Research and Development

In addition to supporting many mission programs and field demonstration activities, NGC also actively conducts a large number of research and development (R&D) activities aimed at supporting future space missions.

R&D

Since its incorporation in 2001, NGC’s team of engineers and support staff have contributed to the successful completion of more than 80 major research and development projects with the Canadian Space Agency (CSA), the European Space Agency (ESA) and a number of major aerospace companies in Canada, Europe and the United States. These projects cover the full spectrum of technology development, from the basic research on robust multivariable control theory, autonomous guidance and state-estimation theory for navigation to the development of simulators and flight software validated in orbit on-board spacecraft.

A non-exhaustive list of recent research and development activities conducted by NGC is provided next, regrouped in the following categories:

Planetary Exploration Mission Concepts and Technologies

REDL – Robust Entry Descent and Landing

The objectives of the REDL study were to identify, analyse and specify Entry, Descent and Landing (EDL) systems for Mars and Moon landing scenarios. NGC’s tasks were to develop and validate robust GNC system concepts, their associated analysis tools and GNC algorithms for achieving specific targeted landing accuracies, validate the EDL/GNC systems on a high-fidelity end-to-end simulator, demonstrate their robustness for the various Mars and Moon scenarios, perform the on-board implementation of the software on a representative flight-like on-board computer and assess its real-time performance. The objective was to bring them to a technology readiness level of 3-4. In parallel, the study also addressed system-level issues related to the design of the landing scenario, landing trajectory, propulsion architecture, sensor selection and sensor accommodation.

Through the REDL study, NGC designed and validated the complete GNC software for autonomous Moon and Mars robotic exploration missions including:

  • for Mars: autonomous guidance and control of the atmospheric phase using inertial navigation, strategy for intelligent parachute deployment time, autonomous guidance and control of the powered descent phase with feature-based relative and absolute Terrain-Relative Navigation (TRN) for precision landing
  • for the Moon: autonomous braking using inertial navigation and Terrain-Relative Navigation, autonomous guidance and control of the final descent phase with feature-based relative and absolute Terrain-Relative Navigation (TRN) for Precision Landing.

The GNC design has been profiled on a flight-like processor and validated in a high-fidelity simulation environment. The study conducted for the European Space Agency used the ESA Lunar Lander and the Mars Sample Return missions as reference scenarios.

SAGE – Scalable EDL GNC & Avionics System Demonstrator

The SAGE study builds on the REDL experience and embeds autonomous Hazard Detection and Avoidance (HDA) and Failure Detection, Isolation and Recovery (FDIR) designs within the Moon and Mars landing GNC software. The goal of SAGE is to develop and mature to TRL5-6 a scalable Autonomous Guidance, Navigation & Control (AGNC) system capable of bringing safely and precisely valuable assets on the Martian and Lunar surfaces.

The study led to the development of a complete demonstrator of the reference Entry, Descent and Landing AGNC system, including embedded software and hardware-in-the-loop validation in the context of the selected Moon and Mars robotic mission scenarios.

FPNS – Feature-Based Planetary Navigation Subsystem

The FPNS study addressed the development of an innovative combination of Lidar, camera and feature-recognition algorithms that provide planetary orbiters and landers with the ability to determine autonomously their position, velocity and orientation relying only on topographical and radiometric features on the surface of a planet. The system is meant to be applicable to exploration of large planetary bodies with or without atmosphere and small bodies like asteroids and comets. This system is especially designed for exploration missions that require a GPS-like functionality around planets in order to achieve precision orbit determination and/or Precision Landing/sampling.

Feature-Based Planetary Navigation Concept (© CSA)

Formation Flying GNC Technologies

FFSAT – Coupled Attitude and Orbit GNC Algorithms for Small Satellites in Formation using Natural Motion

The FFSAT (Coupled Attitude and Orbit GNC Algorithms for Small Satellites in Formation using Natural Motion) project consisted of the development of innovative GNC algorithms able to perform the coupled attitude/translation manoeuvres of a small satellites Formation Flight mission in the most complex planetary orbital environment, i.e. highly eccentric orbit with perturbations. During this study, NGC consolidated its strong expertise in multi-spacecraft mission GNC design. The formation flight GNC software developed by NGC contains attitude and translation navigation, guidance and control functions. Moreover, this project used the very efficient PROBA-2 Verification and Validation framework to perform the System Integration and Software System-level Tests.

