Martin Nicholas Sweeting

University of Surrey · Surrey Space Centre (SSC)

HydroGNSS is a small satellite mission under the new ESA Scout programme tapping into NewSpace, within ESA’s FutureEO programme. The mission will use an innovative GNSS-Reflectometry instrument to collect parameters related to the Essential Climate Variables (ECVs): soil moisture, inundation, freeze/thaw, biomass, ocean wind speed and sea ice exten...

Space telescopes are our ‘eyes in the sky’ that enable unprecedented astronomy missions and also permit Earth observation integral to science and national security. On account of the increased spatial resolution, spectral coverage, and signal-to-noise ratio, there is a constant clamour for larger aperture telescopes by the science and surveillance...

Proximity flight systems for rendezvous-and-docking are traditionally the domain of large, costly institutional manned missions, which require extremely robust and expensive Guidance Navigation and Control (GNC) solutions. By developing a low-cost and safety compliant GNC architecture and design methodology, low cost GNC solutions needed for future...

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...

Information on battery problems can be useful in guiding research to improve battery technology. Problems that are serious or reoccur are the obvious ones to concentrate on. Observed problems can be caused by more than one phenomenon. However the problem that was observed on the Alsat-1 battery module where some cells were damaged, and the damage w...

Spacecraft Earth Observation systems can provide economic and societal benefits, if part of a sustainable development programme. Small satellites have matured to make these very attractive tools for such national programmes, by themselves or in constellation. Satellite constellations provide a number of benefits over individual satellites, and one...

TechDemoSat-I (TDS-1) is a UK technology demonstration mission launched in July 2014, and hosts cutting-edge UK payloads. SSTL is responsible as the platform provider and mission prime, and also provides the SGR-ReSI instrument, an advanced Global Navigation Satellite System (GNSS) Reflectometry (GNSS-R) remote sensing instrument. GNSS-R is the mea...

Small satellites have played a role in operational meteorology in the early space days, and were soon overtaken by larger and more capable polar and geostationary platforms. Improvements in the capabilities of small satellites deployed in constellations, and innovative payload and measurement techniques have changed that in the past decade. A group...

Illegal logging threatens tropical forests and carbon stocks. Governments must work together to build an early warning system, say Jim Lynch and colleagues.

Modern computers are now far in advance of satellite systems and leveraging of these technologies for space applications could lead to cheaper and more capable spacecraft. Together with NASA AMES's PhoneSat, the STRaND-1 nanosatellite team has been developing and designing new ways to include smart-phone technologies to the popular CubeSat platform...

A novel approach is presented that demonstrates the advantage of mutual coupling in reducing the height of the multimode horn. It is found that this method can reduce the height by an additional 0.4λ for the 3λ×3λ horn aperture and produce a smaller active element volume for the same gain in isolation and above the 81% efficiency from 8.8 GHz to 10...

The use of the Karhunen-Loéve Transform (KLT) for spectral decorrelation in compression of hyperspectral satellite images results in improved performance. However, the KLT algorithm consists of sequential processes, which are computationally intensive, such as the Covariance and Eigenvector evaluations, etc. These processes slow down the overall co...

IntroductionSmall Satellite Design PhilosophySmall Satellite System DesignCOTS Components in the Space EnvironmentMicrosatellite PlatformsMinisatellite PlatformsNanosatellite PlatformsAffordable Launches for Small SatellitesIn-Orbit OperationsSmall Satellite ApplicationsPicosatellites and Recent Advances in MiniaturizationConclusion

There has been increased interest in the exploration of the Moon in recent years. Pin-point precision landing is highly desirable for future lunar missions. This paper is concerned with the design of the on-board data handling (OBDH) subsystem for the pin-point lunar lander of the Magnolia-1 project, funded by NASA. Four proposed on-board data hand...

Emplacement of four or more kinetic penetrators geographically distributed over the lunar surface can enable a broad range of scientific exploration objectives of high priority and provide significant synergy with planned orbital missions. Whilst past landed missions achieved a great deal, they have not included a far-side lander, or investigation...

