Yesterday we loaded the fuel carts at the fuel farm on Pad 39B so that they can be transfered to the Pad 39A service structure to fuel Atlantis when it arrives there in the next couple of weeks. The process is fairly straight forward but for some reason, last night, anything that could go wrong, did.
The carts are uncovered during the walk down before the job and the area is inspected for safety issues as well as to make sure everything is in order and accessible for the technicians when they are out there doing the work. The job is done in SCAPE which is a self contained atmospheric suit which the techs wear to protect them from extremely corrosive, cancer-causing, hydrazine vapors.
The proper connections are made from the facility to the carts via flexhoses and the system is tested with gaseous nitrogen (GN2) in the event of any leaks. When the GN2 is purged from the system the hydrazine begins to flow from a fuel truck that is brought in a few days before. When all is said and done, the process can take roughly 8 hours to fill up the 5 carts (3 APU carts and 2 HPU carts).
** I should note that the HPU carts are for the Hydraulic Power Units which are in the solid rocket boosters and are the counter part to the auxiliary power units in the orbiter**
Last night was full of unfortunate events. From missing papers to batteries dying in flashlights were just some of the minor things. There was a leak in one of the hoses which was detected during the GN2 flow and needed to be fixed. Those were the biggest things to happen before I left at 2100. One of the few good scales we had began acting up, probably because of the rain, and a few other things kept the job from running smoothly. From what I heard, the guys that stayed later were not done until about 0430 this morning. But now the carts are full and, for the most part, ready to be transported to the Pad.
Wednesday, October 31, 2007
Tuesday, October 23, 2007
Launch Day!
As of yesterday afternoon there was a 60% chance of launch delay. I worked an overnight shift 1700 - 0130 EDT and we did some tests on the orbiter and boosters. We made sure that the program panels were set for the launch and the safing switches were in position in the event of an emergency. I came back to my apartment to get a couple hours of sleep and headed back down to work at 0800.
I was keeping tabs on the weather radar and had a live stream on my computer for NASA TV while I was sitting at my desk. The weather was looking great despite the poor forecast. Low level rain clouds were predicted for the day but it turned out to be scattered at a relatively high level. A fairly perfect day to launch a rocket. OV103 - Discovery took of as scheduled at 1138 in the morning to deliver the Harmony module to the International Space Station.
I was keeping tabs on the weather radar and had a live stream on my computer for NASA TV while I was sitting at my desk. The weather was looking great despite the poor forecast. Low level rain clouds were predicted for the day but it turned out to be scattered at a relatively high level. A fairly perfect day to launch a rocket. OV103 - Discovery took of as scheduled at 1138 in the morning to deliver the Harmony module to the International Space Station.
Sunday, October 21, 2007
Material Reviews and The Coming Week
I went in to work yesterday to help close some older papers. The first one I tackled was a material review (MR). Basically, there were a bunch of problem reports (PR) taken out on one of the pieces of ground service equipment (GSE) but the problem is that the panel became obsolete and was replaced by a new panel. The panel, know as the -613 panel, provided an interface to flow gaseous nitrogen (GN2), gaseous helium (GHe), and fuel for the orbiter. One of the main problems is that a couple of the supports were becoming corroded and needed to be fixed. Also, the rotating service structure (RSS) had been modified and at the time the old panels were temporarily removed but when the modification was complete the new panels were put into service. So in the end these old service panels are sitting around with little to no use. But as mentioned in another post, you can't do ANYTHING on the space center without a piece of paper saying you can do it.
The MR that I wrote stated, but in a more official manner, what I just described above and went into further detail on how it poses some serious safety issues and it would not be cost effective to reinstall the panels. It was requested that the panels be 'abandoned in place' and later scrapped for parts. The MR has to go through a review board and approved by Boeing and NASA.
Not very exciting, but it's what I do.
Saturday marked the start of the countdown for STS-120. At 1400 EDT the clock started ticking down. It also marked the start of the S0007 (pronounced soo-seven), which is the shuttle launch procedure book. There are about 6 seperate books that deal with S0007 based on where the count down is (i.e. T-48 hrs to T-43 hrs). At this point personnel are on console for pretty much the duration of the countdown until launch performing tests, checks, purges, and other things to get the shuttle ready to go.
