Month: March 2014
Four members of the SCRAP team paid a visit to the EISCAT radar facility in Tromsö, Norway to learn about its features and limitations.
What was found is that the radar very well fits the specifications set by the SCRAP team. The EISCAT radar will be used during the launch campain in 2015.
It will be used to search for and detect the copper cloud ejected by the rocket.
/The SCRAP Team
A make believe game!
One day you wake up and feel like having your own satellite in space. Although the motivations are not that clear, you already have planned what you want inside it: a recording camera, a photograph camera, a Walkman (to play your favorites music in space), a cell phone, a watch, a laptop, a bip and a palmtop. But a detail: you live in the 90’s:
Insouciant, you go to the rocket company to make an estimation of how much it will cost to put your gadgets up there (your mom did not let you make the rocket). In the rocket company, a sharp dressed businessman tells you that each kilogram in low Earth orbit will cost you about 30 thousand dollars and all your gadgets must fit inside a round cookie box, otherwise you will have to pay double.
Then, you come back home cursing your mom for not letting you play with rockets.
Maybe you have not noticed, but you just faced an everyday problem in space business: no matter what will be put in space, it must be compact and light! Every single day, engineers rack their brains to make things smaller and lighter. So to think even more in a way arrange them tighter.
Maybe you never stopped to think about it, but this thinking exercise has propelled many of the technologies that ended up in our hands. From micro-components to composite structures, many things began as a matter of saving weight and space.
If the make-believe you had had been born nowadays, maybe you could go to the rocket company carrying only this. (You would face a lot of further problems but let’s stop here! Hahaha)
In our case, the SCRAP experiment has already been born with several dimensional constraints, which means that we are obliged to adapt our system to some defined volumes. For example, the Free Flying Units (FFU’s) are “cookie boxes” of 240 mm diameter and 80 mm high, which must fit antennas, batteries, navigation systems, circuit boards, wires, parachute, gun cartridges, cooper particles, explosives and so on.
In order to squeeze everything inside, first, the team makes long meetings where members try to bring out ideas, designs, constraints, requirements, etc. Here, the board is often used when languages (sometimes we share three of them!) are not enough to explain shapes and arrangements.
The next steps often involve basic Computer Aided Designs (or CADs) to simulate the arrangement with the exact dimensions and constraints.
Once the perfect setup is achieved, we can either buy or manufacture the pieces. But we can talk about it another day! 😉
If you are part of a scientific project, chances are you work in a “lab”, one of these strange places where scientists are locked in to keep them away from regular people. Now, there are two types of labs, the first category is the one most people think of, with fancy doomsday devices or people in white coats mixing colorful liquids.
But in fact, most labs fall into the second category, where the first and foremost working tool is computers (let’s not even speak about pure theoretical research, which basically involves a white board, a marker and hours of pacing back and forth in a corridor). Computers are essential to, well… compute, and especially carry out simulations. Though they will never replace a well-prepared experiment, simulations allow us to explore many scenarios and tweak all the parameters in order to get a hold on an optimal situation. The SCRAP team doesn’t escape that rule, and while our members in the basement are busy exploding stuff and trying to make the building collapse, the other half of the team is
playing video games programming.
Particle charging, gas dynamics of a cloud expanding into vacuum, electron density fluctuations, all these processes can’t be tested in our lab so we have to rely on what the simulations tell us and make sure the models we use are accurate enough.
Will the simulation group get its final results before the testing group? The race is on.
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Here you have it: The REXUS 17 and 18 Rocket Set ups! These are only preliminary and we will let you know if they change but as it looks now we will be going on the REXUS 17 rocket together with the british team WUSAT and reflying hungarian team Gekko-R! In our partner rocket REXUS 18 we have the italian team PHOS together with the german teams ACTOR, LICOD and SMARD. This is exiting! We know the other teams from the Selection workshop in Noordwijk and Student Training week in Kiruna so its pretty exiting to carry this out together. Concerning the set up the only worry we have had is that the team WUSAT will like us also shoot out FFUs from their module and we hope there will be no collusion with our units or it affecting our cloud. But hopefully there will be no problems of this as WUSAT are suppose to be released at an higher altitude with a totally different trajectory.
