PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = "2005-11-21, D. Heather, Version 1.0 2006-03-10, D. Heather, Version 1.1, change to the definition of the mission phase times" RECORD_TYPE = STREAM OBJECT = MISSION MISSION_NAME = "SMALL MISSIONS FOR ADVANCED RESEARCH AND TECHNOLOGY" OBJECT = MISSION_INFORMATION MISSION_START_DATE = 2003-09-27 MISSION_STOP_DATE = 2006-09-03 MISSION_ALIAS_NAME = "SMART1" MISSION_DESC = " Mission Overview ================ SMART-1 is the first of the Small Missions for Advanced Research and Technology (SMART), which are elements of ESA's Horizons 2000 plan for scientific projects. A brief description of the mission and its objectives can be found in the SMART-1 Archive Plan [S1_ARCH_PLAN_2003], and in papers by [MARINI_ET_AL_2002] and [RACCA_ET_AL_2002]. A detailed description of the mission analysis can be found in the Consolidated Report on Mission Analysis [CREMA_2001]. The SMART missions aim at testing key technologies for future cornerstone missions. The primary technological objective of SMART-1 is the flight demonstration of Solar-Electric-Primary-Propulsion (SEPP) for a scientific lunar orbiting spacecraft delivered from launch into a geostationary transfer orbit (GTO). The spacecraft was designed to operate with minimum ground intervention (e.g. one pass every 4 days). However, the use of ground stations throughout the mission was on availability basis with, on average, a pass once a day. SMART-1 was launched from Kourou at 23:14 UTC on 27th Sept 2003 as a co- passenger on an Ariane-5 launcher. The launch mass of the spacecraft was 367kg, including 82.5kg of Xenon propellant for the SEPP and 19kg instrument payload. After release into the geostationary transfer orbit (GTO) the spacecraft acquired initial attitude, autonomously deployed the solar arrays and entered a checkout phase. The GTO had the following parameters. A=24702.3km E=0.71578 Inc=6.999deg RAAN=250.965deg APER=178.246deg Perigee=7020.8km Apogee=42383.7km The first firing of the SEPP occurred at 12:20:21 UT on 30th September 2003. The escape from the Earth was performed by gradually expanding the orbit from the initial geostationary transfer orbit parameters. Continuous thrusting was required for a little over 80 days in order to pass the main radiation belts as quickly as possible, pushing the perigee out to 20,000km. After this point, the orbit was optimized by a series of thrust and coast arcs, and by exploiting weak gravity assists. By these means, the orbit plane was changed to capture the lunar orbit. Details of the thrusting power and schedule throughout the Earth Escape Phase are provided in the S1_EP_THRUST_LOG file, which can be found in the DATA/THRUST directory of the SMART-1 auxiliary data set [S1_ESOC_AUX_DATA] (S1-L-ESOC-6-AUXILIARY-DATA-V1.0). As can be seen from this file, there were 19 flame-outs of the thruster during the Earth Escape Phase, all of which were caused by relatively minor issues and triggered cautionary safe modes. The spacecraft was captured by the Moon on 17th November 2004 at 14:18:26, marking the beginning of the nominal LUNAR PHASE. After this, the electric propulsion was again used to gradually spiral down to the final observation orbit. On 10th January 2005 it was decided to pause the thrusting so as to evaluate the remaining fuel margin and the performance of the SEPP. After evaluating the situation, it was found that the thruster had performed beyond its nominal specifications, and ample fuel remained for transfer to the baseline orbit and continued operations into a possible mission extension. Thrusting resumed on 10th February 2005 and continued until the baseline science orbit was reached on 13th March 2005. In total, SMART-1 took just over 17 months to travel from the initial geostationary transfer orbit around the Earth to the observation orbit around the Moon. With this mission profile, the flight dynamics and control of a full-scale planetary mission with SEPP was tested by SMART-1 [SCHOENMAEKERS_ET_AL_1999]. The baseline lunar orbit was polar with the perilune close to the lunar South Pole, at an altitude ranging between 500 and 550km. The apocentre extended up to 6400km. The argument of the perilune drifted from approximately 250 to 280 degrees, allowing observations at high resolution in the southern lunar hemisphere. The orbital period was around 5 hours with a communication pass, on average, every 5 orbits (i.e. once each day). In general, SMART-1's status as a technology demonstration mission does not afford the mission the right to scheduled ground station passes. It therefore has to rely on the spare-capacity left over from other ESA missions resulting in a random distribution of ground station availability. SMART-1 has been granted a 12 month extension to take official operations through to 1st August 2006. The orbit for the Extended Phase is similar to that of the nominal Lunar Phase, with a more variable perilune, after further SEPP thrusting pushed the initial altitude down to around 400km. The altitude will vary from 400 to 700km, with apocentre again out to around 6400km. The south pole remains the focus with the argument of the pericentre drifting from 250 to 290 degrees. The orbital period remains around 5 hours, with a pass, on average, once each day. The spacecraft is three-axis stabilized and powered by two solar arrays attached to the +/- Y panels, stretching 14m from tip to tip. Each array comprises 3 panels, with a total active surface area of around 10 square metres. The spacecraft is roughly cubical with the thruster mounted on a 2- axis orientation mechanism, acting in the -Z direction. Also on the -Z panel is the Plasma Probe assembly (PPU) that forms part of the Electric Propulsion Diagnostic Package (EPDP). The +/- X panels hold the low gain S-band antennas and all of the remaining science / technology experiments. The +X panel contains the X-Ray Solar Monitor (XSM), the X/Ka band antenna and transponder (KaTE), one of two Spacecraft Potential, Electron and Dust Experiment (SPEDE) booms, and a medium gain antenna. The - X panel contains the second boom of SPEDE, an infra-red spectrometer (SIR), a compact X-Ray spectrometer (D-CIXS), a micro-imaging camera (AMIE), and a solar cell (SC) and Quartz Crystal Micro- balance (QCM) that complete the Electric Propulsion Diagnostic Package (EPDP). Instruments and Experiments =========================== The SMART-1 spacecraft contains technology demonstration elements both in the spacecraft bus and in the payload. In addition to the technological demonstrations, the payload is scientifically relevant, tailored for a variety of studies of the lunar surface and for observations of selected targets during the spacecraft's long journey to the Moon. SMART-1 carries seven instruments with a total mass of around 19kg. In addition to the stand alone instrument observations, they will support three further experiments in science and technology. The two aspects of scientific use and of technology demonstration are deeply interlaced. The instruments and experiments can be clearly divided into categories depending upon their use for monitoring of plasmas and the SEPP, remote imaging and spectrometry, advanced telemetry and telecommunications, and supporting science/technology investigations, as described below. Plasma investigations --------------------- With the demonstration and characterization of the SEPP as a key objective of the SMART-1 mission, two plasma diagnostic instruments were selected in the payload: SPEDE (Spacecraft Potential, Electron and Dust Experiment) and EPDP (Electric Propulsion Diagnostics Package). SPEDE ===== SPEDE is used both to monitor the SEPP and to study space weather and solar wind interaction with the Earth and the Moon [LAAKSO_FOING_2001]. The instrument comprises two 60cm probes on the side panels, and can detect charged particles in the 0-40 eV range. The sensors can either monitor the potential difference between the sensor and the spacecraft, or can be used to measure the electron flux. Details of the SPEDE experiment can be found in their flight user manual [FUM_SPEDE_2002]. EPDP ==== The primary diagnostics for the SEPP are undertaken by EPDP, a suite of four sensors that detect both ions and neutral Xenon atoms deposited onto the spacecraft surface. A Plasma Probe Assembly (PPA), consisting of a Langmuir Probe (LP) and a Retarding Potential Analyser (RPA) is mounted on the -Z panel, close to the SEPP thruster, and is used to detect non-neutralised