KEPLERWilliam Borucki, PISolar System Exploration SubcommitteeSante Fe, New MexicoFebruary 14-15, 2005

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Stellar Occultations & High-Precision CCD Photometry•Timothy Brown, HAO, UCAR •Edward Dunham, Lowell Obs.•John Geary, SAO •Ronald Gilliland, STScI•Steve Howell, U. Ariz •Jon M. Jenkins, SETI InstituteDoppler Velocity Planet Searches•William Cochran, UTexas•David Latham, CfA, SAO•Geoff Marcy, U. Cal., BerkeleyStellar Variability•Gibor Basri, U. Cal., Berkeley•Andrea Dupree, CfA, SAO•Dmiter Sasselov, CfA, SAO

Theoretical Studies•Alan Boss, Carneige Institute Wash.•Jack Lissauer, NASA AmesMission Operations•Donald Brownlee, U. of Washington•Yoji Kondo, NASA GSGCGeneral Overview•John Caldwell, York U.•David Morrison, NASA Ames •Tobias Owen, Hawaii•Harold Reitsema, Ball Aerospace Co.•Jill Tarter, SETI InstituteEducation and Public Outreach•Edna DeVore, SETI Institute •Alan Gould, Lawrence Hall of Science

William J. Borucki, PI, and David Koch, Deputy PI

Science Team

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KEY QUESTIONS:

• Are terrestrial planets common or rare?

• How many are in the habitable zone?

• What are their sizes & distances?

• Dependence on stellar properties

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Scientific Goals

• Determine the frequency of terrestrial and larger planets in or near the habitable zone of a wide variety of stellar spectral types

• Determine the distribution of sizes and semi-major axes of these planets

• Identify additional members of each photometrically discovered planetary system using complementary techniques

• Determine the distributions of semi-major axis, albedo, size, and density of short-period giant planets

• Estimate the frequency of planets orbiting multiple star systems

• Determine the properties of those stars that harbor planetary systems

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Use transit photometry to detect Earth-size planets 0.95 meter aperture provides enough photons Observe for several years to detect the pattern of transits Monitor stars continuously to avoid missing transits Use heliocentric orbit

Get statistically valid results by monitoring 100,000 stars • Use wide field of view telescope • Use a large array of CCD detectors

21 CCD Modules are the Heart of the Kepler Mission

Mission Design

KEPLER: A Wide FOV Telescope that Monitors 100,000 Stars for 4 years with Enough Precision to Find Earth-size Planets in the HZ

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DISCOVERY MISSION # 10Goal: Determine the frequency of Earth-size & larger planets in the HZ of a variety of star types

Expected science results; hundreds of Earth-size and larger planets if they are common

Science Team; 27 from US, Europe, & Canada

Single science instrument: Photometer (0.95m aperture, 42 CCDs, 420-890 nm, passive cooling, focusable primary)

Launch date: October 2007

Heliocentric Earth-Trailing Orbit

Operational life: 4 years

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B

THE TERRESTRIAL ACCRETION ZONE AND THE HABITABLE ZONE

FOR VARIOUS STELLAR TYPES

Stellar Radii and Planetary Orbital Semi-Major Axis (A.U.)

1001010.10.010.001

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M Rad

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Planetary Orbital Period (Yr)1.0

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Solar System

Continuously Habitable Zone (Kasting, Whitmire and Reynolds, 1993)

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rbit

Zone of Accretion for Earth-like Planets (Wetherill, 1991)

7/98

Each main sequence spectral type (B, A, F, G, K, M) is shown in black to indicate the star's mass and radius on the left side of the diagram. The Habitable Zone (green) and the planets in our solar system (blue) are shown. The Kepler Mission is capable of detecting Earth-size and larger planets in orbits of up to two years.

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COMPARISON OF SOLAR SYSTEM TO OTHER PLANETARY SYSTEMS

Theory of Formation of SS expected to produce inner terrestrial planets, outer giants, circular orbits.

