Biologically Inspired Radiation-Reflecting Ablator (BIRRA) for Enabling Entry Descent and Landing Missions to Gas Giant Planets or Radiation-Intensive Environments
Principal Investigator: Sylvia Johnson
Radiative heating during reentry becomes very significant as vehicles get larger and enter at high speeds. The specifics of the radiation depend on upon vehicle characteristics, speed and the atmosphere. Radiative heating occurs very early during reentry and at specific wavelengths, dependent upon the atmosphere. Thermal protection systems capable of dealing with such heat fluxes can be very heavy. An alternative is to make a heat shield that can reflect the radiation. One approach to radiation reflection is through photonic effects. Photonic effects rely on ordered structures of the same size as the radiation, and although it is possible to fabricate such structures it is currently time consuming and expensive.
An alternative approach is to use the ordered structures that are found in nature to make materials that can be used to reflect radiation. This project is exploring that approach to forming radiation-reflecting materials.
Collapsible Space Telescope (CST) for Nanosatellite Imaging and Observation
Principal Investigator: Elwood Agasid
Traditional imaging spacecraft are fixed in specific orbits and can be costly to reorient, or require a long development time prior to launch. In contrast, small spacecraft adhering to the CubeSat standard, can be built much more quickly and reach orbit as secondary payloads on a wide array of launch vehicles.
Despite their broad use within the university and scientific communities, the unique potential nanosatellites offer for high-quality, low-cost, rapid deployment imaging applications has not yet been successfully realized.
A wealth of key technologies have been developed within the nanosatellite community to include propulsion, ADCS, launch systems, and communications that enable low cost, rapid deployment, with precision spacecraft positioning and orientation capabilities. These innovations integrated with a deployable telescope yield a compact imaging system with unprecedented mission flexibility and performance for a fraction of the cost of a standard imaging system.
The ability to integrate a 15-20 cm telescope in a 6U nanosatellite demonstrates the applicability of nanosatellites for space science, operational, and exploration applications heretofore requiring larger platforms, and showcase low-cost integrated optical technologies. The goal of this project is to construct high fidelity tabletop deployable telescope structures. The products of this project include: low fidelity optical components to verify and refine deployment; selection and integration of sunshade and baffle material; validation of deployed telescope truss tube stiffness and repeatability to determine collimation requirements; preliminary design of primary and secondary mirrors, and the identification of optical and baffling tolerances requirements.
Computational Modeling of Ablative Materials: Application to Phenolic Pyrolysis
Principal Investigator: John Lawson
Ablative materials are required for the most demanding atmospheric reentry missions. These materials are often carbon fibers embedded in a phenolic polymer matrix. At high temperature, phenolic undergoes pyrolysis where the polymer is transformed into a pure carbon solid called char. There is currently no robust computational methodology for pyrolysis to guide improvement in thermal protection system (TPS) materials or make predictions of TPS performance under operating conditions.
Many NASA missions, including crewed missions to Mars, are not possible with current ablative materials. This project will examine different computational methods to model pyrolysis of phenolic to guide/accelerate development of novel materials and understand their behavior under operating conditions.
Computational modeling will enable the rapid and efficient development of the next generation of high performance ablators that are critical for NASA entry vehicles. Pyrolysis of phenolic polymers, for example, is a chemically reactive process fundamental to ablative TPS, but the basic chemistry of pyrolysis is not well understood. Improved understanding will (1) facilitate the design of new, novel ablative materials and (2) improve material response models used for TSP design.
The principal product of this project will be an assessment of simulation methodologies for phenolic pyrolysis. A new capability with these methods can then be applied to a range of problems in computational modeling of ablative materials.
Encapsulation Technology for Delivery of Medical Therapeutics
Principal Investigator: David J. Loftus, M.D., Ph.D.
The fastest growing area of medical therapeutics development is the field of peptide and protein therapeutics. For treatment of space radiation illness, a novel approach would be to implant cells in the body that are pre-programmed to deliver agents in response to radiation, such as a solar particle event. This approach would provide more rapid response to the radiation threat, and a more physiological dosing, for more effective treatment. Commonly, protein and peptide therapeutic agents have limited shelf-life (1-2 years); implantation technology gets around this issue for long-duration space travel (3+ years). To realize the vision of cell implantation to produce therapeutic proteins, technology for encapsulation of the cells is key: to prevent rejection of the cells by the host immune system, and to allow release of therapeutic agents from the capsule. Porous carbon meshwork technology, developed at NASA Ames, may provide a method for successful encapsulation of cells that secrete therapeutic proteins, that meets the medical needs of long-duration space flight.
