Outer Solar System (OSS)A Planetary and Fundamental Physics Mission to Neptune, Triton and KBO

B. Christophe on behalf of OSS Team

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OSS

Eddington’s Parameter at 10-7

Deep SpaceGravity at 10 pm/s2

NeptuneTriton

Kuiper Belt Object

Od

ysse

y, C

osm

ic V

isio

n 1

Mis

sion

to

test

dee

p sp

ace

grav

ityA

rgo

, New

Fro

ntiers 4

Mission to N

eptune, Triton and K

BO

Planetary PhysicsFundamental Physics

Inline with Fundamental Physics Roadmaps Advisory Group Report

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Deep Space Gravity Test

Accurate Navigation of S/CAccurate Navigation of S/C

Radio-Science

Laser-Science

PositioningPositioning

1-way or2-waysX+Ka band

VLBI

What is the S/C trajectory ?What is the S/C trajectory ?

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Laser Science: two concepts

One-way pulsed laser(proposed by E. Samain – OCA)

Two-ways continuous coherent laser(proposed by P. Wolf – SYRTE)

Clock

Spectral Filter

Linear Photo-

Detection

Coarse Timing (FPGA)

Res = 10 ns

Temporal Filter (x pseudo

random code)

Calculator

Fine Timing(Vernier)

Res = 10 ps

Frequency Synthesis

Telemetry

Laser pulse

Clock

Spectral Filter

Linear Photo-

Detection

Coarse Timing (FPGA)

Res = 10 ns

Temporal Filter (x pseudo

random code)

Calculator

Fine Timing(Vernier)

Res = 10 ps

Frequency Synthesis

Telemetry

Laser pulse

TESA TCL Terminal

PLL Laser

USO

100 MHzfrom ground

to ground

PBS

1064 nmMercury Ion JPL or Horace Syrte clock

Adaptative Optics on ground

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Deep Space Gravity Test

Accurate Navigation of S/CAccurate Navigation of S/C

Radio-Science

Laser-Science

PositioningPositioning

1-way or2-ways

Non Gravitational ForcesNon Gravitational Forces

DC Accelerometer< 10 pm/s2

X+Ka bandVLBI

Is S/C on a geodesic ?Is S/C on a geodesic ?

What is the S/C trajectory ?What is the S/C trajectory ?

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DC Accelerometer GAP

Noise of MicroSTAR

1.E-13

1.E-12

1.E-11

1.E-10

1.E-09

1.E-08

1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00

Frequency (Hz)

No

ise

(m

/s2 /H

z1/

2 )

Total

Detector

Wire damp

ADC

CPD

Meas

Recomb

PID

Electrostatic accelerometer MicroSTAR based on heritage of

CHAMP, GRACE and GOCE missions(developed by ONERA)

Bias Rejection System rotating stage with piezo-electric motor

(developed by ZARM)

Perfo ~ 1 pm/s2

For more details, see Benjamin Lenoir Poster

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General Relativity Test / Geodesy

Deep Space Gravity(OSS)

Gravitational Wave(LISA)

Equivalence Principle(Microscope)

GRACE / NGGMCHAMP GOCE

Orbit determinationMeasure of NG

Variation of Laser LinkDrag Compensation

Differential accelerationDrag Compensation

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OSS Spacecraft

RPW (x3)

MAG

Imaging instruments

Laser telescope

HGA

Towards Earth

Towards ram

Boresights direction for planetary observation GAP on

settable plate

ASRG

ASRG

4 tanks symmetric wrt GAP,

interconnected fluid

Imaging instruments

Fundamental Physics Inst.

