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Full-Text Articles in Astrodynamics
Analysis Of Suborbital Launch Trajectories For Satellite Delivery, Mark R. Goodell
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 …
Propulsive Capability Of A Reel-In Tether With Safe Separation Between Payload And Orbiter, Jay H. Rothhaupt
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 …
Navigation Of A Satellite Cluster With Realistic Dynamics, J. Timothy Middendorf
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 …
Perturbation Theory For Restricted Three-Body Orbits, David A. Ross
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 …