SMART-1: Difference between revisions
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The Smart-1 Infrared Spectrometer was an [[Infrared spectroscopy|infrared spectrometer]] for the identification of mineral spectra of [[olivine]] and [[pyroxene]]. It detected wave lengths from 0.93 to 2.4 µm with 256 channels. The package weighed 2.3 kg and had a power consumption of 4.1 Watt.<ref>{{cite journal| title= Scientific objectives and selection of targets for the SMART-1 Infrared Spectrometer (SIR)|author= Basilevsky A. T., Keller H. U., Nathues A., Mall J., Hiesinger H., Rosiek M.|journal= Planetary and Space Science|volume= 52|pages= 1261-1285|year= 2004 }}</ref> |
The Smart-1 Infrared Spectrometer was an [[Infrared spectroscopy|infrared spectrometer]] for the identification of mineral spectra of [[olivine]] and [[pyroxene]]. It detected wave lengths from 0.93 to 2.4 µm with 256 channels. The package weighed 2.3 kg and had a power consumption of 4.1 Watt.<ref>{{cite journal| title= Scientific objectives and selection of targets for the SMART-1 Infrared Spectrometer (SIR)|author= Basilevsky A. T., Keller H. U., Nathues A., Mall J., Hiesinger H., Rosiek M.|journal= Planetary and Space Science|volume= 52|pages= 1261-1285|year= 2004|doi=10.1016/j.pss.2004.09.002 }}</ref> |
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===EPDP=== |
===EPDP=== |
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Revision as of 12:21, 20 October 2006
Template:Infobox Spacecraft SMART-1 was a Swedish-designed European Space Agency satellite that orbited around the Moon. It was launched on 27 September, 2003 at 23:14 UTC from the Guiana Space Centre in Kourou, French Guiana. "SMART" stands for Small Missions for Advanced Research in Technology. On September 3, 2006 (05:42 UTC), SMART-1 was deliberately crashed into the Moon's surface, ending its mission.[1]
Spacecraft design
SMART-1 was about one metre (approximately 3 feet) across, and lightweight in comparison to other probes. Its launch mass was 367 kg or 809 pounds, of which 287 kg (633 lb) was non-propellant.
It was propelled by a solar-powered Hall effect thruster (SNECMA PPS-1350-G ) using xenon propellant, of which there was 82 kg (50 litres by volume at a pressure of 150 bar) at launch. The thrusters used an electrostatic field to ionize the xenon and accelerate the ions to a high speed. This ion engine setup achieved a specific impulse of 16.1 kN·s/kg (1640 seconds), more than three times the maximum for chemical rockets. Therefore 1 kg of propellant (1/350 to 1/300 of the total mass of the spacecraft) produced a delta-v of about 45 m/s. The thruster had a weight of 29 kg with a peak power consumption of 1200 watts.[2]
The solar arrays made 1190 W available for powering the thruster, giving a nominal thrust of 68 mN, hence an acceleration of 0.2 mm/s² or 0.7 m/s per hour (i.e., just under 0.00002 g of acceleration). As for all ion-engine powered craft, orbital maneuvers were not carried out in short bursts but very gradually. The particular trajectory taken by SMART-1 to the Moon required thrusting for about one third to one half of every orbit. When spiralling away from the Earth thrusting was done on the perigee part of the orbit. The total delta-v expected over the thrusting lifetime of 5,000 hours is about 4 km/s, corresponding to a total impulse of 1.5 MN·s.
As part of the European Space Agency's strategy to build very inexpensive and relatively small spaceships, the total cost of SMART-1 was a relatively small 110 million euros (about 126 million U.S. dollars).
SMART-1 was developed by the Swedish Space Corporation[3] and built by Saab Ericsson Space in Linköping[4] on behalf of ESA.
