Unity

Unity (a.k.a, Node 1) was launched into orbit on December 4, 1998 aboard space shuttle Endeavour on the first shuttle mission to the ISS, STS-88. Unity was the first U.S.-built module to be launched, built by Boeing at the Marshall Space Flight Center.

Unity is made of aluminum and weighed almost 26,000 pounds at launch, inclusive of two Pressurized Mating Adapters (PMAs)  that were initially attached at the forward and aft berthing mechanisms.

Unity has a total of six Common Berthing Mechanisms.  These mechanisms allowed the station to expand in future missions to connect additional modules needed to provide living, experimental, storage, and various logistic functions.

Unity is part of ISS combo kit #1 from AXM.  This particular kit must be purchased.  The fee for this kit is well worth the price. In my opinion, it's a very small price to pay for the high quality and craftsmanship exhibited by all of AXM's kit designs on his site.

This particular kit is comprised of 5 pages: 1 page of parts containing the main Unity module, another page containing parts for PMA-1 and PMA-2, a page containing the parts for the Russian-built Strela crane, a page providing parts for the US-built Orbital Replacement Unit Transfer Device (OTD), and a page containing the Early Communication Antennas (ECOMM) graciously provided by AXM upon my request. The assembly manual for the main module and PMAs is 9 pages, with instructions for the Strela (4 pages) and OTD (3 pages) located in separate documents.

I started the build by cutting out the circular areas of the radial berthing mechanisms of the main body.

Following my established method for obtaining a flush fit at the seam, I cut off the glue tab for the main body part and then re-glued it to the back inside edge with a slight overlap.

I allowed the glued tab to dry and then rolled the main body part using a colored pencil to gently curve the paper and glued the section together at the tab.  I then undertook the tedious task of cutting out the 4 berthing mechanisms (many angle and curve cuts here).  AXM did a great job in designing these parts, providing a concave recessed look!

Anticipating future module connections to Unity, I decided to employ neodymium magnets for connection of modules to the radial and forward berthing ports (the aft port is permanently connected to Zarya via PMA-1). I glued two magnets to the inside forward and aft location of each radial berthing port.  

I cut out the forward and aft berthing mechanism caps and glued them to the main module.  I set a glue bottle on top of the assembly to obtain a flush join.

Next, I cut out the forward and aft end cap rings and flanges, assembled them (using the tab overlap technique for a flush seam), and affixed them over the berthing mechanism caps.

I then turned my attention to the berthing mechanism petals.  There are four petals located on each port. Having studied various photographs of the petal position when a module is berthed to a given port, I decided to color in the backside of each petal using the same color (beige) that is used on the front of each petal.

I scored the back of each petal at the bend point to ensure the proper lay of each petal in the un-berthed position.

I then affixed the petals to each berthing mechanism location and added the tool bag at the prescribed location on the starboard aft side of the module. 

I then turned my attention to the module's four trunnion pins.  These pins secured the module within the shuttle bay during its trip into orbit.  The pins actually protrude from the module surface, however the design depict them as two dimensional. I decided to embellish the model and add the pins (using 18 gauge insulated wire pieces), affixed on top of the thermal covers provided in the model kit.  I used additional insulated wire pieces to affix the early communication antennas to the port and starboard berthing ports.

Next, I commenced working on assembling the PMAs.  I first built the zenith and nadir multiplexer/de-multiplexer (MDM) units for PMA-1, along with the zenith MDM sunshade.  

I cut out the main PMA-1 body (many angled cuts to this piece) and scored the back side along prescribed fold lines.

I then cut out the PMA-1 base and docking ring.  I folded and joined the PMA-1 body, affixed it to the base, assembled the docking ring, and joined the ring to the PMA body. I then added the MDMs and the zenith MDM sunshade to prescribed points.

Moving onto PMA-2, I followed a similar assembly sequence as with PMA-1. I cut out the main PMA body, scored the backside, assembled the PMA body, affixed the body to the base, assembled the docking ring, and joined the docking ring to the PMA body. PMA-2 has two Grapple Fixtures located at the zenith on port and starboard sides of the unit.  I built both components and affixed them to the prescribed locations, adding a black wire piece to the center of each grapple fixture base in order to to add some 3-dimensional realism.

