43 research outputs found
Tracking Data Certification for the Lunar Reconnaissance Orbiter
This paper details the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF) tracking data certification effort of the Lunar Reconnaissance Orbiter (LRO) Space Communications Network (SCN) complement of tracking stations consisting of the NASA White Sands 1 antenna (WS1), and the commercial provider Universal Space Network (USN) antennas at South Point, Hawaii; Dongara Australia; Weilheim, Germany; and Kiruna, Sweden. Certification assessment required the cooperation and coordination of parties not under the control of either the LRO project or ground stations as uplinks on cooperating spacecraft were necessary. The LRO range-tracking requirement of 10m 1 sigma could be satisfactorily demonstrated using any typical spacecraft capable of range tracking. Though typical Low Earth Orbiting (LEO) or Geosynchronous Earth Orbiting (GEO) spacecraft may be adequate for range certification, their measurement dynamics and noise would be unacceptable for proper Doppler certification of 1-3mm/sec 1 sigma. As LRO will orbit the Moon, it was imperative that a suitable target spacecraft be utilized which can closely mimic the expected lunar orbital Doppler dynamics of +/-1.6km/sec and +/-1.5m/sq sec to +/-0.15m/sq sec, is in view of the ground stations, supports coherent S-Band Doppler tracking measurements, and can be modeled by the FDF. In order to meet the LRO metric tracking data specifications, the SCN ground stations employed previously uncertified numerically controlled tracking receivers. Initial certification testing revealed certain characteristics of the units that required resolution before being granted certification
Large Area Crop Inventory Experiment (LACIE). Level 3 Baseline; LACIE Project Documentation Plan
There are no author-identified significant results in this report
Proceedings of the Large Deployable Reflector Science and Technology Workshop. Volume 1: Executive Summary
A large ambient temperature, for infrared submillimeter telescope in space was discussed. The results of the scientific and technical activities were summarized. The scientific effort consisted of reviewing the science rationale for the Large Deployable Reflector (LDR) and arriving at a concensus set of scientific requirements. The telescope requirements were then compared to the current and anticipated state of the various technologies involved, and the technological shortfalls identified
MEMBANGUN JARINGAN KOMPUTER NIRKABEL DENGAN PENGOPERASIAN SISTEM OPERASI UNIX DENGAN IMPLEMENTASI IPV6 PADA FREEBSD
Wireless network is a quite new technology in computer network world. It can connect computers without any wireless, but it use radio frequency at 2.4 GHz. For computer network still use wire to connected computers. Wireless is use the air medium, so there is different medium between wire and air. To connect these two medium networks we need other hardware. The hardware is called access point, but there is other problem comes. Access point price is quite expensive, so to handle this problem people were tried to look for another alternative. The alternative is use a personal computer with FreeBSD operating system. Operating system UNIX FreeBSD is a computer software that manage and control the operation of computer system based on UNIX. Free is defined as free software, or can be used as desired by users. While the BSD (Barkeley Software Distribution) is a development of the UNIX source code that to create as operating system portable, multi-tasking, multi-user, hierarkis system and utility. As utility Unix C-Shell, VI, TCP/IP and memory virtual, to created for build a stable FreeBSD. In its development, UNIX FreeBSD also effectthe development of UNIX systems that exist. As basic utilities Unix C-Shell, VI, TCP/IP and virtual memory, example httpd-2.0, thttpd, exim, courier-imap, was created to be able to adjust to the BSD features. FreeBSD operating system support dual stack (IPv4 and IPv6). IPv6 stack is installed by default on FreeBSD operating system. Besides the basic application FreeBSD also supports IPv6 which can be installed trough port mechanisme. FreeBSD is believed to be operating system for serves that handle high loads. At the time, recorded some of the worlds busiest internet sites such as yahoo.com, hotmail.com, ftp.cdrom.com for use. But it can't simulate access point perfectly because access point is hardware. It doesn't matter that can't simulate perfectly because not all feature that access point have are use. Keyword: Operating System Unix FreeBSD, wireless LAN, computer networ
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Analytical and Experimental Study of The Effects of Non-Condensable in a Passive Condenser System for The Advanced Boiling Water Reactor
The main goal of the project is to study analytically and experimentally condensation heat transfer for the passive condenser system relevant to the safety of next generation nuclear reactor such as Simplified Boiling Water Reactor (BWR). The objectives of this three-year research project are to: (1) obtain experimental data on the phenomenon of condensation of steam in a vertical tube in the presence of non-condensable for flow conditions of PCCS, (2) develop a analytic model for the condensation phenomena in the presence of non-condensable gas for the vertical tube, and (3) assess the RELAP5 computer code against the experimental data. The project involves experiment, theoretical modeling and a thermal-hydraulic code assessment. It involves graduate and undergraduate students' participation providing them with exposure and training in advanced reactor concepts and safety system
Large Area Crop Inventory Experiment (LACIE). Level 3 baseline; research requirements, volume 8
There are no author-identified significant results in this report
The High Energy Telescope for STEREO
The IMPACT investigation for the STEREO Mission includes a complement of Solar Energetic Particle instruments on each of the two STEREO spacecraft. Of these instruments, the High Energy Telescopes (HETs) provide the highest energy measurements. This paper describes the HETs in detail, including the scientific objectives, the sensors, the overall mechanical and electrical design, and the on-board software. The HETs are designed to measure the abundances and energy spectra of electrons, protons, He, and heavier nuclei up to Fe in interplanetary space. For protons and He that stop in the HET, the kinetic energy range corresponds to ∼13 to 40 MeV/n. Protons that do not stop in the telescope (referred to as penetrating protons) are measured up to ∼100 MeV/n, as are penetrating He. For stopping He, the individual isotopes 3He and 4He can be distinguished. Stopping electrons are measured in the energy range ∼0.7–6 MeV
Analytical and Experimental Study of The Effects of Non-Condensable in a Passive Condenser System for The Advanced Boiling Water Reactor
The High Energy Telescope for STEREO
The IMPACT investigation for the STEREO Mission includes a complement of Solar Energetic Particle instruments on each of the two STEREO spacecraft. Of these instruments, the High Energy Telescopes (HETs) provide the highest energy measurements. This paper describes the HETs in detail, including the scientific objectives, the sensors, the overall mechanical and electrical design, and the on-board software. The HETs are designed to measure the abundances and energy spectra of electrons, protons, He, and heavier nuclei up to Fe in interplanetary space. For protons and He that stop in the HET, the kinetic energy range corresponds to approx. 13 to 40 MeV/n. Protons that do not stop in the telescope (referred to as penetrating protons) are measured up to approx. 100 MeV/n, as are penetrating He. For stopping He, the individual isotopes He-3 and He-4 can be distinguished. Stopping electrons are measured in the energy range approx. 0.7 - 6 MeV