Mission
As a part of Small Missions for Advanced Research in Technology, SMART-1 tested new spacecraft technologies. The primary objective of SMART-1 was to test the solar-powered ion thruster. A secondary objective was to gather more information about the Moon, such as how it was created. SMART-1 mapped the lunar surface by way of X-ray and infrared imaging, taking images from several different angles so that the Moon's surface can be mapped in three dimensions. It also determined the Moon's chemical composition using X-ray spectroscopy. A specific goal was to use infrared light to search for frozen water at the Moon's south pole, where some areas of the surface are never exposed to direct sunlight. SMART-1 also mapped the Moon's Peaks of Eternal Light (PELs), mountaintops which are permanently bathed in sunlight and surrounded by craters shaded in eternal darkness. SMART-1 also tested the use of miniaturized scientific instruments, which are considered more efficient.
SMART-1 ended its mission by being deliberately crashed onto the Moon's surface. Scientists hope that the impact will have kicked up a large enough quantity of fresh lunar "soil" so that they may study its composition.
Instruments
AMIE
The Advanced Moon micro-Imager Experiment was a miniature colour camera for lunar imaging. The CCD camera with three filters of 750, 900 and 950 nm was able to take images with an average pixel resolution of 80 m (about 260 ft). The camera weighed 2.1 kg (about 4.5 lb) and had a power consumption of 9 watts. [5]
D-CIXS
The Demonstration of a Compact X-ray Spectrometer was an X-ray telescope for the identification of chemical elements on the lunar surface. It detected the x-ray fluorescence (XRF) of crystal compounds created through the interaction of the electron shell with the solar wind particles to measure the abundance of the three main components: magnesium, silicon and aluminium. The detection of iron, calcium and titanium depended on the solar activity. The detection range for x-rays was 0.5 to 10 keV. The spectrometer and XSM (described below) together weighed 5.2 kg and had a power consumption of 18 watts.
XSM
The X-ray solar monitor studied the solar variability to complement D-CIXS measurements.
SIR
The Smart-1 Infrared Spectrometer was an infrared spectrometer for the identification of mineral spectra of olivine and pyroxene. It detected wave lengths from 0.93 to 2.4 µm with 256 channels. The package weighed 2.3 kg and had a power consumption of 4.1 Watt.[6]
EPDP
The Electric Propulsion Diagnostic Package was to acquire data on the new propulsion system on SMART-1. The package weighed 0.8 kg and had a power consumption of 1.8 watts.[7]
SPEDE
The Space Potential Electron and Dust Experiment. The experiment weighed 0.8 kg and had a power consumption of 1.8 watts. Its name was intentionally chosen so that its acronym is the same as the first name of Spede Pasanen, famous Finnish movie actor, movie producer, inventor etc.
KATE
Ka band TT&C (telemetry, tracking and control) Experiment. The experiment weighed 6.2 kg and had a power consumption of 26 watts.
Flight
SMART-1 was launched September 27, 2003 together with Insat 3E and eBird 1, by an Ariane 5 rocket from the Guiana Space Center in French Guiana. After 42 minutes it was released into a geostationary transfer orbit of 7035 × 42 223 km. From there it used its Solar Electric Primary Propulsion (SEPP) to gradually spiral out during thirteen months.
