Wednesday, December 17, 2008
Thursday, November 20, 2008
The image capture sequence is from far left to far right.
The individual frames were captured by the Camera Module's solid state video camcorders. Lens distortions ("pillowing") were not corrected, which is why the curvature of the horizon does not match on either side.
This image shows the REXUS-4 Payload section with the still attached second stage motor. It was assembled from frames captured by the left-hand TV-boom-camera on board the Servce Module (the left-hand boom is the red one pointing upwards and towards the observer in REXUS4 Mosaic 02.jpg).
The differences in shades in both images result from the camera's adaptive exposure time, which leads to some frames being darker than others.
Image Rights: The Mars Society Germany and the University of the Federal Armed Forces of Germany, Munich.
Wednesday, November 5, 2008
Dear Friends of ARCHIMEDES and the Mars Society,
MIRIAM was launched to a 175km peak altitude from the SSC ESRANGE rocket test site near Kiruna, North Sweden on October 22nd, 2008. It rode on top of the REXUS4 sounding rocket managed and built by the EoruLaunch Consortium of the DLR Moraba group of Oberpfaffenhofen, Germany and ESA.
Unfortunately, after a trouble-free testing period leading up to a picture perfect launch, one of MIRIAM's main interlock bolts jammed upon release. Miriam therefore got stuck on the rocket, which subsequently led to the balloon's clamp ring to get stuck as well.
With the stuck clamp ring, the inflation systems deck started to pressurize a still packed balloon, until overpressure pushed the inflation hose off the hose clamp assembly.
The flight system finally released from the rocket, but far too late. And with the deployment coil springs almost fully extended, it also came off far too slowly, eventually colliding with the rocket's payload section.
Unintentionally positive however, the collision caused the stuck clamp ring to come off, causing a rapid deployment of our partly pressurized balloon.
Because the balloon is only attached to the inflation systems deck at the inflation hose clamp assembly, the balloon was immediately set free, but with little over 10% of its intended amount of filling gas.
All other subsystems functioned nominally and behaved just like they did during tests.
Despite the fact that the balloon was deployed and released, the mission was deemed only partly successful, as the deployment came unintentionally and uncontrolled, and because the balloon did not carry its intended amount of inflation gas.
The reason why one of the main interlocks failed is a matter of investigation. This behavior was never observed during tests.
All subsystems of the REXUS-4 rocket have worked beautifully, exactly as predicted and right on time. We therefore owe EuroLaunch as well as the entire crew on ESRANGE great thanks for a beautiful flight, their outstanding technical support and a rocket as precise as clockwork.
While at it, we would like to take the opportunity to thank everyone who contributed to this mission, no matter how small the contribution was, since every contribution helped us getting off the pad!
Shortly after atmospheric reentry, the camera- and antenna booms were torn off the discarded MIRIAM Service Module by aerodynamic forces, as they were not designed to withstand reentry. Miraculously, a short while into reentry, the right camera boom came on-line again and briefly transmitted pictures as it was dangling on its wire harness. Sunlight can be seen shining through gaps between the now empty balloon compartment and the obviously still working flight computer module. The coil spring is a remnant of the long gone blossom container inside which the folded balloon rode into space.
Thursday, October 23, 2008
I am posting yesterday's and today's posts back-to-back, so you may now read the happenings of the launch day below. Today, the day after the launch, moods have improved quite a bit, given that we are getting more and more useful data and can reconstruct more of the mission sequence. Despite the ambiguity and potential damage caused by the collision, most of our systems behaved nominally. Today was a welcome contrast to the stress leading up to the launch, while discussion of our results continued spontaneously throughout the day. A few of us hiked down to the river straddling Esrange. Later at night, a dinner party was held with all the teams, followed by more review of our videos. Let me just say that the people from the Swedish Space Corporation have been extremely hospitable to us and made the stay here a pleasure for all (and always with a great sense of humor).