  

PMA-2 was moved to different locations a few times during the ISS assembly sequence. Anticipating the need to re-position this PMA in future assembly updates, I decided to affix the PMA using magnets. I glued two magnets to the inside lip of the flange on the zenith and nadir locations of the forward berthing port and another two magnets to the inside lip of PMA-2 at the same locations.

I then glued PMA-1 to the aft section of Unity, resulting in the following outcome.

After studying numerous photos of Unity taken during STS-88, STS-96, and STS-101, I decided to add additional detail to the module by adding the various power and communication cables and umbilical connections. First, I needed to come up with something to serve as the umbilical connections located on the PMAs and forward and aft edges of the module.  I decided to use the plastic insulation on some 24 gauge wire.  I painted a section of the wire using a white enamel sharpie.  Next, I scored individual sections of insulation at the prescribed length (based on the pattern printed on the PMAs) and pulled them from the metal wire.  I lost count after cutting 100 pieces!

I then affixed the tubular pieces over their printed counterparts on the PMAs.  I initially tried to glue the tubes atop each printed connection point for the connections located on the forward and aft edges of the module.  However, subsequent cable connections from the module edge to the PMA points resulted in repeated separation from the glue point.  I decided to push a small hole through the module at each connection point and countersink the tube into the hole with a dab of glue.  This approach worked perfectly!

I then proceeded to determine the exact cabling configuration by reviewing numerous photos.  I ended up producing a drawing of the cable configuration to assist with the implementation.

I used 28 gauge craft wire for the cabling.  I was unable to find wire in this gauge that was already coated white, so I ended up painting lengths of the bare aluminum wire using a white enamel sharpie. I was very impressed with the result of my research and labor to add this detail!

 

In addition to the trunnion pins Unity also has a keel pin which helped to hold the module steady in the shuttle bay during launch.  This pin was printed on the main cylinder and I wanted it to be 3-dimensional also. I fabricated the pin using 18 gauge wire and fabricated a mount for the pin using a scratch-built mount.

At this point the module is configured as it was during STS-88.  I fabricated a mono filament hanger with magnets for module display.

I then proceeded to build the ORD and Strela crane components which were added to the module during STS-96, and STS-101. 

I started with the ORD, building the component from the kit, initially adding a handle and paddle extension for realism, and later adding another handle and hand cranks.

The directions called for gluing the ORD directly to the PMA along the port side in horizontal alignment with the associated trunnion pin placement on the module.  I decided to fabricate a mounting nub and secure the crane on the nub to allow for movement of the ORD to various orientations.  I used a 1/16 inch piece of a cocktail toothpick for the nub and affixed the nub to the PMA using a small piece of wire inserted into the end of the nub and pushed into the PMA to better secure it. The nub was painted silver using a sharpie.

Next, I fabricated  the base of the Strela crane.  The ORD was then affixed to PMA-1 and the Strela crane base was placed onto the port-side grapple fixture on PMA-2, completing the configuration of Unity at the conclusion of STS-96.

I then worked on completion of the Strela crane.

During STS-101 the Strela crane base was moved from the PMA-2 grapple fixture to a new mount located on the zenith of PMA-1 and the crane boom was added. I added another nub for the PMA-1 crane location, embellished the crane by adding yaw, pitch, and extend/retract boom hand cranks, fabricated a grapple fixture for the crane mount point, and moved the assembled crane to the PMA-1 location, which resulted in the module configuration at the completion of STS-101.

I then transported Unity to my office and mated it to Zarya, where I added the last detail: a communication cable extending from Zarya to the starboard side early communication antenna.

Both modules are currently on display on one of my desks.  However, I soon plan to re-position them to the ceiling of my office.

Next up - Zvezda. Stay tuned!

ISS "Sunrise"

My 1/100 ISS build has officially started!

The first module, Zarya (Заря́), which means "sunrise" in Russian, has great significance as ushering in the dawn of a new era of international cooperation in space exploration.

Zarya, also known as the Functional Cargo Block (FGB), was launched on November 20, 1998 aboard a Russian Proton rocket from the Baikonur Cosmodrome Site 81 in Kazakhstan to a 400 km (250 mi) high orbit. The module was designed for a lifetime of at least 15 years. The module provided initial power and propulsion functions for the station.  Zarya's construction was funded by the United States.  The module was built at the Khrunichev State Research and Production Space Center (KhSC) in Moscow. Zarya's control system was developed by the Khartron Corp. 

