Aeroelastic Optimization of Sounding Rocket Fins

This research effort develops a multidisciplinary design tool to optimize sounding rocket fin geometries that minimize the mass of the fins while maintaining aerodynamic performance. This research grew out of a design problem experienced by the US Air Force Academy\u27s Falcon LAUNCH program. The Falcon LAUNCH program is a senior design capstone project during which Air Force Academy cadets design, build and fly a sounding rocket over the course of an academic year. In the Spring of 2007, the Falcon LAUNCH V vehicle experienced a catastrophic failure when three of its four fins sheared off due to flutter. When the following year\u27s team developed the fins for Falcon LAUNCH VI, the design requirement that the fins not experience flutter led to substantially more massive fins. The Falcon LAUNCH team needs a design tool that can balance the competing needs for minimal mass sounding rocket components and aerodynamic performance. The tool developed during this research is designed to find an optimal solution for the fin geometry based on the competing needs of minimizing the fins\u27 mass and ensuring the fins will not experience flutter. The design tool then provides for verification of the design throughout the designed flight profile

Aerospike Rockets for Increased Space Launch Capability

The US Department of Defense DOD increasingly depends on space assets for everyday operations. Precision navigation communications and intelligence, surveillance, and reconnaissance satellites are highly leveraged space assets. The launch vehicles that place these satellites in orbit are a major limitation of current space systems. If higher-performing launch vehicles were available, many satellites could accommodate additional capabilities, whether in terms of more sensor channels, types of payloads, electrical power, or propellant for orbital maneuvering and station keeping. Space assets are typically designed to conform to a particular launch vehicle s limitations e.g., engineers might design a satellite to be carried by a Delta IV-2 medium launch vehicle. Essentially, this choice of vehicle fixes the maximum mass of the satellite and, thus, its capabilities. If a launcher capable of placing more mass in the desired orbit were available at similar cost, the satellite s design could allow for additional capability. Furthermore, some payloads are too heavy for present-day launch vehicles to place into a particular orbit. A better-performing launcher would enable us to put those payloads into the desired orbits, permitting new missions and capabilities

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Exchanging Disks in the Tower of Hanoi

We examine a variation of the famous Tower of Hanoi puzzle posed but not solved in a 1944 paper by Scorer et al. [5]. In this variation, disks of adjacent sizes can be exchanged, provided that they are at the top of their respective stacks. We present an algorithm for solving this variation, analyze its performance, and prove that it is optimal. Several exercises are listed at the end, ranging in difficulty from elementary to research level. 1 Introduction The Tower of Hanoi puzzle, invented in 1883 by ' Edouard Lucas and described by him in [4, pp. 55--59], has been undergoing a dramatic revival in popularity during the past 10 years, largely due to its use as a programming exercise in elementary computer courses. Many variations on the original puzzle also have been proposed and solved. For an excellent survey, with an extensive bibliography, see [3]. One variation posed in 1944 [5], however, appears not to have been studied. In this paper we present an algorithm for solving this va..

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4 m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5 m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 yr, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit

Search for New Particles in Two-Jet Final States in 7 TeV Proton-Proton Collisions with the ATLAS Detector at the LHC

A search for new heavy particles manifested as resonances in two-jet final states is presented. The data were produced in 7 TeV proton-proton collisions by the LHC and correspond to an integrated luminosity of 315 nb(-1) collected by the ATLAS detector. No resonances were observed. Upper limits were set on the product of cross section and signal acceptance for excited-quark (q*) production as a function of q* mass. These exclude at the 95% C. L. the q* mass interval 0: 30< m(q)*< 1:26 TeV, extending the reach of previous experiments