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SMEX-Lite
SMEX-Lite represents the next generation of adaptable, low-cost, high-performance spacecraft providing robust solutions for a variety of demonstration and research missions.
- Low or High Data Ingest Applications adapt to Mission Unique Data Processing Needs
- Physical Configuration (Standard Modular shown) is easily tailored to a variety of payload configurations and Launch Systems (Core System is Pegasus/XL Compatible)
- Well suited to LEO or High Altitude Orbits
(Low Mass) within Core Architecture
- High Levels of Radiation Hardness and Low Cost Avionics Architecture
- Selected Redundancy can augment the core SMEX-Lite System for added performance and fault-tolerance
- Core System is dynamically suitable for Spin-Stabilization and is a Robust Solution for Precision Pointing
Profiles
The SMEX-Lite technology, first developed by Goddard Space Flight Center, is based on previous SMEX expertise and incorporates SMEX heritage components. Under a NASA Goddard Space Flight Center Space Act agreement, the technology has been transferred to ATK which leads a team that includes the Hammers Company and Honeywell Technical Solutions, Inc. (HTSI).
The Hammers Company brings its experience in developing software for previous SMEX missions and the SMEX-Lite software design and heritage. The software is an object-oriented, highly modular, and reusable design that allows other functions such as data compression, instrument supervision, and spacecraft autonomy to be efficiently implemented.
Honeywell Technical Solutions, Inc., commerical Data Lynx solution provides low-cost, autonomous, turnkey, end-to-end ground systems, and operations services. Ground stations, control centers, data processing, flight dynamics, communications backbones, simulators and test systems, and mission readinesss and operation services can be provided separately or integrated with existing infrastructure or teams.
| Item Standard |
SMEX-Lite Precision Pointer ⁄
Augmented Core System |
| Mission Life |
The SMEX-Lite Bus Augmentations provide for a 2-3+ year mission life
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| Launch Vehicle |
Taurus⁄Delta⁄DPAF provide adequate Mass Margins, at reasonable cost for LEO Missions, Delta⁄DPAF⁄Dedicated Delta 2320 Support HEOs
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| Readiness |
22 month development provides a fast-track implementation
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| Mission Profile |
Core System directly compatible with LEO Missions (500-900 Km), inclinations at 0° to Polar, Sun-Synchronous up to LaGrange Point Orbits
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| Propulsion |
Mission Unique Option: EO-1 derivative easily accommodated
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| Payload Mass |
400 kg. Payload Mass supported by DISCUS Modular Structure
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| S⁄C Bus Mass |
215 kg. for Core System
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| Total Satellite Mass and Margin |
615 kg. provides 24% margin (average) relative to 760 kg. (Taurus limiting case to Low Altitude Sun-Synchronous Orbit; Delta Options are simpler with Higher Mass Margins)
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| Payload Power |
130 W Orbital Average minimum
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| S⁄C Bus Power |
159 W Orbital Average for Core System
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| Total Satellite Power and Margin |
289 W System Load; (1) 21 Ahr Battery (peak DOD of 30%); 3 M2 Driven Solar Array allows for Random Power Positive Attitudes with 24% margin Relative to 357 W (EOL) output
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| Thermal |
Passive Design MLI and Standard Coatings, Instrument attachment is low-conduction, radially flexible mount
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| C&DH Architecture |
PowerPC⁄750 (1 Mrad Hard): 8-10 MIPS for basic system GN&C and C&DH functions; VX-Works RTOS; significant processing throughput (>200 MIPS) available
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| Payload Data |
Science Data: accommodated via dedicated RS-422 I⁄F (up to 1 Mbps, standard); High Speed Options available
Housekeeping data: accommodated via 1553 Data Bus; 5 Kbps, each, allocated for Payload and S⁄C Bus housekeeping data
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| Data Storage |
2.6 Gbit standard memory; provides a full day of Packetized Data Storage and Autonomy for an Average Data Collection Rate of 30 Kbps (including science and housekeeping); Commercial High Capacity Memory Options Available
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| Command Interface |
1553 Standard Data Bus
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| Guidance, Navigation, and Control |
Stellar Target Profile Architecture; additional Reaction Wheel allows for Offsets to eliminate Zero-Crossings (improves observing efficiency)
Pointing Control: 4.5" (Roll⁄Pitch⁄Yaw)
Pointing Knowledge: 3.3" (Roll⁄Pitch⁄Yaw)
Long Term Stability: same as control
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| Autonomous Operation |
Continuous Autonomy with New Target Command Loads and Downlink Interleaved. Designed for 72+ hour Autonomy Periods
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| Communications |
Core System downlink is accomplished via fixed, Omni-directional,
S-Band Antennae at a data rate of 1.3 Mbps (2.4 Mbps transmit rate including packetization and overhead) produces Link Margin of >7.8 db; (3) 8 Minute Contacts (plus pass set up, etc.) are easily achieved in LEO using 5 meter Ground Antenna (Conservative Link Basis); CCSDS Format, Reed-Solomon Encoded. COP-1 Uplink Protocol
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| Radiation |
~10-13 Krads total dose estimated for 3 Year worst case LEO Mission; Avionics are resistant to >30 Krads dose and are SEU tolerant
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| Fault Toleration |
Single string plus Selected Dual Redundancy in Core System provides graceful degradation: Solar Array Electronics and Drive Motor Windings, Battery Cells, Extra Solar Cells, N+1 Redundancy in Memory Blocks, Gyro, Reaction Wheel, and Star Tracker
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Contact
space@atk.com
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