Solar Sails : Technology and demonstration status

Solar Sail propulsion has been validated in space (IKAROS, 2012) and soon several more solar-sail propelled spacecraft will be flown. Using sunlight for spacecraft propulsion is not a new idea. First proposed by Frederick Tsander and Konstantin Tsiolkovsky in the 1920's, NASA's Echo 1 balloon, launched in 1960, was the first spacecraft for which the effects of solar photon pressure were measured. Solar sails reflect sunlight to achieve thrust, thus eliminating the need for costly and often very-heavy fuel. Such "propellantless" propulsion will enable whole new classes of space science and exploration missions previously not considered possible due to the propulsive-intense maneouvers and operations required

Design of a Mars ascent vehicle using HyImpulse’s hybrid propulsion

The recent growth in maturity of paraffin-based hybrid propulsion systems reassesses the possibility to design an alternative Mars Ascent Vehicle (MAV) propelled by a European hybrid motor. As part of the Mars Sample Return (MSR) campaign, a Hybrid MAV would present potential advantages over the existent solid concept funded by NASA through offering increased performance, higher thermal resilience, and lower Gross Lift-Off Mass (GLOM). This study looks at the preliminary design of a two-stage European MAV equipped with HyImpulse’s hybrid engine called the Hyplox10. This Hybrid MAV utilizes the advantages inherent to this type of propulsion to propose an alternative MAV concept. After a careful analysis of previous MAV architectures from the literature, the vehicle is sized with all its components such as the propellant tanks and nozzle, and the configuration of the rocket is established. A detailed design of the primary structure is addressed. This is followed by a Finite Element Analysis (FEA), evaluating the structural integrity under the challenging conditions of Entry, Descent, and Landing (EDL) on Mars, considering both static and dynamic analyses. The outcome is a Hybrid MAV design that demonstrates feasibility and resilience in the harsh Martian environment, boasting a GLOM of less than 300 kg

A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications

Advances in microelectronics, materials, combined with affordable and frequent launch opportunities has led to a revolution which consists of small satellite missions used for technology validation, Earth observation, space exploration. Small satellites are now being developed in large volumes for mega-constellations for Earth observation, Internet of Things (IoT) and low latency communications (internet) thus democratizing space and making new space applications a reality. Advances in small satellite platforms, miniaturization of instruments and the availability of low-cost launches for small satellites, can enable new, geodetic missions which can benefit from the use of constellations of small satellites. An overview of some of the most important small satellite based geodetic missions is presented, along with a brief overview of new mission concepts which can significantly enhance our knowledge in the geodetic field

Design and structural analysis of a control moment gyroscope (CMG) actuator for cubesats

Following a global trend towards miniaturization, the population of nano- and micro-satellite continues to increase. CubeSats are standardized small size satellites based on 10 × 10 × 10 cm cube modules (1U) and are becoming sophisticated platforms despite their very small size. This paper details the design and the structural analysis of a Control Moment Gyroscope (CMG) actuator for agile CubeSats with a physical size up to 12U, which require high torque actuators. CMGs have inherited torque amplification capabilities and the recent advances in motor miniaturization make them ideal candidates for small satellite missions with slew rate requirements. The system’s requirements are derived based on conceptual agility requirements for an agile (highly maneuverable) CubeSat which needs to achieve a 90° maneuver in 90 s. With specific cost, mass and volume requirements, the proposed CMG design is based on some of the smallest available off-the-shelf electric motors and uses a light aluminum casing design. The proposed design uses stepper motors for the gimbal mechanism as a low cost, compact and low power solution, contributing to an overall low mass of the full CMG cluster. Static and dynamic analyses were performed to assess the mechanical integrity of the system for launch loads. Apart from a necessary custom control electronic board, the complete mechanical assembly has been designed including electrical hardware. Analyses demonstrate that the overall stress levels acting on the system are manageable by the CMG design. Bolted joints are critical and should be studied independently as the chosen model created singularities around these areas. Each individual CMG of the designed pyramidal cluster is shown to weigh about 35 g. Using the proposed CMG design with a customized avionics board, the complete CMG system is shown to weigh 250 g and occupies slightly more than ½U volume for a CubeSat, indicating the feasibility of CMGs for agile CubeSat

