Optimized trajectories to the nearest stars using lightweight high-velocity photon sails

New means of interstellar travel are now being considered by various research teams, assuming lightweight spaceships to be accelerated via either laser or solar radiation to a significant fraction of the speed of light (c). We recently showed that gravitational assists can be combined with the stellar photon pressure to decelerate an incoming lightsail from Earth and fling it around a star or bring it to rest. Here, we demonstrate that photogravitational assists are more effective when the star is used as a bumper (i.e. the sail passes "in front of" the star) rather than as a catapult (i.e. the sail passes "behind" or "around" the star). This increases the maximum deceleration at $\alpha$ Cen A and B and reduces the travel time of a nominal graphene-class sail (mass-to-surface ratio 8.6e-4 gram m$^{-2}$) from 95 to 75 yr. The maximum possible velocity reduction upon arrival depends on the required deflection angle from $\alpha$ Cen A to B and therefore on the binary's orbital phase. Here, we calculate the variation of the minimum travel times from Earth into a bound orbit around Proxima for the next 300 yr and then extend our calculations to roughly 22,000 stars within about 300 ly. Although $\alpha$ Cen is the most nearby star system, we find that Sirius A offers the shortest possible travel times into a bound orbit: 69 yr assuming 12.5% c can be obtained at departure from the solar system. Sirius A thus offers the opportunity of flyby exploration plus deceleration into a bound orbit of the companion white dwarf after relatively short times of interstellar travel.Comment: 14 pages, 7 figures (5 col, 2 b/w), 2 table

Thermal and Mechanical Design and Simulation for the first high precision Quantum Optics Experiment on a Sounding Rocket

The MAIUS-1 payload is a high precision quantum optics experiment about to fly on a VSB-30 sounding rocket with the scientific objective to demonstrate the feasibility of creating the first Bose-Einstein condensates and performing atom interferometry in Space. To achieve these goals the experiment is using various sensitive instruments imposing strong requirements on the thermal and mechanical design. In the introduction this thesis gives a short overview and characterization of available microgravity platforms in Europe. Moreover a detailed characterization of the environment aboard the VSB-30 sounding rocket is presented based on flight data from former MASER and TEXUS missions. In the main chapters the mechanical and thermal design of the MAIUS-1 scientific payload is described in detail. This includes various technical solutions as for example a low-cost vibration isolation, a sealing for RADAX hull segments of pressurized payloads or umbilicals to provide water cooling until lift-off. In addition the test methods and results for the different payload components is presented. The design and test of the ultra-high vacuum system with a nominal pressure of 1E-10 hPa is described in a dedicated chapter. This includes theoretical background on outgassing of technical surfaces and calculation of the conductance of a vacuum system. Different pumping and sealing techniques are introduced. Furthermore the results of intensive testing of Conflat (CF) and Indium sealings under vibrational and static loads are presented as well as test results for the entire pumping system. The thermal control system of the MAIUS-1 scientific payload has been designed using multiple MATLAB codes in combination with ANSYS to estimate the heat flux into the rocket hull by aerodynamic heating during ascent as well as the heat transfer from the heated rocket hull to the system housing walls by natural convection. These codes and their theoretical background are presented herein as well. The thesis closes with recommendations and possible improvements for future space-born quantum optics experiments

Nonterrestrial utilization of materials: Automated space manufacturing facility

Four areas related to the nonterrestrial use of materials are included: (1) material resources needed for feedstock in an orbital manufacturing facility, (2) required initial components of a nonterrestrial manufacturing facility, (3) growth and productive capability of such a facility, and (4) automation and robotics requirements of the facility

Space Resources and Space Settlements

The technical papers from the five tasks groups that took part in the 1977 Ames Summer Study on Space Settlements and Industrialization Using Nonterrestrial Materials are presented. The papers are presented under the following general topics: (1) research needs for regenerative life-support systems; (2) habitat design; (3) dynamics and design of electromagnetic mass drivers; (4) asteroids as resources for space manufacturing; and (5) processing of nonterrestrial materials

Utilization of lunar materials and expertise for large scale operations in space: Abstracts

The practicality of exploiting the moon, not only as a source of materials for large habitable structures at Lagrangian points, but also as a base for colonization is discussed in abstracts of papers presented at a special session on lunar utilization. Questions and answers which followed each presentation are included after the appropriate abstract. Author and subject indexes are provided

Aeronautical engineering: A special bibliography with indexes, supplement 80

This bibliography lists 277 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1977

Proceedings of the 8th Annual Summer Conference: NASA/USRA Advanced Design Program

Papers presented at the 8th Annual Summer Conference are categorized as Space Projects and Aeronautics projects. Topics covered include: Systematic Propulsion Optimization Tools (SPOT), Assured Crew Return Vehicle Post Landing Configuration Design and Test, Autonomous Support for Microorganism Research in Space, Bioregenerative System Components for Microgravity, The Extended Mission Rover (EMR), Planetary Surface Exploration MESUR/Autonomous Lunar Rover, Automation of Closed Environments in Space for Human Comfort and Safety, Walking Robot Design, Extraterrestrial Surface Propulsion Systems, The Design of Four Hypersonic Reconnaissance Aircraft, Design of a Refueling Tanker Delivering Liquid Hydrogen, The Design of a Long-Range Megatransport Aircraft, and Solar Powered Multipurpose Remotely Powered Aircraft

Utilization of lunar materials

Attention is given to lunar core studies, surface soil studies, and surfaces process studies. Also considered are mare basalts, with emphasis on mineralogy and petrology, chemical and isotopic studies, and constraints and models of basalt evolution, along with breccia and highland samples with attention given to geochronology, boulders and consortium studies and the formation of highland samples. Remote sensing and photogeology of the moon, crustal bombardment, physical properties of the moon, and comparative planetology are also discussed.Sponsored by NASA through the Lunar Science Institute and the Johnson Space CenterSpecial Session organized and abstracts edited by David R. CriswellPAERTIAL CONTENTS: Metallic iron as a potential fuel for production of heat on the lunar surface / C. B. Sclar and J. F. Bauer--Effects on the lunar atmosphere resulting from large-scale manned operations / R. R. Vondrak and J. W. Freeman--Solar-cosmic-ray variability / R. C. Reedy--Large-scale processing of lunar materials / K. A. Ehricke--Geotechnical engineering on the moon / W. D. Carrier and J. K. Mitchell--Formation of water and methane, catalyzed by lunar dust / A. L. Cabrera, M. B. Maple, S. K. Asunmaa and G. Arrhenius--Portable lunar surface shelters of liquid metal-textile composites / A. J. Bauman and F-D. Tsay--Chemical engineering on the moon / R. H. Condit--Design of equipment for vapor phase processing of metals / K. E. Drexler--Processing lunar soil for structural materials / P. Grodzka--A way to compare costs of building rotating structures in space / C. H. Holbrow--Powder metallurgical components from lunar metal / A. D. Romig, Jr. and J. I. Goldstein--The moon base power satellite: a preliminary analysis – / B. R. Sperber

Aeronautical engineering: A continuing bibliography, supplement 122

This bibliography lists 303 reports, articles, and other documents introduced into the NASA scientific and technical information system in April 1980