Contents
Welcome to my blog
In this blog I will log my personal experience of the Stratos launch campaign of Delft Aerospace Rocket Engineering of March 2009. This is news from the front of an ambitious student project. I hope you enjoy reading it.
There is also a project blog. You can find this blog together with more general information about what we are doing at the project website.
The way to the North
The Stratos rocket is going to be launched from Esrange. This is a rocket launch site in the northern part of Sweden, near the city of Kiruna.
On the 28th of February 2009, a part of the Stratos team left the Netherlands for a 45-hour journey by train, crossing a distance of about 3200 km. The first train is a CityNightLine, final destination Moscow (really awkward to take a direct train to Moscow from Utrecht Centraal instead of going to destination Bunnik or Eindhoven, for example). We board and hope that while we sleep our train section will be separated and head for Kopenhagen. At 19:29 the train starts rolling, and the adventure begins.
The train is uncomfortable due to unavailability of proper train wagons, resulting in five people sharing six upright chairs for sleeping. By the time that ticket control reaches our end of the train at half past twelve in the night, I have just managed to find a position that is comfortable enough to reach a lower level of consciousness, but by the time that the Danish passport control requires us to flash IDs at them at six in the morning, I know that this is not the best way to spend the night. I silently envy the three people who got the only three beds available, and who, unlike me, have in fact been able to sleep.
At 10 in the morning we reach Kopenhagen Central Station. On the picture Bart and Bryan express really well how we all felt by now (I'm sorry, I know this is not the most charming pictures of you, but I promise I'll make up for it later on by posting a really good picture of you!).
Kopenhagen
Kopenhagen is a nice city, and very different too from the cities that I have seen. It does not appear Dutch, nor German, nor South Europe, but different. I guess it's typical Scandinavian style, and I like it very much. This is the part of Kopenhagen...
... if "It's nice to get up in the morning" Frank were not in the way you would see it...
... that's better. In one of these colourful houses we had a breakfast your average king would be really jealous of. There was hot coffee (better than the questionable but expensive liquid they sell on the train - it worked though) and apple juice aplenty, and a plate full of various parts of cheese, salmon, meat, fruit and bread made one feel much better. The feeling was enhanced by the cosiness of the room, the smoking fireplace and a round of Danish schnapps.
If you looked the other way 60 minutes later you would see the following scene:
... nice old buildings with lots of Roman elements in their architecture - I still need to find out why. Notice Olga, our Ukranian team member in the blue jacket with Dutch Space on the back (still red cheeks from finishing the schnapps in one go), and Auke.
... slightly more to the right you see Christina skating on the ice ring, also in Dutch Space jacket.
... and students walking through an alien city while on a way to a rocket launch look like this:
As a side note: this is what you get when you are on your way with rocket people: you did not know this, but an ordinary street lamp looks just like a launch tower when looked upon from the right angle...
Kopenhagen and with it Denmark shrink to a blob when we cross the Oresund in the X2000 train, which is quite comparable with the German ICE. We enter the country of our final destination: Sweden. We are now 20 hours en-route, and not even half-way. The team spirit is good when we take out our laptops and start perfecting our flight computer software while heading North at 200 km/h. Next stop: Stockholm.
To Kiruna
On the way to Kiruna, the scene changes from plain land with lots of trees and typical red-coloured houses...
... to even more trees and a frozen lake here and there, very few houses ...
... to kilometers of landscape like this: trees, trees, trees, no houses at all, and some snow between the trees.
Then we play cards, have 9 hours of wholesome and refreshing sleep in a nice bed (okay it was dusty and hot in there, but lying down is still infinitely better than what we endured on the first night), and wake up in the middle of a landscape with absolutely nothing but snow and trees:
And six hours after this picture was taken, we arrive in Kiruna, after a long, but surprisingly smooth journey (compliments to travel agency Bryan). You can clearly see that one looks normal again after a good night's sleep: Bryan is merrily clicking away like four (out of ten) other people, and Bart just shows a satisfied smile.