Zarya is part of the free ISS Russian segment kit offered by AXM. The build consists of 5 pages of parts. The accompanying instruction manual provides fairly good assembly directions with many reference photos. An addendum to the instructions includes directions for placement of the Kurs docking navigation antennas and panels on the aft section of the module.

I started by build by first assembling the module's main body cylinder and end caps. 

Here's few important tips to point out at this stage of the build that I would like to pass along for future reference:

1. Use a pen or pencil to help you slowly curve your part into a cylinder.  Be patient and take your time. Don't force the curving process or you will most likely end up with longitudinal creases in the surface. 
2. This particular assembly uses a connector tab that is glued to the backside of each edge so that the edges are flush with one another when joined, avoiding a noticeable overlap on the resulting seam. Not all part joins take this approach.  However, I have found that you can cut the connector tab off and glue it to the backside in most all cases in order to always achieve a flush join, helping to minimize visible seams and improve on realism.
3. Many curved parts have connector tab "teeth".  One important paper modeling word of advice to pass along here - "scoring". Scoring involves making an indentation on the back side of a paper bend in order to achieve a clean crease in your paper that follows the intended crease line.  Use an awl, dull needle, or backside of an exact-o knife to score the paper, making sure not to cut into the material, but rather depress/indent it. Again, take your time and use a straight edge to ensure a true score line that follows the intended tack.

I then proceeded to cut and assemble the module's fuel and oxidizer tanks.

As I mentioned earlier, Zarya was responsible during early phases of the ISS construction for propulsion functions.  Propulsion is necessary for any vehicle orbiting the Earth.  Orbits are not perfect and eventually decay due to ever-changing solar activity that affects density and fluctuations in the Earth's thermosphere, causing drag. Periodic re-boosts must occur in order to avoid orbit decay and maintain proper inclination for constant station communications and future mission optimal orbital rendezvous.  Re-boosts require fuel. Zarya has 24 large steering jets, 12 small steering jets, and two large engines that were used for re-boost and major orbital changes before the arrival of the addition of the Zvezda module.  Zarya's sixteen fuel tanks have a capacity of 5.4 metric tons of propellant. The Zarya engines are no longer used for station-keeping, however the module's fuel tanks are used to supply fuel for the Zvezda engines.

Once I decided to build the ISS, I immediately decided that I would display it by hanging it from my office ceiling.  I pondered for quite a while about how best to hang the model, knowing that the build would take a long time and would require modules to be frequently taken down to attach new modules and components.  I needed a simple mechanism that would support quick and easy detach/re-attach.  I decided to use neodymium magnets as my mounting mechanism, based on my success with using them to easily join the command and service module components in my Saturn V build.  A friend at work suggested that I peruse the offerings at K&J Magnetics.  I was quickly able to find a small ring magnet that provides a 6+ oz. pull force which would accommodate attachment to nylon filament. I'll discuss that part in more detail later in the post.

Using a liberal amount of glue, I mounted a magnet on the inside of the forward edge of the module cylinder at the module's position III (aka zenith). I then glued on the cylinder ends.  At this point I ran into my first challenge: gluing of the elongated fuel tanks to the module cylinder.  These parts have odd angles. The white glue tabs on each tank must align precisely with box outlines on the module cylinder.  The combination of odd angles on the tanks along with the curvature of the cylinder made alignment of the tabs on the box outlines a bit tricky, to say the least.     I was able to affix the tanks, but some glue was dispersed outside of the coverage areas.  Luckily, the areas were inconspicuous or covered by other parts not yet attached (pump panels).  

The aft portion of Zarya consists of two cones butted against one another.  Assembly of this section presented my second technical challenge. The cones are connected by a thin cylinder having "teeth" on both sides.  My difficulty involved precise alignment of the outer edge of each cone against the edge of the cylinder while simultaneously trying to deal with the glue applied to the teeth.  Little time was available to position the cone before the glue adherence prevented adjustment.  I was able to get the aft-side cone positioned correctly. However, I ran into problems on the fore-side cone, which resulted in a very slight crooked alignment against the cylinder edge.  I initially thought about pitching the part and starting over. However, I decided instead to produce another copy of the fore-side cone, printed on regular paper and attach it over the mis-aligned cone.  It worked and the crooked seam was covered!  I glued another magnet on the inside of the structure along the cylinder area at the zenith point and then proceeded to glue the structure to the main module cylinder.

