Bringing "Balance" to the ISS

The Z1 truss was the first latticework structure added to the ISS.  This component provides a number of station functions, including attitude control via a redundant set of control moment gyroscopes (CMGs), two plasma contactors to neutralize static electric buildup on the station's surfaces,  a Ku-Band space-to-ground antenna (SGANT), an S-Band antenna support assembly (SASA), a Manual Berthing Mechanism (MBM) ring used to temporarily "park" PMAs during the station assembly sequence, and various electrical and cooling system assemblies to support  integration of solar power and ammonia-based heat dissipation systems added by future ISS assembly missions. The truss also provided a temporary mount for the P6 truss , delivered during STS-97, which provided early solar power capability to the station.

The Z1 truss and a third pressurized mating adapter (PMA-3)  were launched aboard STS-92 on October 11, 2000.  The components arrived at the station aboard Space Shuttle Discovery on October 13 and were added to the station configuration during a series of four EVAs that occurred between October 15 and 18.

The parts for this step in the build consists of three parts pages and a 14 page instruction manual.  Two of the parts pages are part of the for-purchase AXM combo kit #1 (Z1 truss, PMA-3). The third parts page (S-Band antenna with cover) is part of the STS-92 shuttle kit graciously provided by AXM upon my request.

I started the build by cutting out the main Z1 assembly box and removing the MBM ring and CMG interior areas.

Next, I cut off all joiner tabs and lapped them to achieve a flush fit on all seams.

I then cut out and layered the inner section of the MBM ring to achieve depth and assembled the Z1 main body "cube".

I then moved to the top area of the truss, again applying layering to achieve depth and inserting magnets at the four Rocketdyne Truss Attachment System (RTAS) attachment points to accomodate future magnetic attachment of the P6 truss.  I added a fifth magnet at the center forward point on the top to provide a display hang point for the mated Z1 and Unity components.

Next, I assembled the plasma contactors and DC-to-DC Converter Unit-Heat Pipes (DDCU-HP).

I then affixed the top and bottom sections to the Z1 "cube" and then placed the plasma contactors and DDCU-HPs at prescibed points.

I then built the lower section of the P6 truss, building out the feet with magnets to ensure proper alignment of the P6 base to the Z1 RTAS locations.

 

Next, I turned my attention to building the 4 CMGs and thermal blanket.  Cutting these parts out was a bit tedious due to the numerous curves.

 I then cut out and affixed the trunnion pins and scuff plates.  I used sections of a paper clip for the actual pins.

I then assembled the CMGs, adding a nub to the top of each (using a small section of bamboo skewer) to add realism.  The assembled CMGs were then glued into the proper locations on the aft side of the Z1 "cube".  I consulted various photos of the truss to ensure that the CMGs were inserted at the proper orientation into the cutout areas.

Next, I asssembled the Ku-Band SGANT dish and boom.  I fabricated a nub at the prescribed mount point on the zenith plane to accomodate simple attachment of the antenna boom.

Next, I turned my attention to the fluid line cable tray.  I glued together the front and back sections and then layered key sections cutout from another printout of the parts to obtain depth.  I applied 28-gauge coated wire to add realism.

I assembled covered and uncovered versions of the S-Band Antenna Support Assembly (SASA).  The covered assembly is used initially, replaced by the uncovered version that was placed at the top of the P6 truss during STS-97.

During my studies of various Z1 photos, I learned that a second Ku-Band antenna was added to the Z1 truss during STS-132.  I decided to add a magnet at the prescribed point, which required me to remove the upper right CMG so that the magnet could be glued at the inside zenith area.  I affixed the magnet and re-glued the CMG.

I then assembled PMA-3, following the same process that was used during my prior builds of PMA-1 and PMA-2.

My test fit of the magnetic attachment of the Z1 truss to Unity's zenith docking port identified a need for additional connection force.  I decided to add a magnet at the center of each docking port.  I cut out the porthole cover or each port, inserted a magnet the the center of each cutout, and affixed a cutout of each porthole cover over each magnet to hide it.  I also added a circular cover to the bottom of the Z1 truss with a magnet glued to the backside.  

The additional magnet pair provided the necessary additional force to ensure a snug bond between the Z1 and Unity components.

I then transported the component to my office, where I mated the Z1 and Unity to the other station components.

Now, onto the next component, Soyuz TM-31, which brought the first IIS expedition crew to the station in early November, 2000.  Stay tuned!