DC Accelerometer : 3.5 kg / 3 WRadio-Science: 3.5 kg / 40 WUSO: 1.5 kg / 5.5 W1-way Laser Science: 14.5 kg / 20 W2-ways Laser Science:25 kg / 80 W

Planetary instruments

UV Spectrometer: 5.0 kg / 12 WHigh Resolution Narrow Camera: 9.8 kg / 14 WIR Spectrometer / Wide Angle Camera:

10.1 kg /7.5 WRadio Plasma Wave: 4.7 kg / 7.9 WThermal Map Imager: 7.0 kg / 20 WMagnetometer: 3.3 kg / 3 WDust Particle Detector: 3.5 kg / 9 W

S/C Data Sheet

Mass: 540 kg (48 kg payload)Available Power: 294 W BoL, 250 W EoLComm: 2.1 m antenna, Band KaAttitude Control: 3 axis (±0.03°)Propulsion: 4 tanks of hydrazine

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Self-gravity Management

• Accelerometer at S/C CoG• S/C mass far from accelerometer • Symmetry of tanks• Membranes for ergol location• Thermal Gauging & Book Keeping for ergol mass

Self-gravity < 14 pm/s2

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Conclusions

• OSS was not selected by ESA for Cosmic Vision M3• Fundamental Physics Objectives considered strong• Planetary Objectives considered weak (flyby instead orbiter)• RTG availability considered as a risk• Launcher cost by US considered as a strategic risk

• OSS allows to do pioneer work on• Merging of Fundamental and Planetary Physics as recommended by

FPRAT• Adaptative optics for 2-ways laser link• DC accelerometer with 1 pm/s2 accuracy• S/C design for severe self-gravity requirement

• Future works should concerns• Integration of the DC accelerometer in the S/C• Convincing planetary community of interest of accelerometer

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Acknowledgement to OSS scientific supporters

• European side: PI B. Christophe (ONERA)• CESR (France) : Nicolas André• DLR / Institute of Planetary Research (Germany): Ralf Jaumann, Jörn Helbert, Hauke Hussmann, Nicole Schmitz, Frank Sohl, Katrin Stephan• DLR / Institute of Space System (Germany): Hansjörg Dittus, Marco Sharringhausen, Tim van Zoest• GeoAzur / OCA (France) : Gilles Métris, Etienne Samain• IGEP, TU Braunschweig (Germany): Karl-Heinz Glassmeier, Daniel Heyner• Imperial College (United Kingdom) : Patrick Brown, Michelle Dougherty, Tim Sumner• Institute for Geophysics and Meteorology / Univ. Köln (Germany) : Martin Pätzold• Institute for Planetology / Westfälische Wilhelms Universität (Germany): Harry Hiesinger• Institut für Geowissenschaften / Max Planck Institute (Germany): Frank Postberg, Ralf Srama• Institut für Physik und Astronomie / Universität Postdam (Germany): Jürgen Schmidt• Instituto Superior Técnico (Portugal): Frederico Francisco, Paulo J.S. Gil, Jorge Páramos• JIVE (The Netherlands) : Sergei V. Progrebenko• LATMOS (France): Jean-Louis Bertaux, François Leblanc, Eric Quemerais• LESIA / Observatoire de Paris (France): Antonella Barucci, Baptiste Cecconi, Laurent Lamy• LKB / ENS (France) : Jean-Michel Courty, Brahim Lamine, Serge Reynaud• ONERA (France) : Bruno Christophe, Bernard Foulon, Benjamin Lenoir, Agnès Levy, Vincent Michau, Clélia Robert, Marc Séchaud, Pierre Touboul• Rutherford Appleton Laboratory (United Kingdom): Robert Bingham• Service d'Astrophysique/IRFU CEA Saclay (France) : Roland Lehoucq• SYRTE / Observatoire de Paris (France): Peter Wolf• Universidade do Porto (Portugal): Orfeu Bertolami• University of Oxford (UK): Leigh Fletcher• ZARM (Germany) : Claus Lämmerzahl, Hanns Selig

• US side: co-PI L. Spilker (JPL)• Cornell University: Dr. Don Banfield• JPL / NASA: Dr. John D. Anderson (retired), Dr. Sami W. Asmar, Dr. Glenn Orton, Dr. Kim R. Reh, Dr. Linda J. Spilker, Dr. Thomas R. Spilker• Lowell Observatory: Dr. Will Grundy• Planetary Science Institute: Dr. Candice Hansen• UCLA: Dr. Johnatan Aurnou, Dr. Ravit Helled, Dr. Kunio Sanayagi