Wednesday, December 1, 2010

Dec 1 update

Science update: To continue with what I was saying in the previous post, we are trying to make measurements that will help us understand how aurora might provide energy that can (sort of) cause Earth's atmosphere to swell up. We are doing this by launching a rocket to a very high altitude (something like 475 km) and will measure electric and magnetic fields, as well as electrons and positive ions (charged particles from the solar wind?). Of course, we need to do this at the right time, which can be very tricky.

Here is the situation. The rocket is almost ready to be launched, sitting on a launcher located on the north coast of Norway and pointed in a northerly direction. We (the "science team") are sitting in an observatory called EISCAT, located just outside the town of Longyearbyen on Svalbard, a large island well to the north of Norway. Here, we have lots of instruments that can tell us about the ionosphere (the very upper part of the atmosphere where gobs of electrically charged particles exist). These instruments include gismos to measure Earth's magnetic field (that gets affected by changes in the ionosphere), radar to probe the ionosphere, very sensitive cameras to grab pictures of the aurora above (which tells us about where interesting things are happening in the upper atmosphere), and so on. Once we see that we have the right conditions, we will tell the folks at the rocket range to go ahead and launch - and the rocket will fly over our heads. No, we won't be able to see it, since everything is very dark here.

About where I am sitting: take a look at a map and locate Svalbard, It is very far north - Santa is our neighbor! We are staying in the town of Longyearbyen, which used to be a coal mining town, mainly for Norwegians. Coal mining on Svalbard is still an important activity here, although Longyearbyen has changed and is THE town with an airport. It also happens to be where the University Center in Svalbard is located (http://www.unis.no/). The science people from UNIS have been working very closely with us. The specific observatory that we are sitting in (right now!) is described at http://kho.unis.no/. Try to browse around that website, which describes some of the instruments located in this area. There is even a webcam there, so maybe you can spot if you look during the middle of the night. The photo gallery is neat, too, and I have copied a couple photos below:






This picture shows the two EISCAT radar dishes that measure the ionosphere overhead, as high as 500-600 miles up!!


This picture shows the view we have, looking down the fjord. Actually, we don't ever see anything like this because it is completely dark 24 hours a day!

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About the rocket: putting a rocket payload together is very challenging but a lot of fun. It takes a lot of work, which is accomplished by different teams. For the kind of research we do, the usual arrangement is that NASA provides the rocket itself, the expertise to launch and to retrieve the data that gets measured. The scientists, mostly based at different universities, provide the instruments used to make the measurements. We each have a responsibility to provide various instruments, which we actually build ourselves, with the help of engineers and students. Once we have built these instruments, we deliver them to NASA (usually a few months before launch) to install them into the rocket itself (this is called integration). Some pictures might help:










This is a picture of the payload (the part of the rockets that contains the instruments). The total length of the rocket, when completely assembled, is about 60 feet. Its diameter is only about 17 inches. The payload gets carried on the very front end (top) of the rocket; instruments only take up a few of the entire rocket. Below the instruments are other "systems", like the Attitude Control System (ACS), the Telemetry System (TM) and the igniter section.





Here is a picture from the rocket range, showing the rocket as it gets ready for launch. We are using a 4-stage rocket, so 4 motors are stacked on top of each other to lift the payload where we need it to be. As the rocket motor for each stage burns out, it gets dropped and then the next stage is ignited. In preparing for launch, each stage gets slid onto the "launch rail", which is horizontal as they do so. As each subsequent stage is mounted, they get bolted together and then, finally, the payload is mounted to the motors; once this is done, the rail is elevated and aimed as it needs to be. At this time, we say we are "vertical" (although it is not quite really vertical).

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Daily activity: the routine for us generally consists of "checking in" at the start of our launch window, which starts at 2:00 in the morning. Once we have checked in, we make the trip out to the observatory, which takes about 20 minutes and is, well, interesting. Then, we sit and wait and sit and wait and sit and wait.... until the solar wind (which we monitor continuously) does what we need it to do. While we are waiting, we sit at what is called "T minus 15 minutes and holding for science". That means that all of the many daily checks regarding the rocket itself have been completed and we can launch within 15 minutes once the science team says to "go".

At some point, we expect that the solar wind will do as we hope, the ionosphere will respond accordingly and we will launch. Today, conditions were actually very poor and there is no way that we would have launched even if the rocket was ready. There were also very strong winds at the launcher, which makes things dangerous for launch -- another reason we would not have launched.

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