Tomorrow I will be working 1700 to about 0100 or 0200 and we will be doing what is known as BITE tests on the solid rocket boosters (SRB) and the orbiter. With a BITE test, the system is started, without really being started and runs through all of its processes to check for any kind of malfunctions.
There is a mandatory minimum of 8 hours between shifts. Which means if I leave at 0100, I cannot come back to work until 0900. Which kind of sucks because I have to drive all the way back to Daytona, sleep for a few hours, and then head back to work for the launch. I really haven't figured out what I'm going to do yet. But it should be interesting. I do have a strong hunch that the launch is going to be delayed. The weather does not look too promising for Tuesday. So we'll see.
The MR that I wrote stated, but in a more official manner, what I just described above and went into further detail on how it poses some serious safety issues and it would not be cost effective to reinstall the panels. It was requested that the panels be 'abandoned in place' and later scrapped for parts. The MR has to go through a review board and approved by Boeing and NASA.
Not very exciting, but it's what I do.
Saturday marked the start of the countdown for STS-120. At 1400 EDT the clock started ticking down. It also marked the start of the S0007 (pronounced soo-seven), which is the shuttle launch procedure book. There are about 6 seperate books that deal with S0007 based on where the count down is (i.e. T-48 hrs to T-43 hrs). At this point personnel are on console for pretty much the duration of the countdown until launch performing tests, checks, purges, and other things to get the shuttle ready to go.
Tomorrow I will be working 1700 to about 0100 or 0200 and we will be doing what is known as BITE tests on the solid rocket boosters (SRB) and the orbiter. With a BITE test, the system is started, without really being started and runs through all of its processes to check for any kind of malfunctions.
There is a mandatory minimum of 8 hours between shifts. Which means if I leave at 0100, I cannot come back to work until 0900. Which kind of sucks because I have to drive all the way back to Daytona, sleep for a few hours, and then head back to work for the launch. I really haven't figured out what I'm going to do yet. But it should be interesting. I do have a strong hunch that the launch is going to be delayed. The weather does not look too promising for Tuesday. So we'll see.
Wednesday, October 17, 2007
Auxiliary Power Units
There hasn't been a whole lot of exciting stuff going on. Mostly just writing closures and putting run books together for the launch next week. So here we are, 6 posts deep and it's evident what department I work in but it was never really explained what the system does. So here you go...
The auxiliary power unit (APU) is a hydrazine fueled, turbine driven power unit which produces mechanical shaft power to a hydraulic pump which produces pressure for the orbiter's hydraulic system. There are three APUs on the orbiter. Located in the aft compartment of the orbiter, APUs 1 and 2 are located on the left side and APU 3 is on the right. The three systems are identical but independent.
Each fuel system supplies stored liquid hydrazine to the fuel pump, gas generator valve module, and gas generator. The fuel decomposes extremely rapidly in a catalytic action. The resulting gas is used to drive a two-stage turbine. The gas returns over the the gas chamber to cool it down and then exits through exhaust ports on the top of that aft of the orbiter.
The lube oil of each APU is circulated through a heat exchanger in a respective water spray boiler which cool the lube oil systems. The hydraulic fluid sees the same process to cool it as well.
The APU system is started 5 minutes before launch and remains online through the launch and until the first orbital maneuvering system (OMS) thrusting period where they are shut down until the orbiter is ready to make a return to Earth. During launch the hydraulic fluid powered by the APU applies pressure to actuators for thrust vectoring by gimbaling of the three main engines, supplies load relief to the elevons during the ascent phase, and retracts the fuel and oxidizer umbilicals from the external tank when it is ready to be jettisoned.
About a day before deorbit, one APU is restarted to support checkout of the flight controls which include the elevons, rudder, speed brake, and body flap. The other two APUs are restarted after the deorbit and function through entry, landing, and landing rollout for hydraulic pressure for positioning of the aerosurfaces during atmospheric flight, deployment of the landing gear, brakes, anti-skid, nose wheel steering, and positioning of the three main engines.
The fuel tanks hold about 325 pounds of hydrazine which is enough for the 90 minutes per mission the APUs would normally operate with reserve in the event of an abort once around when the APUs would be active for 120 minutes. They consume about 3 pounds of fuel per hour.