ions in the 0-400eV range. A Quartz Crystal Micro-balance (QCM) and a Solar Cell (SC) are located close to the science / imaging instruments and are used to monitor contamination and deposition effects on the spacecraft. EPDP operated at all start-up and switch-off transients of the electric propulsion, and during thrusting to regularly monitor the performance of the engine and the electrical state of the spacecraft. Details of the EPDP experiment can be found in their flight user manual [FUM_EPDP_2002]. Imaging and Spectrometry ------------------------ SMART-1 carries four imaging and spectrometry instruments: the Advanced Moon Micro-Imaging Experiment (AMIE), the Demonstration of a Compact Imaging X-Ray Spectrometer (D-CIXS) and its supporting X-ray Solar Monitor (XSM), and the SMART-1 Infra-Red Spectrometer (SIR). AMIE ==== AMIE is a miniature 1024 x 1024 pixel CCD camera, equipped with a fixed filter that allows broad-band imaging in 4 different spectral bands (panchromatic, 750, 900 and 950nm). The camera has a 16.5mm aperture and 154mm focal length Tele-objective, providing a square field-of-view of 5.3 degrees and a resolution of about 40 m on the surface at the lowest perilune height (400km). In addition to the broad-band imaging filters, AMIE is equipped with a fixed narrow band filter at 847nm. This filter is used explicitly for the Laserlink experiment, one of three investigations that AMIE will be supporting as part of SMART-1's remit to focus on future spacecraft and mission technologies. The other two investigations are On- Board Autonomous Navigation (OBAN) and Radio Science Investigation with SMART-1 (RSIS). Details of the AMIE experiment can be found in their flight user manual [FUM_AMIE_2003]. D-CIXS ====== D-CIXS is an X-ray imaging spectrometer comprising 24 novel Swept Charge Device (SCD) detectors and a micro-structure collimator/filter assembly. The detectors are arranged in three (2 x 4) arrays of 8 detectors each, providing an overall 32 by 12 degree Field-Of-View in the 0.5-10keV range with a resolution of 140eV. SCDs are based upon CCD technology, but have a significantly lower reading noise and can also operate at higher temperatures than standard CCDs (The D-CIXS SCDs will operate with good signal-to-noise at - 10 degrees Celsius). This is achieved by an electrode and clocking arrangement that 'sweeps' the charge to one collector in a corner of the chip. Details of the D-CIXS experiment can be found in their flight user manual [FUM_DCIXS_XSM_2003]. XSM === An X-ray Solar Monitor (XSM) supports the D-CIXS observations, providing calibration solar spectra for the lunar data collected by D-CIXS from which absolute elemental abundances can then be derived. XSM has a wide 104 degree field-of-view and operates in the 0.8-20keV spectral range. Stand-alone observations of long-term solar X-ray emission will also be made. The detector comprises Silicon diodes cooled by Peltier elements. Details of the XSM experiment can be found in their flight user manual [FUM_DCIXS_XSM_2003]. SIR === SIR (SMART-1 Infrared Spectrometer) is a miniaturised point-spectrometer with a novel InGaAs array detector, designed to provide good signal to noise at temperatures of around -70 degrees Celsius. The spectrometer operates in the 0.9-2.4 micrometer wavelength range and has 256 spectral channels with a resolution per channel of 6nm/pixel. This is coupled to a lightweight off- axis telescope, which has an aperture of 70mm and a field of view of 1.1mrad. A dedicated radiator provides passive cooling of the optics and the spectrometer during observations. Details of the SIR experiment can be found in their flight user manual [FUM_SIR_2002]. Advanced Telemetry and Telecommunications ----------------------------------------- KaTE ===== KaTE (Ka-band TT+C Experiment) is an experimental X/Ka-band deep-space transponder. The instrument is used to test the standard TT+C functions (telecommand, telemetry, and Doppler tracking), and to demonstrate Turbo- encoding in space for the first time [ELFVING_ET_AL_2000]. The estimated gain on the link budget using this encoding is in the order of 2-3dB. Using a medium gain antenna and the turbo-encoding, KaTE is capable of transmitting 500Kbps from lunar orbit. KaTE data are purely technological and are not delivered as part of this archive. Any data from the KaTE instrument that is required for the other SMART-1 experiments are delivered as part of that experiment's data set (e.g. RSIS). Details of the KaTE experiment can be found in their flight user manuals [FUM_KATE_P1_2003] and [FUM_KATE_P2_2002]. Supporting Science / Technology Investigations ---------------------------------------------- The instruments on SMART-1 are also used to support three experiments to demonstrate new spacecraft technologies and novel techniques for future missions. These experiments will test new telecommunication and navigation techniques, investigate the remote monitoring of electric propulsion, and conduct geodetic observations from planetary orbit. Laser-Link ========== The Laser-Link experiment is designed to demonstrate spacecraft acquisition of a deep-space laser-link from the ESA Optical Ground Station (OGS) at Tenerife. To accommodate this experiment, the AMIE camera fixed filter was fitted with an additional narrow-band laser filter at 847nm. With AMIE pointing to the Earth, hundreds of images were taken through the laser filter of the Ti-sapphire laser beam sent by the 1 m telescope at the OGS. An experimental sub-aperturing system was also used at the OGS to try to mitigate the turbulence acting on the laser as it passed through the atmosphere. The characteristics of the OGS listed below [SODNIK_ARROWSMITH_2003]. Transmitter: Sub-aperture diameter: 4x(40 to 300)mm Max. laser power out of telescope aperture: 58 + 72 + 50 + 47mW (average) (it can be twice this value if there is no Electro-Optical Modulator (EOM) in the FPOB). Wavelength: 847nm Modulation format: On-Off Keying (OOK) Modulation frequency: 0 to 100MHz Polarisation: Left Hand Circular (LHC) Receiver (for OGS pointing purposes only): Aperture area: 0.72m^2 Receive path transmission: 0.2 Wavelength range: 530-750nm Coude CCD camera field-of-view: 8 arcmin diameter Number of CCD camera pixels: 1242x1152 Dark current: To be measured (Peltier cooled CCD) Effective focal length: 11.1meters CCD camera pixel field-of-view: 0.42x0.42arcsec During the experiment, the spacecraft was instructed to slew around its x or y axis (depending on the position of the Earth terminator), while the AMIE camera took hundreds of images through the laser-link filter. In these exposures, the focused laser-beam traced a line on the AMIE CCD that contains temporal information on the scintillations resulting from atmospheric transit. Close to the Earth, at distances of around 20,000km, slews could be faster as the intensity of the light was greater. Slower slews were required as the Earth-to- SMART-1 distance increased in order to increase the signal- to-noise ratio. Images of the far field were taken at various distances until the Moon orbit was reached, and the experiment was successful in demonstration open loop pointing and beam addressing [SODNIK_ARROWSMITH_2003]. A summary of the Laser-link operations at various distances from the Earth is provided below. ------------------------------------------------------------------- | Date | Start time | End time | Dist (km) | Slew | Slew | | | | | | deg/s | pixels/s | |----------|------------|----------|-----------|-------|----------| | 14/02/04 | xxxxxxx | xxxxxxxx | 14300 | 0.168 | 31.52 | | 15/02/04 | xxxxxxx | xxxxxxxx | 14300 | 0.168 | 31.52 | | 22/04/04 | 17:49:31 | 15:36:50 | 16100 | 0.168 | 31.52 | | 26/05/04 | 21:21:49 | 02:50:14 | 18500 | 0.168 | 31.52 | | 03/06/04 | 22:00:00 | 01:18:00 | 19200 | 0.168 | 31.52 | | 03/06/04 | 22:05:00 | 23:34:07 | 19200 | 0.168 | 31.52 | | 02/07/04 | 21:00:00 | 01:00:00 | 21500 | 0.084 | 15.76 | | 02/07/04 | 21:15:00 | 22:44:07 | 21500 | 0.084 | 15.76 | | 19/07/04 | 20:45:00 | 22:14:07 | 23000 | 0.084 | 15.76 | | 23/07/04 | 21:00:00 | 22:04:24 | 23000 | 0.084 | 15.76 | | 18/09/04 | 20:40:00 | 00:20:26 | 53000 | 0.042 | 7.88 | | 20/09/04 | 02:00:00 | 05:21:45 | 53000 | 0.042 | 7.88 | | 28/09/04 | 21:40:00 | 00:51:41 | 59000 | 0.042 | 7.88 | | 28/09/04 | 01:10:00 | 04:20:50 | 59000 | 0.042 | 7.88 | | 06/10/04 | 22:09:40 | 04:00:43 | 73000 | 0.042 | 7.88 | ------------------------------------------------------------------- Slew rates and pointing errors for