In this study we will perform key proof of concept tests of a novel cell encapsulation technology that could be used for delivery of protein and peptide therapeutic agents for space medicine applications. The ARC-developed technology uses porous carbon meshwork capsules to contain cells and to serve as an “immune shield” to prevent the cells from being rejected by the host immune system. The pores of the capsule allow the therapeutic agents to be released from the capsule. The encapsulation concept is a key enabling technology for a wide range of Synthetic Biology applications where compartmentalization of the engineered cells is needed.
This project will open up a whole new approach for delivery of protein therapeutic agents, a field that has been stymied for many years by lack of a suitable encapsulation material. Success will also mean a significant advancement of NASA’s vision of technology for autonomous medical care on long-duration space flight. Initially, the primary impact will be in the area of medical care for treatment of space radiation illness, the #1 area of health concern for long-duration space flight. Ultimately, however, we view this as a platform technology. We expect that the encapsulation technology will be able to accommodate new peptide and protein therapeutic agents that will be developed in the future. More broadly speaking, we view the encapsulation technology as an “enabling technology” for the field of Synthetic Biology, because it provides a generic platform that can be used for a wide range of applications where the compartmentalization of engineered cells is needed.
High Energy Density Additives for Hybrid Fuel Rockets to Improve Performance and Enhance Safety
Principal Investigator: Richard Jaffe
Current hybrid-fuel rockets have limited application because of limitations of fuel performance. These hybrid fuel rockets use solid paraffin as the fuel base and add aluminum particles to increase the burn rate. However, the aluminum additive causes the paraffin to break apart during burning. Breakthroughs in fuel burn rate and physical properties are needed if hybrid rockets are to achieve their potential.
A novel high-strain hydrocarbon, called ivyane, has recently been synthesized and shown to have the highest strain energy of any hydrocarbon made to date. Ivyane-paraffin blend should have a faster burn rate, because ivyane has higher energy density. Adding ivyane to paraffin should result in improved performance compared to adding aluminum particles. Strained hydrocarbon additives like ivyane can be used to boost the performance of hybrid rockets by enhancing burn rate and reducing fragmentation of paraffin fuel, increasing the effectiveness of hybrid rockets while maintaining their inherent safety. This approach could make hybrid rocket technology cost-effective for a wider range of space applications.
The goal of this project is to demonstrate the feasibility of preparing ivyane-paraffin blends and characterizing their physical and mechanical properties. This project has the following specific goals:
- Determine the limit of solubility of ivyane in paraffinic hydrocarbons
- Determine density and melting temperature of ivyane-paraffin blends
- Determine effect of ivyane additive on paraffin burn rate
- Overall goal is to develop an improved fuel for hybrid rocket propulsion.
Low Cost Mars Sample Return Mission Study
Principal Investigator: Carol Stoker, M.S.
We are studying mission architecture for Mars sample return. The goal is to explore architecture solutions that return samples to Earth with a single Mars launch. We will examine a next generation lander under development by Space X corp. that is capable of delivering a 1 MT payload to the Mars surface as the landing system. The landed mission elements include a spacecraft stack consisting of a Mars Ascent Vehicle (MAV) and Earth Return Vehicle (ERV) that collectively will carry a sample canister from Mars back to Earth orbit. The MAV will use a one or two stage chemical propellant rocket to achieve trans-earth injection, where it will place the ERV en route to Earth. The study will consider the trade between chemical and electric propulsion for the ERV, and between sending the ERV on direct return to Earth vs Mars Orbit Rendezvous. The lander payload will include sample collection hardware such as an arm, drill, or small rover. Packaging of the MAV/ ERV and sample collection hardware will be a key study product. The study will examine the following elements:
- Design of the MAV /ERV stack with mass and performance uncertainty < 10%, including a sensitivity analysis of the design to technology performance.
- Recommended technology investment strategy to reduce cost risk to MSR architecture of MAV performance.
