Alternatives for Autonomous Navigation of Small Solar System Explorers

G. González Peytaví, A. Probst, T.P. Andert, B. Eissfeller, R. Förstner

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May 2016

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

• Distributed networks in Solar system exploration

• Autonomous navigation – What for?

• AutoNav alternatives – Absolute navigation – Relative navigation

• Evaluation of alternatives

Outline Alternatives for Autonomous Navigation of Small Solar System Explorers

The next 20 minutes…

Increase spatial

coverage

Cooperative Remote Sensing

Increase temporal coverage

Larger baselines

Multi-node experimentation

Controlled baselines

Separation of payload

critical modules

Mission safety Spatially

distributed redundancy

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Distributed networks in Solar system exploration Alternatives for Autonomous Navigation of Small Solar System Explorers

Cooperative Scientific Exploration and Prospection

Attractive solution • reduced launch mass

increments

Strong dependency on SC master • Propulsion • Communication • Navigation

Interplanetary CubeSat Networks

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Autonomous Navigation – What for? Alternatives for Autonomous Navigation of Small Solar System Explorers

During interplanetary cruise

Self-reliant course corrections

Independent targeting/observation sequences

Reduce contact to ground-control for orbit determination

During proximity operations

Near-real time mission planning

Independent surface targeting/observation sequences

Support investigations of trajectory perturbing phenomena

(gravity, radiation, drag, etc.)

Why AutoNav?

𝑂 𝒓� = 100 𝑘𝑘 ,3𝜎 trajectory planning 𝑂 𝒓� = 10 𝑘𝑘 , 3𝜎 rendezvous planning

𝑂 𝒓� = 1⋯100 𝑘𝑘 ,3𝜎 during fly-by 𝑂 𝒓� = 100 𝑘 , 3𝜎 small-body orbiting 𝑂 𝒓� = 1 𝑘 , 3𝜎 small-body landing

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Alternatives – Absolute Navigation Alternatives for Autonomous Navigation of Small Solar System Explorers

Absolute Navigation

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Alternatives – Absolute Navigation Alternatives for Autonomous Navigation of Small Solar System Explorers

Pulsar-based Navigation

Ray et al., 2006

Optical Solar Interferometry

Celestial Navigation

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Alternatives – Absolute Navigation Alternatives for Autonomous Navigation of Small Solar System Explorers

Optical Solar Interferometry

CCD detector Sun entrance

Star-light entrance

Attenuator

Coupled Sun Star Tracker

LOS Velocity Signal Frequency Doppler Shift fD

1 mm/s 8x109 Hz (radio) 0.027 Hz

1 mm/s 5x1014 Hz (visible) 1667 Hz

• Modes: – Sun imager – Sun line-of-sight – Conventional imaging system

(Wide-angle camera)

𝑓𝐷𝐷𝐷𝐷𝐷𝐷𝐷 = 𝑓𝑣𝑐

Resonance Scattering Interferometer

Helioseismic and magnetic Imager (HMI) aboard the Solar Dynamics Observatory. Scherrer, 2005

σ = 0.026 rad σ = 1 cm/s

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Alternatives – Absolute Navigation Alternatives for Autonomous Navigation of Small Solar System Explorers

Optical Solar Interferometry + Celestial Navigation

Cruise Nav.

EKF Particle Filter

�̅�𝑠𝑠 , �̅�𝑠𝑠

Resonance Scattering Interferometer

Coupled Sun Star Tracker

WA Camera

�̅�𝐷𝑟𝑟𝑟𝑟𝐷

𝑙�̅�𝑠𝑠

𝑙�̅�𝐷𝑟𝑏

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Alternatives – Absolute Navigation Alternatives for Autonomous Navigation of Small Solar System Explorers

Optical Solar Interferometry + Celestial Navigation

3σ after 5 yrs UKF PF

15 m

in

𝑂 𝒓� km 126.7 39.0

𝑂 𝒓�̇ km/s 151.1 53.6

24 h

r 𝑂 𝒓� km 207.3 167.9

𝑂 𝒓�̇ km/s 39.3 57.4

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Alternatives – Absolute Navigation Alternatives for Autonomous Navigation of Small Solar System Explorers

Pulsar-based Navigation

NICER X-ray Timing Instrument Source: NASA

3D Position error < 5km with simultaneous observation of 3 pulsars following ROSETTA trajectory (Simulations) Bernhardt, M. G. Bad Honnef ,2015

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Alternatives – Relative Navigation Alternatives for Autonomous Navigation of Small Solar System Explorers

Relative Navigation

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Alternatives – Relative Navigation Alternatives for Autonomous Navigation of Small Solar System Explorers

Surface landmark tracking

Global model matching

Shape Model

Simultaneous Localization and Mapping

Visual Odometry

• Optical Camera • Imaging LiDAR

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Alternatives – Relative Navigation Alternatives for Autonomous Navigation of Small Solar System Explorers

LIDAR Point Cloud Matching

Image: Courtesy of H. Gómez (ISTA)

Light Curves

Source: Dr. T.M.Ho (DLR-Planetenforschung)

Asteroid 2008 TC3

Image Matching – Bundle adjustment

Images: Courtesy of R. Jacob (ISTA)

Navigation side-product: Object state estimation

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Alternatives – Relative Navigation Alternatives for Autonomous Navigation of Small Solar System Explorers

Grid-information maps

• Hazards • Fuel • Landing sites • Terrain slope

Shape reconstruction

Navigation side-product: Target modelling

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May, 2016

Evaluation of Alternatives Alternatives for Autonomous Navigation of Small Solar System Explorers

Criteria Ground-based Radio

Optical Solar Interfer.

Optical Celestial Nav.

Pulsar-based Nav.

Optical Odometry

with Cameras

Optical Odometry with LiDAR

On-board autonomy No Yes Yes Yes Yes Yes

TRL 9 3-4 5-6 5-6 7-8 5-6

Navigation accuracy 10-100 km 300 km 100 - 1000 km 5 – 100 km 100 km - 1 m 1m – 10cm

SoA Power demands 1 kW 100 W 10 - 15 W 15 W 10 – 15 W 5 – 10 kg

SoA Mass demands 10 kg 50 kg 5 – 10 kg 10 – 15 kg 5 – 10 kg 30 – 40 W

Illumination dependant

No Yes Yes No Yes No

Scale Invariant No No No Yes No Yes

Spatial range > 15 AU 4-5 AU 2-3 AU Solar system

< 1000 km < 2-5 km

Development costs

Sensor/Payload reusability

Radio Comm., Radio Science

Sun attitude Imaging, Astronomy

X-ray or Radio

astronomy

Mapping Opt. Comm. Terminal and

Mapping

System complexity Low High Medium High Medium Medium

Other requirements - Thermal Thermal Timing , Thermal, Long

obs.

Thermal Pointing

Alternatives for Autonomous Navigation of Small Solar System Explorers

G. González Peytaví, A. Probst, T.P. Andert, B. Eissfeller, R. Förstner

5th Interplanetary CubeSat Workshop, Oxford, UK, 24-25 May 2016