National Aeronautics and Space Administration Human Exploration of Phobos Mike Gernhardt PhD. Nasa JSC Human Spaceflight Architecture Mars Moons Team • Paul Abell • James Johnson • Dina Poncia • Andrew Abercromby • Dave Lee • David Reeves • Charles Allton • Pascal Lee • Mike WriGht • Paul Bielski • Harry Litaker • Michelle Rucker • Dan Brit • Stan Love • Greg Schmidt • Steve Chappell • Mark Lupisella • Bill Todd • Bryan Cloyd • Dan Mazanek • Pat Troutman • David Coan • Natalie Mary • MaB Simon • Zack Crues • Fay McKinney • Larry Toups • Dan Dexter • Gabe Merrill • Mike Gernhardt • Nathan Moore • Bill Harris • Rob Mueller • A. ScoB Howe • Tom Percy • Steve Hoffman • Tara Polsgrove • Sharon Jefferies • Jason Poffenberger Phobos/Deimos Human Missions Human Architecture Team Task 7C: Mars Moons Phobos 27x22x18 km Deimos 15x12x10 km Mars Moons - Introduction • Mars’ moons are interesQnG scienQfically and potenQally offer engineering, operaonal, and public engagement benefits that could enhance subsequent mars surface operaons o Mars moons interes-ng in themselves and would also likely provide insights into the evolu-on of Mars o Mul-ple scien-fic benefits: 1) Moons of Mars, 2) possibly captured asteroids 3) likely contains Mars surface materials 4) likely collec-on of materials from asteroid belt 5) near-zero latency tele-operaon of Mars surface assets o Poten-ally an affordable and produc-ve first-step towards eventual Mars surface operaons • Provides significant radiaon protecon • Phobos and Deimos are both interesng exploraon desnaons o With current imagery, we know Phobos is interes-ng because of craters and fissures etc. It is also the driving transportaon case and therefore the focus of this study o We are formulang a precursor mission that would look at both moons Maximum VerQcal Jump – 650 lb. Suited Crew (crew + suit + jetpack) Maximum VerQcal Jump w/ 2 m/s Take-Off Velocity 1000.0 666.7 500.0 350.9 1.2 0.0 Vercal Height (m) Weight on Phobos lbf Crewmember in a Suit 0.3 SEV (6,000 kg) 7.7 Time of FliGht Habitat (15,000 kg) 19.2 Moon 2.5 sec. Lander (50,000 kg) 63.9 Phobos 11.7 min. Deimos 22.2 min. Apollo 16 – John YounG’s Jump Salute 5 Mars Moons Trade Tree Based on Campaign Team & Transportation Team Recommendations & Discussions Pre-Staged Mars Moon Work- Destinations Transportation Assets Habitat systems Phobos / Jetpacks Conjunction None Phobos Only Deimos Class Unpressurized Surface Mars Moon Excursion Habitat Direct to Static Vehicle Deimos Only Phobos Mars Moon Relocatable Pressurized Habitat Excursion Phobos + Earth ↔ Mars + PEV(s) Phobos Vehicle Deimos Transit Stack in HMO Parking Orbit SEV-class L1 Mars Free-Return Lander Trajectory L4 / L5 Class Loitering Hab DRO Dual Hab 6 Radiation Exposure u Cumulave exposure calculated using Phase 1 methodology • i.e. Oltaris exposure es-mates adjusted for occlusion of sky due to Mars and Phobos (incl. 10o crater rim for surface missions) u Total radiaQon dose reduced by up to 34% for Phobos surface Hab Updated ReGions of interest on Phobos These are examples of areas of interest on Phobos for inves-gaon: 9 11 1) Floor of S-ckney Crater 2) Side wall of S-ckney Crater 8 3) Far rim of S-ckney Crater 10 4) Overturn of S-ckney Crater and grooves 7 5) Overlap of yellow and 6 white units 1 4 6) Overlap of red and white units with grooves 5 2 3 7) Opposite rim of S-ckney and start of grooves 8) Brown outlined unit and “mid-point” of grooves 9) “End point” of grooves Very likely in reality that some of these sites (i.e., inside S-ckney crater) may have to be expanded to cover larger 10) “Young” fresh crater areas to obtain the desired science. 