Planetary Science Technology Prioritization: Ocean Worlds Technologies

Carolyn Mercer NASA Headquarters

Briefing to the Outer Planets Assessment Group

September 6, 2017 La Jolla, CA

Visions and Voyages “The committee unequivocally recommends that a substantial program of planetary exploration technology development should be reconstituted and carefully protected against all incursions that would deplete its resources. This program should be consistently funded at approximately 6 to 8 percent of the total NASA Planetary Science Division budget.” “The committee recommends that the Planetary Science Division’s technology program should accept the responsibility, and assign the required funds, to continue the development of the most important technology items through TRL 6.”

How to determine “the most important technology items”?

• Planetary Technology Working Group Members surveyed the VEXAG, OPAG, SBAG, Mars Program, and the Decadal Survey

• Then assessed each technology identified by the AGs using the following Figures of Merit: • Critical Technology for Future Mission(s) of Interest • Degree of Applicability across PSD Missions/needs • Work Required to Complete • Opportunity for Cost Sharing • Likelihood of Successful Development and Infusion • Commercial Sustainability

• Corporate knowledge includes previous studies, e.g.:

“PSD Relevant Technologies,” G. Johnston 1/7/11 https://solarsystem.nasa.gov/missions/techreports

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Community Technology Inputs (VEXAG, OPAG, SBAG, Mars Program, Decadal, Surveys) from: Planetary Science Technology Plan, April 9, 2015

Applicable Technology Small Bodies

Outer Planets

Venus Mars MoonSmall

BodiesOuter

PlanetsVenus Mars Moon

Small Bodies

Outer Planets

Venus Mars Moon

In Space PropulsionAerocapture/AeroassistEntry (including at Earth)Descent and DeploymentLanding at target objectAerial PlatformsLanders - Short DurationLanders - Long DurationMobile platform - surface, near surfaceAscent VehicleSample ReturnPlanetary Protection

Energy Storage - BatteriesPower Generation - SolarPower Generation - RPS ?Thermal Control - PassiveThermal Control - ActiveRad Hard ElectronicsExtreme Temp MechanismsExtreme Temp ElectronicsCommunicationsAutonomous OperationsGN&C

Remote Sensing - ActiveRemote Sensing - PassiveProbe - Aerial PlatformIn Situ - Space PhysicsIn Situ Surface - GeophysicalSamplingIn Situ Surface - Long Duration - Mobile

SYST

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ECHN

OLO

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SUBS

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M T

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INST

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NEAR TERM MISSIONS MID TERM MISSIONS FAR TERM MISSIONS

TRL 6 and aboveHigh TRL - limited development and testing neededModerate TRL - major R&D neededLow TRL - notable technical challenges

This decadal Next decadal After that

Outer Planets input based on the OPAG white paper “Outer Planet “Roadmap of 2009

Planetary Science Division Prioritized Technologies April 2016

Prioritized Technologies

Low temp compatible, low power, rad-hard electronicsLow temp compatible actuators/mechanismsPlanetary Protection Techniques/component and material compatibiltySub-surface (>0.2 m) ice acq and handlingice sample returnpinpoint landing on Titan

High performance/low power/rad hard computing and FPGAsLow intenstiy/low temp solar powerRPS surface powerRPS orbital powerSystem autonomy (GNC, Prox Ops, C&DH, sampling ops, FDIR)Power, GNC, Propulsion, comm for small s/chigh bandwidth and datarate commhigh temp-compatible electronicshigh temp-compatible power systemsplanetary ascent vehicle for sample returnheat shield technologies for planetary entry and sample return

surface cryogenic ice sample acq and handlinglow temp batteriespinpoint landing on Europalanding hazard avoidance

life detection for ocean worldslow mass, low power instruments for cold, high rad ocean world environmnentslow mass, low power instruments for small spacecraft

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• Low-Temperature Compatible Low Power, Rad-Hard Electronics and Energy Storage • High Specific Energy, Radiation Tolerant Primary Batteries (Europa)

• Low Temperature Actuators and Mechanisms • Lubrication • Bearings • Testing Facility • Actuators

• Pinpoint Landing on Titan • EDL Architecture Trade Study • Terrain Relative Navigation • Guidance and Control

