Here is my seventh build; the Global Positioning Satellite GPS IIR from Baseband Technologies found on their website Baseband Technologies Inc. | Ultra Low Power GPS Receiver Technologies | Instant position for anything that moves.
Overall this model isn’t a difficult build – off the page. But as I started researching and attempting to modify and correct certain details I found myself more and more on a steep scratch-building and learning curve.
I mixed materials using gloss, card stock, 20lb as recommended for some parts, dowel for the solar panel support, picks for the RCS nozzles and “now for something completely different” galvanized wire. The instructions provided a basic representation of this satellite. But after a brief review of some nice photos from Lockheed and a really good publication called “GPS Block IIR and IIR-M Antenna Panel Pattern, Marquis, Feb2014 - publically releasable data” I suspected that I could modify the pattern to bring more detail into the model.
Scratch built details are the: Earth Sensor, BDS, BDX, Fine Sun Sensor, L Band and UHF antenna baffles, Apogee motor (STAR 37XFP) and the RCS nozzles. I should have done a better job on the baffles. At the time, I rushed my understanding of flattened truncated conics and … frankly they aren’t great. The apogee motor also, is - I suspect – not true to scale, but my scaled measurements frankly looked WAY too big. So I selected a smaller part from a 48th scale build and hoped no one but me would notice. Last but not least are those tree shaped antennas along the x axis. The instructions would have you stack cross pieces of paper with 1-2mm tubes separating and frankly it isn’t to scale and appeared too flimsy. So I opted for galvanized wire. I got some help with how best to build the structure here in the forums. I was surprised with the weight once installed and had to become pretty creative in securing those structures. Ultimately, I passed the wires through two parts of the bus and then looped it back to keep it relatively in the right place. I did have to add some extra external support to the holes as my trial and error assemblies weakened the paper considerably.
This build is on my wish list of models to provide a revised document to supplement the basic parts and instructions. It’s a great addition to my growing fleet with its bristling appearance.
It’s worth noting that this is the legacy version of the GPS satellites launched from 2000 to 2009. Only the first 12 of 20 satellites in this series look exactly like this. The latter 8 have an improved antenna panel and solar arrays. Then following this series are the GPS IIF and the GPS III satellites.
I hope you enjoy the pics. I have included some additional pics from my source material here in my Imgur gallery.
Overall this model isn’t a difficult build – off the page. But as I started researching and attempting to modify and correct certain details I found myself more and more on a steep scratch-building and learning curve.
I mixed materials using gloss, card stock, 20lb as recommended for some parts, dowel for the solar panel support, picks for the RCS nozzles and “now for something completely different” galvanized wire. The instructions provided a basic representation of this satellite. But after a brief review of some nice photos from Lockheed and a really good publication called “GPS Block IIR and IIR-M Antenna Panel Pattern, Marquis, Feb2014 - publically releasable data” I suspected that I could modify the pattern to bring more detail into the model.
Scratch built details are the: Earth Sensor, BDS, BDX, Fine Sun Sensor, L Band and UHF antenna baffles, Apogee motor (STAR 37XFP) and the RCS nozzles. I should have done a better job on the baffles. At the time, I rushed my understanding of flattened truncated conics and … frankly they aren’t great. The apogee motor also, is - I suspect – not true to scale, but my scaled measurements frankly looked WAY too big. So I selected a smaller part from a 48th scale build and hoped no one but me would notice. Last but not least are those tree shaped antennas along the x axis. The instructions would have you stack cross pieces of paper with 1-2mm tubes separating and frankly it isn’t to scale and appeared too flimsy. So I opted for galvanized wire. I got some help with how best to build the structure here in the forums. I was surprised with the weight once installed and had to become pretty creative in securing those structures. Ultimately, I passed the wires through two parts of the bus and then looped it back to keep it relatively in the right place. I did have to add some extra external support to the holes as my trial and error assemblies weakened the paper considerably.
This build is on my wish list of models to provide a revised document to supplement the basic parts and instructions. It’s a great addition to my growing fleet with its bristling appearance.
It’s worth noting that this is the legacy version of the GPS satellites launched from 2000 to 2009. Only the first 12 of 20 satellites in this series look exactly like this. The latter 8 have an improved antenna panel and solar arrays. Then following this series are the GPS IIF and the GPS III satellites.
I hope you enjoy the pics. I have included some additional pics from my source material here in my Imgur gallery.
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