JC2Sat – Japan Canada Joint Collaboration Satellite Formation Flight Mission

NGC supported the CSA in the design and analysis of the JC2Sat mission concept. NGC developed methodologies to support system-level trade-off and feasibility analyses for this drag-based formation flying control demonstration mission. NGC also supported CSA staff by transferring its expertise in model-based spacecraft software design and validation.

JC2Sat

Conceptual view of the JC2Sat-FF satellites flying in along-track configuration (Copyright: CSA, JAXA)

Rendezvous GNC Technologies

RENSES – Relative Navigation State Estimation Software

In the RENSES project, NGC designed, implemented and tested a relative state estimation filter in order to support debris removal and deep-space rendezvous mission. This navigation filter is a key component of a complete Relative Navigation System (RNS), comprising sensors and processing software, which would perform relative state estimation for cooperative or uncooperative targets, in Earth orbit or in deep-space.

MODEL – Orbital Debris Removal Mission Concept

NGC supported a study led by COM DEV establishing a reference concept for an orbital debris removal mission in Low Earth Orbit. NGC designed the reference mission scenario, defined the GNC requirements and performed the design of the GNC system for all phases of the mission.

Mars Sample Return

NGC performed the mission analysis, designed the search orbits, selected the sensors, and designed the navigation algorithms to detect, estimate the relative orbit, rendezvous with, and acquire a sample canister containing Mars surface samples with a spacecraft in a 500-km orbit around Mars, in the context of EXOMARS preliminary mission definition study.

Asteroid Exploration Mission Concepts

NEODQ – Near-Earth Object Don Quixote Mission Phase A

The European Space Agency NEODQ mission definition study aimed at the deflection of an asteroid trajectory so it avoids impacting the Earth. NGC was responsible for the design of the GNC system for both spacecraft; the impactor and the orbiter. A high-accuracy camera-based relative state estimation and a strategy for propulsive manoeuvres at critical instants before impact were developed to achieve the mission requirements. The GNC design for the orbiter included the requirement to rendezvous with the asteroid, maintain a co-orbiting safe position to monitor the impact and acquire safe orbits around the asteroid to determine its new orbit after impact.

MPOLO – Marco Polo Phase A

In this European Space Agency mission definition study aimed at the return of asteroid surface samples to Earth, NGC was responsible for the autonomous GNC system required to acquire, monitor and maintain a safe orbit around the asteroid and to perform the sample acquisition using various candidate solutions (hovering, touch-and-go sampling, landing). NGC developed an innovative navigation technique based on range measurements and a model of the asteroid that enabled the autonomous determination of the inertial position of the spacecraft to high accuracy.

MARCO POLO

Conceptual design of the Marco Polo spacecraft descending towards the sampling site (© ESA, source)

Verification and Validation Technologies

VVAF – Worst-Case & Safety Analysis Tools for Autonomous Rendezvous System

Objective of the study was to define, develop and validate two integrated verification and validation (V&V) frameworks for autonomous rendezvous GNC systems, incorporating respectively an analytical technique and an optimization-based analysis technique. The study defined an offline analytical integrated verification and validation framework that steers Monte-Carlo simulations taking advantage of local worst-case analysis by means of mu-analysis. It assessed the benefits of the integrated V&V frameworks when compared with a traditional V&V framework, using the European Space Agency Mars Sample Return Rendezvous phase as a reference scenario.

ELFTT – Enhanced Linear Fractional Transformation Toolbox

The objective of the ELFTT study was to design and validate a toolbox dedicated to the building and validation of LFT (Linear Fractional Transformation) for space applications. The toolbox incorporates LFT manipulation, building, reduction, verification and analysis functions. It implements flexible attitude dynamics and rendezvous system LFT. Traditional Verification and Validation (V&V) were used to cross-validate the performance of the toolbox.

