A Brief Sketch of Pemaquid

Contents: Plan of Fort William Henry / by Col. Romer -- A brief sketch of Pemaquid / by H.O. McGrillis and J.H. Cartland -- Ancient pavings of Pemaquid / by J.H. Cartlan

The Feasibility of Launching Small Satellites with a Light Gas Gun

This paper summarizes a study conducted for the Defense Advanced Research Projects Agency of the technical and economic feasibility of using a light gas gun to launch small satellites. The launcher concept is based upon a distributed-injection gun, which, in principle, can produce high muzzle velocities at relatively low acceleration levels. To establish initial system requirements for the launcher and spacecraft, the deployment of a large constellation of telecommunications satellites is chosen as a reference mission. This choice reflects the dominance of telecommunications in current commercial LEO market projections, but the results obtained for this mission are later generalized to encompass other applications. The spacecraft mass budget is most affected by large mass fraction allocations for structure and power subsystems. High acceleration loads are responsible for the increase in structural mass, and the increase in battery mass is tied to volume limitations that restrict the battery technology that can be used. The results of the financial analysis suggest that achieving a competitive specific launch cost requires a launch rate beyond current market projections. But a low-volume launch business could provide an attractive total mission cost relative to current systems

The SHARP scramjet launcher

The worlds largest light gas gun at SHARP (Super High Altitude Research Project) is completed and in the past year has launched 9 scramjets. Typical masses and velocities are 5.9 kg at 2.8 km/sec.and 4.4 kg at 3.1 km/sec. In so doing SHARP launched the first fully functioning, hydrogen burning scramjet at mach 8. The SHARP launcher is unique in having a 4 inch diameter and 155 foot-long barrel. This enables lower acceleration launches than any other system. In addition the facility can deliver high energy projectiles to targets in the open air without having to contain the impact fragments. This allows one to track lethality test debris for several thousand feet

Incentives in a Medicaid Carve-Out: Impact on Children with Special Health Care Needs

OBJECTIVE: To evaluate whether a specialty care payment “carve-out” from Medicaid managed care affects caseloads and expenditures for children with chronic conditions. DATA SOURCE: Paid Medicaid claims in California with service dates between 1994 and 1997 that were authorized by the Title V Children with Special Health Needs program for children under age 21. STUDY DESIGN: A natural experiment design evaluated the impact of California's Medicaid managed care expansion during the 1990s, which preserved fee-for-service payment for certain complex medical diagnoses. Outcomes in time series regression include Title V program participation and expenditures. Multiple comparison groups include children in managed care counties who were not mandated to enroll, and children in nonmanaged care counties. DATA COLLECTION/EXTRACTION METHODS: Data on the study population were obtained from the state health department claims files and from administrative files on enrollment and managed care participation. PRINCIPAL FINDINGS: The carve-out policy increased the number of children receiving Title V-authorized services. Recipients and expenditures for some ambulatory services increased, although overall expenditures (driven by inpatient services) did not increase significantly. Cost intensity per Title V recipient generally declined. CONCLUSIONS: The carve-out policy increased identification of children with special health care needs. The policy may have improved children's access to prevailing standards of care by motivating health plans and providers to identify and refer children to an important national program