I will leave Esrange tomorrow morning to return to the U.S. Some of the team will stay behind for a few more days to further evaluate the data. We have learned an incredible amount as a team and individually, from flight operations, team work, procedures, engineering, testing and much more abstract things which can't be summed up in text. The data we gathered will no doubt benefit our knowledge and understanding of such a complex system and guide us to and during future projects. Experimentation and experience go hand-in-hand. We also just had plain fun doing this, and I will certainly miss Esrange and everyone on the team. Of course, the project is far from dead, and therefore most of us are nearly guaranteed to stay in contact and probably cross paths again. I will continue this blog as more information about the flight becomes available. For now, enjoy the pictures of my last day at Esrange below.
Striking the "Dr. Strangelove" pose on a spent Nike booster. These are derived from now obsolete anti-aircraft missiles, some of which did indeed carry nuclear warheads during the Cold War.
The "Highway to the Danger Zone"
Good Bye, Esrange
Sorry this post comes a day late, but the mission sequence necessitated us to stay silent for a while to avoid speculative misinformation and to be sure we know exactly what results we could draw from the mission. Indeed, we are still learning about the flight and probably will be for quite some time into the future. After a much accelerated count-down, Rexus 4 did finally launch and I have attached the video below. I apologize for the marginal quality, as I took this on my small photo-camera. We have slightly better launch videos, but for now this was the most suited to put on the web.
Now, to the mission itself. We still don't know the extend of success of the mission, pending further evaluation of our data. There was, however, a compromising event which affected the mission to some extend. After what began as a picture-perfect launch, MIRIAM began to transmit breathtaking views from space. All cameras worked flawlessly and recorded separation of the service module. However, a short time after MIRIAM separation, the payload section (containing our Camera Module on top and other experiments below) underneath the service module separated from the second stage booster as planned, but then collided with the Service Module. The impact happened approximately 15 seconds after the balloon was ejected and during the inflation sequence. A partially inflated balloon can be see just before impact, validating at least part of the experiment. The collision induced some tumbling and the fate of the balloon and instrument pod are yet uncertain, pending further evaluation of the video material, telemetry data and possibly recovery of either service module or instrument pod (the camera module is already recovered with the rest of the payload section). The service module continued to perform the inflation sequence nominally and continued to relay data until re-entering the atmosphere, offering stunning views of northern Scandinavia.
After hours of watching the tapes, this is the best account we can give so far. What seemed at first like a shocking deja-vu of the previous REGINA mission, turned out to be most likely caused by a distinct issue. As was quickly determined, both our timers and the rocket's timers behaved normally and issued separation signals on time. In contrast to Regina, the added first stage and much higher trajectory should have given us adequate time to distance ourselves from the payload section and booster. This, however, was not the case due to the service module becoming stuck on one of three of servomotors forming the locking mechanism. These servos were tested extensively on the shaker table, but the exact failure mode still needs to be determined. Although all servos opened at least partially, causing the separation signal to appear, MIRIAM did not become lose for another approximately 21 seconds. Even then, it no longer had an appreciable separation impulse, as the separation springs had already triggered. This caused it to drift slowly and delayed from the payload section below, resulting in inadequate separation distance and allowing the following payload section to catch up and collide.
Nevertheless, much useful data could be obtained, and the fate of the balloon is yet to be determined. Despite an unforeseen mechanical failure of the servo, many processes and systems performed beautifully, validating many aspects of our experiment.
Please note that this account is preliminary and unofficial, and as such can only be confirmed by the official press release.
Tuesday, October 21, 2008
Sorry, no pictures today, as the anticipation and stress for all of us has been rising. Hopefully though, the next pictures you will see here will be of a rocket streaking to the sky. During the MORABA/SSC briefing today, we were informed of the critical situation regarding the launch prospects. Due to some glitches on the side of the launch providers, such as a "non-conforming fin," and weather, the schedule has been pushed and squeezed. The two rocket stages were mated and the stabilizing fin was fixed, but one had to ensure it had been fixed "to specifications." As the ever-calm SSC campaign director put it, "it is easier to bend steel than paper." What's more, this also meant the practice count-down had to be postponed, while at the same time, we only have a very small launch window on Wednesday due to wind. Weather is expected to only deteriorate thereafter. Should we not launch this week, launch may still be possible, but with a greatly reduced team (as most will already have left Esrange) and increased work-load. The decision was reached to postpone the practice count-down to Wednesday, at 5am, at a potentially accelerated pace in order to resume the "hot" count down not much later that day. This is thought to give the greatest chance to launch within the unbendable safety regulations.
