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Kuafu A mission to start a mission

William Liu Canadian Space Agency &

Chinese Academy of Sciences

August 29, 2011, 3rd ILWS Science Symposium, Beijing

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KUAFU IN A FEW WORDS

Same principles and equations

Different boundary conditions

Different solution

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Solar Energy Output I = X

Magnetic field complexity results inreconnection and particle ejectionin the solar corona, X

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Solar energy input II = YMagnetic complexity also results in electromagnetic radiation (flares) , Y

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Solar wind at 1 AU = Z

X (primarily) leadsto a variable solarwind at 1 AU, Z

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Magnetopause interaction = W

Credit: University of Michigan

Solar wind condition Z leadsto variable interaction with themagnetosphere at the magneto-pause, W

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Credit: University of Alberta

Energy deposition = U

Energy created through W is dissipated in the ionosphere

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Systems Question

Before, missions were focused on X, Y, Z, W, U, etc. individually

The System Question below is of great interest but seldom simultaneously observed.

U = F1(W,Y)

W = F2(Z, U) (feedback, cf., potential saturation)

Z = F3(X)

Fi is some time integral over the independent arguments

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Kuafu A at the first Lagrangian point

Kuafu B in double Molnya orbit with 6 Re apogeeK-A imaging observation of X and YK-A in-situ observation of ZK-B imaging observation of UK-B in-situ observation of W

Kuafu: System science discoverer24/7 simultaneous imagingsupported by high-resolutionin-situ observation focused onkinetic-to-MHD scale physics

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Kuafu A Imaging

Lyman- imaging of solar disk

Lyman- + whitelight inner coronagraph

Whitelight outercoronagraph

Essential objective is to observe the entiresequence of solar wind acceleration, with special focus on the transition region

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Generation of fast, slow solar wind & CME

• Deepen the knowledge of energy transport process between the photosphere and corona; improve the predictability of solar eruptive events– What is the relationship between CMEs and motions and magnetic field

structures at the surface?– What is the relationship between the energy carried by CMEs and

surface features?– How are CMEs and other solar wind structures accelerated?– What is the directionality of CMEs?– What is the short-term variability of total solar-irradiance?

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Kuafu B Imaging

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Auroral Complexity

The morphology of U exhibits a high degree of complexity

Vortices

Arcs

Turbulence

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12-h Molnya orbit

Stationarity and corotation with respect to a fixed point on Earth

Year 0: long hover in the cusp

63 inclination and 6 earthradii apogee

Long dwell time over ground networks on Earth

Year 0.5: long hover overthe nightside aurora region

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Kuafu spacecraft

图图图图图图图图图图

• Kuafu A– 3-axis stabilized satellite at L1– Total mass 722 kg– Payload 130 kg– Power: SOM 906 W; EOM 752 W– Downlink telemetry 350kpbs.

• Kuafu B (anticipated)– Two 3-axis stabilized satellites in 12-h

Molnya orbit– Mass: 1200 kg per satellite– Science payload ~65 kg per satellite– Power: ~80 W for science payload, 1 kW

overall, per satellite– Downlink: ~ 2Mpbs.

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WHAT NEW BOUNDARY CONDITION

• Canadian Space Agency cannot confirm anticipated participation in Kuafu at this time (despite great interest) due to government austerity measures

• European national agencies cannot provide the majority of Kuafu instruments as originally planned

• Chinese Academy of Sciences insists that Kuafu be a mission based on strong international collaboration

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FIND NEW SOLUTION

• The international situation argues for – Launch Kuafu A first (by 2016), with an enhanced in-situ

instrumentation from international sources– Start immediately with a collaborative framework

committed to launching Kuafu B+ by 2019– Search interim international collaborations with

concurrent missions (MMS, SWARM)• This is riskier than we like, but the risk should be

balanced against the consequence of no Kuafu– Certainty of failure is not better than possibility of success

• A sure winner– Rename the mission iPhone 6.

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Strawman Payload

• Lyman- disk imager• Lyman- + WL inner coronagraph• WL outer coronagrah• Fluxgate magnetometer• Medium-energy ion and electron

analyzer (0.1 – 30 keV)• High-energy particle package• Low-energy ion and electron

imaging spectrometers (1 - 500 eV)

• Induction magnetometers• Radio-burst instrument • Hard-X ray spectrometer• Solar irradiance measurements

• UV LBH-band imager– Band-split for flux and average

energy determination– Day glow suppression for true

global imaging• Fluxgate and induction

magnetometers• Low-energy ion and electron

imaging spectrometers (<100 eV)• Medium-energy ion and electron

analyzer (0.1 – 10 keV)• High-energy electron telescope• Options

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A MORE BALANCED KUAFU

• Simplified imaging– Still maintain the innovation of Lyman-

coronagraphy and tracking of CMEs to 20+ solar radii

• Enhanced in-situ measurement– Better measurement of the solar wind on the sub-

MHD scales will yield better characterization of electromagnetic noises and its potential effect on geoeffectiveness (i.e., relationship to reconnection)

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Conclusion

An ambitious first attempt to observe and understand the causal chain andcomplexity in the Sun-Earth System, simultaneously and continuously.

The challenge is to make it happen.