I then affixed the aft covering.

I moved back to the module's forward section and fabricated and attached the forward steering jets propellant compressor, the conical section that connects the module main body to the forward docking unit, conical section connector panels, forward fuel tank protective shields, and protective shield targets.

I then set to work on adding the aft steering jets located on the port and starboard sides.  The build rendition of these components consists of a platform with a 2 dimensional rendition of the steering jets affixed atop to platform.

I wanted a better rendition. Drawing again from my experience with fabrication of RCS thrusters on the LEM portion of my Saturn V build, I decided to fabricate steering jets to achieve a true 3 dimensional rendition using bamboo skewers.

I moved back to the forward section of the module to fabricate the forward docking assembly.  This component consists of another cone-abutted-to-cone assembly.  The center cylinder section of this component is wider than the aft assembly, which allowed better manipulation of the cone placement and affixing process. I decided to embellish upon the printed PMA power connections, layering wire atop the printed cables to improve upon the realism effect.

I repeated the process for fabrication of the forward steering jets.  I initially made the jet nozzles a little too long and had to cut them down a bit in order to achieve the correct perspective.

Before

After (Starboard)

After (Port)

 I moved onto building of the fore and aft docking units. I started with the forward nadir passive dock, adding the ring first, then building and affixing the capture cone.  The cone is not glued, so that it can be removed in the future to allow attachment of visiting Progress and Soyuz vehicles in the interim, concluding with permanent docking of the Rassvet module.  I added another magnet at the center of this docking point to possibly use magnetic attachment of visiting vehicles.

I then built the forward Androgynous Peripheral Docking System (APDS) and aft active/hybrid docking assemblies. Both assemblies are not glued, to accommodate future connection to Pressurized Mating Adapter #1 (PMA-1) (forward), and Zvezda (aft) as these modules are added to the configuration.

I then moved back to the aft section and attached the Kurs docking navigation antennas and panels.

Moving back to the forward section, I then added the forward Kurs antenna and nadir port docking target.

The only thing left was to build the solar panels.  The kit provides two configurations; deployed and stowed. The second configuration is used later in the ISS assembly sequence.  I decided to go ahead and build both configurations.

AXM indicates printing of the solar panels on 90# card stock.  I followed the prescribed directions and attached the solar panels to the module.  However, I was disappointed in the outcome, as the panels sagged a bit at the outer ends.

I decided to construct the panels again using 110# card stock.  The result was much better, no sagging!  I proceeded to build the stowed solar panel configuration using the same card stock material.  

The build of the stowed panel assembly proved to be the most difficult part of this module's build. The scissor frame for each panel consists of four layers glued together to provide strength. Each of the frame segments required multiple cuts in order to extract the part.

Here's the result - pretty cool!

I used an orange colored pencil on the edges of the deployed and stowed solar panel in order to remove the white edge and add realism.

I was now finished with the prescribed build.  However, I wanted to add some additional touches to increase realism.  I decided to add various Kurs, Komparus, TORU, and Sirius-4 antennas to the module, based on my study of various photos and diagrams of the module. I fabricated the antennas from scratch, using 22 and 26 gauge craft wire, some tiny washers that I picked up during a recent visit to a clock and watch show with my father-in-law, and good ol' trusty bamboo skewer pieces!

All that was left was to attach magnets to nylon filament to support suspension of the module.  I first tried to glue the line directly into the hole of the ring.  The line easily pulled out.  Next, I tried to make a stopper using conical sections of bamboo.  I was unable to successfully wedge the line into the magnet hole using the bamboo. Next, I tried to fabricate a wedge using aluminium foil wrapped around a knotted end of line, dabbed with a bit of glue. The foil was pliable enough to allow formation of a wedge into the hole of the magnet...and it held and provided a flush fit.  I attached both magnets and affixed the line to the module.  Voila!

Zarya is now complete and currently on display at my office.  My wife let me borrow one of her Christmas ornament display stands so that I can display the module on my desk for co-workers to closely inspect before I re-locate it to a ceiling mount. 

I'm ready to move onto the next module, Unity!