The InflateSail CubeSat Mission:The First European Demonstration of Drag-Sail De-Orbiting

The InflateSail (QB50-UK06) CubeSat, designed and built at the Surrey Space Centre (SSC) at the University of Surrey, UK, for the Von Karman Institute (VKI), Belgium – was one of the technology demonstrators for the QB50 pro-gramme. The 3.2 kilogram 3U CubeSat was equipped with a 1 metre long inflat-able boom and a 10m2 deployable drag sail. InflateSail's primary mission was to demonstrate the effectiveness of using a drag sail in Low Earth Orbit (LEO) to dramatically increase the rate at which satellites lose altitude and re-enter the Earth's atmosphere and it was one of 31 satellites that were launched simultane-ously on the PSLV (polar satellite launch vehicle) C-38 from Sriharikota, India on 23rd June 2017 into a 505km, 97.44o Sun-synchronous orbit (SSO). Shortly after orbital insertion, InflateSail booted-up, and, once safely clear of the other satellites on the launch, it automatically activated its payload – firstly, deploying a 1 metre long inflatable boom comprising a metal-polymer laminate tube, using a cool gas generator (CGG) to provide the inflation gas, and secondly, using a brushless DC motor at the end of the boom to extend four lightweight bistable rigid composite (BRC) booms to draw out the 3.1m x 3.1m square, 12 micron thick polymer drag-sail. As intended, the satellite immediately began to lose alti-tude, and re-entered the atmosphere just 72 days later – thus demonstrating for the first time the de-orbiting of a spacecraft using European inflatable and drag-sail technologies. The boom/drag-sail technology developed by SSC will next be used on the RemoveDebris mission, due for launch in 2018, which will demon-strate the capturing and de-orbiting of artificial space debris targets using a net and harpoon system

InflateSail de-orbit flight demonstration results and follow-on drag-sail applications

The InflateSail (QB50-UK06) CubeSat, designed and built at the Surrey Space Centre (SSC) for the Von Karman Institute (VKI), Belgium, was one of the technology demonstrators for the European Commission’s QB50 programme. The 3.2 kg 3U CubeSat was equipped with a 1 metre long inflatable mast and a 10m2 deployable drag sail. InflateSail's primary mission was to demonstrate the effectiveness of using a drag sail in Low Earth Orbit (LEO) to dramatically increase the rate at which satellites lose altitude and re-enter the Earth's atmosphere and it was one of 31 satellites that were launched simultaneously on the PSLV (polar satellite launch vehicle) C-38 from Sriharikota, India on 23rd June 2017 into a 505km, 97.44o Sun-synchronous orbit. Shortly after safe deployment in orbit, InflateSail automatically activated its payload. Firstly, it inflated its metrelong metal-polymer laminate tubular mast, and then activated a stepper motor to extend four lightweight bi-stable rigid composite (BRC) booms from the end of the mast, so as to draw out the 3.1m x 3.1m square, 12m thick polyethylene naphthalate (PEN) drag-sail. As intended, the satellite immediately began to lose altitude, causing it to re-enter the atmosphere just 72 days later – thus successfully demonstrating for the first time the de-orbiting of a spacecraft using European inflatable and drag-sail technologies. The InflateSail project was funded by two European Commission Framework Program Seven (FP7) projects: DEPLOYTECH and QB50. DEPLOYTECH had eight European partners including DLR, Airbus France, RolaTube, Cambridge University, and was assisted by NASA Marshall Space Flight Center. DEPLOYTECH’s objectives were to advance the technological capabilities of three different space deployable technologies by qualifying their concepts for space use. QB50 was a programme, led by VKI, for launching a network of 50 CubeSats built mainly by university teams all over the world to perform first-class science in the largely unexplored lower thermosphere. The boom/drag-sail technology developed by SSC will next be used on a third FP7 Project: RemoveDebris, launched in 2018, which will demonstrate the capturing and de-orbiting of artificial space debris targets using a net and harpoon system. This paper describes the results of the InflateSail mission, including the observed effects of atmospheric density and solar activity on its trajectory and body dynamics. It also describes the application of the technology to RemoveDebris and its potential as a commercial de-orbiting add-on package for future space missions

Official Science Repository of the QB50 Project

QB50 data will provide the opportunity to study the mid-lower thermosphere in unparalleled detail with a completely novel data set. These data will be generated by a constellation of instruments in orbit and they will offer in-situ measurements of the density of the most prominent gases (i.e. N2, NO, O, O2, e-) in the thermosphere. This is an ideal situation for students at universities around the world to use QB50 as a basis for research projects, either at Master degree level or for a PhD since the data will guarantee the chance to publish peer-reviewed scientific articles and possibly provide important discoveries or new phenomena in the thermosphere. The aim for students of postdoctoral researchers is to become involved in the mission operations or data calibration once the mission is flying and so get hands-on experience with the data as they are recorded. This allows the researchers the opportunity to design specific experiments they may wish to try, for example studying a specific region in the thermosphere, or finding specific conjunctions of CubeSats in the QB50 fleet, and respond to interesting events found in the data. The structure of the dataset is given in the readme.txt file