Technical data collected from: http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts-apu.html
Pictures from: http://www.columbiassacrifice.com/&0_shttlovrvw.htm
The auxiliary power unit (APU) is a hydrazine fueled, turbine driven power unit which produces mechanical shaft power to a hydraulic pump which produces pressure for the orbiter's hydraulic system. There are three APUs on the orbiter. Located in the aft compartment of the orbiter, APUs 1 and 2 are located on the left side and APU 3 is on the right. The three systems are identical but independent.
Each fuel system supplies stored liquid hydrazine to the fuel pump, gas generator valve module, and gas generator. The fuel decomposes extremely rapidly in a catalytic action. The resulting gas is used to drive a two-stage turbine. The gas returns over the the gas chamber to cool it down and then exits through exhaust ports on the top of that aft of the orbiter.
The lube oil of each APU is circulated through a heat exchanger in a respective water spray boiler which cool the lube oil systems. The hydraulic fluid sees the same process to cool it as well.
The APU system is started 5 minutes before launch and remains online through the launch and until the first orbital maneuvering system (OMS) thrusting period where they are shut down until the orbiter is ready to make a return to Earth. During launch the hydraulic fluid powered by the APU applies pressure to actuators for thrust vectoring by gimbaling of the three main engines, supplies load relief to the elevons during the ascent phase, and retracts the fuel and oxidizer umbilicals from the external tank when it is ready to be jettisoned.
About a day before deorbit, one APU is restarted to support checkout of the flight controls which include the elevons, rudder, speed brake, and body flap. The other two APUs are restarted after the deorbit and function through entry, landing, and landing rollout for hydraulic pressure for positioning of the aerosurfaces during atmospheric flight, deployment of the landing gear, brakes, anti-skid, nose wheel steering, and positioning of the three main engines.
The fuel tanks hold about 325 pounds of hydrazine which is enough for the 90 minutes per mission the APUs would normally operate with reserve in the event of an abort once around when the APUs would be active for 120 minutes. They consume about 3 pounds of fuel per hour.
Technical data collected from: http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts-apu.html
Pictures from: http://www.columbiassacrifice.com/&0_shttlovrvw.htm
Saturday, October 13, 2007
The Confidence Run
On Wednesday with did OV103's (Discovery) confidence run. This is where we actually turn on and run the APU to make sure there won't be any issues for the launch. I went in to do the walk down in the morning to make sure that the exhaust plugs on Discovery were taken out. The job is run and monitored from the firing room and it is all a matter of pushing a few buttons. Each APU was run for about 5 minutes at regular speed and then for about 15 seconds on high speed. The exhaust from the APU is mostly ammonia. You can kind of see the vapors being ejected when the APU first starts but after a few bursts, you do not see it after about half a minute. So to monitor it there is also a thermal camera pointed at the Orbiter. And since the exhaust is about 900 degrees, you can see it pretty well on the thermal camera.
After the walk down was complete the Rotating Service Structure had to be rolled open to so that the exhaust did no pollute the platforms where the ports were. The RSS moves pretty slow so it does not damage any flight hardware but when its fully open, it is a beautiful sight.
Very rarely is the RSS open. Really the only time it is open for any extended period is a day or two before launch. So this was an occasion I wanted to be around for. I got a couple pictures in the morning before my battery died and then used my lunch break to take my good camera up and get some more, better shots.
After the walk down was complete the Rotating Service Structure had to be rolled open to so that the exhaust did no pollute the platforms where the ports were. The RSS moves pretty slow so it does not damage any flight hardware but when its fully open, it is a beautiful sight.
Very rarely is the RSS open. Really the only time it is open for any extended period is a day or two before launch. So this was an occasion I wanted to be around for. I got a couple pictures in the morning before my battery died and then used my lunch break to take my good camera up and get some more, better shots.
Tuesday, October 9, 2007
Problem Reports and Closures
Going back to another post with saying that EVERYTHING gets documented, today I did my first closures on some Problem Reports. A Problem Report documents a discrepancy on a piece of equipment and steps to fix it. The closure is basically just a summary of the report and a conclusion. It states the problem, what was done to fix it, and the end result. The ones I wrote were for failed GN2 samples and a leaky valve. Simple stuff that was fixed by re-sampling the GN2 and tightening the valve. Pretty basic stuff, but you have to start somewhere.