SMART-1 are provided in the INSTHOST.CAT file, and details of the AMIE camera can be found in their data set. Laser- link data are archived as part of the AMIE data set. The relevant AMIE images are given an IMAGE_OBSERVATION_TYPE value of LASERLINK. OBAN (On-Board Autonomous Navigation experiment) ================================================ OBAN is an experiment designed to test an autonomous navigation code, based on processing of images collected by the AMIE camera and the SMART-1 star- tracker. The experiment used these images to run through a code off-line and on ground, simulating the technique that could be used in a closed loop on- board navigation software system for future missions. The images used were a series of long exposures from AMIE of the Earth, the Moon and some stars. The list of exposures are provided below. ------------------------------------------------------------------- | Date | Image type | Start time | Stop Time | |----------|-----------------------------|------------|------------| | 09/06/04 | AMIE OBAN Earth trialimages | 04:42:23 | 06:52:23 | | 13/06/04 | AMIE OBAN Moon trial images | 09:36:33 | 15:36:33 | | 24/06/04 | AMIE OBAN Stars images | 03:30:00 | 05:05:00 | | 12/07/04 | AMIE OBAN Moon images | 08:35:17 | 09:05:17 | | 12/07/04 | AMIE OBAN Stars images | 09:19:28 | 11:40:17 | | 23/07/04 | AMIE OBAN Moon images | 00:59:22 | 01:59:22 | | 14/08/04 | AMIE OBAN Moon images | 08:50:50 | 09:50:50 | | 14/08/04 | AMIE OBAN Star images | 10:50:50 | 12:50:50 | | 19/08/04 | AMIE OBAN Moon images | 02:30:00 | 02:45:00 | | 19/08/04 | AMIE OBAN Star images | 04:45:00 | 06:20:00 | | 26/09/04 | AMIE OBAN Earth images | 10:37:30 | 11:02:30 | | 26/09/04 | AMIE OBAN Stars images | 12:17:30 | 14:17:30 | | 26/09/04 | AMIE OBAN Moon images | 15:32:30 | 16:02:30 | | 28/09/04 | AMIE OBAN Earth images | 05:50:00 | 06:15:00 | | 28/09/04 | AMIE OBAN Stars images | 07:30:00 | 09:30:00 | | 28/09/04 | AMIE OBAN Moon images | 10:45:00 | 11:15:00 | | 07/10/04 | AMIE OBAN Moon images | 05:09:40 | 05:39:40 | | 07/10/04 | AMIE OBAN Stars images | 06:39:40 | 08:39:40 | | 07/10/04 | AMIE OBAN Earth images | 09:39:40 | 10:04:40 | | 10/10/04 | AMIE OBAN Moon images | 04:00:00 | 04:25:00 | | 10/10/04 | AMIE OBAN Stars images | 05:30:00 | 07:30:00 | -------------------------------------------------------------------- Using these images, the code was used to decorrelate the relative motion of the target from the spacecraft motion and detect the relative velocity vector, to be fed to the navigation and orbit control software. The instrument data relevant to OBAN are archived as part of the AMIE data set. The AMIE images used for this experiment are given an IMAGE_OBSERVATION_TYPE value of OBAN. Star-tracker images are not provided in the archive. RSIS (Radio Science for SMART-1) ================================ RSIS comprises a set of radio science and technology investigations aiming to characterize the Ka-band communication channel and to verify the measurement method of libration from planetary orbit. Libration measurement will be verified by simultaneously imaging the lunar surface using AMIE while tracking the spacecraft orbit to a high accuracy. As such, data from the KaTE and the AMIE instruments are used for this experiment. As the Moon's libration properties are well known, RSIS provides an ideal test of the measurement technique, which requires delicate calibration in successive orbits. The RSIS experiment will test and also help to improve the method by taking repeated measurements. RSIS data are archived in their own RSIS data set containing the relevant AMIE and KaTE data. Details of the experiment are provided within the RSIS data set. Mission Phases ============== SMART-1 has four main mission phases defined for significant periods of spacecraft activity. These are Launch and Early Orbit, Earth-Escape, Lunar Phase, and Extended Mission. At the end of the Lunar Phase, a period of spiraling took place to move the spacecraft in the new Extended Mission orbit. Any data taken during the spiraling is incorporated into the Lunar Phase. LAUNCH AND EARLY ORBIT ---------------------- The Launch and Early Orbit Phase extended from the launch of the spacecraft from Kourou at 23:14 UTC on 27th Sept 2003, through until the first firing of the SEPP to begin the Earth Escape at 12:20:21 UT on 30th September 2003. During this phase, instruments and spacecraft underwent an initial checkout after insertion into the geostationary transfer orbit. No other instrument activities were undertaken. Mission Phase Start Time: 2003-09-27 Mission Phase Stop Time: 2003-09-30 EARTH ESCAPE ------------ The Earth Escape Phase started with the first firing of the SEPP to begin pushing the spacecraft away from the Earth. This occurred at 12:20:21 UT on 30th September 2003. The following 14 months saw the spacecraft gradually work its way toward lunar orbit via a series of thrust and coast arcs and some subtle gravitational assists. Throughout Earth Escape, some commissioning and limited science operations were undertaken by all payload instruments, between the thrusting arcs when the propulsion system was not in use. As part of the technology demonstration, monitoring of the plasma and spacecraft environment was undertaken also during the thrusting arcs by the Electric Propulsion Diagnostic Package (EPDP) and the Spacecraft Potential Electron and Dust Environment (SPEDE). Mission Phase Start Time: 2003-09-30 Mission Phase Stop Time: 2004-11-17 LUNAR ----- SMART-1 was captured by the Moon on 2004-11-17T14:18:26. Apolune at this point marked the official beginning of the first lunar orbit (orbits run from apolune to apolune). From this point, the spacecraft began to use its SEPP to spiral down to the nominal observation orbit. A pause occurred in this thrusting between 10th January 2005 and 10th February 2005 in order to evaluate thruster performance and fuel margin. All instruments exploited the pause in thrusting to undertake some lunar observations and begin commissioning. The orbit at this stage allowed for lunar observations at 'medium' altitudes, with a perilune of 980km, an apolune of approximately 5000km and an orbital period of about 8 hours. This was particularly useful for the AMIE camera, which could deliver contiguous medium resolution coverage from adjacent orbits at these altitudes, and would not be able to obtain global imagery from the nominal orbit. Observations throughout this pause in thrusting were default nadir pointing of the illuminated Moon, focusing on the near side from 12th to 25th January 2005 and more on the lunar farside from 26th January until 9th February 2005. This allowed for a complete medium resolution survey of the Moon with near-global coverage from AMIE in black and white, and localized color imaging. After this pause, the thrusting was restarted until nominal lunar observation orbit was reached on 13th March 2005. SMART-1 arrived in its nominal observation orbit about the Moon on March 13th 2005, with orbit number 48. At this stage, the orbit had a period of approximately 5 hours. Around once every month during the Lunar Phase, the spacecraft approximately retraced its ground track; these intervals are known as 'repeat cycles.' Due to the pause in thrusting and the severe limitations in the operational budget of the spacecraft, the nominal Lunar Phase could only extend through until 1st August 2005 giving just over 4 months of observations from the baseline science orbit. Baseline lunar orbit parameters ------------------------------------ 13th March 2005 to 1st August 2005 ------------------------------------ Perilune: 500 to 550km Apolune: 6200 to 6400km Argument of Perilune: 280 to 250deg ------------------------------------ The observations during this phase were primarily nadir for all instruments and very little targeted, off-pointing observations were made. Towards the end of the Lunar Phase, a further series of SEPP thrusts pushed the spacecraft to the Extended Mission orbit from which more off-pointing science was conducted. Mission Phase Start Time: 2004-11-17 Mission Phase Stop Time: 2005-08-01 EXTENDED MISSION ----------------- SMART-1 was granted a 12 month extended mission, starting from August 1st 2005 and ending around 3rd September 2006, when one option would be to fly the spacecraft into the lunar surface, in co-ordination with a large-scale observing campaign to try to observe and ejecta clouds and impact debris from the collision. A similar experiment was carried out