The manufacture of the NigeriaSat-2 spacecraft was completed in 2010, and was successfully launched in August 2011. This is a state-of-the-art small satellite Earth observation mission including several innovations not previously seen on small spacecraft, which will provide high duty cycle imaging of the Earth in high resolution. It will be used by...

The European Student Moon Orbiter (ESMO) is planned to be the first European student mission to the Moon. Building upon the successful approach pioneered by the European Space Agency's (ESA) Education Office, this mission aims to bring together European universities to design, manufacture and operate a lunar orbiter mission. Following a competitive...

Over the last decade, UK-based small satellite manufacturer Surrey Satellite Technology Ltd (SSTL) has developed and launched 6 Medium Resolution Imagers (MRI) on the SSTL-100 platform as part of the Disaster Monitoring Constellation (DMC). Currently, 5 DMC platforms are in operation augmented by platforms providing both high resolution and the MRI...

This paper focuses on ways in which space is being used to build capacity in science and technology in order to:•Offer increasing support for national and global solutions to current and emerging problems including: how to improve food security; resource management; understanding the impacts of climate change and how to deal with them; improving di...

This paper is concerned with a satellite sensor network, which applies the concept of terrestrial wireless sensor networks to space. Constellation design and enabling technologies for picosatellite constellations such as distributed computing and intersatellite communication are discussed. The research, carried out at the Surrey Space Centre, is ai...

This work aims to present the use of sliding mode control applied to three axis active control system for gravity gradient stabilised microsatellite. The idea to use this method comes from the limitations of the classical methods such as PID controllers which are used in linear regions only. The choice of sliding surface and the adjustment of gains...

Alsat-1 is the first small satellite for the Centre of Space Techniques (CTS) – Algeria. It was designed, built, assembled and tested at Surrey Satellite Technology Limited (SSTL) at the University of Surrey, with the participation of 11 Algerian engineers covering all aspects of micro satellite engineering within a technology transfer programme be...

Surrey Satellite Technology has recently built the NigeriaSat-2 spacecraft. This is a state of the art small satellite Earth observation mission that will provide high resolution 2.5m imagery of the Earth. It will launch in 2010 into a low earth sun-synchronous orbit and will be used by the Nigerian government to monitor a number of environmental i...

Stress in vegetation causes a small shift of the point of maximum slope in the spectral reflectance between 680nm and 750nm - the so-called "red-edge" position (REP). This shift has been used as an indication of stress, both in the laboratory and in field measurements. The shift of the REP can be between 3 and 7 nm and is directly related to variat...

Modern small satellites (MSS) are revolutionizing the space industry. They can drastically reduce the mission cost, and can make access to space more affordable. The relationship between a modern small satellite and a ldquoconventionalrdquo large satellite is similar to that between a modern compact laptop and a ldquoconventionalrdquo work-station...

A new class of distributed space missions is emerging which requires hundreds to thousands of satellites for real-time, distributed, multi-point sensing to accomplish long-awaited remote sensing and science objectives. These missions, stymied by the lack of a low-cost mass-producible solution, can become reality by merging the concepts of distribut...

On-board image compression systems aim to increase the amount of data stored in the on-board mass memory and transmitted to the ground station. This paper presents an overview and analysis of the state-of-the-art in on-board image compression systems. Compression methods and systems implementations are reviewed. Statistical analysis and developing...

Numerous man-made and natural disasters have stricken mankind since the beginning of the new millennium. The scale and impact of such disasters often prevent the collection of sufficient data for an objective assessment and coordination of timely rescue and relief missions on the ground. As a potential solution to this problem, in recent years cons...

A wide range of emerging applications is driving the development of wireless sensor node technology towards a monolithic system-on-a-chip implementation. Of particular interest are hostile environment scenarios where radiation and thermal extremes exist. Radiation hardening by design has been recognized for over a decade as an alternative open-sour...

In this paper, the control system of the first Algerian microsatellite in orbit Alsat-1 is presented. Alsat-1 is a 3-axis stabilised microsatellite, using a pitch momentum wheel and yaw reaction wheel, with dual redundant 3-axis magnetorquers. A gravity gradient boom is employed to provide a high degree of platform stability. Two vector magnetomete...

