Lunar Reconnaissance Orbiter Camera�Nine Years Exploring the Moon� �26 May 2018, ISDC 2018�Mark Robinson, ASU School of Earth and Space Exploration

LRO Overview

• Acquire observations needed to support future human return to Moon according to the Vision for Space Exploration (Jan 2004)
• LRO carries seven science packages
• Spacecraft fabrication by NASA Godard Space Flight Center

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Cancelled 2010, “restored” 2018???

LRO Launched June 2009

LROC Experiment

• Two Narrow Angle Cameras (NACs) for Landing Site Certification
• One Wide Angle Camera (WAC) to Monitor Polar Lighting, Map Resources, Synoptic Mapping
• Sequence and Compressor System (SCS) to manage camera commands & data

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3

WAC

SCS

NAC

Image ~50” wide

LROC designed and built by Malin Space Science Systems (MSSS), San Diego, CA

LROC By The Bits�19 May 2018

• LROC: 2,331,422 observations
• NAC: 1,674,563 images
• 1,527,300 inc < 92° (>3.7E14 pixels*)
• WAC: 656,859 observations
• 337,142 <92° incidence (post 1 Jan 2010)
• NAC 95% coverage (inc<80)
• Goal 100% coverage low incidence(noon) and high incidence (dawn/dusk)
• Downlink through dedicated Ka-band antenna White Sands, NM
• Processing requires high degree of automation
• Archive is ~ 1 petabyte

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18.2-m Ka-band antennas at White Sands NM, shared by Solar Dynamics Observatory (SDO) and the Lunar Reconnaissance Orbiter (LRO)

*374 trillion pixels

50 cm pixels, multi-temporal observations

Apollo Descent Stage

Apollo 16 from LRV

camera

Looking straight down on

Apollo 11 Descent Stage

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Deck 4-m across, 9 m landing pad to pad

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LROC Discovery Highlights

• Ongoing tectonics
• Small, young contractional fault scarps
• Liquid outer core – interior still cooling
• Recent volcanism
• Shallow magma generation
• Still hot lunar interior
• Silicic volcanism
• Complex differentiation in mantle
• Pits
• Pristine preservation of basalt flows
• Potential habitats
• Permanent Shadow Regions
• Lighting conditions
• Traversibility
• Crater topography
• New tool for estimating ages
• Impact event dynamics

• Photometry
• Fine scale structure of regolith
• Engine blast zones
• Ages of Copernican Craters
• Copernicus, Aristarchus, Tycho, Giordano Bruno, and small very young…
• Stratigraphy, Early chronology
• Sequence of early Solar System events
• Recent impacts
• Inner Solar System cratering rate
• Hazard mitigation
• Rate of regolith overturn
• Cartography
• Global accuracy to ±15 m
• Global topography 100 m scale

What Lies Below?

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• Mare Tranquillitatis pit
• Diameter 100 m
• Depth 107 m

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• Are there extant sublunarean tubes?

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• Oblique imaging!

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• Sublunarean void discovered – but how far does it extend? What is its origin?

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• Earth visible from floor

Morning

Noonish

Afternoon, oblique

Descend, bold traveller, into the crater of the jökull of Snæfell, which the shadow of Scartaris touches before the Kalends of July, and you will attain the centre of the Earth. I did it.��- Arne Saknussemm

Jules Verne

Arne Mission Concept

Arne

Lunar Pits

• Investigate the Mare Tranquillitatis Pit (MTP) in terms of sustainable human exploration of the Moon - and beyond
• Focused achievable exploration goals

• Ready made shelter for future lunar explorers, benign T (-25°C)
• Show mare lavas emplaced as thin flows (5-20 m)
• Pristine preservation
• Flow features
• Sublimate minerals
• Regolith? Solar Wind?
• How extensive are sublunarean passages?

Arne – Sublunarean Explorer

Goals

• 1) Investigate suitability of void(s) at MTP for exploitation
• Radiation shield
• Micrometeorite shield
• Benign thermal conditions
• 2) Technology demonstration
• Autonomous landing (precision landing, hazard avoidance)
• Flying payload (autonomous navigation)
• 3) Investigate nature mare flood volcanism
• Thickness of flows (exposed in pit wall)
• Nature of void (lava tube, vent collapse)
• 4) Explore the voids! What else can we find?
• 5) Engage the public

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Concept of Operations (ConOps)

Initial deployment from Orion orbit (~100 km altitude)

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Solid Rocket Motor (SRM) Burn #1 nulls out orbit velocity in xyz

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“Free Fall” to 160 m

Optical Nav via center of pit shadow using IMU and thrusters to keep centered over shadow

100 meters above

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Descend and initiate imaging sequence of pit wall

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Hold your breath!

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ConOps

“Hazard avoidance logic kicks in at altitude 80 m

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Optical lock to large boulders known from LROC as guide to Earth visible spot

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Texture analysis selects final landing spot

Engine cuts off at L-2 second

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“Falls” to smooth spot in Earth view

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Aliveness check all systems including pit-bots (10 minutes)

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Relay full resolution high priority descent data to Earth (20 minutes)

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ConOps

Deploy PB-1, fly past known edge of void (20 m from wall) and attempt 20 meters beyond, then land. Transmit to lander while flying.

PB-2 serves as relay as PB-1 explores beyond 100 m

Arne

• Demonstrate key feed forward technologies
• Understand nature of lunar mare pits

New Craters!

Now fond over 400 resolved craters and over 100,000 splotches

Significance

Measurements instead of models!

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Moon impacted 33% more than modeled

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Top layer (2 cm) of regolith (soil) turns over 100x faster than modeled

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Cratering physics

The Moon Awaits

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LRO and LROC continue to return key observations for exploration and science.