Today was the first time I got to up my unescorted access to use. I only ran some papers to the firing room for signatures and then delivering them to the Pad. Yet another surreal moment as I sat in my car...alone...and stared at the shuttle sitting pretty on the launch pad. I love my job.
Tomorrow is a dress rehearsal for the launch. I am working on being able to sit in on the job, but I'm not sure what it entails for our group. There is going to be the confidence run on Thursday, which is what I'm really looking forward too because it will be the first time I get to see the APUs fired up. For the confidence run, the RSS has to be rolled back. Hopefully I can get some time to go out and get some good shots of the shuttle.
Today was the first time I got to up my unescorted access to use. I only ran some papers to the firing room for signatures and then delivering them to the Pad. Yet another surreal moment as I sat in my car...alone...and stared at the shuttle sitting pretty on the launch pad. I love my job.
Tomorrow is a dress rehearsal for the launch. I am working on being able to sit in on the job, but I'm not sure what it entails for our group. There is going to be the confidence run on Thursday, which is what I'm really looking forward too because it will be the first time I get to see the APUs fired up. For the confidence run, the RSS has to be rolled back. Hopefully I can get some time to go out and get some good shots of the shuttle.
Monday, October 8, 2007
Hey! Two For One! Over the weekend...
This passed weekend was fuel loading for the APU and HPU. The HPU (Solid Rocket Boosters) was done on Saturday and is, from what I understand, a pretty quick job. I wouldn't know because I was not there. I only got approved for extra time for Sunday which was the APU (Orbiter) loading. Which is fine and dandy with me because on Sundays, I make double...but this job is soooo not about the money. It is a plus though. The APUs take a bit longer. It is said that it can take 12+ hours for the loading. On Sunday it took about 11 if you include the time we had to wait before we actually began flowing fuel. I only stayed for 10.
The process is fairly simple. It just takes a long time. First we have to get whatever fuel is left in the tank from the last flight out. The APUs use Hydrazine. In another post, I'll explain how it works. When all of the fuel is out we fill it back up. It is the easiest way to keep track of how much is loaded. In this case, we had to load 356 lbs. Typically is lower but in this case we had to load 26 lbs more to do a confidence run (a test run where on the ground where the APUs are fired up and operate for a given time to make sure they will be a-ok for flight). Next we pressurize the GN2 (gaseous nitrogen) bladder which applies pressure on the hydrazine to force it out since gravity is of little use in space. Once those parts are complete you have to do leave checks to make sure you won't lose anything. Then there is some clean up and then disconnection of the QDs (quick disconnects (fuel lines)).
The GN2 is fed from the facility. Another project of mine for the semester is to process a new piece of equipment which would allow us to pressurize GN2 on the go. At the moment the GN2 is still connected because we will have to re-pressurize after the confidence run. It is connected to the RSS (rotating service structure) which pivots around on the pad to allow access to the Orbiter and installation of the payload into the payload bay.
All around a good day. It started off where we might have had to put off the operation because of inclimate weather but 5 minutes before the drop dead time of 12pm it cleared up and we were good to go. There was some radio problems later on but that was the extent of the bad juju.
The process is fairly simple. It just takes a long time. First we have to get whatever fuel is left in the tank from the last flight out. The APUs use Hydrazine. In another post, I'll explain how it works. When all of the fuel is out we fill it back up. It is the easiest way to keep track of how much is loaded. In this case, we had to load 356 lbs. Typically is lower but in this case we had to load 26 lbs more to do a confidence run (a test run where on the ground where the APUs are fired up and operate for a given time to make sure they will be a-ok for flight). Next we pressurize the GN2 (gaseous nitrogen) bladder which applies pressure on the hydrazine to force it out since gravity is of little use in space. Once those parts are complete you have to do leave checks to make sure you won't lose anything. Then there is some clean up and then disconnection of the QDs (quick disconnects (fuel lines)).
The GN2 is fed from the facility. Another project of mine for the semester is to process a new piece of equipment which would allow us to pressurize GN2 on the go. At the moment the GN2 is still connected because we will have to re-pressurize after the confidence run. It is connected to the RSS (rotating service structure) which pivots around on the pad to allow access to the Orbiter and installation of the payload into the payload bay.
All around a good day. It started off where we might have had to put off the operation because of inclimate weather but 5 minutes before the drop dead time of 12pm it cleared up and we were good to go. There was some radio problems later on but that was the extent of the bad juju.
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