Ground Observation of Lunar Impact by LCROSS

Young-Jun ChoiKASI

LCROSS (Lunar Crater Observation and Sensing Satellite)

It’s about the water … Clementine (1994) Lunar Prospector (1999) LRO (2009)

If water-ice is confirmed, Water Breathable oxygen Rocket fuel

Launch : 18 June, 2009

Shepherding Spacecraft (S/SC)

• Bright Impact Flash• Thermal OH Production• Rapid Thermal Evolution

• Expansion of Plume• Thermal Evolution• H2O ice sublimation• Photo-production of OH

• Residual Thermal Blanket• Expanding OH Exosphere

The combination of ground-based, orbital and in-situ platforms span the necessary temporal and spatial scales: from sec/meters to hours/km

Science for each stage

View of Moon from Earth on 9 October 2009, 4:30 a.m. PT

Viewing the impact

Terrestrial landmasses fac-ing Moon at time of im-pact.

Viewing the Impact

Earth’s morning ter-minator at time of im-pact.

Lunar, Earth-orbiting , and Ground-based Assets

LCROSS observation campaign :Observatories

Earth Orbital HST, Odin, IKONOS, NFIRE, EO-1

Lunar Orbital LRO, Chandrayaan-1

6 7 9

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Ground1. Keck Observatory2. CFHT3. Gemini Observatory North4. Subaru Telescope5. IRTF6. Lowell Observatory7. MRO8. Apache Point9. MMT10. SALT11. Korean ASSI12. SOFIA13. Mount Wilson14. Allen Telescope Array15. Air Force Maui Optical and

Supercomputing Site16. Automated Lunar and Me-

teor Observatory17. IFA,Haleakala

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18 19 20

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Earth Orbit18. HST19 Odin20. IKONOS (GeoEye)21. NFIRE (Missile De-

fense Agency)22. EO-1

Lunar Orbit23. LRO24. Chandrayaan-1

LCROSS observation campaign : KASI observation

Impact flash detection (Mt. Lemmon 1m Tel.) Energy(released by flash) = η K.E.

η : Luminous efficiency (~ 10-5 ~ -6)

Flash duration : 0.06 ~ 0.6 secondFast drift scan

Plume evolution (BOAO 1.8 m Tel.) OH exosphere Volatile gases

LCROSS observation campaign : communication system

LCROSS Campaign Co-ordinator Astronomers

LCROSS SOC Observatories

NASA LCROSS Website Citizen Scientist Portal

Twitter account, Facebook status page(real-time telemetry updates, data)

LCROSS EPO / PAOLCROSS MISSION

OPERATIONS CENTER

Secu

re li

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Voice Loop: Telecon line

Text Chat

Data file transfer: Email & FTP

Website

T-10h T-9h T-8h………………… T-1h

T-50m T-40m T-30m T-20m T-10m T-1 m T-0

The following timeline shows the information conveyed from the Campaign Coordinator (SOC) to the As-tronomers.Times listed below are in reference to Centaur impact (T-0).Campaign Coordinator will provide information at prescribed times as outlined here via text and voice plus will be available & responding to Astronomer questions (text, voice, email) continuously during the duration of timeline.

T-9h - T-1h: Hourly updates regarding Centaur & S/S-C position, sta-tus, payload ops & data return, expected impact location & time.T-1h: Poll Astronomers – who is online, weather, conditions, etc.

T-10h: Begin comm: update on Centaur- S/S-C stack status & posi-tion, expected separa-tion time, expected im-pact location & time.

T-9h 50m: Confirmation of Centaur & S/S-C sepa-ration, update on Cen-taur- S/S-C stack status & position, updates re. impact location & time.

T-50m – T-10m: Updates every 10 minutes regarding Centaur & S/S-C position, status, payload ops & data return expected impact location & time.T-50m: Payload on, indicate are streaming data on-line.

T-10m – T-1: Updates every minute regarding Centaur & S/S-C posi-tion, status, expected impact location & time.

IMPACT

Centaur Separation

T-1m – T-0: Continuous updates regarding Cen-taur & S/S-C.

T-0: Confirmation of impact, indicate exact impact location.

T-0 – T+4: Real-time info re. S/S-C data. T+4 Confirmation of S/S-C impact.

T-0 T+1m T+2m T+3m T+4m T+1h T+2h

T+4 – T+2h+: Comparison of S-S/C data with Astronomer observations.