11) “Deep” groove structure Phobos Exploration EVA Timeline Analysis • For analysis purposes, u-lize DRAFT science “regions” of interest defined by scien-sts (1-11) 9 11 • Defined 1-km diameter “sites” in each region • Traverses would explore “sites” in each region by performing 8 ac-vi-es at 5 smaller “subsites” (~15 m radius) within each 10 “site” • Standard circuit at each “subsite” consists of a standard series of 7 6 tasks, e.g. 2 float samples, 1 soil, 1 core, 1 hammer chip, and an 1 4 instrument deploy task. • 11 near field survey ( 1km dia each) and 55 standard circuits 5 2 3 including drill deploys • 16 detailed EVA Timelines developed (i.e. standard circuit, near- field survey, drill deploy, etc.) for 4 different Ops Cons / work- system combinaons H1 4 Standard Circuit 1 at Subsite 15 m F1 500 m 6 I Legend 5 • F = float S1 SUBSITE C1 • H = hammer chip 3 • SITE 2 S = soil F2 • C = core • i = instr. deploy Work-System Concepts Jetpacks (+ Mobile Payload Carrier) Unpressurized Excursion Vehicle Pressurized Excursion Vehicle 11 Low Energy Escapes from the Surface of Phobos Dots along trajectories indicate 1 hour marks out to 6 hours. The dashed segments then extend out to 1 day. 12 Contingency Return Estimates • Assume return to radiaQon shelter required within 20 minutes (CxP requirement) – Green indicates < 20 mins • Esmates assume uniform Phobos gravitaonal effects and neglect curvature of Phobos • Assumes 0.1 ms-2 max acceleraon / deceleraon Never reach max allowable speed 13 PEV Options • SEV-class vehicle with RCS Sled & Hopper SEV + RCS • SEV-class vehicle with Sled + SEV/HAL- Hopper RCS sled only Derived SEV + RCS Sled • SEV-based taxi/lander • MAV derived MAV-Derived Taxi/ Lander MAV-Derived Taxi/Lander (verQcal) (horizontal) PEV based EVA on Phobos Zack Crues/ER7, Guy de Carufel/OSR, August 20, 2014 Dan Dexter/ER7 15 Common Cabin Approach with Standard Interfaces Expl. Atmos. Validation HAL-Taxi-PEV-MAV-SPR Standard Interface ECLSS Mars Transit Vehicle Habitat Dust Tolerance & Mitigation EVA Systems Core Cabin Begin with cabin design for Mars surface and then work backwards to Mars moons, ARM, etc 17 inteGrated Phobos Model u Combines the following data: • Copernicus es-mates of Delta-V for DRO ↔ Surface and Surface ↔ Surface gross translaons (Dave Lee) • NExSys es-mates of Delta-V for 5m to 500m surface translaons (Zack Crues, Dan Dexter & NExSys team) • Logis-cs es-mates (Kandyce Goodliff’s calculator) • Habitat es-mates (Ma Simon, David Reeves) • Detailed EVA -melines (Steve Chappell) • HMO ↔ Phobos service module es-mates (based on data from Tara Polsgrove) • Iden-fied regions of scien-fic interest (Paul Abell) u Generates mission-level