SAGE : Can we detect gravitational waves with CubeSats? S . Lacour, - PowerPoint PPT Presentation

SAGE : Can we detect gravitational waves with CubeSats? S . Lacour, P . Bourget, M. Nowak, F . Vincent, V . Lapeyrere, L. David, A. Le Tiec, A. Kellerer, O. S traub, J. Woillez

PICSAT • Photometer 100ppm • Technology demonstrator for single mode fibre • Development started Mach 2015 • Launched January 2018 on PS L V C-40 • Lost contact in Mars 2018 2 GDR Ondes Gravitationnelles

Pricing 3 GDR Ondes Gravitationnelles

LISA • Michelson interferometer in space • 2.5 millions kilometers arm length Laser C Proof masses B A From LISA White Book 2017 4 GDR Ondes Gravitationnelles

LISA • 2 off axis telescopes 30cm • 2 optical bench with bulk interferometers • 2 accelerometer (5 centimeters cubes) • 1 Disturbance R eduction S ystem (thrusters) • Thermal stability ! 5 GDR Ondes Gravitationnelles

LISA = > SAGE • 2 off axis telescopes 30cm => 10cm mirrors • 2 optical bench with bulk interferometers => Fibered interferometry • 2 accelerometer (5 centimeters cubes) • 1 Disturbance R eduction S ystem (thrusters) • Thermal stability ! => 100mW laser beam only 6 GDR Ondes Gravitationnelles

SAGE • 60 ° intertwined telescopes: 7 GDR Ondes Gravitationnelles

Spacecraft C Spacecraft B 1e‐8 1e‐8 99.99% 99.99% 0.01% 0.01% Modulator Modulator Phase Phase f1 f2 99% 99% � 12 � 12 50% 50% 1% 1% L D3 D2 D1 a s � 12 � 11 � 13 e r S pacecraft A 8 GDR Ondes Gravitationnelles

Satellite C a) t=0s GEO 42000km 72 000 km => 0.25s Satellite B Satellite A 9 GDR Ondes Gravitationnelles

b) t=0.25s 10 GDR Ondes Gravitationnelles

c) t=0.5s 11 GDR Ondes Gravitationnelles

d) t=0.75s 220 000 km interferometer 1 s light travel time Measurement at zero OPD Satellites on ballistic trajectory 12 GDR Ondes Gravitationnelles

TDI φ 12 ( t ) = 21 ( t + ∆ 21 ) − 12 ( t ) + L 21 ( t ) φ 21 ( t ) = 12 ( t + ∆ 12 ) − 21 ( t ) + L 12 ( t ) h ( t ) = φ 12 ( t ) + φ 21 ( t − ∆ 12 ) + 2 φ 11 ( t − ∆ 12 − ∆ 21 ) φ 11 ( t ) = 1 / 2( 12 ( t ) − 13 ( t )) + φ 13 ( t − ∆ 12 − ∆ 21 ) + φ 31 ( t − ∆ 31 − ∆ 12 − ∆ 21 ) φ 13 ( t ) = 31 ( t + ∆ 31 ) − 13 ( t ) + L 21 ( t ) − φ 13 ( t ) − φ 31 ( t − ∆ 13 ) − φ 11 ( t − ∆ 13 − ∆ 31 ) φ 31 ( t ) = 13 ( t + ∆ 13 ) − 31 ( t ) + L 12 ( t ) − φ 12 ( t − ∆ 13 − ∆ 31 ) − φ 21 ( t − ∆ 21 − ∆ 13 − ∆ 31 ) + 2 φ 11 ( t ) − 2 φ 11 ( t − ∆ 21 − ∆ 12 − ∆ 13 − ∆ 31 ) h ( t ) = L 12 ( t ) + L 21 ( t − ∆ 12 ) + L 13 ( t − ∆ 12 − ∆ 21 ) + L 31 ( t − ∆ 12 − ∆ 21 − ∆ 13 )) − L 13 ( t ) − L 31 ( t − ∆ 13 ) − L 21 ( t − ∆ 13 − ∆ 31 ) − L 12 ( t − ∆ 13 − ∆ 31 − ∆ 12 ) 13 GDR Ondes Gravitationnelles

SAGE ? Graph From ESA Gravitation Observatory Advisory team, final report 2016 14 GDR Ondes Gravitationnelles

1 pm (73 000 km arm length) 15 GDR Ondes Gravitationnelles

Sensitivity of SAGE 9 µN/m 2 1‐6 µN/m 2 Solar Wind Solar Wind 16 GDR Ondes Gravitationnelles

Sensitivity of SAGE 17 GDR Ondes Gravitationnelles

Sensitivity of SAGE Radiation Pressure 18 GDR Ondes Gravitationnelles

Sensitivity of SAGE 19 GDR Ondes Gravitationnelles

Sensitivity of SAGE Radiation Pressure Solar Wind 20 GDR Ondes Gravitationnelles

Diffraction analysis 1km 250mW 2.5nW 72 000 km • Diffraction + fiber inj ection coupling cause an energy loss of 1.5 10 -10 between the two satellites: 100mW=>15pW s p hc λ = 23 pm/ H z 2 �P phot ons 21 GDR Ondes Gravitationnelles

Sensitivity of SAGE Photon Noise Radiation Pressure Solar Wind 22 GDR Ondes Gravitationnelles

Sensitivity of SAGE 23 GDR Ondes Gravitationnelles

But… • No 10 4 IMBH? M. Colpi, A. Sesana, 2018 A. Sesana, M. Volonteri, and F. Haardt, 2007 24 GDR Ondes Gravitationnelles

But… • No 10 4 IMBH? M. Colpi, A. Sesana, 2018 A. Sesana, M. Volonteri, and F. Haardt, 2007 25 GDR Ondes Gravitationnelles

But… • Technical challenges: – Orbitography – Thermal expansion (20pm/ sqrt(Hz) 26 GDR Ondes Gravitationnelles

To conclude LIGO timeline 27 GDR Ondes Gravitationnelles