Planetary Lander Technology Projects

Research projects on planetary lander technology that the Space Technology Centre has either led or had a significant role in are described below:

PANGU Enhancement

The PANGU Enhancement project for ESA is led by the Space Technology Centre. The aim is to provide a tool which is able to support the design of advanced navigation and hazard avoidance techniques based on vision, lidar and/or radar altimeter sensors.

PlanetSim

Details coming soon.

Multi-Purpose Vision Navigation

Details coming soon.

PANGU Asteroids and Whole Planet Simulation

Simulated Asteroid

The PANGU Asteroid and Whole Planet Simulation study extended the capabilities of the PANGU tool to include the realistic generation and visualisation of complete asteroids and the simulation of entire planets to be viewed from orbital distances.

Additional research to enhance the rendering speed of PANGU and to increase the size of terrain that can be modelled within PANGU was successfully completed. This work introduced support for rendering models with the ROAM algorithm and the addition of a dedicated memory management system to allow unused portions of a model to be unloaded from memory.

LunarSim

Various ESA planetary lander missions (e.g. Euromoon 2000) were being considered that required a lander guidance system. A vision-based navigation system had been proposed and prototyped in the ESA 3D Planetary Modelling study led by Joanneum Research (Austria), in which Steve Parkes was involved. The prototype used a physical terrain mock-up and a robotic arm holding a camera, to simulate the descent of a lander towards the lunar surface. Steve Parkes realised that an alternative simulation method was required because of the cost and time taken to build different lunar surfaces. A computer simulation of the lunar surface and camera could be used to provide realistic lunar surface images for testing the vision-based navigation system. Steve received a small contract from ESA to prove the concept and a prototype planet surface simulation system was developed. LunarSim showed that realistic cratered terrain models could be created using fractal techniques. An almost unlimited variety of lunar surfaces could be generated automatically and used for extensive testing of vision-based lander navigation systems.

LIDAR-GNC

PANGU simulated Martian surface

PANGU simulated Martian surface

The LIDAR-GNC research was done as a sub-contractor to EADS Astrium SAS. The aim of this work was to extend PANGU to cover realistic Martian surface generation including boulders and sand dunes and to simulate a scanning LIDAR sensing the Martian terrain. The LIDAR sensor simulation is capable of simulating a range of scanning LIDAR instruments and takes into account spacecraft motion during the scanning interval. PANGU models and the LIDAR simulation have been integrated in a guidance and navigation control system prototype by Astrium.

Robust Entry Descent and Landing System for ExoMars

FEIC feature tracking on a PANGU generated image sequence

The Robust Entry Descent and Landing System (EDLS) for ExoMars study aims to develop technologies to ensure a safe landing of ExoMars on the surface of Mars. The overall project is being led by LogicaCMG.

The overall project objectives are to:

  • Assess a number of novel but pragmatic and achievable candidate methodologies to:
    • Improve the accuracy of a landing from ballistic entry.
    • Reduce the risk of mission failure during the terminal phase.
  • Quantify the impact of key atmospheric variables on the propagation of the injection covariance matrix during entry, descent and landing thereby allowing:
    • A more rigorous approach to be taken to the design of the overall EDLS solution
    • Novel methods for accuracy improvement and risk reduction to be developed in a realistic environment

The principal objective for the University of Dundee was to:

  • Investigate processing of sensor data to estimate the transverse velocity of the lander.


HARVD: High-integrity, Autonomous, multi-range RendezVous and Docking

HARVD VRML Satellite Model

HARVD VRML Satellite Model

The overall objective of the HARVD (High-integrity, Autonomous, multi-range RendezVous & Docking) study is to develop a European capability for autonomous orbital rendezvous and docking. The detailed design of a high-integrity, autonomous, multi-range, rendezvous and docking control system is being developed for future solar system exploration missions. A demonstration system including the onboard GNC hardware and software components is being developed. Its real-time performance and autonomous operation is being evaluated covering far-field to terminal rendezvous. Two types of mission are being examined: planetary sample return and associated rendezvous of return capsule with orbiting Earth return vehicle, and in-orbit servicing of both cooperative and non-cooperative spacecraft.

NPAL: Navigation for Planetary Approach and Landing

Feature tracking across a sequence of planetary surface images

The University of Dundee worked with EADS Astrium, Galileo Avionica, INETI and SciSys to develop an intelligent camera for vision-based navigation of a planetary lander. This research funded by ESA within the Navigation for Planetary Approach and Landing (NPAL) study was led by EADS Astrium in France. The camera unit performs image processing to select image feature points and to track them from frame to frame. With knowledge of the tracks of several feature points and the linear and rotational acceleration of the spacecraft, provided by an inertial measurement unit, it is possible to reconstruct the path of the spacecraft and to determine its position and orientation relative to a planet’s surface.

LIDAR-LAPS

The LIDAR-LAPS research is being undertaken as a sub-contractor to EADS Astrium SAS. The aim of this work is to extend PANGU scanning LIDAR sensor to support a different type of scanning pattern from the LIDAR-GNC and LIDAR-ILT projects. The LAPS system consists of a laser which emits pulses every 100 μs asynchronously to two oscillating mirrors controlling the beam direction in azimuth and elevation. The two mirrors scan the field of view driven by independent triangle waves. As with the LIDAR-GNC and LIDAR-ILT projects, the sensor simulation takes into account spacecraft motion during the scanning interval.