- Accommodation analysis of the MAV/ERV vehicle in a capsule form factor lander.
- Accommodation analysis of the sample collection hardware in the remaining volume of the capsule. The type of sample collection system possible depends on what landed payload mass is available after accommodating MAV/ERV. Options include (in order of increasing mass) a sampling arm, a drill, and a rover. Each of these has unique accommodation requirements.
- Analysis of how to accomplish planetary protection within this mission architecture.
The final product will be a report detailing the results of the analysis.
Manipulating the Toughness of Rocks through Electric Potentials
Principal Investigator: Friedemann Freund
Rocks in the Earth crust contain – in their minerals – previously unrecognized defects, which release electronic charge carriers when the rocks are mechanically stressed. These charge carriers are defect electrons in the oxygen anion sublattice, O– in a matrix of O2–, known as positive holes. These charge carriers have some truly amazing properties. They can flow out of the stressed volume and spread into the surrounding unstressed rocks. Important to this project is the fact that the wave function associated with these positive holes appears to be highly delocalized, meaning that hundreds of their O2– neighbors loose some of their electron density. This in turn must affect the bond strength between anions and cations, and thereby affect many fundamental physical properties of the rocks, including their volume and their mechanical strength. This is a quantum mechanical effect, which has far-reaching theoretical and practical implications.
We have conducted three sets of experiments using high intensity ultrasound waves to activate positive hole charge carriers in a gabbro, a typical rock from deep in the crust:
- Measure the bending of a cantilevered rock beam;
- Measure the stiffness of the rock in three-point bending experiments;
- Measure the volume expansion when positive holes are activated.
In cases 1 and 2 we have been able to show that the effect exists and is measurable. In particular, in case 2 we have demonstrated a decrease on the order of 10-15% in the flexure module. In case 3 we have received credible evidence that the rock volume does increase. More experiments are warranted to determine the magnitude of the effect.
Members of the Team:
- Dr. Minoru M. Freund, Center of Nanotechnology and Advanced Space Materials, NASA Ames Research Center (deceased)
- Dr. Claes Hedberg, Professor of Mechanical Engineering, Blekinge Institute of Technology, Sweden
- Dr. Kristian Haller, Research Scientist, Mechanical Engineering, Blekinge Institute of Technology, Sweden
- Dr. Parul Agrawal, Thermal Protection Materials Branch, NASA Ames Research Center
- Dr. Ramen Bahuguna, Professor of Physics, San Jose State University
- Dr. Peter Beyersdorf, Professor of Physics, San Jose State University
Student Members of the Team:
- John Pham, SJSU
- Daniel Jednorozec, SJSU
- Anvesh Cherukupally, U of AZ
- Mark Cordier, SJSU
Micro-atmospheric Microwell Plate Technology
Principal Investigator: Michael Flynn
Microwell-plate technologies are commonly used for bioassays, combinatorial chemistry, and cell culture experiments and are ideal formats for use as small satellite payloads. However, valuable research in space science cannot be effectively accomplished without significant improvements in our ability to deliver, remove, and measure gases in these formats. Complications arising from spacecraft atmospheric variations and the buildup and depletion of gases in solutions at the micro-scale can mask subtle interactions that are critical to achieving microgravity science objectives. This work will evaluate the feasibility of developing a sealed microwell-plate with a micro-atmospheric control system. Such technology would enable a wide range foundational research in Space Synthetic Biology, Fundamental Space Biology, and Astrobiology, ultimately generating knowledge required to engineer a potentially broad range of space biotechnology applications.
In microgravity, where buoyancy driven mixing is minimal, the buildup of carbon dioxide in solutions containing bacteria can adversely impact growth rates and mask more subtle effects. Likewise, the delivery of oxygen and removal of metabolic by-products at the bottom of a microwell in microgravity is difficult to achieve and even more difficult to measure. Gas that builds up and is not removed will supersaturate the growth medium and form bubbles causing interference with detection and analysis instrumentation. Also, the control of humidity levels in a microwell is important. What is needed is a standard microwell-plate that is sealed with a transparent cover slip and has the capability to control, mix, and measure gas concentrations inside the microwells. This work will demonstrate the feasibility of two key aspects of the system. These include the demonstration of the capability to measure gases at a nano scale at the bottom of a microwell and a study of the benefits of growing a microbial culture in a sealed microwell with a controlled micro-atmosphere.