The orbit can be seen up to October 26, 2004 at moontoday.net, when the orbit was 179 718 × 305 214 km. On that date, after the 289th engine pulse, the SEPP had accumulated a total on-time of nearly 3648 hours out of a total flight time of 8000 hours, hence a little less than half of its total mission. It consumed about 58.8 kg of xenon and produced a delta-v of 2737 m/s (46.5 m/s per kg xenon, 0.75 m/s per hour on-time). It was powered on again on November 15 for a planned burn of 4.5 days to enter fully into lunar orbit. It took until February 2005 using the electric thruster to decelerate into the final orbit 300-3000 km above the Moon's surface.[8]
| Epoch (UTC) | Perigee (km) | Apogee (km) | Eccentricity | Inclination (deg) (to Earth equator) |
Period (h) |
|---|---|---|---|---|---|
| September 27, 2003 | ~7 035 | ~42 223 | ~0.714 | ~6.9 | ~10.6833 |
| October 26, 2003, 21:20:00.0 | 8 687.994 | 44 178.401 | 0.671323 | 6.914596 | 11.880450 |
| November 16, 2003, 04:29:48.4 | 10 843.910 | 46 582.165 | 0.622335 | 6.861354 | 13.450152 |
| December 8, 2003, 06:41:47.6 | 13 390.351 | 49 369.049 | 0.573280 | 6.825455 | 15.366738 |
| December 29, 2003, 05:21:47.8 | 17 235.509 | 54 102.642 | 0.516794 | 6.847919 | 18.622855 |
| February 1, 2004, 22:46:08.6 | 20 690.564 | 65 869.222 | 0.521936 | 6.906311 | 24.890737 |
| March 1, 2004, 00:40:52.7 | 20 683.545 | 66 915.919 | 0.527770 | 6.979793 | 25.340528 |
| August 25, 2004, 00:00:00 | 37 791.261 | 240 824.363 | 0.728721 | 6.939815 | 143.738051 |
| October 1, 2004, 21:30:45.9 | 69 959.278 | 292 632.424 | 0.614115 | 12.477919 | 213.397970 |
| October 26, 2004, 06:12:40.9 | 179 717.894 | 305 214.126 | 0.258791 | 20.591807 | 330.053834 |
After its last perigee on November 2,[9] on November 11, 2004 it passed through the L1 Lagrangian Point and into the area dominated by the Moon's gravitational influence, and at 1748 UT on November 15 passed the first periselene of its lunar orbit. The osculating orbit on that date was 6704 × 53 208 km,[10] with an orbital period of 129 hours, although the actual orbit was accomplished in only 89 hours. This illustrates the significant impact that the engine burns have on the orbit and marks the meaning of the osculating orbit, which is the orbit that would be travelled by the spacecraft if at that instant all perturbations, including thrust, would cease.
| Epoch (UTC) | Periselene (km) | Aposelene (km) | Eccentricity | Inclination (deg) (to Moon equator) |
Period (h) |
|---|---|---|---|---|---|
| November 15, 2004, 17:47:12.1 | 6 700.720 | 53 215.151 | 0.776329 | 81.085 | 129.247777 |
| December 4, 2004 10:37:47.3 | 5 454.925 | 20 713.095 | 0.583085 | 83.035 | 37.304959 |
| January 9, 2005, 15:24:55.0 | 2 751.511 | 6 941.359 | 0.432261 | 87.892 | 8.409861 |
| February 28, 2005, 05:18:39.9 | 2 208.659 | 4 618.220 | 0.352952 | 90.063603 | 4.970998 |
| April 25, 2005, 08:19:05.4 | 2 283.738 | 4 523.111 | 0.328988 | 90.141407 | 4.949137 |
| May 16, 2005, 09:08:52.9 | 2 291.250 | 4 515.857 | 0.326807 | 89.734929 | 4.949919 |
| June 20, 2005, 10:21:37.1 | 2 256.090 | 4 549.196 | 0.336960 | 90.232619 | 4.947432 |
| July 18, 2005, 11:14:28.0 | 2 204.645 | 4 600.376 | 0.352054 | 90.263741 | 4.947143 |
ESA announced on February 15, 2005, the endorsement of a proposal to extend the mission of SMART-1 by one year until August 2006. This date was later shifted to September 3, 2006, to "favour scientific observations from Earth".[11]
Lunar impact
SMART-1 impacted the Moon's surface as planned, on September 3, 2006 at 05:42:22 UTC, ending its mission. Moving at approximately 2,000 m/s (4,500 mph), SMART-1 created an impact visible with ground telescopes from Earth. It is hoped that not only will this provide some data simulating a meteor impact, but also that it might expose materials in the ground, like water ice, to spectroscopic analysis.