esQmates and comparisons of 70+ fiGures of merit includinG system masses, loGisQcs, crew Qme, EVA Qme, EVA overhead, EVA producQvity, and propellant Human SpacefliGht Architecture Team NASA internal Use Only – Not for DistribuQon 18 HAT Task 1x PEV 2x PEV 2x PEV 2x PEV Minimal Minimal Taxi (1 as Taxi) (1 as Taxi) 7C: (1 as Taxi) Taxi / Lander Moons of + + DRO Habitat Surface Hab Mars + Log Modules Mobile Hab Crew/ Duraon 2 crew / 4 crew / 4 crew / 500 4 crew / 500 2 crew / 50 4 crew / 500 @ Phobos 50 days 50 days days [1000 d] days [1000 d] days days [1000 d] Pre-Staged to -PEV+RCS Sled -PEV + RCS sled -PEV + RCS Sled - Mobile Hab Nothing Nothing Phobos -Log. Modules -Habitat -Habitat (incl. prop) Pre-Staged 33,536 kg 31,893 - 37,383 32,000 kg - 11,021kg - Mass (kg) [45,246 kg] [40,509 - 46,098] [43,943kg] -Minimal Launched to -PEV Taxi+SM Taxi / Lander + -Minimal Taxi + -PEV Taxi + SM - PEV-Taxi + SM - PEV-Taxi + SM HMO -Log Modules SM SM -Log Modules Mass to HMO 35,703 kg 25,305 kg 25,305 kg 25,305 kg 24,303 kg 13,579 kg % Science Sites 100% 100% 100% [200%] 100% [200%] 20% 100% [200%] achieved Radiaon Dose 97% 97% 94-96% 66-80% 97% 66-80% vs. HMO-only RCS Sled, RCS Sled, Hab landing legs, Phobos-specific RCS Sled, Hab landing op-onal op-onal RCS Sled, - elements op-onal Hopper legs Hopper Hopper op-onal Hopper 19 Phobos Mission Mass (deltas to Mars Orbital Mission) 20 20 Cases 2.1, 2.2, 2.3, 2.4, & 2.7 How Long to Complete “Reference Science Content”? (From Phase 1 analysis, 100% = Standard EVA task circuit completed at 11 regions x 5 sites per region) Case 2.6 21 21 Phobos Hopper ATHLETE (6 Limbs) MMSEV cabin Pros: - Exisng technology - Footpads can be swapped for wheels or other ATHLETE-derived limbs implements for Mars surface use ATHLETE-derived leg MEL (kg) qty Hip yaw 20.8 1 20.80 Hip pitch 24.4 1 24.40 Lower thigh 4.6 1 4.60 Knee pitch 16.4 1 16.40 Knee roll 13.8 1 13.80 Shin 1.8 1 1.80 Cons: Ankle pitch 11.2 1 11.20 - LandinG strain on ATHLETE Ankle roll 13.6 1 13.60 Ratchet sprinG for FT sensor 10 1 10.00 joints Footpad cylinder 55 1 55.00 capturing landing energy Footpad sha 3.6 1 3.60 - Six limbs Good for walkinG, Footpad spring 2 1 2.00 but maybe not necessary Footpad 23 1 23.00 Ball joint footpad with Avionics 43.3 1 43.33 for hopper passive spring for Total / leg 243.53 Total suspension system 6 1461.20 leveling Human SpacefliGht Architecture Team NASA internal Use Only – Not for DistribuQon 23 Human SpacefliGht Architecture Team NASA internal Use Only – Not for DistribuQon 24 Mars Moons Task Conceptual Design • Conceptual design of a mobile surface habitat – Close on concept(s) for mobile Phobos surface habitat; consider cis- lunar, transit, and Mars surface commonality as much as possible – Include propulsion and legs for landing and for gross and local mobility once on surface ATHLETE ? ARM-Derived Fixed LeGs Mobile Surface Hab Exploration Assumptions H1 9 11 4 1 8 500 m 15 m F1 10 6 I 7 5 6 SITE S1 SUBSITE 1 C1 4 3 2 5 F2 2 3 Standard Circuit at Subsite Legend • F = float • Assumes a mobile habitat / • H = hammer chip • S = soil vehicle that uses thrusters • C = core for gross reposioning • i = instr.