While the surface missions to the Moon of the 1970s achieved a great deal, scientifically much was also left unresolved. The recent plethora of lunar missions (flown or proposed) reflects a resurgence in interest in the Moon, not only in its own right, but also as a record of the early solar system including the formation of the Earth. Results from...

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/hyperspect...

SSTL is currently building a next generation small satellite for 2.5m imaging, and is in the process of extending this design to achieve sub 1-metre imaging. Both of these satellites will build on the extensive heritage that SSTL has gained across numerous Earth observation satellites to date. This paper firstly discusses the trade-offs associated...

During 2007, the GIOVE-A mission has transitioned from an experimental mission into what is effectively an operational mission. The small satellite approach used in the development of the mission, and the lessons learned from this mission, are being applied in the development of SSTL's Geostationary communication satellite platform. Furthermore, ES...

On board image data compression is an important feature of satellite remote sensing payloads. Reconfigurable intellectual property (IP) cores can enable change of functionality or modifications. A new and efficient lossless image compression scheme for space applications is proposed. In this paper, we present a lossless image compression IP core de...

On the 28th November 2002, Algeria's first enhanced micro satellite was launched into a 686km low earth orbit onboard a Cosmos 3M rocket from Plesetsk. The spacecraft was designed, manufactured and launched as a technology transfer programme between the National Centre of Space Techniques (CNTS) Algeria and Surrey Satellite Technology Limited (SSTL...

A new dimension of wireless sensor network architecture design is emerging where hundreds to thousands of ultra-light (<10 >g) low-cost sensor nodes are required to collectively perform a spectrum of distributed remote sensing missions in hostile conditions, predominantly those encountered in space. Environmental extremes, such as mechanical, therm...

Small low-cost satellites, pioneered at Surrey, are revolutionizing space. This paper gives an overview of antenna technologies for applications in small satellites. First, an introduction to small satellites and their structure is presented. This is followed by a description of the technical challenges of antenna design for small satellites. Vario...

This paper describes the various steps of the design and the implementation of the new reduced model of the extended Kalman filter (EKF) for small Euler angles on the Algerian microsatellite (Alsat-1). A specific implementation of the EKF is proposed to extract attitude and body rate in a circular low earth orbit (LEO) with a boom deployed for pass...

Returning to the Moon has been advocated by a large number of international planetary scientists in order to answer several key scientific questions. The UK also has an active lunar science community keen to support (robotic) lunar exploration missions. However, for several years these interests have been eclipsed by the drive to Mars. Recently the...

A control system is proposed for a low Earth orbit gravity gradient stabilised microsatellite using Z wheel. The microsatellite is 3-axis stabilized using a yaw reaction wheel, with dual redundant 3-axis magnetorquers. Two vector magnetometers and four dual sun sensors are carried in order to determine the full attitude. The attitude was estimated...

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 performanc...

Automatic band-to-band registration of multispectral images is the most critical pre-processing requirement for imaging tasks performed on board satellites, such as data fusion, intra-band coding, change detection, spectral signature based classification, etc. The performance of these tasks depends on the robustness and accuracy of band registratio...

A new class of remote sensing and scientific distributed space missions is emerging that requires hundreds to thousands of satellites for simultaneous multipoint sensing. These missions, stymied by the lack of a low-cost mass-producible sensor node, can become reality by merging the concepts of distributed satellite systems and terrestrial wireless...

Distributed space mission concepts are emerging for scientific applications requiring constellations of hundreds of thousands of satellites. Analogous to proliferating terrestrial wireless sensor networks, massively distributed sensor networks will enable the observation of real-time multi-point phenomenology. For example, an ionospheric plasma dep...

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 S...

In this paper we describe a generic receiver as a single channel S-band receiver and it is composed of two modules. The first module (down converter) consists of an input band pass filter, LNA, image rejection filter and down-converter with a PLL local oscillator. The second module consists of the IF module derived from the VHF receiver. The IF mod...