ESA estimated that impact occurred at 34°24′S 46°12′W / 34.400°S 46.200°W. [12]These numbers can be entered into NASA's World Wind, to see where on the Moon it crashed. At the time of impact, the Moon was visible in North and South America, and places in the Pacific Ocean, but not Europe, Africa, or western Asia.
This project has generated data and know-how that will be used for other missions, such as the ESA's BepiColombo mission to Mercury.
The Committee on Space Research has established rules to protect planets and moons from possible contamination by spacecraft. In response to concerns of SMART-1 contaminating the Moon, ESA claims that "every chemical element present on SMART-1 and in its instruments exists naturally on the Moon".[13]
Important events and discoveries
- September 27, 2003: SMART-1 launched from the European Spaceport in Kourou by an Ariane 5 launcher.
- June 17, 2004: SMART-1 took a test image of Earth with the camera that would later be used for Moon closeup pictures. It shows parts of Europe and Africa. It was taken on May 21 with the AMIE camera, a compact imaging device with a weight of 450 grams.
- November 2, 2004: Last perigee of Earth orbit.
- November 15, 2004: First perilune of lunar orbit.
- January 15, 2005: Calcium detected in Mare Crisium.
- January 26, 2005: First close up pictures of the lunar surface sent back.
- February 27, 2005: Reached final orbit around the Moon with an orbital period of about 5 hours.
- April 15, 2005: The search for PELs begins.
- June 8, 2005: ESA announces that calcium was detected on the Moon.
- September 3, 2006: Mission ends with a planned crash into the Moon during orbit number 2890. [14]
References
- ^ http://news.bbc.co.uk/1/hi/sci/tech/5309656.stm
- ^ Kugelberg J., Bodin P., Persson S., Rathsman P. (2004). "Accommodating electric propulsion on SMART-1". Acta Astronautica. 55: 121–130. doi:10.1016/j.actaastro.2004.04.003.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ http://www.ssc.se/default.asp?groupid=2004121510349606
- ^ http://www.dn.se/DNet/jsp/polopoly.jsp?d=597&a=569860&previousRenderType=6
- ^ Josset J. L., Beauvivre S., Cerroni P., De Sanctis M. C., Pinet P., Chevrel S., Langevin Y., Barucci M. A., Plancke P., Koschny D., Almeida M., Sodnik Z., Mancuso S., Hoffmann B. A., Muinonen K., Shevchenko V., Shkuratov Y., Ehrenfreund P., Foing B. H. (2006). "Science objectives and first results from the SMART-1/AMIE multicolour micro-camera". Moon and Near-Earth Objekts Advances in Space Science. 37: 14–20.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Basilevsky A. T., Keller H. U., Nathues A., Mall J., Hiesinger H., Rosiek M. (2004). "Scientific objectives and selection of targets for the SMART-1 Infrared Spectrometer (SIR)". Planetary and Space Science. 52: 1261–1285. doi:10.1016/j.pss.2004.09.002.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Di Cara D. M., Estublier D. (2005). "Smart-1: An analysis of flight data". Acta Astronautica. 57 (2–8): 250–256. doi:10.1016/j.actaastro.2005.03.036.
- ^ Rathsman P., Kugelberg J., Bodin P., Racca G. D., , Foing B., Stagnaro (2005). "SMART-1: Development and lessons learnt". Acta Astronautica. 57 (2–8): 455–468. doi:10.1016/j.actaastro.2005.03.041.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ http://www.moontoday.net/news/viewsr.html?pid=14345
- ^ http://www.moontoday.net/news/viewsr.html?pid=14573
- ^ http://www.esa.int/esaCP/SEMQFHL8IOE_index_0.html
- ^ http://www.esa.int/SPECIALS/SMART-1/SEMBY5BVLRE_0.html
- ^ ESA SMART-1 Impact FAQ, Q.8&9
- ^ http://www.esa.int/SPECIALS/SMART-1/SEMV386LARE_0.html