• Pinpoint Landing and Hazard Avoidance (Europa)

• Ice Penetration and Sampling • Low-Mass, Low-Power Excavation • Sample Handling and Transport • Surface cryogenic ice sample acquisition and handling (Europa) • Bioburden Reduction-Tolerant Hardware

• Planetary Protection Techniques/Component and Material Compatibility • Expanded Bioburden Reduction Technique Toolbox • Backward Contamination Technology Demonstration

• Ice Sample Return • Integrated Cryogenic Chamber • Responsive Systems for Containment

Ocean Worlds Prioritized Technologies

8/30/17

• Lander • Surface cryogenic ice sample acquisition and handling • Pinpoint Landing and Hazard Avoidance • High Specific Energy, Radiation Tolerant Primary Batteries

• Autonomy • Ice Penetration and Sampling

• Low-Mass, Low-Power Excavation • Sample Handling and Transport • Bioburden Reduction-Tolerant Hardware • Low Temperature Actuators and Mechanisms (as needed for sample acquisition/transfer)

• Lubrication, Bearings, Testing Facility, Actuators • Planetary Protection Techniques/Component and Material Compatibility

• Expanded Bioburden Reduction Technique Toolbox • Backward Contamination Technology Demonstration

• Low-Temperature Compatible Low Power, Rad-Hard Electronics and Energy Storage

• Pinpoint Landing on Titan • EDL Architecture Trade Study • Terrain Relative Navigation • Guidance and Control

• Ice Sample Return • Integrated Cryogenic Chamber • Responsive Systems for Containment

Ocean Worlds Prioritized Technologies

8/14/2017

Draft 1st Tier

Draft 2nd Tier

Draft 3rd Tier

• Lander

• Surface cryogenic ice sample acquisition and handling • Sample acquisition 10 cm below surface • Sample temperature < 150 K • Sensing to enable autonomy

• Pinpoint Landing and Hazard Avoidance

• Determine position <50m and touchdown velocity <0.1 m/s with 1200 krad TID • Generate 100m x 100m map with 5 cm ground sampling from 430m at 0.5 Hz with

1200 krad TID

• High Specific Energy, Radiation Tolerant Primary Batteries • Provides 20 to 30 day mission life for a 100 kg battery package for the landed system • In addition to power, the batteries dissipate heat that is harvested for thermal

management • High radiation and Planetary protection sterilization are critical requirements

Ocean Worlds Prioritized Technologies

8/29/2017

Ice Penetration and Sampling Technical Goal

Mission Applications

System-level ice penetration and sampling capability to enable ice exploration in Ocean Worlds at temperatures @ ~100K and depths of 10 to 2,000 meters. Major hurdles are to operate in extreme cold ~@100K and to stay within plausible mass , power, and volume (order of magnitude 100kg, 100W) constraints of near-term landed missions while meeting COSPAR requirement that probability of forward-contamination of the ocean be less than 10-4 per mission. Technology advances are required in: • Low-power, low-mass excavation, • Sample handling and transport, and • Bioburden Reduction-Tolerant Hardware

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• Discovery of macromolecules indicating extant life may exist can be looked-for in water that periodically erupts onto the surface and freezes, or in convecting ice, or in the liquid water ocean.

• Enceladus plume vents may be explored, including down to liquid water.

• Low probability of contamination of the sample during mission to meet COSPAR and eliminate chance misinterpreting earth life as alien life.

• Depths > 10 m enables sampling of pristine material, e.g. almost entirely unaffected by the radiation environment of Europa.

• Enables sampling of liquid water from oceans covered by the shallowest ice thickness, or in convecting ice that

has been in contact with the liquid oceans in the relatively recent past • Convection zone on Europa likely to be at least one or a few km depth.