It has been 35 years since the last human presence on the Moon. Since then, our knowledge of the Solar System has expanded immeasurably, bringing us up against questions that are impossible to answer on Earth. There is now a global renewed interest in returning to the Moon, driven by the demands of science and as a stepping-stone for human explorat...

The ESA Proba-1 platform has now been in orbit since October 2001. Since that time significant value has been obtained from the CHRIS hyperspectral imager, with over 10,000 acquired images. To day CHRIS still offers the highest spatial resolution of any spaceborne hyperspectral instrument. The original intent of the CHRIS/Proba-1 programme was to a...

This paper has proposed an automatic onboard multispectral image compression system, for LEO Earth Observation satellites. This system has combined tiling, sub-pixel band registration, radiometric calibration, and multispectral image compression, to achieve automatic on-board image processing requirement. Two radiometric calibration methods are com...

This paper describes a new high performance Earth Observation Platform, the SSTL-300, which has been developed to provide customers with a capability that has previously only been available at much higher cost and on larger platforms. This platform offers a 7-year mission lifetime with a very high operational availability. The main payload is a ver...

For many of the proposed planetary exploration missions, robotically collected sample materials must be returned to the Earth for more detailed analysis. For the more interesting locations in the solar system, full planetary protection guidelines must be taken into account to prevent cross contamination. So far, few missions have demonstrated re-en...

A new dimension of wireless sensor network architecture design is emerging where hundreds to thousands of ultra-light (<10 g) low-cost sensor nodes are required to collectively perform a spectrum of distributed remote sensing missions in hostile conditions, predominantly those encountered in space. Environmental extremes, such as mechanical, therma...

An Analytic solution of Nadir attitude pointing equation of gravity gradient satellite stabilised is presented. The attitude equation is Euler linearised equation for near Nadir pointing axially symmetric satellite including only gravity gradient torque and assuming other torques such as magnetic torque, aerodynamic torque, solar radiation pressure...

In the past several years, a plethora of spacecraft control techniques have been developed that address the challenging attitude tracking, stabilization and disturbance rejection requirements of these missions. One major aspect that has been typically missing in the research area of attitude control development is the experimental validation of the...

Returning to the Moon has been advocated by a number of planetary scientists in order to answer several key scientific questions. The UK has an active lunar science community keen to support (robotic) lunar exploration. However, for several years, these interests have been eclipsed by the drive to Mars. Recently there is a renewed global interest i...

On the 28th of November 2002 and from Plesetsk in north of Russia, Cosmos-3M rocket put into a 700 km sun synchronous orbit the first Algerian microsatellite Alsat-1. Alsat-1 is 90 kg enhanced microsatellite, stabilised 3 axis for imaging mode and was designed and built by a join team of Surrey Technology Limited – UK and Centre National des Techni...

Near Earth Objects (NEOs) are comets or asteroids that intersect or pass near to our planet posing a real and underestimated danger to mankind. While the probability of impact is low, the consequences of such an impact could be apocalyptic. Various programs are underway to discover these kilometer-sized objects from Earth. However, once targets of...

A cold gas propulsion system is used for orbital maintenance on board microsatellite. Cold gas thrusters are the simplest way of achieving thrust. A microsatellite could be a part of the constellation and to maintain a daily coverage, it will be equipped with a propulsion system for an orbit control. A constellation of several microsatellites could...

Alsat-1 is an enhanced micro-satellite platform, increased in mass and capability from the standard spacecraft of recent years. Larger solar panels provide more power, and increased accuracy in attitude determination and control allow more demanding payloads to be accommodated. Alsat-1 has flown a 32 m ground sampling distance tri-band multi-spectr...

A new dimension of space mission architecture design is emerging where hundreds to thousands of very small satellites will collectively perform missions in a distributed fashion. To support this architecture, high volume production of femto-scale satellites at low cost is required. This paper reports on the assessment of using SpaceChip, which is a...

From early 2003, Surrey Satellite Technology Limited (SSTL), together with its partners from Algeria, Nigeria and Turkey, has operated the Disaster Monitoring Constellation (DMC). During this period we have demonstrated the utility of a low-cost satellite system that uses optical sensors and is capable of providing daily imaging globally. For examp...