at the end of the Lunar Prospector mission. The orbit for the Extended Mission still has a period of approximately 5 hours and a repeat cycle of approximately once per month Extended Mission Orbit parameters -------------------------------------- 1st August 2005 to ~3rd September 2006 -------------------------------------- Perilune: 400 to 700km Apolune: 6200 to 6400km Argument of Perilune: 250 to 290deg -------------------------------------- Several mission sub-phases also exist. These are dictated either by the scientific objectives of the mission (for the Extended Mission Phase) or by flight dynamics requirements (for the episodic thrusting required to 'spiral down' to the final Lunar Phase and Extended Phase orbits) [FREW_ALMEIDA_ 2005]. Details of these sub-phases and their orbital parameters are discussed below. Mission Phase Start Time: 2005-08-01 Mission Phase Stop Time: 2006-09-03 (TBC) Extended Mission Sub-phases =========================== The selection of the Extended Mission sub-phases has been driven by the illumination conditions, as these have a major impact on the science that can be achieved by the payload. The local solar elevation at the equator varies greatly throughout the extended mission, and the sub-phases have accordingly been devised with an emphasis on a selection of science themes. Summary of Sub-Phases for Extended Mission ========================================== ********************************** Name: Push-broom 1 (noon-midnight) ********************************** START_DATE: 2005-10-17 STOP_DATE: 2005-12-25 Local Solar Elevation: greater than 60deg Scientific Focus: Mineralogy Observation Types: Nadir color observations, High-rate D-CIXS, Southern hemisphere targets DESCRIPTION: The push-broom mode has baseline operation parameters defined according to the thermal constraints of the spacecraft. When flying in this mode the spacecraft Y-panels are illuminated and the star-trackers are at risk of over-heating. It was therefore necessary to find periods when the thermal constraints could be relaxed to allow for push-broom operations. As a consequence, push-broom mode can only operate under the following conditions: 1. The Sun is within 30deg from the orbit plane 2. The spacecraft is in low thermal mode 3. Push-broom operations are limited to the dayside from 80 deg south to 45 deg north 4. The spacecraft is nadir pointing for the rest of the orbit In addition to these restrictions, the spacecraft must complete a wheel off-loading every orbit. Cooling of the star trackers is completed by maintaining an inertial attitude as the spacecraft crosses the terminator. This keeps the +Z panel protected from illumination that could otherwise violate the thermal constraints of the payload. When these additional issues are taken into account, the final operational constraints for the push-broom mode are: 1. Only 1 hemisphere of push broom will be completed per orbit 2. One dark-side of cool down will follow this with the spacecraft in an attitude that meets the platform safety requirements. In the Push-broom 1 sub-phase, southern hemisphere operations will be the focus, as the spacecraft will have time to slew to nadir while on the dark side before crossing the terminator. Northern hemisphere push-broom requires the slew to accommodate the orbital plane crossing, and this will therefore be completed more in the Push-broom 2 sub-phase after the easier southern hemisphere operations are complete. The illumination conditions during push-broom mode are ideal for colour imaging from nadir pointing using the AMIE camera. The camera filters then pass over the same target area, and the signal-to-noise is excellent. These conditions are also well suited for global mapping by D-CIXS and observing some nadir targets for SIR. ****************************** Name: Medium Solar Elevation 1 ****************************** START_DATE: 2005-12-26 STOP_DATE: 2006-01-22 Local Solar Elevation: greater than 30, less than 60deg Scientific Focus: Morphology, Photometry Observation Types: Off-Nadir observations, Target Tracking, Stereo, Multi- phase angle studies DESCRIPTION: Illumination constraints of the Y panel mean that push-broom cannot operate during medium solar elevation phases. Instead, SMART-1 will operate in nadir pointing modes during this sub-phase with limited off-nadir pointing, typically of less than 5 deg. During this phase, the spacecraft will slowly roll around the +Z axis throughout the illuminated phase. As with the push-broom modes, inertial cool down will be completed each orbit. Colour imaging will no longer be practical in the medium solar elevation sub- phase as a result of the slow roll around the +z axis. The area that would be covered by all filters in the AMIE camera is extremely limited, and the focus instead is shifted to morphology and photometric observations of selected targets. Observations in this sub-phase will form part of a multi- phase angle campaign that runs throughout the mission. With the limited off- nadir pointing, it will also be possible to perform target tracking for SIR crater scans and AMIE stereo imaging. ********************************* Name: Northern Winter (dawn-dusk) ********************************* START_DATE: 2006-01-23 STOP_DATE: 2006-03-19 Local Solar Elevation: less than 30deg Scientific Focus: Morphology Observation Types: Polar, Multi phase angle studies DESCRIPTION: SMART-1 will pass through a 'dawn-dusk' terminator orbit during the Northern Winter sub-phase, during which the local solar elevation of the sub- spacecraft point will remain below 30deg. The poor sub-spacecraft illumination restricts nadir observations to morphology and ongoing phase- angle studies. This mission phase will contain the bulk of across-track, off- nadir observations. ****************************** Name: Medium Solar Elevation 2 ****************************** START_DATE: 2006-03-20 STOP_DATE: 2006-04-16 Local Solar Elevation: greater than 30, less than 60deg Scientific Focus: Morphology, Photometry Observation Types: Off-Nadir observations, Target Tracking, Stereo, Multi- phase angle studies DESCRIPTION: As for Medium Solar Elevation 1 mode. This will also act as contingency for observations that were not successful in the first medium solar elevation phase. ********************************** Name: Push-broom 2 (noon-midnight) ********************************** START_DATE: 2006-04-17 STOP_DATE: 2006-06-11 Local Solar Elevation: greater than 60deg Scientific Focus: Mineralogy Observation Types: Nadir color observations, High-rate D-CIXS, Northern hemisphere targets DESCRIPTION: As for Push-broom 1 mode. The focus in this period will shift to northern hemisphere targets. This will also act as contingency for observations that were not successful in the first push-broom phase. *********************************** Name: Low Altitude (end of mission) *********************************** START_DATE: 2006-06-12 STOP_DATE: 2006-09-03 (TBC) Local Solar Elevation: N/A Scientific Focus: Morphology Observation Types: High resolution DESCRIPTION: This sub-phase represents the end of the mission as SMART-1 enters a low altitude orbit. This sub-phase may end with SMART-1 flying into the lunar surface in co-ordination with a large scale observing campaign to try to observe and ejecta clouds and impact debris from the collision. The exact timing of the end of this phase, and the end of the mission, depends on flight dynamics restrictions that will not be known until nearer the date. The science focus for this phase will also not be known until a better understanding of the orbit and the timing are gained, although it is of course likely that there will be attempted high resolution observations. " MISSION_OBJECTIVES_SUMMARY = " Mission Objectives Overview =========================== The primary objective of SMART-1 is to test new technologies for use on future missions. As such, a series of technological objectives are present in the spacecraft, the operational procedures, and in the payload. The mission will carry out testing of a ground to spacecraft laser link at a range of distances from the Earth, and will also test some software code designed to autonomously navigate future spacecraft with no ground interaction. In addition, a new X and Ka band transponder will be tested and techniques to demonstrate in-flight measurements of planetary libration will be carried out on the Moon where the various librations are already very well understood. In addition to these technological