Work to date includes a preliminary design study of a micro-atmospheric system including an engineering assessment of a microwell-plate microfluidic system, survey of potential sensor systems, and potential adsorbents. The system incorporates a new class of nanosensors to measure gas concentrations above a growth medium, gas phase adsorbents as gas reservoirs and partial pressure control actuators, and micro pumps and valves to circulate gases and insure good mixing. The technology will provide a method to assess and control atmospheric variation and nano-scale mixing in biological or non biological payloads.
Miniaturized Power Processing Unit Study: A Cubesat Electric Propulsion Technology Enabler
Principal Investigator: Shakib Ghassemieh
This study investigates the technical requirements and potential solutions for miniaturized High Voltage Power Processing Units with the objective of enabling Microfluidic Electric Propulsion (MEP) thrusters for cubesats and large missions.
For the long term evolvement of Electric Propulsion thrusters, Power Processing Units need to significantly reduce the mass, volume, and thermal properties. This will allow for usage of these thrusters from the micro down to pico-sized satellites, and enable long duration missions. Enabling the thruster technology will increase mission capabilities requiring orbital maneuvers including attitude control, spin, orbital inclination changes, de-orbiting, orbital transfers, swarm and formation flying.
The study focuses on the trade space to develop the Key Performance Requirements (KPRs) for the Power Processing Units and evaluates them against the current state of the art for technical feasibility. Topics investigated include:
- High Voltage parts evaluation
- Power Budget
- Output Power
- Number of control channels
- Operational modes
- Radiation Tolerance
- Power Efficiency
- Vendor Parts Availability
NanoSatellite Thermal Overload Protection System (nSTOPS)
Principal Investigator: Antonio Ricco
As small satellites are increasingly considered for low-cost space experiments beyond Low Earth Orbit (LEO), a means to control excessive onboard temperatures must be developed for orbits of high sun exposure. A 3-cube satellite covered on 4 sides by body-mounted solar panels, with radios on one end and a de-orbit mechanism on the other, offers little surface area upon which to locate thermal radiators, which would be ineffective in any case because the satellite’s passive magnetic orientation system cannot ensure that they face away from the sun.
In this project we modeled, developed, and tested a laboratory version of a means to electrically dissipate excess thermal energy from 3-cube (and larger) nanosatellites. The self-deploying “nanokite” de-orbit mechanism demonstrated on the Organism/Organic Exposure to Orbital Stresses (O/OREOS) nanosatellite was used to support a resistive electrical thin-film heater. Excess electrical energy from the solar panels, which ordinarily leads to electron-hole recombination that heats the panels and the underlying satellite, could be routed to such an outboard heater, which in this case was separated by about 20 cm from the main satellite body and faced away from the payload and bus. This thermal dissipative mechanism can add much-needed thermal control with no moving parts, a few grams of added mass, and a few cm3 of added volume.
The products of this project include a thermal model, laboratory prototype, and documented results.
Novel Photobioreactor Development for Space Applications
Principal Investigator: Leslie Prufert-Bebout
Currently human life support in space depends on chemical and physical means re-supplied from Earth. Longer duration, remote manned space missions in the future will require regenerative, lightweight life support systems capable of recycling carbon, nitrogen, phosphorus, and trace elements independently in closed loop systems. On Earth human life depends upon a vast diversity of microbial communities perfectly adapted to fill these and many other critical roles, including the production of food, fuels and pharmaceuticals essential to human well-being.
In space, we are only beginning to explore the means to transport and optimize these inter-connected microbial support functions. Microbial systems will encounter similar challenges in space as humans (microgravity, radiation tolerance), in addition to micro-scale, low Reynolds number materials exchange phenomena; these will require systematic assessment, development, adaptation and optimization towards various applications. In order to enable a research program that addresses all of these factors, a platform that is reliable, flight ready and specifically designed for optimized microbial ecosystem growth, monitoring and regulation in space is required. Ideally, this platform should be designed with enough flexibility to serve as a standard platform for both experimental and functional application purposes.
