Rehabilitation of the South Jetty, Ocean City, Maryland (open access)

Rehabilitation of the South Jetty, Ocean City, Maryland

Partial abstract: Frequent dredging requirements and scouring at the foundation of Ocean City Inlet's south jetty resulted in a study to determine the source of the shoaling and scouring. The study concluded that sand was being transported northward along Assateague Island, through and over the south jetty, and deposited inside the inlet. The sand was then transported north by ebb currents where it encroached on the Federal navigation channel. A rehabilitation program was initiated to create a littoral barrier to eliminate the shoaling problem and to repair the scour hold. Three headland breakwaters were constructed to stabilize Northern Assateague Island. The site was selected as part of the Monitoring Completed Coastal Projects (MCCP) Program to determine how well the rehabilitation project accomplished its design purpose.
Date: March 1994
Creator: Bass, Gregory P.; Fulford, Edward T.; Underwood, Steven G. & Parson, Larry E.
System: The UNT Digital Library
Aerodynamic, structural, and trajectory analysis of ASTRID-1 vehicle (open access)

Aerodynamic, structural, and trajectory analysis of ASTRID-1 vehicle

The Johns Hopkins University/Applied Physics Laboratory, JHU/API, in support of Lawrence Livermore National Laboratory, LLNL, is conducting aerodynamic, trajectory, and structural analysis of the Advanced Single Stage Technology Rapid Insertion Demonstration (ASTRID) vehicle, being launched out of Vandenberg Air Force Base (VAFB) in February 1994. The launch is designated ASTRID-1 and is the first in a series of three that will be launched out of VAFB. Launch dates for the next two flights have not been identified, but they are scheduled for the 1994-1995 time frame. The primary goal of the ASTRID-1 flight is to test the LLNL light weight thrust on demand bi-propellant pumped divert propulsion system. The system is employed as the main thrusters for the ASTRID-1 vehicle and uses hydrazine as the mono-propellant. The major conclusions are: (1) The vehicle is very stable throughout flight (stability margin = 17 to 24 inches); (2) The aerodynamic frequency and the roll rate are such that pitch-roll interactions will be small; (3) The high stability margin combined with the high launcher elevation angle makes the vehicle flight path highly sensitive to perturbations during the initial phase of flight, i.e., during the first second of flight after leaving the rail; (4) …
Date: February 10, 1994
Creator: Glover, L. S.; Iwaskiw, A. P.; Oursler, M. A.; Perini, L. L. & Schaefer, E. D.
System: The UNT Digital Library