demonstrations and experiments, the payload has been tailored to complete some high level scientific observations of targets during the Earth Escape phase, and some detailed observations of the Moon during the Lunar and Extended Mission phases. The Moon was chosen as a target for SMART-1 as it is currently undergoing a period of renewed interest, with many recent orbital missions investigating the surface in unprecedented detail and raising new questions that require further study. It was recognized that SMART-1 could contribute some new and exciting data relevant to some of these issues. In particular, it will perform the first global X-ray spectroscopic study of the Moon using the D-CIXS instrument, which could provide new insights into the evolution of the lunar crust and the development of the Mg-suite of rocks. SIR will provide high spectral and spatial resolution spectroscopy of selected targets and ground tracks, and will help to evaluate the distribution of olivine in lunar rocks, which is not yet well understood from other remote sensing studies. AMIE will provide photometric, morphological and geological contexts for the other instruments, as well as limited multi-spectral data for mineralogical studies. The South polar region of the Moon has been proposed as the focus of European lunar science activities on the following grounds: 1. The possibility of ice deposits has now been confirmed by the results of the Lunar Prospector neutron spectrometer. These deposits and their locale are of significant interest to future lunar missions and require focused studies. SMART_1 will provide high resolution imaging and deep exposures of these regions in an attempt to shed more light on our understanding of potential water ice traps in areas of permanent shadow. 2. The South pole is on the rim of the South-Pole-Aitken basin (SPA). At more than 1500km in diameter, this is the largest such feature on the Moon, and has penetrated deep into the farside crust, potentially excavating mantle material. There is a strong interest in investigating the mineralogical composition of these ejecta at close range, as they provide a vertical profile of the farside crust down to several tens of km. All SMART-1 instruments will examine the SPA in detail providing morphological, geological and geochemical data. The SMART-1 payload had the following broad science and technology objectives: AMIE ==== Science objectives: - Imaging / mineralogical investigation of South-Pole-Aitken Basin - Deep imaging of regions in permanent shadow (ice deposits) - Study of regions in eternal light (crater rims) - Mapping of high latitudes regions (south) mainly at lunar far side - Local Spectro-photometry and physical state of the lunar surface - Ancient Lunar Non-mare volcanism and early thermal history Technical objectives / associated experiments: - Laserlink Experiment - Flight demonstration of high technology - Navigation aid. On-board autonomy investigation Summary of AMIE Science Objectives: +++++++++++++++++++++++++++++++++++ The AMIE camera uses a fixed filter with 3 spectral filters (750, 915, 960nm). This spectral range provides a powerful tool for discriminating between mafic minerals which dominate in the lunar mare (revealed by the Fe2+ absorption feature at 0.95 um) and the anorthosite rich lunar highland material. It also makes possible a study of surface alteration processes under the influence of the solar wind and micrometeorites (the maturation process). The lunar South-Pole ++++++++++++++++++++ AMIE directly contributes to the characterisation of surface mineralogy and geology, via multi-spectral imaging. Mineralogical and geological imagery will have a strong focus in and around the South-Pole-Aitken basin. The large digital dynamics of AMIE and the low read noise of the CCD (lower than 100 electrons; much less than 1 DN) make the camera highly suited to obtaining direct imaging information on permanently shadowed areas and their immediate surroundings. Models show that icy deposits can only survive in small craters in permanently shadowed areas which protect the deposit from sunlight diffused by the rims. A solid angle contribution of as little as 0.005 steradians from such sunlit regions should make it possible to observe features within regions of permanent shadow. Photometric Observations ++++++++++++++++++++++++ At the equator, AMIE images will be very helpful to better understand the photometric characteristics of the lunar surface at different wavelengths. The strategy with AMIE will be to only adjust the acquisition time for these studies, as this has the least impact on the photometric response. Current investigations of early lunar volcanism and impact melt contributions to crustal layering are hampered by the fact that the optical heterogeneities related to the local physical properties of the surface at the subpixel scale have been overlooked until now. AMIE will help to address this through a combination of its high resolution stereo imaging with local digital elevation models (DEM) and spectral datasets, under various geometry conditions. Lunar non-mare Volcanism ++++++++++++++++++++++++ Non-mare volcanism has equally major implications for the thermal history and crustal evolution of the Moon. AMIE will aim to detect and characterise the small 'red spots' that indicate non-mare volcanism, using high spatial resolution combined with spectro-photometry. Summary of AMIE Technical / Experiment Objectives +++++++++++++++++++++++++++++++++++++++++++++++++ Laserlink +++++++++ The main objective of the laserlink part of AMIE is to study the influence of the turbulent atmosphere of the Earth on ground to space laser communication links and to validate the models developed to predict this influence for varying air mass and link distances. The main technological objective is the investigation of the effectiveness of an incoherent four sub-aperture system (installed in the OGS) for improvement of ground to space communication data rate, without the use of adaptive optics. The four sub-aperture system is intended to reduce the effect of short-term beam wander (speckle) in a ground to space communication system which is caused by the turbulent atmosphere of the Earth. Four beams emitted from the OGS pass different turbulent areas of the atmosphere (until they finally overlap) and thus generate individual speckle pattern in the far field. Because of them being incoherent the individual speckle fields superimpose and do not interfere, producing a more homogenous far-field illumination. Further technological objectives are: to study the effects of the turbulence of the Earth's atmosphere on the far- field of a laser beam as transmitted from the OGS in Tenerife to space, to demonstrate laser beam transmissions to a spacecraft at deep-space distances (beyond geostationary orbit) and to verify laser-beam pointing strategies based solely on spacecraft ephemeris predictions. Initial results from the experiment are available in [CESSA_SODNIK_2004]. On-board Autonomous Navigation (OBAN) +++++++++++++++++++++++++++++++++++++ Investigation objectives: - To verify the operation of an autonomous navigation code for deep-space target identification, tracking and flight operation management. - To test it in a as-likely-as-possible environment, but not as a an on-board tool. DCIXS / XSM =========== Science objectives: - First global map of the Moon in X-rays, mapping of key rock-forming elements (Si, Mg, Al and Fe) - Determination of the Mg number across the Moon - Geochemical / stratigraphic investigations of large craters, basins and mare deposits (especially the South-Pole-Aitken Basin). - Evaluation of key lunar resources - Study of lunar plasma interaction with solar wind - Investigation of Earth's X-Ray aurora and magnetotail - Study of targets of opportunity (e.g. comets) during cruise - Long term evolution of solar flares (via XSM) Technical objectives: - In-flight demonstration of SCD technology - Flight demonstration of high technology micro collimator structures and their design potential Summary of D-CIXS/XSM Science Objectives: +++++++++++++++++++++++++++++++++++++++++ The D-CIXS instrument will provide the first global map of the Moon in X- rays, with better than 50km spatial resolution at perilune. It will map the absolute abundances of key elements across the Moon, such as Si, Mg, Al and Fe, which will help to constrain theories of lunar origin and evolution. Other elements will be detectable when favourable conditions