With these goals in mind, we have developed the Surface Attached Bioreactor (SABR) platform. SABR makes use of interfacial phenomena to drive mass transport, which enables its operation independent of gravitational and inertial forces, making it a perfect match for extraterrestrial applications. Moreover, the significant reduction in water and overall system mass achieved by SABR make it ideal for space missions for which mass is a significant concern due to fuel up-launch requirements.
To date SABR has passed the following milestones:
- Demonstrated growth of algal biomass using 25 times less water than conventional photobioreactors
- Demonstrated CO2 scrubbing at two to four times higher rates than conventional reactors, with a factor of 3x less weight
- Proven salt buildup mitigation capability
SABR can be used for a wide variety of single cell type or mixed culture systems. It can also be used with both photosynthetic (artificial or solar irradiance) and non-photosynthetic systems. The platform can be adjusted either to grow and harvest cells, or to maintain cells and harvest metabolic products by means of a passive collection design feature.
The SABR project is a collaboration between the NASA Ames Research Center, Systems Biology and Ecology Lab in the Exobiology Branch, and the Solar Energy and Biofuels Lab in the Mechanical Engineering Dept., at the University of Texas Austin. The project benefits in leveraging from 25 years NASA experience in the elucidation and manipulation of microbial carbon and nitrogen cycling pathways, including the current Dept. of Energy funded collaboration with colleagues at Lawrence Livermore National Labs and Stanford on biohydrogen production.
Phase 1 prototype and biological performance characteristics led to the SABR project being awarded additional funding through the OCT office to incorporate enhanced imaging and monitoring capabilities. Future platform enhancements for target applications will be constructed using specifically designed microbial communities for transcriptome array analyses in space coordinating genetic signaling to functional performance for modeling and prognostics development for reliability in long term operations.
Photon-Counting Integrated Circuit (PCIC) Photodetector Arrays
Principal Investigator: Ted Roush
Technological improvements in sensors available to NASA have a significant cross-cutting impact for an array of NASA instruments measuring over a broad range of the electromagnetic spectrum. Improvements of detector performance would cause a significant shift in capability.
The commonly used avalanche photodiode (APD) boosts the signal level of input optical power. However, high avalanche excess noise and extreme sensitivity to bias voltage makes it very difficult to achieve high gain or gain uniformity across an APD 2-D focal plane array, let alone the Geiger recovery time. The PCIC is an enabling technology potentially providing for greater detector sensitivity in a wide range of thermal and radiation environments.
Radiation Nose for Monitoring Radiation in Space Missions
Principal Investigator: Meyya Meyyappan
Radiation exposure is a serious issue in manned space exploration. The impact of radiation on electronic equipment and other payloads is also a major concern. The knowledge base in these areas is typically developed on ground-based testing and modeling efforts. As a rule, there is no in situ monitoring of various radiations and their energy levels as the equipment needed for measurement is bulky, expensive, and requires special training for operation.
The goal of this project is to develop a postage-stamp sized chip to detect radiation sources (alpha, gamma, X-ray, protons, etc.) and their energy levels, like a radiation nose (r-nose). This system will use a conventional silicon complementary metal oxide semiconductor (CMOS) chip, except that the silicon dioxide dielectric will be replaced with a liquid dielectric.
Some liquids react to radiation exposure with a change in molecular structure, leading to a change in properties such as dielectric constant and polarization. Inspired by such responsivity of liquids, we propose to construct a transistor with a radiation-responsive liquid as a gate dielectric replacing the conventional oxide gate layer. The current voltage characteristics of the liquid gate dielectric transistor would change upon exposure to any type of radiation. Different types of liquids that specifically interact with various target radiations can be used in an array of transistors serving as a radiation nose to discriminate different radiation sources. Moreover, the fluidity of the liquid facilitates the exchange of the damaged liquid with fresh liquid after some time, allowing a reusable sensor.
Selection of liquid-state gate dielectric is important for an acceptable device performance, and the choice should satisfy the following requirements: insulating properties, proper dielectric constant, dielectric strength, thermal stability, high purity, low moisture absorption, low viscosity, and responsive to radiation. The product of this project is a radiation sensor chip and test results for gamma radiation.
Availability of on-site or in-situ monitoring of various radiations in real time would enable safer long duration manned flights. Currently such monitoring is not possible due to lack of technology.