Observations show that a large fraction of stars have giant planets in inner orbits with high eccentricity

Implications are that planetary systems can be very different from SS. SS must have had special circumstances

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FOV

FIELD OF VIEW IN CYGNUS

A region of the extended solar neighborhood in the Cygnus region along the Orion arm has been chosen. The star field is far enough from the ecliptic plane so as not to be obscured by the Sun. This field also virtually eliminates any confusion resulting from occultations by asteroids and Kuiper-belt objects. Comet-sized objects in the Oort cloud subtend too small an angular size and move too rapidly to be a problem.

180°

Perseus arm

Orion arm

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Scutum armKepler Mission search space

Sun

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HI distribution

Clusters HII regions

Sag.arm

EXTENDED SOLAR NEIGHBORHOOD

Schematic of the Galaxy. The stars sampled are similar to the immediate solar neighborhood. Young stellar clusters, ionized HII regions and the neutral hydrogen, HI, distribution define the arms of the Galaxy. The FOV location is not critical to the results of the mission, other than providing a large sample of main-sequence stars.

Kepler FOV

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Stellar Activity Levels

-3.5

-5.0

-4

-4.5

-5.50.5 0.6 0.7 0.90.8

Very Active2.6 %

Active27.1%

(B-V)

Inactive62.5%

Very Inactive 7.9%

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Signal Detectability

SNR = (Ntran)1/2 (Rp/R*)2 / [(i2+ v2)+ 1/F]1/2.

Where Ntran is the number of transits observed, Rp is the radius of the planet, R* is the radius of the star, F is the stellar flux measured in photoelectrons, and (i2+v2) is the signal variance due to instrument noise and stellar variability.

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MERIT FUNCTION (MF)Quantifies science value as f(instrument & mission

properties)

Merit Function properties• Models of planetary systems, instrument specs., detection

approach, catalog of all target stars & their properties

• Score is 100 based on currently predicted instrument perform.

a) 60 pts for planets in HZ, 30 pts for planets outside HZ, 10 pts for p-modes

b) Small planets have higher value than bigger (40,20,5,1)

c) Outer planets have higher value than inner planets (r2)

• Adjustable parameters for instrument specs & performance, mission parameters, and surprises of nature

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SUMMARY• Graceful degradation• Greatest sensitivity

– Mission lifetime– CDPP

• Four year mission provides comprehensive determination of frequency of Earth-size and larger planets

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Validation of Discoveries

SNR > 7 to rule out statistical fluctuations

Three or more transits to confirm orbital characteristics

Light curve depth, shape, and duration

Image subtraction to identify signals from background stars

Radial velocityMedium resolution to rule out stellar

companionsHigh resolution to measure mass of giant

planets

High spatial resolution to identify extremely close bkgd stars

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Operations Organization

Science Ops Center - Ames

• Scientific direction • Select target stars • Manage Instrument • Diff. ensemble photometry • Stellar light curves • Transit search • Candidate planet list • Direct follow-up observing • Final planet determination

Complementary Observing - SAO/UA/UC-B

• Stellar classification • Elim. false positives - low resolution

spectroscopy • Stellar properties • Giant planet mass - high resolution

spectroscopy

Data Management Center - STScI

• Calibrate data • Archive data • Difference images • HST follow-up • PSP and DAP

Education Public Outreach - LHS/SETI

• Formal education • Informal education • Public outreach

DSN

Mission Ops Center - Honeywell

• Cmd/control spacecraft • DSN scheduling • Acquire all data • Engr. data archive • Anomaly response

Sustaining Engneering - Ball Aerospace

• Manage MOC • Ensure spacecraft health/safety • Anomaly resolution

Raw data

Cmd/data

Calibrated dataTarget list

Results

Stellar data

Observ- ing request

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Educational & Public Outreach

Lesson plans

Planetarium programs

Amateur obs,

KeplerCam

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4Moderate

(2)Moderate

(2)Schedule

Identify all specifications, ICDs, and plans which must be complete to support program schedule. Complete sign-off of SRD before ATP of Phase B and sign-off of MRD 2 months after ATP.