preside (i.e. under flare conditions). Magnesium Number ++++++++++++++++ The determination of the magnesium number [Mg/(Mg + Fe)] across the Moon is of fundamental importance as it provides critical information regarding the evolution and separation of materials during the magma ocean period of lunar history as various suites of rocks developed. A global determination via remote sensing has yet to be achieved. Geochemical Investigations of Impact Basins, Crater and Maria +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ D-CIXS will probe the geochemistry of the larger impact basins, focusing on the South Pole-Aitken basin, which may contain exposed mantle material. D- CIXS will also examine the deeper layers of the crust by studying the central peaks of the largest impact craters, and the central regions of the large impact basins. The time series of lava flows can reveal petrological evolution, and large scale observations of elemental variation across different lava flows in the maria will be made to contribute to our understanding of this evolution. These results will also have direct relevance to lunar resource evaluation, as a precursor to future exploitation of the Moon as a base for space exploration. Lunar plasma interaction ++++++++++++++++++++++++ Recent Japanese X-ray observations of the Moon suggest that X-ray production on the night side is due to the impact of energetic particles, while measurements by GGS/Wind and Lunar Prospector show that the energetic electrons of the solar wind are not shielded by the shadow, and that 1keV energy electrons are on occasion accelerated towards the surface. With its large effective area, D-CIXS aims to provide the high-quality spectroscopy necessary to identify the processes involved in this interaction. The Earth's X-ray aurora ++++++++++++++++++++++++ This objective is to be completed during Earth Escape Phase. Recent results from the X-ray emission of the aurora suggest that a significant portion of the flux is due to the Argon line at 2.957 keV. This contaminates efforts to deconvolute the incident electron spectrum and hence understand the global energetics. Spectra taken by DCIXS will clearly resolve this line, and hence remove the ambiguity. At distances up to about 18 Earth radii, DCIXS will be able to make measurements of the conjugacy of the northern and southern hemisphere X-ray aurora. These will be the first such measurements, and should be of importance in understanding global auroral energy budgets. The Earth's Magnetotail +++++++++++++++++++++++ This study will be undertaken during the Earth Escape Phase. DCIXS is shielded against electrons of energy up to 6keV. Electrons more energetic than this are extremely rare in the solar wind. They do however occur in the Earth's magnetotail. While the increased background may degrade the X-ray performance of the instrument on the occasions when it enters the tail, there is interesting science to be done in mapping the structure of the tail. As the orbit is slowly increased from geostationary to lunar radius, the instrument will perform a detailed map of the width of the tail. Astronomical Cruise Science +++++++++++++++++++++++++++ This objective forms part of the Earth Escape Phase. D-CIXS is well suited for certain astronomical observations and the long Earth-Escape phase provides the ideal platform from which to make such observations. D-CIXS can monitor up to 15 or 20 sources for periods of up to 5 months (with daily observations) and can therefore alert the astronomical community to unusual or rare outburst phenomena on superluminal jet sources in AGN or other similar objects. D-CIXS can also monitor the much brighter galactic sources for spectral and time variability and again look for longer term variability in these sources. Targets of Opportunity ++++++++++++++++++++++ One of the objectives of D-CIXS is to exploit any targets of opportunity that may arise during the unusually long Earth Escape Phase of the mission. These are detailed within the D-CIXS data set catalogs. XSM Solar Monitoring ++++++++++++++++++++ As well as providing important calibration solar X-ray spectra during the Lunar Phase and Extended Mission Phase, XSM will also undertake some important science during the Earth Escape Phase. XSM is very sensitive to solar flare activity and during a flare the measured total spectrum will be largely dominated by the flux from the event. In these situations, the contribution from the solar network can be neglected, especially in the higher energies above about 3keV. Thus XSM will be able to monitor the long term evolution of flares, with the added dimension of good energy resolution. Long term monitoring of the X-ray spectral variability of the Sun excluding the flare events is also significant, especially in comparison with similar studies for other active stars. Technology Objectives +++++++++++++++++++++ The capability of these X-ray detectors, based on Swept Charged Devices, to withstand the space environment whilst maintaining good sensitivity will be proven by this mission. An in-flight calibration of the detectors will be provided by the Earth-Escape phase observations of well-known astronomical X- ray sources. The measurements made of the low flux levels from the lunar surface against the background of the solar wind electrons will demonstrate the design possibilities of the micro-collimation techniques. EPDP ==== Science / Technology Objectives: - Monitoring of the Hall thruster plume interaction effects on the SMART-1 spacecraft. - Measurement of ion energy and current density distribution via a Retarding Potential Analyser (RPA). - Measurement of the plasma potential, and the electron density and temperature using a Langmuir Probe (LP). - Measurement of the mass deposition rate from the thruster using a Quartz Crystal Micro-balance (QCM) - Investigate the degradation of the solar output power with the mass deposition on a Solar Cell (SC) - Investigate / model the effect of deposition on the thermo-optical and electrical parameters of different materials (SC and QCM) Summary of EPDP Objectives: +++++++++++++++++++++++++++ The Electric Propulsion diagnostic Package (EPDP) will monitor the performance of the SEPP and obtain information on the interaction of the Hall thruster plume with the rest of the spacecraft subsystems. These data will be invaluable for future spacecraft intending to use primary electric propulsion, particularly as testing of these systems on ground is difficult and can produce variable results. Data from EPDP will also be use to develop and validate modeling tools designed to fully characterize and investigate the use of this new technology in deep space. Retarding Potential Analyser (RPA) ++++++++++++++++++++++++++++++++++ The ion energy and the current density distribution will be measured by the RPA, which is located parallel to the thruster with its axis oriented towards the thruster. The ions that will be measured with this sensor are the low energy charge exchange ions (up to a few tens of eV) mainly responsible for the so-called 'backflow contamination'. Part of the slow charge-exchange ions flow back to the spacecraft due to the potential distribution in front of the thruster. The impact of high energy beam ions on the ceramic discharge surface create sputtered materials which go into the plume. A fraction of this becomes charged and therefore can also flow back to the surface. The measured current distribution and energy of these ions will allow the investigation on the erosion of surfaces, deposition of the eroded material and electrical effects. Langmuir Probe (LP) +++++++++++++++++++ The LP measures the plasma potential, and the electron density and temperature. The charge-exchange ion trajectories will be determined by the potential distribution around the spacecraft created by space charge effects. Therefore it is extremely important to have a measurement of the electron density in a monitored area when the thruster is firing and when its operation is finished. The LP will give information on the plasma potential at one side of the spacecraft while the SPEDE langmuir probe will provide information on the plasma potential at the other side of the spacecraft. The electron temperature expected at the location of the EPDP will be between 1 and 5 eV. SMART-1 LP measurements will provide invaluable in-flight data on the real electron behavior without the constraints inherent to on-ground testing. Quartz Crystal Micro-balance (QCM) and Solar