We are there! (well almost)
(By now we are tired of jokes like "We are DARE"... still two weeks of those to go...).
Arrival at Esrange
From Kiruna Central Station it is still a 45 minute drive over icy road to Esrange. We have rented a van, and are driven safely to the gates of Esrange by Christina. On the way we desparately try to get a glimpse of the ice hotel in Jukkasjärvi, but it was not very well visible from the road. We do, however, get to see reindeers looking for food just beside the road! (but of course I'm way to slow to take a picture)
At Esrange we meet the three heroes who drove the van with the rocket (and at least half of our workshop) to here over 2700 km of road. It is a good to see them again, and I am also happy to see some people of the Esrange staff again, ready for what promises to be an extremely busy two weeks.
This is all nice and well, but there is not much time to talk: priority number one is actually to get a room key and go shower, because we are all starting to feel like astronauts who have been in space for 6 months: after almost 50 hours of travelling water streaming over your body and washing away the dirt, sweat and who knows what else (now I don't care anymore), gathered during our time on the train, makes you feel reborn.
Then we set up shop: DARE takes over one floor of the Esrange hotel. We put shields on the doors identifying the purpose of the room. "ElOps" (Electronics Operations), one of the luxurious double rooms, looks like this in no time at all:
We put down ESD (ElectroStatic Discharge, actually anti-electrostatic discharge) mats. Even though it's cloudy you can still zap yourself if you touch the ESD mat, which proves all the more that all this ESD stuff is not being overcautious but a bare necessity when it really gets cold and dry here).
A fourth laptop, and electronics in huge ESD bags follow, and we are ready for the nice dinner. After dinner we bring each other up to speed in our first team briefing. Inevitably some people want to see fire (why else would you build rockets?), and we tell about our respective trips at the fireplace in hotel Aurora. We hear about lynxes in the forests around Esrange, beer being frozen while in the back of the van, cross-country skiing and tours through the holiest of places here: rocket motor storage.
Walking around at Esrange strangely feels a bit like coming home, even though I have been here before just for a few days. I attribute this to our kind Swedish hosts, but it may just be that I am very much looking forward to the rest of our stay here.
Second day at Esrange
Morning at Esrange. It is 06:20 when we meet outside hotel Aurora to go to our first meeting of the day at 06:30 with the Esrange Launch Officer. Despite their extremely busy schedule with a twin balloon launch and two other rocket launches the Esrange staff is able to squeeze in the necessary meetings with us, if you are willing to get up early. After a presentation of our safety-critical systems we actually get a compliment from the launch officer that ours may be the most advanced rocket ever launched from Esrange (next to a lot of other "firsts", like composite rocket motors and carrying the Esrange home-made GPS beacon onboard a rocket). The fact that he is comfortable with it shows in a tiny but honest smile, and we are happy too.
We are shown around (again, we were here last October but now it feels different) in the blockhouse, which contains several desks with lots of green and red lights for go/no go indication (the lights are especially important when people are constantly screaming over the radio as T=0 approaches). It reminds all of us to the many movies about space flight in the sixties: most of the equipment looks old-skool Apollo style, which is quite a contrast with our own rocket's systems. We see where the magic happens, and our project leader is even granted the right to push the red button (it's not hard to see which of all red buttons is THE button). Normally this is done by the launch officer, but for eager students they can apparently make yet another exception.
The meeting is effective, educative, and it is concluded that we should update our checklists a little bit, but that overall there are no problems foreseen and it will be a straightforward launch, which will help us being allocated a launch slot sometime in the coming days. By the time that the rest of the world is slowly waking up, we move towards the breakfast room and the day is a success already.