This meant that the rocket was fully assembled tonight, while MIRIAM was partially pressurized with Helium and secured at the top of the rocket. The rest of the pressurization will happen tomorrow, most likely between practice and real count downs (necessitating special security passes for the team members handling MIRIAM on the launch pad). MIRIAM needs to be pressurized in two stages, as the gas under pressure is heated, and thus expands, and needs to be allowed time to cool down before "toping it off."
Luciana and I also held our trajectory briefing later in the evening, after the launch-prep team had secured MIRIAM on the rocket. After programming and ironing out our trajectory visualizations and calculations for most of the day, I think the briefing gave everyone a good idea of the series of events and flight paths of the MIRIAM components during the mission. Now, all we can do is hope it all goes as planned, and the very first purpose-designed inflatable atmospheric entry vehicle will be deployed in space tomorrow.
Monday, October 20, 2008
There won't be a long update today, since I had to attend briefings and work on our trajectory simulation for most of the day instead of shadowing people and taking pictures. We were joined by four more visitors of the German Mars Society and had a project-internal morning meeting to discuss our go-ahead plan and status. Everything seems to be going well. In the afternoon, the site operators held a joint briefing regarding launch prospects and safety. It looks like, while the winds won't be perfect, we are still scheduled to launch on Wednesday morning. One potential issue surfaced involving a missed opportunity to do an RF-interference test between us and another experiment on board, which will have to happen tomorrow morning. Other scenarios such as contingency planning for launch aborts etc., and their effect on our battery life, were discussed. The safety briefing was necessarily serious, as expected from any undertaking involving high explosives and accidents have happened. Our use of cellphones and controlling potential sources of static discharges are highly monitored, as well as access to the restricted areas during countdown.
As far as the trajectory simulation goes, Luciana and I are preparing a general trajectory briefing for our team tomorrow. Our actual trajectory is determined by the Rexus 4 operators, but since we have the service module and re-entry vehicle which detach from the rocket, a rough idea of the flight paths is desired. We are using the same program developed by the University of the Federal Armed Forces, which I adapted for use with MIRIAM during my summer internship. Since MIRIAM is a technology demonstrator for a Mars mission, we do not expect the re-entry ballute to survive re-entry on Earth, and much depends on when exactly the balloon will burst.
Lastly, I will share some pictures, courtesy of Jürgen.
Sunday, October 19, 2008
At last, MIRIAM is GO for flight commissioning.
Speaking of charged atmosphere, it seems like the elements conspired to reward us for our efforts. After our dinner, a few of us discovered a faint glow in the sky while setting out a freshly baked cake to cool. Sure enough, a dazzling display of green Aurora Borealis ensued. Having checked the space weather reports in hopes of seeing this phenomenon, we knew there was a slight but better-than-usual chance to see them tonight, but it was still a surprising event. The event didn't last much longer than half an hour, with ever changing intensity, so the timing was perfect. We did manage to take a few pictures, albeit without stabilization in (obviously) low-light conditions. This was certainly a moment to be savored with our own eyes, and the pictures do not do them justice.
About half-way to the top of the hill.
Me on top of the hill. You can see the launch site in the background
Saturday, October 18, 2008
First, I have updated yesterday's post with pictures, so feel free to take a look. The second day at Esrange began with with a moment of classic jetlagged disorientation, forcing me to take a second to figure out where I was, what time it was and what I was suposed to be doing when I got up. Once I got my bearings, we met up for breakfast at the main building and I joined a group for a shopping adventure to Kiruna. We are expecting more than 18 people and visitors of our group at launch day, and while Esrange provides some meals, we needed a lot more supplies. On the way there, we took advantage of the beautiful weather to take some landscape pictures:
The shopping trip took us quite bit longer than we initally thought, as trying to please everyones taste while finding groceries in a foreign language proved to be more difficult than we realized. When we returned in the afternoon, Hannes, the project leader, was already busy testing some of MIRIAM's systems. Today, most of that focused on the camera module. Since there will be several camera systems on board, let me explain each of them and their function.