8/29/17

Low Temperature Actuators and Mechanisms Summary of Lubrication, Bearings, Test Facility, and Actuators

Many of the following current technology can survive -190˚C, but for very short time or few cycles. • Piezo Actuators: Piezo materials suitable for cryogenic temperature are at TRL4-5, however drive electronics is

lagging. More focus on 100V electronics is required. • Brushless DC / stepper electromagnetic motors • Shaft / sensor fabricated with additive manufacturing • Cryo actuators

1. Advanced dry lubricant materials that can survive -240˚C to 125˚C temperature cycling and operate at -240˚C 2. Lubrication materials that do not require lubricants such as bulk metallic glasses 3. Bearings innovative approaches that use either gas, liquid, magnetic, dry lubricant or lubricant free approaches

such as bulk metallic glass that can survive -240˚C to 125˚C temperature cycling and operate at -240˚C 4. Actuators that push performance of actuators to operate at -240˚C and exploit potential of sensorless

commutation and that can survive -240˚C to 125 ˚C temperature cycling, operates at -240˚C and radiation tolerant to total ionizing dose (TID) = 300 krad (Si)

5. Testing facilities that can simulate Titan’s lake using liquid methane (“wet ” environments) 6. A survey of commercial cryogenic technologies to mature and adapt these technologies for low temperature

space flight use

5/26/17

Technical Goal

State-of-the-Art

Prioritized Technology: Ice Penetration and Sampling – Bioburden Reduction-Tolerant Hardware

Technical Goal Technical Status • Development of Ice penetrating and sampling hardware

for Ocean Worlds missions that is compliant with planetary protection requirements and tolerant to at least one of the NASA-qualified methods for bioburden reduction.

Example: Europa Clipper mission has a requirement to ensure a <1x10-4 probability that a single viable Earth organism remains on the surface of Europa after a possible spacecraft impact, due to the potential for rapid communication between the subsurface and surface of that moon

• Experimental testbeds for validation of complex designs and operational cases that permit design revision prior to flight builds

Current NASA Methods for Bioburden Reduction: NASA has qualified two approaches for bioburden reduction:

(1) Dry Heat Microbial Reduction, (2) Vapor Hydrogen Peroxide;

Other techniques need investigation (gamma, plasma, etc.)

Overlap of DHMR compatibility with High-Temperature Parts: NASA EEE Parts Selection processes should be evaluated to expand use to MIL-SPEC 810F (High Temperature Compliant) parts as well as Automotive Industry Parts (AEC series), both of which are qualified to operate at temperatures that are much higher

Limited development of system-level techniques: There is a need for integrated/scaled up methods for large-scale bioburden reduction

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8/30/17

Planetary Protection Expanded Bioburden Reduction Technique Toolbox

Technical Goal

Mission Applications

Forward Contamination Risk Reduction for: • Europa: Clipper, Lander, Sample Return • Enceladus: Plume Sample Return, Lander Sample Return • Ceres, Vesta, Mars, TItan: Landers, Rovers/Boats, Sample Return Risk mitigation for activities common to the project lifecycle: Current mitigations are conservative implementations, given limited technology development (for example, rework recontamination after integration has not been explored experimentally from a planetary protection POV) Synergistic impacts : At NASA—human exploration; Outside NASA--Department of Defense and National Institutes of Health applications for use with biohazard/bioweapon decontamination activities.

To enable planetary protection (PP) capabilities to meet the 10-4 inadvertent contamination probability for forward planetary protection through expansion of bioburden reduction technique toolbox and materials compatibility: Near Term: Compatibility and Specifications Expansion - materials compatibility, increased size scale and expanded specifications for Heat Microbial Reduction – expanded specs: mated surfaces, embedded organisms ; Vapor Hydrogen Peroxide – validate VHP model, dose dependences of dose (e.g. pressure, time, temp, geometry) Mid Term: - Development of Alternative Approaches: Gamma Radiation –develop specs for in-flight and pre-launch dose condition; DoD Techniques – Leverage & tailor existing approaches for spacecraft applications Long-Term: Scaling and Risk Mitigation: Interrupted microbial reduction processing experimentation (e.g. Does 110C at 20h + 110C at 30h = 110C at 50h?); Summed bioburden reduction approaches e.g. VHP+HMR, HMR+VHP

8/30/17

Backup

Prioritized Technology: Ice Penetration and Sampling – Low-Mass, Low-Power Excavation

Technical Goal Technical Status Establish one or more methods to extract samples from ice (with possible salts, sulfur and biomolecules) in Ocean Worlds at progressively increasing depths, eventually all the way to the liquid water: • Pristine as possible (at least at micro-scale) • Reduce cross-contamination • Must tolerate sulfur-rich environment (e.g. sulfuric acid)

Landed missions expected to have saws, drills, melt-probes, etc. deployed from within the lander body onto or into the ice.