The next meeting is a safety briefing. Things like when to observe radio silence when and where, and what to do in case of emergency, etc. We also meet the designers of the GPS tracking system called ETAG, and discover that the difference between the way that we work and the way that professionals work is actually not all that different. I will leave it up to you to decide whether that means that a) in fact the difference between professionalism and amateurism has nothing to do with age but it is that in the former case you actually know what you are doing; or b) that in fact we are more closer to how things go in industry than we might think. Here the people, like us, clearly come in two flavours: people good at electronic hardware and some extravagant people that know how to supply it with the necessary software. We know what these people talk about, we speak the same language. It is also nice to see 1) that the people love their job and 2) that they all like our project.
The rest of the day is spent between updating checklists, checking whether our electronics survived the trip, playing in the snow and visiting the rocket graveyard. A peak outside of my window gives the following view on the main building:
The yellow globes are radar domes packed with RF equipment for various systems. You may not see it but next to these there are antennas scattered everywhere in various sizes. Amongst other purposes these systems are used to check whether there is radio silence at the launch pad. No transmissions may take place within a certain range from loaded rocket motors, and we need to switch our cellphones off.
In the evening we have our daily team briefing, see the next picture, during which we exchange experiences of the day, and make plans for the next day. The blue screen you see on the picture is a separate TV channel available in every hotel room on which the countdown clock can be seen, and you also see that radio silence is to be observed.
I have been staying up to see some Aurora Borealis, but unfortunately no such luck. Signing off now, and may tomorrow bring us less funny problems and more of the good feelings that we had today.
Visiting the launch pad
And now for something completely different. Instead of tinkering with our electronics again, today we decided to clear our minds a little bit and go skiing. For me that was the first time, so I hit the snow every now and then, but with half a meter of the stuff between you and hard rock that's quite okay. After we prepared our skies we headed for the launch pad. This is a bunch of students skiing around the MAXUS launch building:
While we were there it looked normal, but now I'm writing this I realize that it is actually quite cool to be skiing around on a rocket base...
Inside the blockhouse (not the blue building on the previous picture but a little further on the base), there are a lot of consoles Apollo style. On the next picture I am standing near the console that the launch officer will use for our launch, and I am ready to push the button. We have been told how the launch system actually works, and it is not like you can push the button and hell will break loose, but still there is something magical about it...
I have been appointed Payload Engineer, and I will be responsible for the communication with the rocket during the countdown. One of my jobs will be to monitor the status of the rocket, and to initiate the final arming and check whether all systems are ready for launch. I will be sitting just around the corner, and I will be talking to the Esrange operations officer to give GO or NO GO for our system. Some other team members will be at the main building to monitor the telemetry that our rocket transmits.
During countdown there must be radio silence when there are people on the pad, and only the rocket transmitters are on when we are in the blockhouse. This means that our means of communication are the fancy red phones you see on the picture.
After our ski trip we tested our improved software, and we are happy to see that everything worked out as planned. I am getting more and more confident that our systems are ready to fly a perfect flight, but I would like to do some more testing before giving the go for flight. In a meeting this morning that was for the other student teams for the REXUS campaign we were warned that there are two kinds of team: the ones that say they don't have any problems and the ones that keep on fooling around with the systems until just before launch. Past experience has shown that the latter teams usually have a good flight while those that say they hadn't any problems were the ones that suffered from failures. From this I conclude that we will be all right!
After the skiing we played a horrible game of pool in the recreation room, and then, finally, there was dinner, with the largest piece of salmon I ever saw. Life is not that bad after all...
Thursday
We are told by various people that they are quite impressed with the complexity of our system, most importantly the system for controlling the second stage, so my system. Today we also saw a glimpse of the real hardware that they are using, and I am surprised to see that they use mechanical timers instead of our electronic timers on the microcontroller.
A mechanical timer is about the size of a 1 dl soda can, and once it is running it will activate a switch after a certain number of seconds. It is demonstrated for us: it does work the same like the egg timer you use in your kitchen, and it even sounds like it. If we had to use mechanical timers for all the timers that we use in our electronics, we would need a separate rocket to fly the timers only! So I guess that modern microtechnology still has to prove itself in the rocket business, so we add it to our list of another "first" at Esrange when we do our launch.