BILSAT: Advancing Smallsat Capabilities

Small spacecraft technologies and capabilities are evolving to the point where the BILSAT 120kg spacecraft will this year demonstrate capabilities and performance similar to the 320kg UoSAT-12 mission launched in 1999. Over the past few years, the design of small satellites has evolved from simple curiosities to effective, high performance systems, capable of competing with much bigger and much more expensive spacecraft. Within the framework of an agreement between SSTL and TUBITAK-BILTEN (The Information Technologies and Electronics Research Institute), a non-profit government laboratory located in Ankara, Turkey, a Technology Transfer Program was started in August 2001. This program includes the design, manufacture and launch of one Enhanced SSTL microsatellite platform, one engineering model for use in Turkey and the training of engineers in all aspects of the spacecraft design. Detailed design began using the Enhanced SSTL microsatellite platform as the starting point. The end product that will be launched in the summer of 2003, is the most advanced spacecraft ever designed by SSTL, carrying two advanced payloads developed by TUBITAK-BILTEN. The spacecraft is a highly optimised satellite, with a mass of 120kg and including 14 cameras (in several imager arrangements), a 10m/s class resistojet propulsion system, VHF/UHF and S-band RF systems, tried and tested OBDH units in parallel with newly designed mass data storage and processing units, all this topped by a high performance AODCS subsystem, including two star trackers, GPS receiver (for both orbit and attitude determination), rate gyros, four momentum/reaction wheels, and what will be the first operational use of Control Momentum Gyros on a small spacecraft, to perform high agility manoeuvres. These units will be used to achieve the missions specified for this project, mainly full imaging of Turkey, stereoscopic imaging of selected targets, a Digital Elevation Map of Turkey, and communications. The present paper discusses briefly the technical characteristics of the spacecraft, but focuses on the mission aspects and how the different subsystems (namely the new subsystems and payloads) will be used to accomplish the mission. The operational modes of the spacecraft are discussed and the interaction of the AODCS subsystem with the OBDH and Imaging system is described in detail

Autonomous unmanned heterogeneous vehicles for persistent monitoring

Swarms of unmanned vehicles (air and ground) can increase the efficiency and effectiveness of military and law enforcement operations by enhancing situational awareness and allowing the persistent monitoring of multiple hostile targets. The key focus in the development of the enabling technologies for swarm systems is the minimisation of uncertainties in situational awareness information for surveillance operations supported by ‘system of systems’ composed of static and mobile heterogeneous sensors. The identified critical enabling techniques and technologies for adaptive, informative and reconfigurable operations of unmanned swarm systems are robust static sensor network design, mobile sensor tasking (including re-allocation), sensor fusion and information fusion, including behaviour monitoring. The work presented in this paper describes one of the first attempts to integrate all swarm-related technologies into a prototype, demonstrating the benefits of swarms of heterogeneous vehicles for defence applications used for the persistent monitoring of high-value assets, such as military installations and camps. The key enabling swarm system technologies are analysed here, and novel algorithms are presented that can be implemented in available COTS-based unmanned vehicles. The algorithms have been designed and optimised to require small computational power, be flexible, be reconfigurable and be implemented in a large range of commercially available unmanned vehicles (air and ground).European Defence Agency: PP-15-INR-0

EuroDRONE, A European unmanned traffic management testbed for U-space

EuroDRONE is an Unmanned Traffic Management (UTM) demonstration project, funded by the EU’s SESAR organization, and its aim is to test and validate key UTM technologies for Europe’s ‘U-Space’ UTM program. The EuroDRONE UTM architecture comprises cloud software (DroNav) and hardware (transponder) to be installed on drones. The proposed EuroDRONE system is a Highly Automated Air Traffic Management System for small UAVs operating at low altitudes. It is a sophisticated, self-learning system based on software and hardware elements, operating in a distributed computing environment, offering multiple levels of redundancy, fail-safe algorithms for conflict prevention/resolution and assets management. EuroDRONE focuses its work on functionalities which involve the use of new communication links, the use of vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) technology to communicate information between drones and operators for safe and effective UTM functionality. Practical demonstrations that took place in Patras/Messolonghi in 2019 are presented and show the benefits and shortcomings of near-term UTM implementation in Europe