• The ACE mission is operating nominally (however, without the SEPICA instrument) in 2013 at L1 for over 15 years. The first two detectors, M1 and M2, are position-sensitive ”matrix” devices (Figure 17) that form the hodoscope measuring the trajectory and energy loss of incident nuclei. Nominal life of the mission is 2 years with a five-year goal. The ACE RTSW network uses a beacon to deliver an operationally useful subset of its space physics data to various ground stations around the world in real-time. I sent out a command file from a radio dish on the other side of the world (we were talking to Cassini via the 70-meter dish at Canberra, Australia), it traveled through space at the speed of light toward Cassini, registered onboard and radiated back down. Objective: measurement of the three components of the magnetic field. ULEIS (Ultra-low Energy Isotope Spectrometer): PI: G. Mason, U. of Maryland, R. Gold, JHU/APL. 409-448, URL: http://sd-www.jhuapl.edu/ACE/ULEIS/UMd/docs/instrument/Space_Sci_Rev_1998_Mason.pdf, 21) http://www-ssg.sr.unh.edu/tof/Missions/Ace/index.html?sepicamain.html, 22) E. Möbius, L. M. Kistler, M. A. Popecki, K. N. Crocker1 M. Granoff, S. Turco, A. Anderson, P. Demain, J. Distelbrink, I. Dors, P. Dunphy, S. Ellis, J. Gaidos, J. Googins, R. Hayes, G. Humphrey, H. Kästle, J. Lavasseur, E. J. Lund, R. Miller, et al., “The Solar Energetic Particle Ionic Charge Analyzer (SEPICA) and the Data Processing Unit (S3DPU) for SWICS, SWIMS and SEPICA,” Space Science Reviews, Vol. Although warmer than predicted, temperatures of the spacecraft sunward top deck and thermal blankets are within specifications. It is also of interest to extend the SEP measurements to as high an energy as possible to understand the acceleration process in these events. RF communications with ACE are in S-band (2097.9806 MHz for the uplink and 2278.35 MHz for the downlink.). The deflection, which is inversely proportional to energy per charge, E/Q, is determined in the back portion of the instrument (dE/dX device and a position-sensitive silicon solid-state detector). 1) 2). Data of SEPICA is only available until Feb. 4, 2005 when further problems arose resulting in a de facto retirement of the instrument. Science and engineering data are collected during one 3-4 hour pass per day. Ace simply means ace, as in a person who excels at their job or the highest value playing card in the deck. Reiche, E. Sartori, J. Schimpfle, E. Seidenschwang, M. Shappirio, K. Stöckner, S. C. Taylor, P. Vachon, M. Vosbury, W. Wiewesiek, V. Ye, “The Solar Energetic Particle Ionic Charge Analyzer (SEPICA) and the Data Processing Unit (S3DPU) for SWICS, SWIMS and SEPICA,” URL: http://www-ssg.sr.unh.edu/tof/Papers/SEPICA/SEPICA_LONG.pdf, 24) http://www.srl.caltech.edu/ACE/CRIS_SIS/cris.html, 25) E. C. Stone, C. M. S. Cohen,W. Shown is a single side of one SEPICA fan. Energetic particles enter a multi-slit collimator, which selects those incoming particles that target a narrow line in the detector plane (indicated by F, the ”focal line”). The fully assembled CRIS instrument consists of two boxes bolted together (Figure 18). When the autonomy system is running, it scans the rules at a regular interval, evaluating each rule in turn and executing any that evaluate to “true.”. “The Ace is in the middle of everything.”, Director, NASA Planetary Science Division: There are two identical telescopes in SIS, each composed of 17 high-purity silicon detectors (Figure 16).
29, No 3, 2010, pp. The EPAM detectors consist of three silicon solid-state detector systems: 1) LEMS (Low Energy Magnetic Spectrometers); 2) LEFS (Low Energy Foil Spectrometers); and 3) CA (Composition Aperture). The subsystem is a hydrazine blowdown unit that uses nitrogen gas as the pressurant and is made up of four fuel tanks, four axial thrusters for velocity control along the spin axis, and six radial thrusters for spin plane velocity control and spin rate control. View all Images Image Details Spacecraft: Advanced Composition Explorer (ACE) Views: 2,418 Full-Res TIFF: 2. The sequence of commands could also include pauses in the sequence to provide relative timing of commands. SWEPAM (Solar Wind Electron, Proton, and Alpha Monitor): PI: D. McComas, LANL. Measurements by a technique considering a particle's energy loss ΔE in a detector ( multiple ΔE versus residual energy E). Electronics (redundant): 2100 g. total, 2.4 watts, electronics: regulated 28 V ± 2% On January 21, 1998, NOAA/SEC (Space Environment Center) at Boulder, CO, and the ACE project opened up the ACE Real Time Solar Wind (RTSW) monitoring capability to the public. SWEPAM is of SWOOPS heritage flown on the Ulysses spacecraft. The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: ”Observation of the Earth and Its Environment: Survey of Missions and Sensors” (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. 14). Legend to Figure 6: Top — Solar wind dynamic pressure in the ecliptic plane at ~1 AU, taken from IMP-8, Wind, and ACE and inter-calibrated through OMNI-2. The Ace is also first person to respond when a problem pops up.
“This is real time, where the rubber hits the road,” said David Doody, a space flight operations engineer on Cassini. 24). McClure said there are times when someone tries to make Ace into an acronym, such as Assistant Chief Engineer. Objective: measurement of elemental and isotopic composition of solar energetic particles, anomalous cosmic rays, and interplanetary particles from He to Zn over the energy range from 10 - 100 MeV/nucleon.
NASA space scientists and engineers speak in an often bewildering shorthand slang of acronyms to describe complicated jobs, procedures and machines. Phillips Davis SWICS (Solar Wind Ion Composition Spectrometer): PI: G. Gloeckler, U. of Maryland. SEPICA consists of three independent sensor units, called ”fans”. Each of the three fans is symmetric about the plane with the high voltage deflection plate. Each of the strips on M1 and M2 is individually pulse-height analyzed with its own 12 bit ADC (Analog Digital Converter) when an event occurs so that the trajectory of heavy ions traversing the system can be separated from the tracks of low energy H or He that might happen to hit one of these detectors at the same time. 257-284, URL: http://www.srl.caltech.edu/ACE/ASC/DATA/pdf_docs/ACE_Spacecraft_SSR.pdf, 5) S. B. Jacob, E. R. Christian, D. L. Margolies, R. A. Mewaldt, J. F. Ormes, P. A. Tyler, Tycho von Rosenvinge, T. B. Griswold, “Advanced Composition Explorer (ACE),” NASA brochure, 2nd edition, 2002, URL: http://helios.gsfc.nasa.gov/ACEbrochure-2nd-ed_final.pdf, 6) George J. Cancro, “APL Spacecraft Autonomy: Then, Now, and Tomorrow,” John Hopkins APL Technical Digest, Vol. The Cassini Ace monitored seven computer screens reporting on spacecraft systems and science data and keeps various mission teams informed about the spacecraft's status.