• Europa lander pre-project has conducted many experiments of cutting cryogenic ice, mostly with saws.

• 3D-printed 316 stainless saw blade has cut -85C ice. • Many approaches exist for sampling between 0.2

and 2 meters: circular or chain saws, heated blades or scoops, etc.

• Wireline drills allow open-hole drilling or coring without lining the hole in formations where mechanical properties allow a hole to remain open without lining.

• Novel approaches to melt probes (e.g. putting heat source in Dewar to eliminate horizontal heat leak) may allow deep penetration within mass/power/volume limits.

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8/29/17

Technical Goal Technical Status • Develop process for sample handling and hardware

transport system for samples from the point of extraction taking into account

• forward contamination constraints, • ensuring Earth life is not ingested into instruments,

and • specific sample preparation requirements for each

instrument. • method to handoff sample to instrument or sample

return

• Sample handling and transport has not been attempted at cryogenic temperatures by robotic spacecraft.

• Biomolecule detection may be done at liquid water temperatures, so cyrogenic handling may not be required for all (or any) instruments.

Prioritized Technology: Ice Penetration and Sampling – Sample Handling and Transport

Prioritized Technology: Low Temperature Actuators and Mechanisms Summary of Lubrication, Bearings, Test Facility, and Actuators

Many of the current technology can survive -190˚C, but for very short time or few cycles. 1. Lubricants: Dry lubricants (e.g. PGM-HT, sputtered MoS2) and non

lubricated systems (e.g. bulk metallic glass (BMG) developed but further testing is needed to define their LT capabilities

2. Bearings: Many bearing types under development (gas, liquid, active magnetic, permanent magnet) as well as non-lubricated bearings (e.g. BMG) are at various stages of readiness

3. Actuators: Piezoelectric, brushless actuators at -190˚C currently operational – shaft sensors are evolving rapidly. Eg. JWST 1-time deployable actuators were tested to -190C

4. Testing: Testing capabilities are limited. JPL has a liquid methane bath but facility needs maturing for component testing

1. Europa [Near Term] robotic arm, gimballed antenna and camera requires a range of capabilities (lubrication, bearings, actuators and gearboxes). 2. Titan landers [Mid/Far term] pin point landing enabled. If capability realized, mission duration will be extended 3. Ice penetration and sampling on Ocean Worlds in the Mid/Far Term on missions would be extended from a couple weeks to few months. 4. Enabling this low temperature technology will allow us to reduce mass, power consumption (no heaters), and thermal losses (less cables) which ultimately,

extends mission life. If actuators need not need heaters to operate, more power would be available for instrument operation and would extend the mission life. e.g. M2020, it could take up to 3 hours with energy as high as ~400Wh in order to warm up one of the arm actuators from -100C to -30C. Having actuators that operate at -240 would save energy and warm up time, which would increase science operating time and extend mission life. Thermal leaks will be reduced with no heater, PRT and control cables. The heat loss for a 1 meter 20AWG copper that links cold sink at -240˚C to hot source at 10KC is ~0.2W. Reducing the number of wire from 20 wires to 10, would save about 2W power. Fewer heaters also help reduce thermal contamination of the area of interest. Although heaters, PRTs, and thermostat are low mass, savings from no MLI could be considerable as the typical A142 20-layer MLI is 1kg/m2. Required MLI is highly dependent mission architecture but baseline area for MSL type mission is about 3-4 m2.

5. Another improvement very much needed is to increase target lifetime low temp cycles of operation from 500-1000 cycles to a few million cycles for the actuators. For Mars2020, the requirement for MOXIE is to run 3000rpm for 10 hours; translating to about 4 million cycles testing needed (2X life). In addition, percussion actuators requirement is 25Hz for 30 hours (or 5.4 million cycles if tested at 2X life).

