Tuesday, May 24, 2016

A "Star" On The Horizon

Zvezda (Звезда́, meaning "star" in Russian), is the third component of the ISS. Also known as DOS-8 and Service Module (SM), the module provides the structural and functional capabilities for the Russian Orbital Segment of the station.

The module was launched atop a Proton rocket emblazoned with the Pizza Hut logo from launch pad Number 23 in Area 81 of the Baikonur Cosmodrome on July 12, 2000.  The module autonomously docked with the aft section of Zarya a few days later on July 25.  Arrival of the module introduced life support capabilities, living quarters for two crew personnel, and functional control and power systems that were crucial to support the first ISS crew who would arrive at the station later in the year.

The kit for this module is part of the free ISS Russian segment kit offered by AXM. The kit consists of 2 pages containing main module components, one page containing the solar array panels, and another page containing the Service Module Debris Panel (SMDP) bundles. The SMDP panels were delivered and installed on Zvezda in 2002 (Expedition 5, EVA 1) and 2007 (Expedition 15, EVA 1 and 2) . These panels shield vulnerable sections of Zvezda's mid-section conical area from micro meteoroid impacts. The SMDP parts will be added to the project module in the future, following the overall ISS assembly timeline.

I started the build by cutting out the parts comprising the large cylindrical section and joiner tab (detached from the section in order to perform an overlap join, as mentioned in previous build posts).

Zvezda contains a total of 14 windows. Both the large and small cylindrical sections of the module contain a majority of these windows. The large cylinder has two windows, oriented on the port and starboard sides where crew living compartments are located. The small cylinder and conical section connecting the two cylindrical sections contain a total of seven windows on the nadir plane that are used for earth observation. 

I wanted to add detail for the windows in order to to provide a more realistic look.  I decided to cut out the portholes for windows depicted in the plans that aren't covered and layer a piece of clear plastic (plastic wrap from a cigarette carton works best) under each cutout in order to introduce a window glass reflection when the light catches these areas.

I backed each cutout area with a printout of the window area  that was printed on regular paper.  I used regular paper here in order to alleviate introduction of extra stiffness when forming the cylinder curve.

I also cut out the porthole covers from another printout of the page and layered these covers over the printed covers in order to achieve a more realistic three dimensional look.  You can see one of the covers not yet affixed in the photo below just to the left of the part.

Next, I cut out the fore and aft end caps for the large diameter cylinder.  I then affixed a neodymium magnet to the inside of the cylinder for ceiling mount purposes, placing the magnet just forward of the zenith roll thruster cluster. I then affixed the cylinder end caps, built and affixed the thruster blocks to the aft endcap, inserted the aft docking tube and outer ring. 

I moved onto cutting out the part for the conical area located between the two cylindrical sections.

I then formed the conical section, affixed the inner circular stiffener cutouts, affixed the large nadir-facing window porthole cover and space target circle.  I then attached the completed cone to the forward end cap of the large cylinder.

Next, I joined end caps to the small cylinder, cut out and formed the forward conical reduction sections, affixed the forward conical sections to the forward end of the small cylinder, and then attached the small cylinder to the large cylinder via the mid-line conical connection. I layered port hole covers and other panels on the conical section to increase detail and realism. 

I then moved onto building the spherical transfer compartment.  This part is identical to the one built for the Zarya module. I first cut out the cylindrical part for this component.

Next, I cut out the zenith and nadir docking port parts, assembled them, and affixed them to the cylinder. I then affixed the port, starboard and forward cones, capped the port and starboard cones, glued neodymium magnets to the inside of the zenith and nadir docking ports to accommodate future docking of modules to these ports, and inserted the docking cylinder into the forward docking port.

I then affixed the spherical transfer compartment to the front of the module by applying a fine bead of glue along the back edge of the sphere and then applying pressure to adhere it to the forward cone by standing the module on its forward end.

Next, I built the forward docking port and inserted it into the cylinder.  Note that this part is removable to accommodate insertion of the docking tube when Zvezda is mated to the aft docking port of Zarya.

I then formed the window shades for three windows located on the nadir plane of the small cylinder and attached them. 

I then proceeded to build the OHA antenna and affix it to the aft of the module.  I also added the fixed star mappers to prescribed positions on the forward zenith plane of the small cylinder.

Next, I cut out select portions of the aft section detail patterns and layered then over the existing patterns to enhance the three dimensional perspective. I also added the regul antennas at the 2 and 8 o'clock positions.

I decided to build up the small cylinder zenith base point platform to increase detail and realism.  I achieved this by cutting out the platform pattern from another copy of the small cylinder, fabricating a box form using a copy of one of the docking ring outer covers, and then placing the platform pattern atop the box form.  I  implemented additional height of the circular and square patterns by layering the same pattern for each shape until the desired height was achieved.  I also layered the hand holds in this area to add depth.

I then worked on the solar panels, cutting out the front and back parts, gluing them together using a glue stick, and affixing the post mount points.  I trimmed the q-tip stem to the proper length and cut down the diameter on each end so that the stem would snugly fit into the post mount points.

I then fabricated Regul Omni and Kurs-P antennas using tips from bamboo skewers and small watch washers.  These antennas reside on the end of each solar panel. A short piece of 28-gauge wire was inserted into the end of each antenna to facilitate attachment of antennas to the solar panel edge.

The next step involved adding small wire segments for the six CTTV antennas on the large cylinder near the aft of the module.

I also fabricated a mast for the magnetometer using a piece of 28-gauge white coated wire with a small segment of wire insulation affixed perpendicular to the end.  The magnetometer will be added after Progress M1-3 has been docked to the aft port of Zvezda to coincide with the ISS build timeline.  

The SMDP panels are added to Zvezda much later in the build sequence.  However, I went ahead and cut out the panels, creased and bent the edge folds, and grouped the panels into four designated sets to facilitate adding them to the module at the appropriate time.

Zvezda has been relocated to my office and is currently on display affixed to a display stand on one of my desks.  I will soon relocate it to the ceiling, where it will be docked to Zarya.

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