On the topic, we should present what the other experiments are about shortly. So on our rocket we have WUSAT-SOLSPEC from the University of Warwick, they are creating a Cubesat-based transit spectroscopy which will be measuring the Sun’s spectrum at different atmospheric path lengths as an analogy to the study of exoplanet atmospheres. We will also be flying with Gekko – R from the Budapest University of Technology and Economics who will measure the variations of electric conductivity with altitude by recording the mobility spectrum of positive and negative ions. Fourth team on the rocket is the REM-RED also from Budapest University of Technology and Economics (GM Sounding Rocket Experiment to Measure the Cosmic Radiation and Estimate its Dose Contribution) who aim to design and develop a GM counter system for sounding rockets and to quantify the cosmic radiation up to the maximum altitude of the REXUS rocket.
On the other rocket, starting from the top we have ACTOR (Aerogel Cells Tested On REXUS) who will test the isolating capability of cellulose aerogels under the conditons of space by measuring the heat flow during the flight with alternating pressure and temperature and comparing the results with other known isolation materials. Then we have PHOS (Pulsating Heat pipe Only for Space) who want to characterise the start-up and the stationary operations of a large diameter aluminium PHP (Pulsating Heat Pipe) operating in milli-g environment, by analysing the temporal trend of the local fluid pressure and temperature, and the external wall temperature in several locations.
LICOD (Light-induced compression of dust clouds) will also be flying on the REXUS 18 rocket to investigate the movement of optical thick dust under the influence of photophoresis for application in the context of planetary formation in protoplanetary disks and dust storm in the Martian atmosphere. And last but not least SMARD (Shape Memory Alloy Reusable Deployment Mechanism) who will test a prototype of the solar panel deployment mechanism for the CubeSat MOVE2, the successor of First-Move.
To read more about the other experiments click on this link: http://www.rexusbexus.net/index.php?option=com_content&view=article&id=132&Itemid=78
Welcome to our crib!
Here, at the Alfvén Laboratory, lies the place of Space and Plasma Physics at KTH.
We spend most of our time down in the basement, as does KTHs previous REXUS team ISAAC.
Here we have a lot of equipment for building and testing our experiment. The left picture show the room with the vacuum chamber, where we run our tests where we spread particles. Even further down in the building, there are people working with plasma, and some stairs up, people are assembling parts for satellites! So we have some really experiences people nearby at all times.
A lot of our meetings are held in this place.
There is also a library where students that are somehow related to a Space and Plasma physics project can sit.
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So now the student training week has unfortunately come to an end and it’s back to work at KTH (on top of the exams we all have this week). The training week has been very informative but also rather busy with lectures from 8 am to 6 pm most days. Then again, we were pretty good at enjoying ourselves at the end of the day, but those pictures will NOT be shown on the official SCRAP experiment webpage… Let’s just say that if you can’t buy the beer at Esrange, you bring it yourself. 😀
We also got to see some nice parts of northern Sweden such as the Kiruna Mine and the Icehotel. Actually we kinda had our own local guide (Hannes), but he wasn’t there for the Kiruna trip (which is kind of understandable as it might feel somewhat pointless to be a tourist in your own town).
The SCRAP experiment would like to sincerely thank all the other teams for a great week but most importantly the supervisors from ESA, SSC, ZARM and DLR whose commitment to the project has made all of this possible. Good luck everyone and we will see each other next time in Germany at CDR!
And oh, don’t worry, the pictures shown are only of the things we were specifically told we could show you, so there’s no secret material here (I hope).
the SCRAP team
To get a useful spectrograph, it would be good to know the requirements in advance. But finding out the requirements appeared to be difficult. For the wanted spray result, we could model the scattering with mie-scattering models for spherical particles. But when particles stick together, they form a new geometry, for which there are no known scattering models. One plan, right now, is to use models of scattering for ellipsoidal particles, to give an approximation of several particles stuck together. The animation below, shows the scattering intensities in different directions (light is incident from the left) and for 5 different wavelengths (the five pictures in the animation). The red, green and blue shows the different polarization components. One good thing is that the intensity for different wavelength shifts, but another thing that complicates matters, is that the intensity changes rapidly with angle. We thus also need to get an accurate value of the scattering angle of a certain spectrum.