6. Enabling these lower temperature technologies will enable science in Europa, Titan, and other ocean worlds.

1. Advanced dry lubricant materials that can survive -240˚C to 125˚C temperature cycling and operate at -240˚C

2. Lubrication materials that do not require lubricants such as bulk metallic glasses

3. Bearings innovative approaches that use either gas, liquid, magnetic, dry lubricant or lubricant free approaches such as bulk metallic glass that can survive -240˚C to 125˚C temperature cycling and operate at -240˚C

4. Actuators that push performance of actuators to operate at -240˚C and exploit potential of sensorless commutation and that can survive -240˚C to 125 ˚C temperature cycling, operates at -240˚C and radiation tolerant to total ionizing dose (TID) = 300 krad (Si)

5. Testing facilities that can simulate Titan’s lake using liquid methane (“wet ” environments) are practically non existents

6. A survey of commercial cryogenic technologies to mature and adapt these technologies for low temperature space flight use.

5/26/17

Technical Goal Technical Status

Mission Applications

Low Temperature Compatible Low Power, Rad-Hard Electronics and Energy Storage

Technical Goal Technical Status

Mission Applications Duty Cycled Lander or Probe for Ocean Worlds and Europa: Small mobility platforms and science instruments that can remain in sleep mode at -240⁰C without sustained heating, relying on local heaters for “start up” and self-heating during operation, could reduce the required heater power by >95%. For a 1 meter diameter probe, this could result in 0.63kg/day mass savings for the mission from time of separation from the spacecraft (coast) to end of the landed mission. Alternatively, this stored energy could be used to increase probe lifetime or functionality. Long life science crafts, aerial or small distributed probes: Surface missions to Ocean Worlds and Europa will require subsystems, arms, instruments, actuators, and appendages to operate at -240⁰C. Cold-operational distributed electronics for these platforms can limit the number of wires and length of cables between electronics and their associated actuators/instruments. This will drastically reduce mass, power, signal losses and noise, while increasing redundancy. The use of distributed motor control could reduce actuator harness mass by 90%. Additional technologies needed for these probes include high specific energy -80⁰C primary batteries that are able to meet the above technical goals. Such batteries can potentially extend mission life by 400%.

1-SOA for cold survivable electronics is defined by the Mars Temperature Cycle Resistant Electronics technology. This packaging technology is capable of +85 to -120⁰C cycling for 2000 cycles (TRL 9).

2 and 3-NASA technology for lunar applications developed -180⁰C SiGe based custom electronics and models on a presently obsolete 0.5µm SiGe BiCMOS technology (TRL 5). Mars Focused Technology (MFT) developed a custom Operational Amplifier on 0.35 µm SOI CMOS rated at -180⁰C to +120⁰C and 300krad (TRL 9). Teledyne and MIT Lincoln Lab have developed cryogenic capable custom ROICs and ASICs on an older generation CMOS technology (TRL 9).

4-DS-2 low rate micro-probe primary batteries, manufactured by Yardney Tech., capable of -80⁰C operation (TRL 9). JPL RTD (346) investment in small lab scale cells with -120⁰C operation (TRL3).

1-Electronic packaging technology and materials that can survive -240⁰C to +125⁰C thermal cycling.

2-Localized heater and control electronics (total ionizing dose (TID) = 300 krad (Si), -240⁰C operation).

3-Sense and control electronics capable of operating from +125 to -240⁰C, under TID=300krad (Si), with noise levels of 6nV/ and power levels < 1 mW at -240⁰C.

4-Primary batteries, capable of storage at -240⁰C, with subsequent warm-up and operation at -140⁰C (low rate) or -80⁰C (high rate) with improved specific energy (>200Wh/kg). Batteries will be compatible with planetary protection bakeouts.

5/26/17

• Only Titan lander mission to date was the Huygens Probe; 3σ landing ellipse of ~ 400x50 km with 150 minute parachute descent from 155 km

• Ballistic entry with no parachute has been simulated to minimize dispersion; with Huygens-like aeroshell (60° spherecone), it still takes ~ 60 minutes to get to the surface, with landing ellipse ~ 200 km major axis

• Entry body designs allowing deeper penetration/lower dispersion have been studied extensively, but have not been used in planetary missions

• Hypersonic entry guidance is at TRL 9 for Mars; may have limited value at Titan because steep entry angle minimizes error growth

• Mars “multi-target” precision landing is at TRL 6 with landing error < 40 m by using terrain-relative navigation (TRN) and guided propulsion system to reach the nearest safe landing site known from prior landing site reconnaissance. Significant changes are needed to apply this to Titan.