We have another skiing trip today to visit the launch pad. Some people are complaining about muscle aches from skiing, and suddenly I realize that that is also what was the strange feeling in my body that was bugging me all the time since I got up in the morning. Skiing today is at least as much fun as yesterday, and we slide down the slope just here at the base several times until it is nearly dark and we are all eager for a hot shower and a hot meal.
We had a balloon launch scheduled for 00:30, but it was cancelled due to high winds, so in the evening we worked on preparing the parachute deployment system into the rocket. I feel like we are actually getting ready before our own flight readiness review tomorrow.
Snow and wind
I have just returned from an excursion with almost the entire group. We went on a trip in the area to the North of Kiruna. First we drove to the train station in Kiruna, where we were picked up with another van. The team was split in two: the first team went on snow mobiles, and the other team with a dog sled. First we got warm overalls that we just put over our jeans and jackets, and we also got real boots. I was in the second team, so my first task was to help with getting the dogs connected to the sled. My dog was a bit scared of all the newcomers at first, but I just had to push him forward, where he was joined with the other dogs. The four of us had to take seats in the sled, and Christina was allowed stand behind us, next to the driver, because she spoke Norwegian :-).
Off we went. In the beginning it went downhill fast, and a bumpy ride to say the least. The driver told us that he participates in dog sled races of 500 km long. Driving tourists around is good for the dogs to develop strong muscles, and next to this he does long trips with a single person sled to train for endurance. It was a great experience, because not only is a dog sled an unusual vehicle, but also the landscape is awesome: there is absolutely nothing but snow and trees and some hills. About snow, by the way: the snow flakes that are currently falling here are really the classic snow flakes, not the white blobs that we call snow in The Netherlands. Here, every snow flake is different, and a piece of art in itself.
After about 15 km, give or take a few, I really have no idea how far it actually was, we met the other group that took a separate route with snow mobiles. There was a tent in which there was a fire, hot coffee and home-made cakes. I don't know how you call the tent, but in North America I would call it a wigwam. Round, made out of natural materials and an opening at the top to let out the smoke from the fire.
Then it was time to switch vehicle and learn how to drive a snow mobile. There were two people on one snow mobile. After a small instruction we just set off. There is quite a network of snow mobile tracks, and we drove after each other with about 15 meters safety distance. Maximum speed was about 40 km/h (a pity since the engines are powerful enough to achieve 120 km/h), but still it was fast enough to be really cool. There was nothing all around us, and yet there were quite a few people on the road (actually I'd better say "track" here, because there are no roads). Halfway we switched places, and now I was in the back seat. I tried to take pictures with Bryan's camera, but it's quite hard to get focus when you're on a bumpy track. I will add pictures later on, so be sure to check out this post again in a few days.
About the past few days: some new people have arrived by plane: Ragiel, Arjan, Peter and Chris. They brought with them a lot of things that we had forgotten. For the electronics group the most important items were two tracking beacons, and two new transmitter boards. A few days ago we had given up hopes on flying our own transmitter, because we just haven't had enough time to work on it. At the moment things are looking very positive: we can talk to the transmitter chip and it transmits something. Below: our transmitter. The blue wire is the antenna, and the red wires are for testing purposes: to these we can attach an oscilloscope (yes, we brought even an oscilloscope up here) to see what signals are going between the microcontroller on the transmitter board and the transmitter chip itself.
Things are not looking very well for a launch anytime soon, because the balloon campaign keeps delaying, and with it it delays the rocket launches. We are last in the food chain here, so we can do nothing but wait and beg for some time of Esrange staff now and then to help us out or to give us access to secured places, for example the place where our rocket motors are stored.