A Compass for Zvezda

Shuttle flight STS-106 was launched from pad LC-39B at the Kennedy Space Center on September 8, 2000.  The purpose of this mission was to prepare the station for the arrival of Expedition 1 crew members later that year.

STS-106 delivered over 6,000 pounds of cargo and supplies to the ISS including components for the Elektron oxygen generation system and three batteries to complete the configuration of Zvezda's solar panel-based power system.

STS-106 crewmembers also performed an EVA during the mission to connect power and data cables between Zarya and Zevzda and install a magnetometer on the nadir plane of Zvezda's main section. The magnetometer provides accurate 3-D position data to Zvezda's guidance computers. The precise location data helps to minimize fuel used by Zvezda's station-keeping thrusters.

I fabricated the magnetometer mast using white-coated 28-gauge wire.  The component on the end of the mast is a small section of insulation from 30-gauge wire, pierced with a needle on one side to affix it to the mast.

I chose not to add cabling between Zarya and Zvezda at this time. I expect that I will need to remove Zvezda from it's ceiling mount in order to affix the SMDP panels to Zvezda's conical section later in the build timeline.  The panels were installed during Expedition 5 EVA 1 which occurred on August 6, 2002, and  Expedition 15 EVA 1 and EVA 2 which occurred on May 30, 2007 and June 6, 2007.

Progress M1-3 Arrival

Progress (Прогресс) M1-3 was the first cargo transport spacecraft to visit the ISS.  Also known as Progress 1P, the spacecraft is a variant of the Progress-M, designed to carry cargo, along with propellant used by the Zarya and Zvezda modules' station-keeping engines.

Progress M1-3 was launched atop a Soyuz-U rocket at Site 1/5 of the Baikonur Cosmodrome on August 6, 2000.  The spacecraft autonomously docked with the aft port of Zvezda on August 8. Cargo was unloaded from the spacecraft by and STS-106 and STS-92 shuttle crews visiting the station in late September and October.  The spacecraft was undocked, de-orbited and subsequently burned up in the atmosphere over the Pacific Ocean on November 1, 2000.  The first ISS crew, Expedition 1, arrived at the station the next day aboard  the first Soyuz spacecraft to visit the station, Soyuz TM-31, docking at the recently-vacated Zvezda aft port.

The Progress M kit consists of two pages and is free for download from AXM.  The accompanying instruction manual is 19 pages and contains instructions for assembling both the Progress and Soyuz spacecraft.  The Progress M kit includes insignia used by all Progress M flights to the ISS.

I started the build by cutting and assembling the spherical cargo module.  There are 4 rings that make up this section.  AXM indicates that time should be taken to glue each section and allow it to thoroughly dry before moving to the next ring in order to achieve the best shape.  I followed AXM's prescribed advice and was very pleased with the outcome!

Next, I cut out, curved, and joined the storage tank and propulsion module sections of the spacecraft.  I detached and overlapped the glue tab for each in order to achieve a flush seam. I also used a black color pencil on all join edges to reduce appearance of the seams. I then glued and attached all three parts together.

I then proceeded to cut out the booster attachment structure and scored the backside of each connector tooth in order to obtain a smooth bend along the top edge and bottom flange of the booster attachment.

           

I then cut vertical slits at prescribed locations on the propulsion module section to accommodate insertion of the solar panels.  I cut out the solar panels and glued them together making sure to precisely align the edges of each half.  I allowed enough time for the glue to dry and then used an orange color pencil on all edges of the assembled solar panel.  Next, I inserted the solar panel though the vertical slits and then glued the bottom attitude control engine plate to the bent teeth.

Building upon my success with adding realism to Zvezda build using layering, I layered certain parts onto the attitude control engine plate in order to achieve some depth. Raising the height of key elements on this section certainly added to the realism!

Next, I attached the docking port ring, service port hatches, horizon sensors, docking camera, and large Kurs antenna shields.  I embellished the printed forward, side, and aft Kurs antennas using tips of a bamboo skewer painted white to introduce more depth and realism.

I then assembled the forward-facing Kurs-1 and Kurs-2 antennas and attached them underneath the large Kurs shields.

I concluded the build by assembling the docking mechanism and inserting it into the top of the spacecraft.  I placed a magnet under the docking probe tip in order to facilitate future docking of the spacecraft (re-branded to coincide with follow-on missions) to the nadir and zenith docking ports on Zvezda and Zarya. 

 Progress M1-3 has since been docked to Zvezda's aft port.

The next component in the assembly sequence is the Z1 Truss.  Stay tuned!