Cell (SC) ++++++++++++++++++++++++++++++++++++++++++++++++++++++ The QCM and SC will together provide information on the contamination / interaction of the plasma thruster with the rest of the SMART-1 spacecraft. The QCM will provide a measure of the mass deposition rate from the thruster while the SC will look into the degradation of the solar output power with the mass deposition on the sensor. The thruster will cause erosion and deposition of material on all the surfaces impacted by the plasma, plus the re-deposition of these eroded materials on the surrounding surfaces. These affects will be monitored by a combination of QCM and SC data. Once the deposition rate of the materials is known, then it will be possible to calculate the effect of deposition on the thermo-optical and electrical parameters of different materials. SPEDE ===== Science / Technology Objectives: - Monitor the disturbances (electron flux, wave electric fields, and spacecraft potential variations) induced by the propulsion system. - Monitor the variability of the electron density and wave electric fields first during the Earth spiraling phase and then during the Moon phase - Monitor space weathering of atmosphereless bodies in the Solar System (the Moon) Summary of SPEDE Objectives: ++++++++++++++++++++++++++++ SPEDE (Spacecraft Potential, Electron and Dust Experiment) comprises two electric sensors to measure the electron flux and wave electric fields in the vicinity of SMART-1. The cylindrical sensors are mounted on the tips of two 60cm booms. SPEDE will be used to monitor the disturbances in the electron flux, wave fields and spacecraft potential that arise both from the use of the SEPP, and that occur while in Earth and lunar orbit. Monitoring of thruster effects ++++++++++++++++++++++++++++++ Charged clouds expanding from the propulsion system may interact with the solar wind and the surface of the spacecraft to give rise to significant variations in the spacecraft potential and electron flux, contamination of the spacecraft surfaces, and generation of wave electric fields. Consequently, operation of the SEPP thruster causes disturbances in the spacecraft environment that could adversely affect instrument observations, and may cause surface contamination in the vicinity of the science instruments. Particularly large effects in the spacecraft potential can be immediately observed if the exhaust ions are not properly neutralized by the cathode electron emitter. SPEDE is located opposite to the EPDP LP, and data from both of these instruments combined will provide a complete view of the spacecraft potential. Monitoring electron densities in the inner magnetosphere +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ In the Earth spiraling phase, the SMART-1 spacecraft will stay in the inner magnetosphere, during which the spacecraft will be accelerated by the ion propulsion engine. In the coast arcs between thrusting, SPEDE will measure the distribution of thermal plasma in the Earth's plasmasphere and detect the position of its outer boundary, the plasmapause, which is usually located at a distance of 3-7 Earth radii at the equator. As long as the perigee of the orbit is less than 3-4Re (20,000km), the plasmapause is crossed twice per orbit. When the perigee is between 20,000 and 40,000km, the plasmapause is not always encountered, particularly during magnetic storms. Space weathering of the Moon ++++++++++++++++++++++++++++ The Moon has no magnetic field and atmosphere, and is therefore continuously exposed to the interplanetary space environment. The fast solar wind stream hits the dayside lunar surface and produces a tenuous wake. The coupling of the solar wind with the surface produces disturbances at the edge of the wake region, which will be monitored with the SPEDE observations. When the Moon is immersed in the Earth's magnetosphere, different kinds of interaction processes will occur. SPEDE observations are used for studying these various solar wind-Moon interaction processes. SIR === Science Objectives: - Obtain high spatial and spectral resolution data to study mineralogy of selected lunar targets (e.g. olivine distribution on crater central peaks) SIR data will contribute to investigations of: - Origin of the Moon and the Earth-Moon system - Character and evolution of the primitive lunar crust - Thermal evolution of the Moon and lunar volcanism - The impact record and redistribution of crustal materials Technology Objectives: - To space qualify a miniaturized version of a commercially available low- mass NIR grating spectrometer. Summary of SIR Science Objectives: ++++++++++++++++++++++++++++++++++ SIR is a highly compact grating near infrared spectrometer covering the wavelength range of 0.9 to 2.4 um. he spectral resolution is delta lambda Rayleigh = 22nm (delta lambda pixel = 6nm), and the angular resolution is approximately 1.11 millirad. Therefore, SIR is very well suited to study the mineralogy of surfaces of solid planets such as the Moon. Most lunar rocks are identified by the absorption bands of their mineral constituents (e.g. mafic minerals) which have diagnostic absorption features between 0.6 and 2.5um, mainly due to the electronic transitions in Fe+2. SIR is able to take both single spectra and bursts of spectra, for high- resolution mapping and angular spectroscopy, carried out when the camera AMIE is pointed to a feature on the lunar surface to enhance the SNR by longer exposure. Mineralogical studies using SIR ++++++++++++++++++++++++++++++++ The NASA Apollo missions to the Moon culminated in a sample return. Laboratory studies of these samples provided a wealth of information about composition of the lunar crust. Since Apollo the advancement of ground based telescopes and sensors in visible and NIR allowed to put these results into a more global context. These observations, although not complete, indicate clearly that the lunar crust is much more heterogeneous than suggested by the returned samples alone. This underlines a continued need to obtain further high spatial resolution (i.e. from spacecraft) data in visible and NIR of the lunar crust. By improving our global map of key minerals such as olivine (which is notoriously difficult to detect through other means), SIR will provide a better understanding of the distribution of the materials that have shaped the Moon both thermally and physically. The distribution of minerals such as pyroxenes and olivines are dependent upon the thermal and physical evolution of the Moon, and the redistribution of such materials via impact cratering and basin formation can also be better understood through these measurements. By focussing on central peaks in impact craters, SIR will also be investigating the vertical distribution of these minerals, determining the depths at which the materials would originally have been before excavation via the impact event. Summary of SIR Technology Objectives: +++++++++++++++++++++++++++++++++++++ SIR will space qualify a miniaturized version of an existing, commercially available, low mass near-infrared (NIR) grating spectrometer. The commercial spectrometer is built around a monolithic quartz body and uses an InGaAs diode array detector sensitive in the 0.9-1.7um wavelength range. The need for lower operating temperatures and the radiation protection of the sensor,as well as an increase in wavelength range up to 2.4um required significant modifications to the original commercial instrument. KaTE ==== Technology Objectives: - Validation of onboard technology - Demonstration of link performance - Increased scientific yield by high rate Ka-band telemetry and Turbo codes - High navigational accuracy - Radio Science Libration Experiment - Validation of Ka band ground station Summary of KaTE Objectives: +++++++++++++++++++++++++++ The general objective of the KaTE (Deep Space X/Ka-band TT+C) experiment is the demonstration of an X/Ka-band TT+C system as a key spacecraft technology for future deep space missions. Sensitivity and the phase noise performance are the two key drivers for the design of a deep space transponder to be used for TC/TM and radio science. KaTE can operate down to input power levels as low as -150dBm (a thousand times more sensitive than the SMART-1 baseline transponder). The digital design allows for flexibility in its use compared to the traditional analogue design. For example, KaTE can be programmed to acquire the uplink signal autonomously (without ground based sweep). The KaTE experiment will demonstrate