TOPIC: S3 Spacecraft and Platform Subsystems

• Processors - General purpose (processor chips and radiation-hardened by design synthesizable IP cores) and special purpose single-chip components (DSPs) with sustainable processing performance and power efficiency (>500 MIPS at >100 MIPS/W for general purpose processing platforms, >5 GMACs at >5 GMACS/W for computationally-intensive processing platforms), and tolerance to total dose and single-event radiation effects. Concepts must include tools required to support an integrated hardware/software development flow.
  
• Radiation-hardened non-volatile low power memories.
  
• Radiation-hardened physical layer components for onboard data busses (e.g. Ethernet).
  
• Tunable, scalable, reconfigurable, adaptive fault-tolerant avionics.
  

1. Optical systems, lasers and detectors require tight temperature control, often to better than +/- 1°C. Some new missions such as LISA require thermal gradients held to even tighter micro-degree levels.
   
2. Exploration science missions beyond earth orbit present engineering challenges requiring systems which are more self-sufficient and reliable.
   
3. The introduction of low-cost, small, rapidly configured spacecraft requires the development of new thermal technologies to reduce the time and costs typically required for analysis, design, integration, and testing of the spacecraft.
   

• Methods of precise temperature measurement and control to tight temperature levels.
  
• High conductivity, vacuum-compatible interface materials to minimize losses across make/break interfaces.
  
• High conductivity materials to minimize temperature gradients and provide high efficiency light-weight radiators, including interfaces to heat pipes and fluid loops that overcomes issues with CTE mismatch.
  
• Advanced more efficient thermoelectric coolers capable of providing cooling at ambient and cryogenic temperatures,
  
• Advanced thermal control coatings, particularly those with low absorptance, high emmittance, and good electrical conductivity. Also, variable emittance surfaces to modulate heat rejection are needed.
  
• Single and two-phase mechanically pumped fluid loop systems which accommodate multiple heat sources and sinks, and long life, lightweight pumps for these systems. Also includes advanced fluid system components such as accumulators, valves, pumps, flow rate sensors, etc. optimized for improved reliability, long life, and low resource needs.
  
• Phase change systems for Mars or Lunar applications. Reusable phase change systems are desired which can be employed to absorb transient heat dissipations during instrument operations. Technology is sought for phase change systems which can then either store this energy or provide an exothermic process which would provide heat for instrument power-on after the dormant phase.
  
• Ionic liquids, salts composed of separate cations and anions, have been known but not intensely studied. Because of their tunable and thus extremely favorable solvent and materials properties, ionic liquids are potentially useful for a wide range of space applications, e.g. liquid-mirror telescopes and heat transfer of fluids that could enhance lunar regolith geothermal potential many-fold.
  
• Efficient, lightweight, oil-less, high lift vapor compression systems or novel new technologies for high performance cooling up to 2 KW.
  
• Advanced thermal modeling techniques that can be easily integrated into existing codes, emphasizing inclusion of two-phase systems and mechanically pumped system models.
  
• Integration of standardized formats into existing analytical codes for the representation and exchange of thermal network models and thermal geometric models and results.
  
• Analytical codes to automate the generation of reduced thermal models from larger models, including routines to verify the accuracy of the reduced models.
  

• Novel methods or approaches for radiation-tolerant, sensorless, autonomous control of Stirling converters with very low vibration and having low mass, size, and electromagnetic interference (EMI);
  
• High-temperature, high-performance regenerators and linear alternators;
  
• Advances applicable to Venus surface missions including high-temperature heater heads (> 850°C), joining techniques and regenerators (~1200°C), and combined electrical power generation and cooling systems applicable to Venus surface missions (~1200°C);
  
• Concepts for Stirling engine power from cold energy lunar regolith down to 2-3 meters below the surface, including Stirling Engines that will provide up to 100 watts with a mass less than 50kg for the surface lunar environment with the hot side operating at about 256 K and a cold side at about 100 degrees lower.
  

• Low-bandgap cells having high efficiency and high reliability;
  
• High temperature selective emitters;
  
• Low absorptance optical band-pass filters;
  
• Efficient multi-foil insulation.
  

• Photovoltaic cell and blanket technologies capable of low intensity, low-temperature operation applicable to outer planetary (low solar intensity) missions;
  
• Photovoltaic cell, blanket and array technologies capable of enhancing solar array operation in a high intensity, high-temperature environment (i.e. inner planetary and solar probe-type missions);
  
• Lightweight solar array technologies applicable to solar electric propulsion missions. Current missions being studied require solar arrays that provide 1 to 20 kilowatts of power at 1 AU, are greater than 300 watts/kilogram specific power, can operate in the range of 0.7 to 3 AU, provide operational array voltages up to 150 volts and have a low stowed volume.
  

• Lightweight tanks;
  
• Actuators and regulators;
  
• Self pressurizing propellants.
  

• Hall thruster power processing unit (PPU) capable of 3 ½ kW, 5A, and 700 V with a maximum mass of 5.25 kg;
  
• High specific impulse/low mass electric propulsion systems for sample return missions;
  
• Future low cost/low mass electric propulsion systems;
  
• Thrusters should provide thrust up to 20 mN with a specific impulse between 1600 to 3500 seconds;
  
• Corresponding power processing units capable up to 1 kW of input power;
  
• The total system mass should not exceed 3 kgs (roughly 1 kg for a thruster and 2 kg for a PPU).
  

• High temperature devices and components (up to 450°C);
  
• Advanced electronic packaging for thermal control and electromagnetic shielding.
  

• Highly reliable, radiation tolerant, special purpose data processing devices (FPGA, multi-core, DSP) that enable accelerated onboard data processing;
  
• Hybrid onboard processing architectures using multiple heterogeneous processing elements (CPU, FPGA, DSP, multi-core);
  
• Architectures providing software-based radiation mitigation strategies for commercial processing elements.
  

• Hybrid system design tools that (a) take full advantage of hybrid processing platforms, and (b) automate/accelerate the design and verification process.
  

• Solid propellant technology with specific impulse performance potential higher than HTPB and CTPB;
  
• Propellant blend with high performance and low storage and operating capability down to 150 K;
  
• Low temperature seals and components;
  
• Light weight and reliable thrust vector control;
  
• Other light weight system and component technologies.
  

• Higher performing monopropellants with specific impulse >240 secs;
  
• High chamber pressure thrusters > 500 psia;
  
• Pressurization component technologies to reduce system mass (filters, solenoid valves, latch valves, tanks, fill and drain and check valves);
  
• Small lightweight pump technologies to operate at >500 psi output pressure;
  
• Non-pyrotechnic isolation valves.
  

• Precision flight path control for highly repeatable terrain monitoring over daily, seasonal or multi-year cycles;
  
• Highly accurate UAV platform attitude control with corresponding science payload instrument stability and pointing accuracy;
  
• Lower-cost over-the-horizon telemetry alternatives for real-time collaborative data sharing and decision-making involving multiple in-flight and ground-based instruments;
  
• Drop-sonde and surface sampling probes remote from the unmanned aircraft;
  
• Airframe icing detection and mitigation to enable UAV severe weather flight operations;
  
• UAV flight systems to enable long endurance inclement weather operations; systems such as fuel anti-freezing thermal management will be needed.
  

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