There is one camera in the instrument pod of balloon itself which will image the separtion from the sounding rocket and the atmospheric entry from the balloon's perspective. There are also two cameras on deplyable arms on the service module which will monitor the inflation of the balloon and ejection of balloon/instrument pod from the service module. There is a third set of cameras which will stay behind on the sounding rocket interface to film the separation of the service module. Since the camera module, which includes a TV-camera and four digital recorders, remains on the rocket, it can be recovered after the launch to bevaluated later. As an interesting side-note, the digital recorders were salvaged from the previous "REGINA" sounding rocket experiment (which tested the ejection of the balloon without inflation). While the digital video recorders were initially considered "nice to have" rather than an essential feature, the team is still trying hard to make them work for us once again by troubleshooting software issues and rewiring some connections. The camera module's control computer, "CamCon" and the instrument pod control computer, "PodCon," communicate which each other through an IR system after separation. The camera systems are explained in the pictures below.
Camera Systems of the Service Module and the
The camera module which remains on the rocket.
The Esrange main building.
Friday, October 17, 2008
I finally arrived at Esrange this afternoon. The weather here is quite nice, with temperatures hovering around freezing and occasional light snow.
Flying over north Sweden.
Dusk at Esrange.
The flights went well, and while waiting for the flight to Kiruna at Stockholm, I ran into a familiar face of a team member from the UniBW, where I interned the past summer. There were also a few people on the flight from the MORABA (German: "Mobile Rocket Base") team from the German Aerospace Center who are providing the launch.
MORABA Engineers working the telemetry systems.
Disembarking at Kiruna.
The flight to Kiruna is basically only used by people bound to the Esrange facility or for local miners. Once we landed, it was obvious as to why that is. After disembarking on a tiny, snowy airfield, we were surrounded by nothing but boreal forrest and a few lakes. Don't get me wrong, the landscape is absolutely beautiful, but there isn't much around save for the few satellite dishes from Esrange and the naerby ESA satellite tracking station which could be seen from the airplane.
The ESA Satellite Tracking Sation seen on approach.
After an approximately 20-minute drive we reached the Esrange gates. We got our security passes (during launch capaigns, everyone needs to be accounted for and sign into designated areas for range safety) and drove to the processing building where we met up with most of our team (except for Dany and Kevin, who were in the control room). We ran some basic tests on MIRIAM and chatted with people from the MORABA team and some of the other small experiments bound to launch on the REXUS 4 rocket. I also checked into my room at the on-site "Aurora" Hotel and toured the rest of the facilities. Although most of the team has been here for a few days, MIRIAM didn't arrive until yesterday due to some shipping delays. However, the system arrived in-tact and ready-to-go. Much testing and some reprogramming of the mission timers remains to be done, however, due to a small change in the trajectory. Because of this and weather considerations, we'll probably be expecting a launch on wednesday rather than tuesday.
MIRIAM is being prepared for her big day.
The assembly area was quite busy.
Later today, some of us drove to Kiruna, a good 30 minutes away, for dinner. I tried some reindeer meat and it was quite tasty. We'll be doing more testing tomorrow and go on a shopping trip for basic necessities. I think that'll be all for today, as it's getting late and I need to sleep out the jetlag and rest my back from far to many hours on planes.
Wednesday, October 15, 2008
Here, you will find updates on the Archimedes project and the MIRIAM technology demonstrator which will be launched on a sounding rocket from the ESRANGE facility near Kiruna, Sweden, next week.
I initially started this blog for my personal reflection and to document the trip to Sweden for friends, family and the Engineering Leadership Program of my University, which has kindly agreed to partially sponsor my trip. However, this blog may also be of interest to anyone following the project. You can learn more about me and my involvement with the Archimedes project in the "About Me" section.
I will leave for Sweden tomorrow and am planning to provide regular updates and images when I arrive. I will also introduce the rest of the team and provide more technical background information once I am there. In the mean time, if you would like to learn more about the project, please follow this link to the project's main page. You can also view the project abstracts on the right menu bar.