the use of Ka-band technology for the first time. The demonstration of Turbo code technology is essential to demonstrate the increased telemetry performance with a potential increase in performance of 1 to 2dB foreseen. The bulk of the KaTE experiment shall take place during the Lunar phase. RSIS ==== Science/Technology Objectives: - To validate techniques of measuring the rotational state of a celestial body from orbit. - To evaluate the magnitude of the physical librations of the Moon Summary of RSIS Objectives: +++++++++++++++++++++++++++ The Radio Science Investigation with SMART-1 (RSIS) experiment will show the possibility to combine different already existing SMART-1 payload capabilities to measure the rotational state of a celestial body from orbit. The experiment deals with the comparison between the attitude of the spacecraft and the current orientation of the Moon considered as a triaxial body. Due to the small amplitude of the Moon's physical librations, the tracking capability granted by Ka link are vital to the success of the experiment. RSIS will therefore make use of both KaTE and AMIE. During the experiment, a collection of pictures captured by AMIE is carefully referenced in time using an onboard clock, and in space (with respect to the position along the orbit from which they were taken) by the use of tracking form Earth using the X/Ka link. Attitude information from the SMART-1 star-trackers combined with the knowledge of AMIE's position on the spacecraft, will provide information about the direction of AMIE field of view. Image processing of the pictures captured by AMIE at different times along SMART-1 mission lifetime should allow for an evaluation of the magnitude of the physical librations of the Moon. As the libration data for the Moon are already well known, RSIS will be able to provide a demonstration of the measurement technique from orbit. This kind of measurement will be of importance to future missions to planetary bodies whose libration properties are not yet well known/understood, such as Mercury. RSIS will be active during 3 orbits of the very first phase of the Moon observations, and during 3 orbits a the very end of the Lunar Phase. The six months interval between these measurements is required in order to obtain the same Sun illumination conditions. Ground Segment Overview ======================= The SMART-1 ground segment can be subdivided into three main entities: the Mission Operations Centre (MOC), the Science and Technology Operations Co- ordination (STOC) and the Experiment Operations Facility (EOF). Mission Operations Centre (MOC) ------------------------------- The MOC is located in ESOC in Darmstadt, and comprises the Main Control Room (MCR), the Flight Dynamics Room (FDR) and Dedicated Control Rooms (DCRs) and Project Support Rooms (PSRs). The MCR will be used for SMART-1 during the Launch and Early Orbit Phase (LEOP), and throughout the lunar capture when considerable flight operations requirements will be present. Outside of these critical phases, the SMART-1 routine operations will be conducted from a Dedicated Control Room (DCR). All ESA ground stations interface to the MOC via the OPSNET communications network. This is a closed Wide Area Network for data (telecommand, telemetry, tracking data, station monitoring and control data) and voice. OPSNET will support the SMART-1 TM data rate of 65 Kb s-1 transfer to the MOC. It is expected that the Perth ground station in Australia and the Maspalomas or Villafranca ground stations in Spain will be the main stations. The MOC will undertake the derivation of operational requirements for the spacecraft, prepare operations plans and procedures and will execute the actual spacecraft operations. They will maintain mission control hardware and software an undertake the flight dynamics studies to analyse attitude and orbit profiles. Science and Technology Operations Co-ordination (STOC) ------------------------------------------------------ The STOC, located in ESTEC in Noordwijk, provides the working interface between the MOC and the Principal Investigators and Technology Investigators. All science and technology operations are co-ordinated through this interface, as are the data collection and exploitation. The STOC in turn interface with the MOC, delivering inputs to them for payload commanding at spacecraft level, and delivering the specific telecommand sequences and operational timelines for the payload. The STOC will co-ordinate the following for the SMART-1 payload: - Allocation of observation slots. - Coordination and approval of the use of ground and on-board resources. - Adequate allocation of the combined operations of instruments. - Generation of the Experiments Operations time-line. - Supervision of the experiment TC packets generation. - Monitoring of the distribution of the TM packets to the PIs/TIs. - Raw data storage during the mission and support to science archiving and exploitation. Experiment Operations Facilities (EOF) -------------------------------------- The EOFs are the sites of the various PI / TI teams. They operate their instruments / experiments remotely in co-ordination with the STOC, and supported by the advice of the Science and Technology Working Team (STWT). All EOF requests for experiment commands and data delivery are routed through the STOC. ACRONYM LIST ============= AMIE Advanced Micro-Imaging Experiment D-CIXS Demonstration of a Compact Imaging X-ray Spectrometer DCR Dedicated Control Room DEM Digital Elevation Model DN Data number EPDP Electric Propulsion Diagnostic Package EOF Experiment Operations Facility EOM Electro-Optical Modulater ESA European Space Agency ESTEC European Space Research and Technology Center FDR Flight Dynamics Room GTO Geostationary Transfer Orbit H/W Hardware KaTE X/Ka Band Telemetry Experiment LEOP Launch and Early Orbit Phase LHC Left Hand Circular LP Langmuir Probe MCR Mission Control Room MOC Mission Operations Center NIR Near Infra-red OBAN On-Board Autonomous Navigation OGS Optical Ground Station OOK On Off Keying PI Primary Investigator PPA Plasma Probe Assembly PPU Plasma Probe Assembly Unit PSR Project Support Room QCM Quartz Crystal Micro-balance RPA Retarding Potential Analyser RSIS Radio Science Investigation on SMART-1 SC Solar Cell SCD Swept Charge Device SEPP Solar Electric Primary Propulsion SIR SMART-1 Infra-red Spectrometer SMART-1 Small Mission for Advanced Research and Technology - 1 SPA South-Pole-Aitken basin SPEDE Spacecraft Potential, Electron and Dust Experiment STOC Science and Technology Operations Co-ordination TC Telecommand TI Technology Investigator TM Telemetry TT+C Tracking, Telemetry and Communication XSM X-ray Solar Monitor " END_OBJECT = MISSION_INFORMATION OBJECT = MISSION_HOST INSTRUMENT_HOST_ID = S1 OBJECT = MISSION_TARGET TARGET_NAME = MOON END_OBJECT = MISSION_TARGET OBJECT = MISSION_TARGET TARGET_NAME = SUN END_OBJECT = MISSION_TARGET OBJECT = MISSION_TARGET TARGET_NAME = EARTH END_OBJECT = MISSION_TARGET OBJECT = MISSION_TARGET TARGET_NAME = PLASMA END_OBJECT = MISSION_TARGET OBJECT = MISSION_TARGET TARGET_NAME = ARCTURUS END_OBJECT = MISSION_TARGET END_OBJECT = MISSION_HOST OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "CESSA_SODNIK_2004" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "CREMA_2001" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "ELFVING_ET_AL_2000" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "FREW_ALMEIDA_2005" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "FUM_AMIE_2003" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "FUM_DCIXS_XSM_2003" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "FUM_EPDP_2002" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "FUM_KATE_P1_2003" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "FUM_KATE_P2_2002" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "FUM_SIR_2002" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "FUM_SPEDE_2002" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "LAAKSO_FOING_2001" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "MARINI_ET_AL_2002" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "RACCA_ET_AL_2002" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "S1_ARCH_PLAN_2003" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "S1_ESOC_AUX_DATA" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "SCHOENMAEKERS_ET_AL_1999" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "SODNIK_ARROWSMITH_2003" END_OBJECT = MISSION_REFERENCE_INFORMATION END_OBJECT = MISSION END