Surprisingly, rocket launches are found to be less dangerous than balloon launches. The current balloon campaign involves a balloon of 400.000 m^3 gas that can lift the 700 kg gondola with payload. Once it is launched, there is only one control, which is a pyrotechnically activated cutter to cut the balloon away from the payload. Then it is up to the winds to decide where it lands. To determine the moment of the cut, they use up to date weather information. The position of the balloon is plotted on a map and an arrow shows there the gondola will land. On the map there are coloured squares which indicate the local population density, and when the arrow points to a gray square there is only a very small chance of crashing down on an unfortunate human being. Small villages have yellow to red squares, so when the arrow is pointing there they just let the balloon float onwards.
Balloon trajectories are very much dependent on the winds that can vary rapidly, and since a flight can last up to 10 hours, it is hard to accurately predict the flight path. Not so with rockets: their flight is relatively short, with 15 minutes flight time for the largest rockets (700 km altitude). So, people are much more stressed for a balloon campaign than for a rocket campaign. Before the balloons have been launched, there will be very little attention for our rocket campaign.
Tonight we have planned a full system-level test of our electronics, and I have good hopes that we can program one set of electronics with the final flight software and have this capsule on standby in case suddenly a launch opportunity arises. Then we still have the second set to tinker with. I will now go and see whether it is indeed fit for flight. Below is our flight computer (there are also board on the other side). Take note of the wire harness, which was quite tricky to make. The white box does not fly, it is used to put software on the microcontrollers, so to tell the microcontrollers what to do.
We do not only fix our own hardware: while we're at it, the electronics group also fixes old laptops so that they can be used to feed camera images to a web video stream.
Below: a view on radar hill from next to the Esrange hotel. Our rocket should not fly there. The car on the right is plugged in a power socket to keep the engine somewhat warm in the freezing cold. Most parking places in this part of Sweden have such a box to plug in.
Balloon launch
First of all: as promised I added pictures of our trip with dog sleds and snow mobiles to the previous post.
Yesterday was an interesting day. Our transmitter works better and better, and we drove up to radar hill to test whether it has some range. We could still receive it clearly. I still need to implement proper non-return to zero (NRZ) or Manchester encoding of the signal, or else I need to implement transparent UART mode. Now it is a combination of both, but we still have some time :-). Next to the work on the transmitter, a system-level test of all flight-critical components was done. The entire sequence was gone through with simulated data, and it worked beautifully. The transmitter and the camera are nearing completion and will probably fly.
We have customized the beacon device we got from Esrange by soldering wires and a resistor on it to be able to connect it properly to our own systems, and we tested the software patch that we requested to the Esrange person who programmed it. This is so that we can control the transmitter of the beacon via our own system while it is on the launch pad. It is required that you can switch radios on and off on remote command, because it is not allowed to have transmitters on when there are people near an armed rocket. The energy coming from radio transmitters can set off the explosive devices in the rocket, which is of course dangerous when it happens while not intended.
Frank also put glue on the more heavy components, so that they are still on the board when they have experienced a deceleration of 45 g (something that has a mass of 10 grams then suddenly weighs 0.5 kg).
The picture below, made by Frank, shows a picture of a cellphone in a jar of water. It was promised that he who still had his mobile phone switched on when in the launch area while there was radio silence, would find his cellphone in the jar instead of "Whiskey in the Jar". Apparently the project manager kept his promise...
During the test, I put some test code on the pyroboards. The test commands require that you pay close attention to what you are doing. We had six ports to test, and the first test went okay. When, however, the second port was tested, I used my test commands in the wrong sequence. What happened next is that our flight computer lit up in a bright light and I heard a rustling sound. Smoke started appearing out of our flight hardware. I disconnected the battery, and at the same time one resistor fell off the pyro board, which had soldered itself loose due to much too strong currents for too long a time. Reactions varied: I immediately knew what was the cause, and I saw that only the pyro board was damaged. The battery was still okay. So, the damage was minor. Mark and Hein, those who will be next to the rocket during the final stages of arming, have confidence in the system, because this showed that the currents flow through the safety instead of through the squib, so that means that the system is safe. I have removed the test commands from the software, reprogrammed all the pyro boards and hope that this will never happen again. A test of the other ports showed that the pyro boards are working properly and we are confident that we have a safe and reliable system. The picture below shows the pyro board, and the red circle indicates the spot where once there was a resistor.
