Traditionally Very-High Resolution (VHR) optical missions come with costs that run into hundreds of millions of dollars [1]. Fundamentally, these mission costs arise from the complex technical challenges of achieving high quality, precisely positioned imagery from space. As is frequently the case, performance and cost have conflicting drivers for high resolution optical spacecraft stemming from the demand for larger payloads and larger platforms to support them.The Surrey Satellite Technology Ltd. SSTL-Mini Precision is an imaging spacecraft that employs the latest developments in payload and platform technology to achieve very high-resolution imaging performance within a compact form factor. Using a half-pixel offset sensor 0.3m ground sampling is achieved from a 500km orbital altitude generating high resolution imagery at a reduced cost than has traditionally been feasible for missions of this class.

Small satellite is a disruptive technology in space industries. Traditionally, space industries were dominated by satellites which have thousands of kilograms and are bulky and expensive. Small satellites denote a new generation of miniaturized satellites which, by taking advantages of modern technologies (e.g., integrated circuits, digital signal processing, MEMS, and additive manufacturing), can achieve a significant reduction in volume, mass, development time, and cost of satellites. During recent decades, small satellites, including CubeSats, NanoSats, MiniSats, and MicroSats, have undergone rapid developments, and are playing an increasingly larger role in exploration, technology demonstration, scientific research, and education. These miniature satellites provide a low-cost platform for missions, including planetary space exploration, Earth observations, fundamental Earth and space science, and developing precursor science instruments like laser communications and millimeter-wave communications for intersatellite and intrasatellite links, and autonomous movement capabilities. They also allow educators an inexpensive means to engage students in all phases of satellite development, operation, and exploitation through real-world, hands-on research and development experience on rideshare launch opportunities. A number of miniaturized satellites can form spaceborne wireless sensor networks in the space, which are also going to play an important role in Internet of Space (IoS) of the future.

Earth orbiting satellites come in a wide range of shapes and sizes to meet a diverse variety of uses and applications. Large satellites with masses over 1000 kg support high-resolution remote sensing of the Earth, high bandwidth communications services, and world-class scientific studies but take lengthy developments and are costly to build and launch. The advent of commercially available, high-volume, and hence low-cost microelectronics has enabled a different approach through miniaturization. This results in physically far smaller satellites that dramatically reduce timescales and costs and that are able to provide operational and commercially viable services. This paper charts the evolution and rise of small satellites from being an early curiosity with limited utility through to the present where small satellites are a key element of modern space capabilities.

Image compression is an important requirement of imaging payloads on board Earth Observation satellites. This paper presents a new on-board real-time compression system, capable of lossless and lossy image compression. A cost-effective lossless image compression scheme, based on the CCSDS recommendation, is proposed and tested with multi/hyperspectral images. An efficient hardware implementation is achieved using FPGA-based acceleration. The hardware accelerator design is optimized by employing novel techniques at algorithmic and logic levels.

In the Consultative Committee for Space Data Systems - Lossless Data Compression (CCSDS-LDC) algorithm a small region of image data is compressed independently to achieve error-resilience functionality, which is one of the most distinct requirements for space applications. 2-D or 3-D predictions are believed to bring superior compression performance, however they interfere with the error-resilience property. This paper proposes a new scan scheme to address the problem. By combination of multidimensional predication and embedded radiometric calibration technique, the proposed system performs very effectively on remote sensing panchromatic and multispectral images. Finally a high-level reconfigurable model for the hardware implementation of the proposed system is developed targeted at FPGA devices.

A new dimension of wireless sensor network architecture design is emerging where hundreds to thousands of ultra-light low-cost sensor nodes are required to collectively perform a spectrum of distributed remote sensing missions in hostile conditions, predominantly those encountered in space. Research is underway to investigate the feasibility of fabricating survivable self-powered sensor nodes monolithically with commercially available SiGe BiCMOS technology. This paper presents simulation and test chip results of two novel and essential building blocks: a photovoltaic/solar cell power supply and an environmentally tolerant microprocessor, based on radiation hardening by design and asynchronous logic.

This paper describes a new high performance cost effective Earth Observation Platform, the SSTL-300 and associated optical sensor suite, offering a 7-year mission lifetime with a very high operational availability, for a mission cost an order of magnitude less than commercial high resolution Earth observation spacecraft. The paper will detail the SSTL-300 main payload, a very high-resolution imager with panchromatic multispectral channels. The paper will also outline an additional payload, the Medium Resolution Imager (MRI), which offers the widest swath of any comparable Earth Observation spacecraft. Earth images can be geolocated with high accuracy without the need for ground control points. Simultaneous high- and medium- resolution imaging is possible, coupled with either on-board lossless data compression for store-and-forward operations or near real-time imaging & down-linking for a range of targets close to the ground station. The SSTL-300 offers a range of imaging modes, including: strip mapping, fast response scene capture and stereo imaging offering swath widths up to 60 km at high-resolution. Details of the nominal (sun-synchronous) orbit for the SSTL-300 will be provided stressing the balance between single spacecraft and constellation (multiple cooperating spacecraft) performance. The latter requires an accurate and reliable, yet low cost propulsion system which SSTL has developed, but is commonly featured on low cost small spacecraft.

Capture effect can improve the throughput of random multiple access protocols. An evaluation model of the capture effect is proposed for coherent BPSK demodulation. The model introduces the concept of carrier synchronisation probability conditioned upon the carrier-to-interference ratio into the evaluation of the capture probability. Moreover, the effect of bit-sync offset of interfering packets on the capture probability is also taken into account. An attempt is made by means of the proposed model to investigate the capture effect in the LEO satellite channel. The result shows that a relatively large link margin can result in a remarkable capture probability, and consequently benefit slotted ALOHA protocols with a substantial throughput improvement.