In this paper, we describe the UHF transmitter amplification chain of the satellite engineering model communication subsystem, part of Alsat-1 project. To be able to deliver a power of 10W to the transmit antenna, with an input signal of 5dBm delivered by the UHF VCO, an amplification chain is required. The chain is constituted by the driver, inter...

Many types of antenna have been used for spacecraft applications in low Earth orbit. Many designers have concentrated on the use of simple and mechanically stable devices such as monopole arrays constructed from steel tape. As the requirement for payload communication increases however, the requirement for more optimal antennas is highlighted. The...

The attitude determination and control system Alsat-1 uses a Y momentum and Z reaction wheels, 3-axis magnetorquer rods and a single butane gas thruster for orbital maintenance. The magnetorquer rods do momentum maintenance and notation damping for Y/Z wheels, vibration damping and yaw phase control. This paper describes the attitude determination...

EyasSAT is a revolutionary concept in space systems engineering education. Up until now, space systems engineering has been typically conducted behind the cloak of clean rooms protecting intellectual property by a select few individuals with millions of dollars at stake. To the contrary, EyasSAT has ushered in an opportunity for large numbers of st...

The Venus Entry Probe study is one of the European Space Agency's (ESA) technology reference studies. It aims to identify; the technologies required to develop a low-cost, science-driven mission for in-situ exploration of the atmosphere of Venus, and the philosophy that can be adopted. The mission includes a science gathering spacecraft in an ellip...

Current commercial Earth Observation satellites have very restricted image processing capabilities on-board. They mostly operate according to a ‘store-and forward’ mechanism, where the images are stored on-board after being acquired from the sensors and are downlinked when contact with a ground station occurs. However, in order for disaster monitor...

The goal of attitude determination is to determine the orientation of the spacecraft relative to either an inertial reference frame or a frame referenced to some specific object of interest, such as the Earth. To do this we need the following: (1) First of all we must have available one or more reference vectors, i.e. unit vectors in known directio...

On the 28^th of November 2002 and from Plesetsk in north of Russia, Cosmos-3M rocket put into a 700 km sun synchronous orbit the first Algerian microsatellite Alsat-1. Alsat-1 is 90 kg enhanced microsatellite, stabilised 3 axis for imaging mode and was designed and built by a join team of Surrey Technology Limited - UK and Centre National...

Small satellites have historically been forced to use low cost propulsion, or to do without in order to maintain low cost. Since 1999 an increasing number of SSTL's customers have demanded the capability to precisely position and subsequently manoeuvre their satellites, driven largely by the current attraction of small satellite constellations such...

On the November 28th, 2002 at 06:07 am GMT, the first Algerian microsatellite AIsat-1 was launched from the cosmodrome of Plesetsk in Russia into a 700 km sun synchronous orbit. Alsat-1 is an enhanced microsatellite (90 Kg), stabilised in 3 axis for image acquisition mode. It was designed for disaster monitoring and is a part of the international c...

A robust centralised transmission control policy of framed-ALOHA protocols is presented for low Earth orbit (LEO) satellite store-and-forward communications. This first-order recursive control is capable of maintaining the offered traffic load at nearly constant, optimal level, basing upon maximum likelihood estimate (MLE) of the offered load in th...

Surrey is currently engaged in launching its first constellation to provide daily global coverage at moderate resolution in three spectral bands, as part of an international initiative to provide global disaster monitoring. The first spacecraft in this disaster monitoring constellation (DMC), AlSAT-1, was launched in November 2002 and is now operat...

Security techniques for commercial satellites are insufficiently developed despite the explosive growth of security services in earthbound applications at present. Recently, the issue of satellite security has gained in importance in connection with attempts to intercept satellite data. This paper first gives a brief overview of security services,...

The Disaster Monitoring Constellation (DMC) is an international micro-satellite con-stellation, currently capable of providing 32m spatial-resolution, tri-band, multi-spectral imagery over a 600km swath of any location in the world, within a 24-hour period. These satellites are soon to be augmented by further spacecraft, each carrying an addi-tiona...