In the afternoon we went skiing again. This time we skied to rocket graveyard. Here all spent stages are stored. It will be a while before DARE produces rockets of this size, but who knows...
We got up at four in the morning to see the launch of the small balloon that should have flown one month ago already. It was very cold, and utterly boring. When we now speak about "balloon people", we actually mean the stereotypical scientists walking around here that have been delaying the rocket launches. The delays are caused by a lack of leadership: they haven't bought enough liquid helium for a second attempt, so they are waiting until they are sure that they have the best opportunity, because there is no second try, and they are continuously debating whether or not to go ahead with the launch while the best weather conditions you could ever want are becoming worse. Tonight they may fly the really big balloon, and we all hope that they just get on with it, so people's minds can turn to rockets instead of the balloons. If only the launch of a balloon were interesting, but no.
Below a picture of the balloon launch: to the left you see the balloon. At launch the balloon is released, and is then held down by the yellow trick on the right, Hercules (dubbed a "echtemannenmachine"). It can control a balloon capable of lifting up to 8000 kg. Once the balloon is upright above Hercules, the truck drives in the direction of launch, and then the balloon is released. It is visible for some 20 seconds, then it is gone. No bang, no fire, no smoke, just a rustling sound as the balloon settles itself in the wind. I hope that the rocket launches will be more exciting...
Scrapheap challenge
Even though we brought half our workshop to here, there are always things that are missing. Especially in the electronics department, we could use some extra components. Luckily we have Chris with us. He was able to fix our blastcams (cheap-ass camera's that we place near the tower to take close-up pictures of the launch) by searching through the containers in the waste sorting station, and finding a piece of tin to use as cooling fin. Just a small piece, but enough to solve our problem.
Later on, we found out that we needed a capacitor for the audio cable between a transceiver and the microphone connector of the ground station laptop (we are currently still developing our telemetry system). I drove with Chris back to the launch pad, found some old electronics that had a few capacitors. We soldered off one, and used it for our cable. The heat shrink tubing (according to Wikipedia this is the proper translation of "krimpkousje") did not shape properly with a hair blower, so I went to the kitchen and held it above the cooking plate. Not ideal, but it worked. At this point you may think this is typical for students, but no: today we discovered that also with the multimillion dollar campaigns they sometimes find scientists soldering in the hotel kitchen....
As I mentioned, we are still working on our telemetry system. Software demodulation is more difficult than I thought, but we still have some time. One try was to use our transmitter in the opposite way by configuring as a receiver. Together with Eric I changed the program for transmission to reception, we tried it, and then the most astonishing thing happened: it worked right away. The only thing is that we still have some digital noise, but other than that it already looks quite okay.
The customized ETAG (Esrange Throw Away GPS, I only found out today what the abbreviation stood for...) was tested and worked.
In the evening there was another balloon launch, the big one that has been delaying the rocket launches all the time. The launch was quite spectacular (for a balloon that is), mostly because of the way that the balloon rose and took its new shape when it was released. So now that the balloons are away, it's rocket time: the countdown is set to start at 8:34, and the planned launch time is 11:04.
At some point we had to stop working, because it was team picture time again. Here we stand on the road towards the launch pad, with "Danger Areas" on the background.
