Development and Flight Results from the C3D2 Imager Payload on AlSat Nano

An experimental CubeSat camera system using 3 separate CMOS imagers was flown in 2014 on UKube-1. In response to an announcement opportunity in December 2014, we proposed an upgrade to our C3D imager payload, which was accepted to fly on AlSat Nano. Launched in September 2016 the system has been operational for over 1 year and has returned both images and housekeeping data, including detailed temperature and radiation dosimetry measurements. Through these in-orbit demonstrations on CubeSans, the image sensors and payload have attained TRL9, and these are now being used in other flight opportunities. In this paper we describe the C3D imager payload, which comprises 3 independent CMOS image sensors used in different camera systems; two wide field cameras are specifically optimised with one to observe the Earth from the 650 km orbit, and the other with its focus set to 40 cm to observe a deployable boom from the CubeSat. The experiment controller also contained thermometry and two RADFET dosimeters, one located on the payload, with the other deployed at a different point on the spacecraft. In this paper we will describe the experiment design and operational performance, and review the in-orbit data obtained during the operations covering over 17 months in-orbit, in addition to discussing lessons learned from the flight experience. We also discuss further developments of the payload concept which we are currently working on toward future flight opportunities

Technological development of the OGRE focal plane array

The Off-plane Grating Rocket Experiment (OGRE) is a high resolution soft X-ray spectrometer sub-orbital rocket payload designed as a technology development platform for three low Technology Readiness Level (TRL) components. The incident photons will be focused using a light-weight, high resolution, single-crystal silicon optic. They are then dispersed conically according to wavelength by an array of off-plane gratings before being detected in a focal plane camera comprised of four Electron Multiplying Charge-Coupled Devices (EM-CCDs). While CCDs have been extensively used in space applications; EM-CCDs are seldom used in this environment and even more rarely for X-ray photon counting applications, making them a potential technology risk for larger scale X-ray observatories. This paper will discuss the reasons behind choosing EM-CCDs for the focal plane detector and the developments that have been recently made in the prototype camera electronics and thermal control system

TreeView: A small satellite supporting precision forestry for nature-based solutions in a changing climate

The expansion of tree cover is a critical component of the path to net zero and the development of sustainable cities, but reaching this target will require extensive management of this resource. Through leveraging next-generation optical sensor technology and innovations across the payload and spacecraft development, TreeView will provide multispectral data at a ground sampling resolution on the scale of individual trees, providing measurement and monitoring capabilities from space at an unprecedented level. TreeView has been funded through to a Preliminary Design Review (PDR) by the UK Space Agency’s National Space Innovation Programme. This exciting mission aims to deliver a new perspective on urban green infrastructure in the UK and internationally, and assess the health of larger forest stands. The mission has a challenging target of an end-to-end budget of £15M and to achieve this, cost, size, weight and power limits are imposed on the payload and spacecraft. Meanwhile, signal to noise performance, spatial and spectral resolution have been set to provide new and unique data not available from Sentinel-2 or commercial providers

Confronting law affectively: encounters of a Patpong sex tourist

When considering spaces of sex-work such as Patpong in Bangkok, Thailand, the inclination is to be drawn into habitual debates concerning the legitimacy of sex-work and the clear objectification of sex-workers. While these concerns are valid and real, there are significant absences in terms of the theoretical mapping of the space, such as the affect of the presence of law, bodies, space and the sexual encounter itself. Law emerges as the most significant presence, since it both forms the transactional surface of Patpong and produces the confusion and revilement that results from the confluence of cold legal exchange with the tactile intimacy of the sexual encounter. This text explores the ethnographic space of Patpong in order to understand ways in which law’s transactional, effective surface is both embodied through subjectivication and spatially emplaced, yet also disrupted through the affective agency of the bodies and spaces it enfolds in order to produce this surface. This exploration will point to the limitations of law’s effective surface and suggest ways in which law might be located within a regime of affect, which returns the law to the body it subjectivises

Comprehensive line-spread function error budget for the Off-plane Grating Rocket Experiment

The Off-plane Grating Rocket Experiment (OGRE) is a soft x-ray grating spectrometer to be flown on a suborbital rocket. The payload is designed to obtain the highest-resolution soft x-ray spectrum of Capella to date with a resolution goal of R  (  λ  /  Δλ  )    >  2000 at select wavelengths in its 10 to 55 Å bandpass of interest. The optical design of the spectrometer realizes a theoretical maximum resolution of R  ≈  5000, but this performance does not consider the finite performance of the individual spectrometer components, misalignments between components, and in-flight pointing errors. These errors all degrade the performance of the spectrometer from its theoretical maximum. A comprehensive line-spread function (LSF) error budget has been constructed for the OGRE spectrometer to identify contributions to the LSF, to determine how each of these affects the LSF, and to inform performance requirements and alignment tolerances for the spectrometer. In this document, the comprehensive LSF error budget for the OGRE spectrometer is presented, the resulting errors are validated via raytrace simulations, the implications of these results are discussed, and future work is identified

Life, time, and the organism:Temporal registers in the construction of life forms

In this paper, we articulate how time and temporalities are involved in the making of living things. For these purposes, we draw on an instructive episode concerning Norfolk Horn sheep. We attend to historical debates over the nature of the breed, whether it is extinct or not, and whether presently living exemplars are faithful copies of those that came before. We argue that there are features to these debates that are important to understanding contemporary configurations of life, time and the organism, especially as these are articulated within the field of synthetic biology. In particular, we highlight how organisms are configured within different material and semiotic assemblages that are always structured temporally. While we identify three distinct structures, namely the historical, phyletic and molecular registers, we do not regard the list as exhaustive. We also highlight how these structures are related to the care and value invested in the organisms at issue. Finally, because we are interested ultimately in ways of producing time, our subject matter requires us to think about historiographical practice reflexively. This draws us into dialogue with other scholars interested in time, not just historians, but also philosophers and sociologists, and into conversations with them about time as always multiple and never an inert background

Observations of vertical mixing in autumn and its effect on the autumn phytoplankton bloom

This work examines the seasonal cycle of density structure and its influence on primary production in a temperate shelf sea, with a particular focus on the breakdown of stratification in autumn. We do this by combining new, high resolution observations of water column structure, meteorological forcing, nitrate and chlorophyll fluorescence collected between March 2014 and July 2015 on the North West European Shelf. Our results challenge the generally accepted assumption that convection dominates over wind driven mixing resulting in seasonal breakdown of stratification. Furthermore we found, that vertical mixing in autumn not only transformed the vertical density structure but also the vertical structure of chlorophyll biomass and surface nutrients. The subsurface chlorophyll maximum was eroded and a vertically homogeneous profile of chlorophyll biomass established itself above the pycnocline. This increased mixing also led to replenishment of surface nitrate concentrations, which supported an autumn phytoplankton bloom. While the significance of phytoplankton blooms in autumn has previously not been well quantified, we argue that these can act as a significant contributor to the seasonal drawdown of carbon

Making Different Differences: Representation and Rights in Sexuality Activism

This paper argues that current iterations of lesbian, gay, bisexual, transgender and intersex (LGBTI) rights are limited by an overreliance on particular representations of sexuality, in which homosexuality is defined negatively through a binary of homosexual/heterosexual. The limits of these representations are explored in order to unpick the possibility of engaging in a form of sexuality politics that is grounded in difference rather than in sameness or opposition. The paper seeks to respond to Braidotti’s call for an “affirmative politics” that is open to forms of creative, future-oriented action and that might serve to answer some of the more common criticisms of current LGBTI rights activism