Synthetic Biology and Microbial Fuel Cells: Towards Self-Sustaining Life Support Systems
Principal Investigators: John Hogan and Michael Flynn
NASA ARC and the J. Craig Venter Institute (JCVI) are collaborating to investigate the development of advanced Bio-Electrochemical Systems (BESs) for human life support in space. BESs utilize specifically-adapted microorganisms that can either generate electrical power during the metabolism of substrates (Microbial Fuel Cell – MFC), or can conversely utilize electrical current to “drive” microbial metabolism for the production of products (Reverse MFC). BESs possess numerous advantages for space missions, including rapid processing, reduced biomass formation, and energy efficiency. Additionally, the use of advanced Synthetic Biology techniques offers the potential to genetically modify microorganisms to further increase system capability and performance.
The initial goal of this work was to examine technology infusion of BESs for wastewater treatment and other human life support functions. Tasks included:
- Identification of potential integration scenarios that use BESs to treat space-based wastewaters
- Investigation of appropriate synthetic biology research and development areas that advance the use of BESs for space
- Investigation of potential power production efficiency and utilization strategies to determine power offsets and power “self-sustainability”
- Investigation of BESs as a means to use electrical power to perform biological processing
This work led to additional funding from NASA’s Office of the Chief Technologist to continue and expand collaborations with the J. Craig Venter Institute and Stanford University to examine the potential to integrate a Reverse MFC to convert human metabolic carbon dioxide to methane and water for air revitalization and resource recovery. This work is being performed within the NASA Ames Research Center Space Synthetic Biology program. The project is focusing on defining optimal process integration scenarios, and will result in the development of both unique BES reactor hardware and a genetically modified organism designed for optimal carbon dioxide conversion. Additional efforts include developing space-based BES design concepts, integration analyses, increasing system efficiency, and investigating additional BES applications. These combined efforts will leverage NASA’s expertise in space-based wastewater treatment and air revitalization with advanced synthetic biology and BES research and development at the J. Craig Venter Institute and Stanford University to significantly forward BES technology development for both space missions and terrestrial applications.
Synthetic Biology Tool Kit for Manned Missions Outside Low Earth Orbit
Principal Investigator: Lynn Rothschild
Human missions outside low earth orbit will require on-site synthesis of materials to reduce mass requirements. In addition, any long-term mission is likely to encounter unexpected problems that require tools or materials that were not included in mission planning.
Currently if genetic engineered organisms are used in space, the molecular engineering is done prior to launch. Problem solving on missions relies on the materials and capabilities that are carried on the mission. More likely, products are brought into space rather than synthesis capability.
Synthetic biology is the design and construction of new biological functions and systems not found in nature. Just think….
Biological tools can be used to synthesize many materials on site as they are needed, reducing mission weight and storage requirements for unstable materials.
DNA can carry huge amounts of information and functional capabilities in an extremely low-weight form. Simple molecular biology tools could be used to create new tools on-site, during a mission using recipes developed on earth in response to unexpected mission needs
What we envision
A 5 kilogram kit could replace hundreds of kilograms of materials on a long term mission. On-site supply of unstable materials could reduce weight and complexity of storage requirements for the mission. An Apollo 13-like capability to respond to unknown problems could make the difference between success and failure on a mission where timely resupply is impossible
- Create a flexible synthetic biology tool kit that can be used to supply a large variety of materials for the mission
- Carry an diverse set of genes with the widest possible range of capabilities
- When the unexpected occurs, develop solutions on earth using the synthetic biology kit, the gene set and other flexible manufacturing capabilities included on the mission
- Transmit a recipe to the mission
- Crew members use the kit to create new materials that will help them deal with the problem.
Woven TPS – A Revolutionary Approach to Tailorable TPS Design & Manufacturing for Thermal Management Systems & Entry, Descent & Landing Systems
Principal Investigator: Don Ellerby
The thermal protection material system (TPS) is the barrier that protects the space vehicle from atmospheric entry heating. Woven TPS is a concept that leverages the mature weaving technology that has evolved from the textile industry to design TPS with tailorable performance by varying a material’s composition and properties by the controlled placement of fibers within a woven structure. The resulting woven TPS can be designed to perform optimally for a wide range of aerothermal environments encompassing NASA’s future mission needs.