Sunday, September 4, 2011

ILV Transfer

Well, I only had to work 9 hours today. Yesterday I was there from 8am (a late start for me!) until 9pm, so it was another long day of testing our RF links between the spacecraft customer, and the end point on the Launch Platform.
This morning they transferred the Integrated Launch Vehicle (rocket and payload) from the Assembly and Command Ship to the Launch Platform.
I did some of my 'normal' RF work with the other Engineer I work with, and he went home about noon, as we had all our tasks for the day finished. Then I went over to the LP to help the Engineer we have come down from Seattle do the RF Spectrum Survey we always do.
The Command receivers on satellites are very sensitive, so we look for all the emitters we can find. We use an Agilent spectrum analyzer with an HPIB-to-USB adapter on a laptop running the Agilent "Bench Link" software. This allows us to do a trace capture of what the analyzer displays, and save it as a "CSV" file that we can export to an Excel spreadsheet. We sweep from 200MHz to 40GHz, going in 60* steps around the compass. This gives us 360* coverage so we can "see" any emitters out there. We do this in several ranges because we use several different antennas and low-noise preamps. Each sweep at each frequency segment and compass heading takes anywhere from 5 to 45 minutes, depending on how stringent the requirements are, and that determines how we set the analyzer for things like Resolution Bandwidth and Frequency Span. It's not an unpleasant task, but time consuming, and a bit boring at times. The harbor area is really "dirty" at certain frequency ranges, and we can spot every ship and boat with an out-of-spec radar!
Tomorrow the ILV gets rolled out, stood vertical on the pad, and our testing enters the final phase. If all goes well on Monday, we should be done by 9pm, a 14-hour day. Tuesday will be an "RnR" day, and the LP departs Wednesday morning for the launch site, and we'll leave three days later on Saturday.

3 comments:

  1. I didn't realize, back in the day, that radar could be "dirty" ... but I knew what "Do not rotate or radiate while men are working aloft" meant!

    I haven't commented lately, but still read the posts; it's fascinating to see all the pre-launch work that must be done.

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  2. Heh- Out of spec is not always a 'bad' thing... sometimes it's the perfect ID for a specific unit... Just sayin...

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  3. Yep, and "Emitter Fingerprint", so to speak....

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