Science Requirements and Mission Requirements Definition

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4Moderate

(2)Moderate

(2)Schedule

Early completion of optics design and analysis to support preparation of specifications for early procurement.

Optics procurement

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6Significant

(3)Moderate

(2)Technical

Extrapolation of present IR&D activity that addresses packaging of electronics and CCD focal planes. Early build and test of Pathfinder FPA using EM CCDs. Completion of Pathfinder before detail design and fabrication of Flight FPA. Extensive thermal model analysis using TSS and TAK III, updated with test data as available.

CCD Module / electronics packaging, metrology and thermal control in an FPA this size.

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8High(4)

Moderate(2)

Schedule/Cost

Develop device specification that permit high yields (Don't need SOA performance). Parallel procurement from two vendors. Early delivery of Engineering Model CCDs from both vendors with an option to procure all CCDs from any single vendor after EM assessment.

CCD procurement delivery schedule

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Risk FactorImpactLikelinessRisk TypeMitigation ActionsRisk Item

Database Index

Table G-9. Our Initial Risk Assessment/Mitigation Top Risks

PHASE B WORK: PRELIMINARY DESIGN, RISK MITIGATION, & LONG LEAD ITEMS

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SCHEDULE & MISSION STATUS

Bill Borucki

CDRPhase B

Phase C/DPhase E

06 07 08 09 10 11 12 130502 03

PDRSRR

04

Launch

CY01

ATP End normaloperations

End extendedoperations

Phase F

Phase C/D work has started.

JPL management team is integrated into Kepler team.

17 flight-grade CCD detectors have been received.

Optics are being polished.

FY’05 budget reduction will delay the October 2007 launch.

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Proposed in 2000 for 2005 launch at $299M

Concept study for 2006 launch ($ for NIAT, inflation, and increase in booster cost)

Kepler selected but required to slip the launch to 2007 launch and add JPL $40M cost increase

Change to full-cost accounting adds $20M

Mission cost at $467M

FY’05 funding reduction causes additional delay and cost increase

MISSION COST HISTORY

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FOLLOW UP OBSERVATIONS

For false positive elimination and understanding of the Kepler planetary candidates:1. 300 m/s RV measurements, mr=9-16, avg of 2.5 spectra eachTerrestrial planetsCase 1, no terrestrial planets~140 false positives (105 go away with DIA after 4 years)~131 hr on 2m telescope = ~ 22 nights @ $1500/night -> $33Kthis price depends on being able to buy 1/2 nights or only using time in June-Aug.Case 2, ~2160 terrestrial planets found~2300 candidates~2155 hr on 2m telescope = ~ 359 nights @ $1500/night -> $538KGiant planets~610 candidates~572 hr on 2m telescope = ~95 nights @ $1500/night -> $142K2. AO images of 300 candidates mr=9-16 from 1st 90 days~300 stars~79 hr = ~13 nights usually need bigger telescope (>= 4m) to get the AO instrumentsFor characterization to understand the sample of planet bearing stars and their planetary systems:3. Further characterization of the starsR= spectra of 300 selected candidates mr=9-12 or brighter, 1 spectrum each~xx hr on 2 m telescope = ~xx nights = xx/4 nights/year~9 Kepler observers -> xx/4/9 nights/yr/observer4. To search for giant members of system with a terrestrial planet10 m/s RV measurements of 100 selected candidates, mr=9-12 or brighter, 12 spectra each~950 hr on 10m telescope = ~158 nights = 40 nights/yr~4 Kepler observers -> 10 nights/yr/observer5. .Further characterization is left to the community.

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STELLAR CLASSIFICATION PROGRAM