Flow characterization and boundary layer transition studies in {VKI} hypersonic facilities

info:eu-repo/semantics/publishe

Effect of the solar activity variation on the Global Ionosphere Thermosphere Model (GITM)

The accuracy of global atmospheric models used to predict the middle/lower thermosphere characteristics is still an open topic. Uncertainties in the prediction of the gas properties in the thermosphere lead to inaccurate computations of the drag force on space objects (i.e. satellites or debris). Currently the lifetime of space objects and therefore the population of debris in low Earth orbit (LEO) cannot be quantified with a satisfactory degree of accuracy. In this paper, the Global Ionosphere Thermosphere Model (GITM) developed at the University of Michigan has been validated in order to provide detailed simulations of the thermosphere. First, a sensitivity analysis has been performed to investigate the effect of the boundary conditions on the final simulations results. Then, results of simulations have been compared with flight measurements from the CHallenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) satellites and with existing semi-empirical atmospheric models (IRI and MSIS). The comparison shows a linear dependency of the neutral density values with respect to the solar activity. In particular, GITM shows an over-predicting or under-predicting behaviour under high or low solar activity respectively. The reasons for such behaviour can be attributed to a wrong implementation of the chemical processes or the gas transport properties in the model

Experimental characterization of liquid jet atomization in Mach 6 crossflow

The atomization of water liquid jet in Mach 6 air crossflow is investigated. Experiments are conducted in the VKI H3 Mach 6 hypersonic wind tunnel. A flat plate, with a flush mounted 1mm diameter circular injector, is used to inject water into the crossing hypersonic air stream. The mean and Sauter mean diameter of the liquid droplets are measured at different locations along the median plane on the jet using Phase Doppler Interferometry technique. The droplet size measurements are analyzed and treated to characterize the atomization process of the liquid jet. The measured mean and Sauter diameters are compared with the existing correlations in the literature. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc.status: publishe

Natural and Induced Transition on a 7deg Half-Cone at Mach 6

Pressure fluctuations caused by instabilities in the boundary layer are among the causes which lead to transition on a space vehicle during atmospheric re-entry. The knowledge of these unsteady fluctuations could help to identify the mechanisms which take part into the transition process and better predict them. In this framework and in support of the EXPERT PL4/PL5 post-flight analysis, surface pressure measurements have been performed in the VKI H3 Hypersonic Wind Tunnel. A 7deg half-angle cone with exchangeable nosetip was equipped with a stream-wise array of high frequency pressure transducers (PCB 132A31). Instabilities in the boundary layer have been investigated on a smooth surface and behind an isolated roughness element. Experimental data are then compared with linear stability theory computations, in support to the e^N transition prediction method and to the calibration of the ground facility. The results provided on a simplified ground test model, show the growth of second mode waves under a laminar boundary layer and their break down to turbulence as a function of Reynolds number and streamwise location. Moreover the effect of an isolated roughness element on the boundary layer has been characterized in terms of generated instabilities

InflateSail De-Orbit Flight Demonstration – Observed Re-Entry Attitude and Orbit Dynamics

The InflateSail (QB50-UK06) CubeSat, designed and built at the Surrey Space Centre (SSC) for the Von Karman Institute (VKI), Belgium, was a technology demonstrator built under the European Commission’s QB50 programme. The 3.2 kilogram 3U CubeSat was equipped with a 1 metre long inflatable mast and a 10m2 deployable drag sail and was one of 31 satellites that were launched simultaneously on the PSLV (polar satellite launch vehicle) C-38 from Sriharikota, India on 23rd June 2017 into a 505km, 97.44o Sun-synchronous orbit. Shortly after insertion into orbit, InflateSail automatically activated its drag-sail payload, and, as planned, began to lose altitude, causing it to re-enter the atmosphere just 72 days later – successfully demonstrating for the first time the de-orbiting of a spacecraft using European inflatable and drag-sail technologies. This paper discusses the dynamics we observed during the descent, including the sensitivity of the craft to atmospheric density changes. The InflateSail project was funded by two European Commission Framework Program Seven (FP7) projects: DEPLOYTECH and QB50. QB50 was a programme, led by VKI, for launching a network of 50 CubeSats built mainly by university teams all over the world to perform first-class science in the largely unexplored lower thermosphere

Study on breakup of liquid ligaments in hypersonic cross flow using laser sheet imaging and infrared light extinction spectroscopy

status: publishe