SAFEV – Robust Flight Control System Design Verification and Validation Framework

The objective of the SAFEV study was to develop an Enhanced Design, Validation and Verification Framework that includes methodology, algorithms and tools for uncertain nonlinear time-varying safety critical systems (e.g. launchers). The framework reduced significantly the design, validation and verification effort. Building on VVAF, NGC’s contributions to this project consisted of designing and applying two enhanced analysis techniques:

  • the offline approach NGC developed in VVAF for worst-case tracking that consists in integrating linear robustness analysis by means of mu-analysis to a traditional Monte-Carlo V&V framework or to global optimisation framework in order to steer the simulations in an area of the uncertain parameters space for which the system behaviour is critical
  • the online approach that consists of adapting the LFT as a function of the evolution of the nonlinear simulation in order to always perform the most accurate local analysis. The simulations themselves are driven by optimisation in order to track the worst case.

Earth Observation Mission Concepts

POETE – Platform for the Observation of the Earth and for In-Orbit Technology Experiments

Through the POETE study (CSA-funded), NGC acted as the prime contractor in the design of a microsatellite forest fire and environment monitoring mission. In the study, the mission, payload and system requirements were derived, the mission orbital constellation was designed, the operational scenario was defined and the feasibility of the concept was assessed.

Overview of the Platform for the Observation of the Earth and for in-orbit Technology Experiments (POETE) mission concept (© CSA)

TICFIRE – Thin Ice Cloud in Far IR Experiment

In the TICFIRE mission study, NGC derived the orbit, navigation and pointing requirements for a microsatellite observation mission of the thin ice clouds above the Arctic led by UQAM.

Overview of the Thin Ice Cloud Far IR Experiment (TICFIRE) mission concept (© CSA)

AIS-C – AIS Constellation Phase A

In this study, NGC supported COM DEV in the design and performance evaluation of a microsatellite constellation for the tracking of ships. NGC established a list of candidates meeting the mission requirements and performed trade-offs based on coverage performance, data latency, maintenance requirements and cost.

Advanced Attitude and Orbit Control System Technologies

ACTAS – Advanced Control Techniques for Autonomous Satellites

The ACTAS study, conducted under ESA contract, demonstrated the feasibility of simple and reliable 3-axis spacecraft attitude control laws solely based on the Earth magnetic field. The final goal of this project is to define an in-flight demonstration using the existing PROBA platform magnetic sensors, actuators and momentum bias, with the acquisition and continuous maintenance of satellite Earth and Sun pointing and the evaluation of the achievable performance. As part of the PROBA-V mission, NGC has further evolved the ACTAS algorithm. It is now used as the PROBA-V spacecraft safe mode.

ASETAS – Advanced State Estimation Techniques for Autonomous Spacecraft

The ASETAS studies, conducted under ESA contracts, were aimed at developing innovative techniques for the autonomous determination of the orbit and attitude of a spacecraft. In ASETAS-1, a simple technique was developed to determine 3 of the 4 orbital elements of a circular (or near-circular) orbit based on the assumption that detecting the entry and exit from eclipse, via temperature, light or solar-array current sensors, provides some information on the orbital state. NGC has demonstrated and validated by simulation this algorithm. In ASETAS-2, an Unscented Kalman Filter (UKF) for attitude and orbit determination was addressed, assessed in detail and compared with the more common Extended Kalman Filter (EKF). Both the EKF and the UKF have been flown on the PROBA-2 spacecraft in order to assess their relative performance in orbit. Deep-space exploration missions would benefit from such technology.

HAHA – High Accuracy High Agility Attitude Determination and Control System for Earth Satellites

In this study partially funded by the Canadian Space Agency, NGC designed innovative AOCS functions required to provide high-accuracy and high-agility capabilities to Earth satellites. These functions include the estimation of environmental perturbation torques (including magnetic and solar radiation pressure), a guidance law for Earth limb pointing and a control law for using more than 3 reaction wheels in an optimal manner despite constraints of zero-speed crossings, saturation and momentum management, in order to increase pointing accuracy and agility.