in tether for propulsion of a payload following deployment from an orbiter. The distance between the payload and orbiter at closest passage is addressed. A literature review revealed several tether concepts, extensive tether research, and numerous mathematical models. However, previous work in the area of reel-in tethers is limited to propulsion feasibility. The reel-in tether is operated following optimum ejection of the payload from the orbiter using a free arc and subsequent full arc. The free arc of zero tether tension provides initial separation. Switching to a full arc of continuously-maximum tension …

Perturbation Theory For Restricted Three-Body Orbits, David A. Ross

Theses and Dissertations

A perturbation theory for restricted three-body orbits, using a periodic trajectory as a reference solution, is investigated. The nearly- periodic equations of motions are derived by analogy to a linearization about an equilibrium point. In this case, the linearization produces a set of time- periodic equations of motion that, according to Floquet, are completely solved by a periodic trajectory. The four-dimensional phase space of the restricted three-body problem is the first surveyed for regions of periodic motion, via the surface of section phase plot. Upon extraction of a periodic orbit, nearly- periodic orbits are integrated. The integrated state vector is …

Navigation Of A Satellite Cluster With Realistic Dynamics, J. Timothy Middendorf

Theses and Dissertations

Previous work in the area of estimation of relative positions within a satellite cluster showed favorable results. However, the work was done using point mass orbits in the truth model. This thesis investigates the estimation of relative satellite positions operating in near circular orbit including the J₂ term in Earth's geopotential. The iterated, extended Kalman filter is used as the on-board estimator in order to gain better performance in the face of the non-linearities. The dynamics in the estimator are based on the Clohessy- Wiltshire equations for relative orbital motion. Inputs to the host estimator are range measurements from …

Analysis Of Suborbital Launch Trajectories For Satellite Delivery, Mark R. Goodell

Theses and Dissertations

A computer simulation program was used to analyse performance of suborbital launch trajectories using a hypersonic NASP derived vehicle for satellite deployment. The trajectory investigated for this project involved satellite deployment as suborbital speeds. To deploy a satellite in this manner, a booster motor is used to insert the payload into orbit while the launch vehicle reenters and returns to earth. A simplified energy analysis was also formulated and used to determine the sensitivity of suborbital trajectory performance to specific design parameters. Results show that suborbital launch trajectories can increase the useful payload to orbit capacity over an identical vehicle …

Nonlinear Analysis Of A Spinning Symmetric Satellite In An Elliptical Orbit, Michael Ulisse

Theses and Dissertations

Controlled and uncontrolled equations of motion for a spinning symmetric satellite in an elliptical orbit are analysed using Floquet theory, Poincare maps, and continuation. The equations of motion for the uncontrolled system are derived via energy methods. A simple feedback controller design and one based on Floquet theory are presented. Parameters varied in the equations of motion include the spin about the symmetry axis of the satellite, the inertia ratio of the satellite, the eccentricity of the orbit, and the controller gains. Floquet analyses determine local stability and bifurcation points. Poincare maps exhibit some interesting and complex structure in the …

Realistic Orbits About The Martian Moons, Samuel R. Bryant

Theses and Dissertations

Orbits about the Martian moons, Phobos and Deimos, previously found to be stable by the Poincare surface of section technique in a restricted three- body system, were investigated with non-zero eccentricity of the moons added to the dynamics of the planar four-body system (Mars, moon sun, artificial satellite). Although not strictly applicable to this case, the surface of section technique was used to verify whether or not the previously found stable orbits were realistic when a real world perturbation was added to the system dynamics. The surface of section technique involves the numerical integration of several orbits with the same …

Numerical Analysis Of Critical Inclinations About The Planet Mars, Kenneth J. Hyatt

Theses and Dissertations

This study investigated critical inclinations about the planet Mars. Averaged equations of motion were numerically integrated over a time span of ten Earth years for various inclinations, eccentricities, and perigee heights. Each orbit (i.e. set of initial conditions) produced a standard deviation of the variations in eccentricity (SDE) and inclination (SDI). These were calculated using a polynomial approximation to the variations. Surface plots of SDI and SDE vs the initial conditions are then examined to ascertain the critical inclinations.

Analysis Of Parking Orbits For A Sts External Tank In Low Earth Orbit, James E. Cross

Theses and Dissertations

A study was conducted of a single external tank in low earth orbit. Criteria for a parking orbit are then defined. Various orbits are then selected by varying the semi-major axis, eccentricity, and inclination. The resulting equations of motion for each of the above orbits (including atmospheric drag and a 2x0 gravity model) are numerically integrated over a time span of 90 earth days. An examination was made of the lowest initial altitudes which allowed the external tank to remain in the orbit window.

Weatherford Air Show And General Thomas P. Stafford Museum Dedication, City Of Weatherford

Programs

This is a program from the 1987 Weatherford Air Show and General Thomas P. Stafford Museum Dedication in Weatherford, Oklahoma.

Unless stated otherwise within this repository collection, all materials are shared under the following Creative Commons license: [Creative Commons Attribution-NonCommercial 4.0 International License].

Dynamic Analysis Of An Earth-Orbiting Satellite Deploying Hinged Appendages, Kevin Fielding Oakes

Mechanical & Aerospace Engineering Theses & Dissertations

The planar liberational dynamics of an arbitrary spacecraft with deployable hinged appendages is presented here both analytically and numerically. The system model consists of a central rigid satellite moving about the earth in a circular orbit at a uniform orbital rate. Attached to the satellite are two unfolding rigid booms with specified mass and length. Tip masses are included at the ends of each boom and deployment is driven by torsional springs at both frictionless hinge points. The equations of motion are developed for both a single- and double-appendage model through the use of Lagrange's equations. The formulation accounts for …

Second Annual Great Oklahoma Balloon Race & Airshow Gala Reception, Clarence E. Page Oklahoma Air And Space Museum

Programs

This is the program from the second annual Great Oklahoma Balloon Race & Airshow Gala Reception in honor of Astronaut, Lt. General Thomas P. Stafford. The event was held at the Clarence E. Page Oklahoma Aviation and Space Hall of Fame and Museum in the Kirkpatrick Center in OKC, OK, on Thursday, August 16th, 1984.

Unless stated otherwise within this repository collection, all materials are shared under the following Creative Commons license: [Creative Commons Attribution-NonCommercial 4.0 International License].

Modal Control Of An Unstable Periodic Orbit, William Wiesel, William Shelton

Faculty Publications

We apply Floquet theory to the problem of designing a control system for a satellite in an unstable periodic orbit. Expansion about a periodic orbit produces a time periodic linear system, which is augmented by a time periodic control term. We show that this can be done such that a) the application of control produces only inertial accelerations, b) positive real Poincare exponents are shifted into the left half-plane, and c) the shift of the exponent is linear with control gain. We apply these developments to an unstable orbit near the Earth-Moon L₃ point perturbed by the Sun. Finally, …

Apollo/Soyuz Tv Guide: "Soyuz, Soyuz, This Is Apollo...", Bob Button

Articles

This is a TV Guide from 1975 that features a story about the televised Apollo/Soyuz mission.

Astronaut Activity Involving Pete Conrad, Elliot See, Thomas Stafford And Ed White, Nasa

Videos

Astronaut Activity Involving Pete Conrad, Elliot See, Thomas Stafford and Ed White

• This item documents the time period of July 8, 1963–July 12, 1963.