Data transmission with an optical linkbetween a nanosatellite and the groundF. Millour, M. Benabdesselam, P. Bendjoya, P. Berio, M. Carbillet, F. Cauneau, A.

Chiavassa, J.-Y. Dauvignac, L. Deneire, P. Exertier, F. Falzon, P. Gourbesville, S. Lagarde,

T. Lanz, F. Mady, F. Martinache, D. Mary, A. Memin, G. Metris, P. Michel, L. Rolland, X.

Roser, A. Soulain, R. Staraj, P. Stee, ...

Pico Nano Micro Mini Moyen Gros

Hubble Space Telescope

11 tonnes

Corot

630 kg

Microscope

303 kg

ISO

1800 kg

Suncubes

35 g

Robusta

1,3 kg

What is a cubesat?

Standard platform to make space reachablefor universities• 10x10x10 cm cube (1 unit or 1U)• 1 W available electrical power• 1.3 kg• You can combine cubes

(1.5U, 2U, 3U, …)• Reasonable budget

for an university (1U = 250 k€)

Real-life project to train students↗ TRL of new technologiesSmall scientific missions

What is a cubesat?

Standard platform to make space reachablefor universities• 10x10x10 cm cube (1 unit or 1U)• 1 W available electrical power• 1.3 kg• You can combine cubes

(1.5U, 2U, 3U, …)• Reasonable budget

for an university (1U = 250 k€)

Real-life project to train students↗ TRL of new technologiesSmall scientific missions

The « new space » revolutionExample: Planet labs, 190 satellites in orbit today

Nice / le Ray stadiumbeing dismantled in 2017

The « space data highway »

• LASER comm. between satellites: data rates > 1Gbps

• Demonstration between SENTINEL 1A and Eutelsat on 2016 June 2nd

• No cluttering of radio frequencies

• Difficult to intercept

• Higher data rates

OCSD-1 NASA mission

• 1.5 U• 6W LASER for downlink (power

dependent on pointing accuracy)• LASER uplink receiver• Laser ranging• Earth-monitoring camera• Ranging camera• Retro-reflectors, LED beacons• 2 SDR radios @900MHz• GPS• Full-featured ADCS including

• Magnetometer, Gyro,

• Sun sensors,

• Magnetic coils,

• On-board computer,

• Earth sensor,

• Reaction wheels,

• 2 star trackers

• Thruster

• Launched in 2015

• Failure of the on-boardcomputer after a software update

CSUCA

Where do we stand?

• Mission definition in progress:

• 1 Sicence goalatmosphere pollution measurements

• 1 Technology goalLASER communications

• Platform choice1U

• 7 partner labs / schools(LEAT, ParisTech Sophia, Polytech Sophia, Géoazur, I3S, LPMC, Master MAUCA)

• 2 companies:Sophia Conseil & Thalès Alenia Space

• Other universities

• Université de la Sapienza

• CSU Toulouse et CSU Grenoble

• 1 Site Internethttps://nanosat.univ-cotedazur.fr

• 1 compte twitter uca3_satlire : « UCA cube sat »

Can we do the same as OCSD-1in a different way?

Corner cube was invented in 1917 by Henri Chrétien(Obs. Nice) !

The idea:

Ground

Satellite

Ground

Satellite

Advantages:• No LASER in the satellite (less

power)• Corner cube larger angle

acceptance (~10o)

Difficulties• Complexity shifted to

ground station

Corner cube (retro-reflector)Prismatic

Ball lens

Cat’s eye

Telecentric cat’s eyeIllustration from Rabinovitch et al. 2004

Light modulator

Navy Modulating Retro-reflector ~10MHz(Goetz 2010)

LCOS ~1KHz(cristaux liquides)

~100KHz

What are our needs?• Form factor 1/1.5/2/3U?

• What electrical power is needed?

• SCAO (attitude control)

• Ground station (Calern telescope?)

• On-boardcompuating?

• GPS

• Radio

Work done

• CNES visit in 2016

• 3 Polytech students 2016/2017

• CSUCA set-up• organisation,• offices,• Projet manager: S. Ottogalli

• Documentation

• Montpellier cubesat meeting

• Paris cubesat meeting

• Set-up of a collaboration withMontpellier

Work in progress• 1e stagiaire de M2 arrivée début Janvier à Lagrange : Manel Maamri

• Étude système, définition et spécifications mission,documentation, gestion de projet.

• 4 étudiants de M1 Polytech Nice Sophiasur le prototype de station Sol radio

• 1er Audit du CNES le 30 Janvier : labellisation JANUS

• Formation à IDM / CIC les 5/6/7 Février au CNES

• 5 autres stagiaires M1 et M2 attendus entre Février et Juin

• Implantation mécanique (M1) Arthur Stibbe en Mars à Lagrange

• Charge utile scientifique (M2) en attente

• Charge utile + station sol communications LASER (M2) en attente

• Station Sol radio (M2) pas encore d’étudiant

• GPS (GNSS / M2) Florian Zedek en Mars à Geoazur

• Revue de projet de phase 0/A en Juin 2017

Work in progressPolytech Nice student’s project:Build a prototype radio ground station

SatNOGS