• Parafoils for cargo delivery on Earth achieve landing error < 100 m with onboard GPS/inertial navigation and guidance and control (G&C) systems.

Prioritized Technology: Pinpoint Landing on Titan

Technical Goal Technical Status

Mission Applications

• Class 1 (above) enables landing in southern hemisphere lakes (with more diverse chemistry than northern seas) and dry lakebeds (access to probable evaporite deposits; sediment coring, Titan history)

• Requires medium diverts (~ 50 to 100 km) with moderate final position error (~ 20 km or less) • Class 2 enables landing among dunes, near shores, or in river valleys, allowing sampling of a wider range of organic terrain and

geologic/climate history • Requires smaller diverts (~ 5 to 50 km) with small final position error (< 1 km).

• Class 3 enables landing in river deltas or at specific sites desired for sampling • Requires large diverts with small final position error

• Given difficulties of terrain-relative navigation with low resolution Cassini imagery and Titan’s hazy atmosphere, autonomous targeting with onboard terrain classification may be enhancing or enabling for all of these

System-level EDL capability that enables three classes of landing sites: • Class 1: Anywhere in ellipses with 3σ major axis < 50-100 km • Class 2: Within ~ 100 m of small targets widely distributed in large

ellipses. Analogous to Mars “multi-target” precision landing. • Class 3: Within ~ 1 km of point targets Major hurdle to overcome is large dispersion incurred due to high winds during long descent in Titan’s thick, tall atmosphere and low gravity Technology advances are required in: • Aeroshell shape optimization to reduce drag, for rapid entry to low

altitudes (< 100 km) to minimize wind-induced dispersion • Guided entry and descent systems that bridge the gap from the

dispersion of ballistic entry to the capability goals above • Navigation systems that provide adequate terrain-relative position,

velocity, and altitude information • Onboard terrain classification systems that enable autonomous

targeting

5/26/17

Prioritized Technology: Pinpoint Landing on Titan EDL Architecture Trade Study

Technical Goal Technical Status • Modeling, simulation, and algorithm proof-of-concept testing to quantify

potential cost/benefit of alternate approaches, as follows • Model the expected delivery error and navigation state knowledge error

at atmospheric entry for relevant mission architectures • Conduct study of entry body geometry optimization to reduce drag,

hence reach lower altitude with less dispersion, while maintaining adequate volume and aspect ratio for descent system/lander

• Extend prior algorithm development to evaluate feasibility, expected performance, and maximum operational altitude of TRN methods that match multi-modal imagery; develop new methods to recognize key terrain features onboard during descent (e.g. lakeshores, dunes). Potential to achieve position estimation error between 100 m and 5 km

• Given results of TRN study, assess expected control authority, controllability, and lander delivery error of alternate approaches to G&C, including entry guidance, parafoils, and propulsion.

• Since Huygens, there has only been one published Titan lander study (Titan Lake Probe study in 2010 for Decadal Survey) • Used ballistic entry and unguided parachute concept similar to

Huygens; ellipse estimated to be about 200 km major axis • There has been one published paper analyzing landing dispersions as a

function of wind variations with season and latitude (Lorenz and Newman 2015) • Also assumed Huygens-like EDL. Estimated ellipses were on the order

of 300 km • One paper (Ansar and Matthies 2009) conducted limited proof-of-concept

demonstration of ability to do onboard registration of VNIR descent imagery to orbital VNIR, infrared, or radar imagery to enable TRN despite the hazy atmosphere and low resolution orbiter imagery, which precludes direct application of TRN methods used for Mars

5/26/17

Prioritized Technology: Pinpoint Landing on Titan Terrain Relative Navigation (TRN)