Yesterday evening we, finally, saw Aurora Borealis. It was very faint in the beginning, and then suddenly the sky became bright with light. Beautiful, it was moving very rapidly. The colours were mostly green, with a bit of red as well, and I also saw a part where there was a small rainbow. At the time I did not have my camera with me, so I was not able to take a picture of the brighest part, but I went back inside to fetch my camera and to put on some thermal underwear, because it was freezing cold: -15 degrees and quite some wind from the North. It is not easy to capture the faint light, but here it is:
This is the readout of the weather station at the reception: -15 degrees and dropping.
Rockets and helicopters
This morning was strange: I woke up, showered, 10 minutes later I was in the restaurant eating my breakfast. I just took my first bite, then Mark told me that there was an extra seat in the helicopter that would go on a reconnaissance flight. "When?" "Now, they are waiting." I finished my breakfast as fast as I could, took some warm clothing ("Take warm clothes because we may need to leave you behind when something happens"... right....). Next thing I knew was that I was flying in a helicopter over a really beautiful landscape: the sky was very clear, the Sun at 10 degrees above the horizon, bathing the snowy but oh so desolate landscape in a very soft and warm light.
The purpose of the flight was to see where there were people and herds of reindeers, and to see whether they would not be near the nominal impact point of the rocket (the REXUS 6, not our own). There were some small villages here and there, and some lonely houses in the middle of nothing. We flew northwards, to about 80 km away. We got that close to the finnish border that the Esrange person got a message from his mobile operator that he was now connected to the finnish mobile network. Also Norway was only 20 km away.
After a flight of one hour Esrange came into view again, and we had a very soft landing. Actually the helicopter flight was much smoother than, say, Dutch regional trains, only with a lot more noise. We came back into the restaurant again, to find people green of jealousy. Sorry guys, just a matter of being in the right place at the right time, I've had my turn, you're next.
After a while we drove up to radar hill to see the rocket launch of REXUS 5. It was beautiful, that's how we like it. One particular cool thing was that the roaring sound only entered my ears 7 seconds after I saw the first flash of light. The rocket was gone in no time, and it will impact 600 seconds later. I did take some pictures, but I have no time now to edit them, but I promise to add them later on.
No launch until Monday
This morning preparations were started at 04:00, because at that time we could access the motor assembly hall again. At 06:30 we all went up to Radar Hill to watch the launch of REXUS 5. The launch was almost as cool as the previous one, only today low-hanging clouds prevented us from seeing the rocket as long as yesterday. Then it looked like we were go for our launch, with a countdown starting at 13:00. However, at 12:00 it was decided not to launch today, because it would still take at least two hours before the countdown would be started, which would leave us with very little daylight time, so that the chances of successful recovery would be dramatically reduced.
So, we went on preparing, with a possibility of launch tomorrow morning, if the weather allows. Later today, however, there was an announcement: the management had decided that given the fact that the Esrange crew was very tired and that launching on Saturday would mean even more overtime for the staff, so next option for us is Monday. There will be a meeting at 09:00, at which it will be decided whether there would be a go for a launch. The weather forecasts are not to good, but maybe we can launch Monday morning, and otherwise Tuesday should certainly be doable.
From a safety point of view this is of course the right decision, because both we and the Esrange crew is tired, and that will increase the chance of accidents. And anyways, life at Esrange is not too bad, but still it would have been nice to launch today or Saturday and then go home as planned. Nothing we can do about it, we just wait. The positive thing is that this gives us time to think, and prepare better for the campaign, so it should be going really smoothly on Monday when we launch.
REXUS 6 launch and aurora pictures
In the picture below you see the launch of the REXUS 6 on Thursday.
And below a picture taken one hour ago of the aurora borealis. This time I was able to capture it when it was at its brightest. This makes up somewhat for the disappointment earlier today.
Launch opportunity tomorrow
Tomorrow at 09:00 there is a meeting with Esrange staff to decide whether there can be a launch on Monday. We will get up more early, so that everything is prepared and ready even before the meeting, in order to start the countdown as soon as possible after the meeting. When the one hour countdown will start exactly is not known at the moment: this will be discussed during the meeting.