Technical Goal Technical Status • Develop TRN subsystem, including descent camera, image processing

algorithms, and coprocessor, enabling position estimation during descent with error < 5 km, or < 100 m relative to shorelines and sand dunes

• Subgoals: • Determine best choices of spectral band for orbital maps and descent

imaging for onboard registration; develop and validate appropriate descent camera and image processing algorithms algorithms

• Develop and validate algorithms for onboard recognition of terrain features, e.g. shorelines, dunes, river valleys, etc

• Develop and validate navigation state estimation algorithm that fuses inertial measurements and image processing-based measurements

• Develop coprocessor with sufficient performance for the image processing algorithms developed above, e.g. leveraging FPGA-based coprocessor from Mars TRN subsystem or leverage NASA investment in High Performance Space Computing (HPSC) program, as needed

• Although TRN for Mars is at TRL 6, techniques for Mars are not adequate for Titan. Orbiter imagery of Titan is 2-3 orders of magnitude lower resolution than for Mars and is in different spectral bands (infrared, radar) than existing descent cameras (600 to 1000 nm), so different onboard descent image registration techniques may be needed

• Multi-modal image registration algorithms (e.g. mutual information) have had limited testing for Titan TRN but are only at TRL 3.

• Below altitude of 10-20 km, onboard registration of descent and orbiter images is infeasible, due to low resolution of orbiter images. Onboard visual tracking or recognition of terrain features may be needed to maintain position knowledge below such altitudes.

• Above altitude of ~ 40 km, current descent cameras cannot see the surface due to atmospheric haze. Large diverts for pinpoint landing may need to initiate guidance at higher altitudes, requiring feasibility study of new descent camera at longer wavelength to see from higher altitude

Prioritized Technology: Pinpoint Landing on Titan Guidance and Control (G&C)

Technical Goal Technical Status

5/26/17

• Develop a Guidance and Control system that enables divert range and landing accuracy required for the landing site classes described earlier with error < 5 km, or < 100 m relative to shorelines and sand dunes.

• Develop and test prototype(s) of gliding decelerator(s) and associated G&C systems. Integrate with TRN subsystem and conduct field testing on Earth near sea level for V&V of performance models.

• Hypersonic entry guidance is at TRL 9 for Mars from the MSL mission. It is unknown if this is useful at Titan, due to much steeper atmospheric entry angles and much less accurate navigation knowledge at entry.

• At Mars, rocket-powered terminal descent provides diverts of a few 100 meters to a few km. Titan may need much larger diverts (> 100 km); gliding decelerators (e.g. parafoils) might achieve this with much less cost than thrusters, without risk of heating or contaminating samples with thruster plume.

• Autonomously guided gliding systems (parachutes, parafoils, etc) on Earth achieve glide ratios from 0.5:1 up to ~ 10:1 and delivery errors < 100 m with GPS/inertial navigation and wind predictions

• Landing hazard tolerance and landing hazard detection/avoidance are being addressed in Europa lander studies; much of that work should carry over to Titan.

• Mars (MSR), asteroid (OSIRIS-REx), comet (CSSR in New Frontiers 4) return sample without cryocooler, potentially with phase change material to maintain < 263K through sample recovery on Earth.

• Cryocoolers exist for cooling small flight instruments, but not for the larger volume return samples. The ice samples are much larger, thus, thermal mass of samples are also much larger than the current instruments.

• No Integrated Cryogenic Chamber has been developed. • The Verveka et al. Cryogenic Comet Nucleus Sample

Return study (NASA SDO-12367) suggested two cryocoolers to keep samples below 125K, one powered by the spacecraft and one powered by batteries in the earth entry vehicle. The study assumed a 30 cm long by 15 cm diameter cooled volume.

Prioritized Technology: Ice Sample Return – Integrated Cryogenic Chamber (ICC)

Technical Goal Technical Status Preserve an ice sample at cryogenic temperatures during return and Earth re-entry for three classes of missions: An integrated cryogenic chamber includes three types of technologies: Phase Change Materials (PCM); multistage shield and heat switch; and mechanical cryocooler. • Class 1: Sample kept between 100K – 150K

• Adapt current PCM (e.g. Argon), cryocooler, shield, and heat switch tech. for larger heat sink caused by sample size. Develop baseline integrated Cryogenic Chamber.

• Class 2: Sample kept between 65K - 100K • Improve from class 1, heat switch reliability &

multistage switch. • Class 3: Sample kept 55K - 65K

• Improve from class 2; Adapt N2 PCM • Improve heat switch reliability & improve efficiency

of passive radiator cooling; • develop battery powered 2nd stage cryocooler for

earth entry vehicle • Perform trade studies between use of passive thermal

radiators (PTR), size of cryocoolers, and number of cryocoolers for different mission classes and Understand location of cryocoolers: internal or external to the earth entry vehicle.

• Challenges: If batteries power a cryocooler in earth return vehicle, then battery life could be a concern. The ICC needs a hermetic seal to maintain the vacuum in the ICC needed to minimize heat transfer.

5/26/17

Prioritized Technology: Ice Sample Return Responsive Systems for Containment

Technical Goal Technical Status • Low TRL (<2): Temperature regulation technologies, whether by

active or passive control, are needed to minimize thermal impact of transport from an Outer Planets body to Earth.

• Hermetic Sealing Status:. NASA has previously funded SBIR I/II work to develop hermetic sealing of metal canisters via brazing. Technology to develop sealing under thermal conditions that may result in melting or sublimation are needed. Trapping and containment of evolved gases/over pressure relief need development as well as low-power consumption T monitoring.

• Thermal Control Status: NASA has funded concept studies over the years. Hardware technology development for thermal insulation designs, passive/active cooling (power levels consistent with current and potential power allocations)

Actively monitor and maintain containment of samples with minimal degradation in relevant Ocean World environments from sample collection through Earth entry and return and under hermetic sealing conditions.

Mission Applications What is enabled if we achieve the goal? Both Science and PP

Reduced Risk to Samples: Controlled and monitored environments allow for accurate modeling of degradation of biosignatures and loss and evolution of volatiles during the return process. Backward Contamination Risk Reduction for: • Europa: Clipper, Lander, Sample Return • Enceladus: Plume Sample Return, Lander Sample Return

Reduced Uncertainty: Maintenance and collection of data associated with containment hardware provides solid inputs to Earth Safety Analysis, reducing risk for Restricted Earth Return missions which may undergo non-NASA regulatory tests/measurements prior to release from containment.

Near Term: Development of Hardware: Breadboard containers with capacity to trap and contain evolved gases, maintaining a constant seal under changing ambient temperatures and pressures Mid Term: - Monitoring Systems : Develop techniques for monitoring of containment variables (Temp, Pressure, leak rate) from time of sealing through return. Long-Term: Active Control Systems : Maintain sample temperature via active power regulation & novel passive insulation methods (may be cryogenic or non-cryogenic, depending on target body)

8/30/17

Planetary Protection Backward Contamination Technology Demonstration

Technical Goal

Mission Applications

Sample Return Mission Architectures and Hardware that is Compliant with a Robust Earth Safety Analysis: • Europa Lander, Enceladus Plume, Enceladus Lander, Mars Lander

Backward Contamination Risk Reduction for: • Europa: Clipper, Lander, Sample Return • Enceladus: Plume Sample Return, Lander Sample Return • Ceres, Vesta, Mars, TItan: Landers, Rovers/Boats, Sample Return

Reduced Uncertainty: Passenger list assessment with roundtrip testing addresses current known limits in understanding of microbial lethality for space conditions

To enable planetary protection capabilities to meet • Forward Contamination: 10-4 inadvertent contamination probability • Backward Contamination: 10-6 probability of contamination from Break The Chain (BTC) and sample containment

Near-Term: Forward Contamination Detection: Bioinformatics development for low biomass environments, sample collection and processing developments, development of enhanced modeling for metagenomics response to sterilization and initial BTC breadboard. Mid-Term: BTC + Microbial Contaml Testing: breadboard testing (TRL 1-3) with low biomass detection/evolution and fail safes Long-Term: Round-Trip BTC Testing: Round Trip testing of BTC system including sterilization + relevant environments exposure demo with biomass passenger evolution, including microbes with known specific lethality constraints and fail-safes

8/30/17