I am now uploading the final flight software into the electronics. Everything is tested and ready for flight. We even have telemetry (two weeks ago there was only a test print of the transmitter and no software... good job Eric). Unfortunately we had to scrub the camera, because it simply did not want to cooperate.
So, more news after 09:00 tomorrow morning, and hopefully we can start the countdown before or right after lunch. I am ready... stratosphere here we come!
Tall rockets catch a lot of wind
The launch preparations of today were aborted due to the wind: the wind varied between 8 and 12 m/s, and beforehand a wind limitation of 6 or 7 m/s was agreed, and so we did not launch. The forecasts for tomorrow are good: at 10 AM only 2 m/s, so I think that is a good time to get the bitch up in the air (we have two capsules, and the primary flight one is called Annabel).
In the picture above you see the announcement on the blue screen. These are all over Esrange, so you can see the current status at all times. At the top there is the countdown clock. Interesting to note is that the wind was blowing that hard that snow was blown onto the screen of my laptop...
Tomorrow the go/no go decision meeting is at 08:30 AM, and I think that afterwards operations will start quite quickly if the weather is as predicted.
At the moment the temperature here is around zero, which is really really warm. After two weeks of a nice -10 degrees on average, your reference of hot and cold starts shifting. I guess that is also how people survive up here.
I have cleaned up ElOps (Electronics Operations), the nickname of the room of Bryan and me. During the past two weeks ElOps was the focal point of all action, and as a result it was a gigantic pigsty. There were cables, laptops, people and empty mugs of hot chocolate everywhere, and every 5 minutes someone would pop in and say "Yo, what's up, you guys fixed it already or what?". Not anymore, I am now sitting in an unusually peaceful and tidy room, and strangely enough the quiescence makes it almost like we have launched already. The rest of the day I think people will spend partly on answering long-overdue emails, finishing reports, updating blogs....
In the evening we may finally have the much anticipated LAN-party (what else could you do in the middle of nowhere with a bunch of laptops?) - apparently, without any coordination being required, everyone brought his favourite game to here, so that a LAN party would be amongst the possible entertainment options in the unlikely event that we would have some free time.
The opportunity for tomorrow looks even better than today's one, so let's hope for the best, and that tomorrow I can write here that we are holder of the European altitude record for amateur rocketry!
European altitude record achieved!
We did it! Today at 11:28 local time the Stratos was launched, and fast it went! I was in the blockhouse behind my laptop, checking out the status of the rocket systems. It went smooth, no problems with the electronics whatsoever - I could hardly believe it. Then there was the final minutes of the countdown: there was dead silence in the blockhouse, tension rising every minute... then at T -5 s the fire button was pushed, and at T = 0 the zero pulse from the main building initiated the firing sequence. 1.5 s the motors were at full thrust, and the rocket was away really fast.
So far so good, personally I expected nothing less (but then I didn't design the motors). But then came the most important part for me. When I got confirmation from the spectators on radar hill and the telemetry station that the sustainer had ignited, I was really happy, because this meant that my system, the pyrotechnical activation system, had worked well: it did fire when it should, and it didn't when it shouldn't.
Slightly afterwards we received information from Esrange telemetry that the GPS beacon showed that we had reached a preliminary 12.5 km above sea level altitude. This is higher than the previous record of 10.7 km, so it meant that we are now record holders of the European altitude record for amateur rocketry!
On the picture below you see Stratos heading towards the stratosphere.
More pictures and movies you will find on the internet, and I am sure that most of it will be accessible via the website of the project. I have not had the time to take many pictures today.
This will be the last post of this blog, because tomorrow morning at 06:00 our plane leaves from Kiruna airport, and the day after will be the first day back in the real world for me. It was cool to get here, it was even cooler to be here, but there is also a time to leave for home again.
Signing off now. I would like to thank all the readers of this blog for following the campaign, and I hope you enjoyed reading my experiences from the project. Cheers from Esrange!
Martijn