+--------------+-------------------------------------------------------+
| ![           | **TO:** Bob Miley/OZ2 (281) 244-8261                  |
| ](media/imag |                                                       |
| e1.wmf){widt | **NASA Contact:** Larry Walter/ER3 (281) 483-5591     |
| h="1.4277777 |                                                       |
| 777777778in" | **Analyst:** Dax Slaughter/MAGIK Team (281) 244-8524  |
| height       |                                                       |
| ="1.33194444 | **DATE:** February 17, 2000 **Action Item #:** 1146   |
| 44444444in"} |                                                       |
|              | **RE:** Impacts of Alpha Magnetic Spectrometer        |
|              | Orientation Changes                                   |
|              |                                                       |
|              | **CC:** Phillip Callen/ER3, Skip Hatfield/OM7, RS     |
|              | Library                                               |
|              |                                                       |
|              | **PAGES:** 12                                         |
+--------------+-------------------------------------------------------+

The MAGIK Team has analyzed both the assembly operations and the
maintenance operations related to the Alpha Magnetic Spectrometer (AMS)
using a model of the AMS provided by the designers. This model was
modified according to drawings given to us by Bob Miley. The
modifications include moving the keel pin and rolling the AMS 10 degrees
with respect the ISS X-axis. Finally, the analysis reanalyzes Action
Item \# 1110 using a corrected Express Pallet location.

In performing our assembly analysis we assumed the AMS is manifested
such that the keel pin is forward in the payload bay. The grapple
fixture locations have not changed and, therefore, the results of the
grapple fixture analysis can be referenced in Action Item #1110. Further
we assumed that only the International Space Station (ISS) zenith,
inboard S3 attach site is useful for this payload.

## Assumptions:

-   Assembly operations completed at UF4 timeframe

-   OTCM GF on Express Pallet (EXP) payload ORU is rotated 20 degrees
    from vertical

-   Keel location moved 11.97 inches towards the AMS centerline

-   AMS rotation point is about the model origin

-   When AMS is rotated, the AMS position in ISS Y-axis is 9.84 inches
    inboard of the inner edge of the S3 outboard, upper Payload Attach
    Site (PAS) operational envelope (as defined in SSP 57003 Figure
    3.1.3.1.1.1-1)

-   AMS manifest keel location is 1175.20 inches

![](media/image2.png){width="6.604166666666667in" height="4.9375in"}

Figure 1: Clearance Between AMS and ATA on SLP is 16 inches

The AMS unberth and installation operations can occur as they are
documented in the MAGIK Robotic Assembly Analysis for DAC 8 -- JSC
39458. The SRMS removes the AMS from the payload bay and hands it to the
SSRMS, which is based on the Mobile Base System (MBS) Power Data Grapple
Fixture (PDGF) #1. The Mobile Transporter is located at the S1-B6
worksite during the hand-off and can remain there during AMS
installation. The SSRMS has sufficient reach to place the AMS on the S3
zenith inboard payload attach site (PAS) without relocating the MT. It
was determined that the S1 outer, upper camera cannot be present during
the AMS installation operations due to interference with the SSRMS wrist
cluster. Whether the AMS is installed prior to the Express Pallet (EXP)
or after the EXP, the clearance between the AMS (on the ISS zenith
inboard attach site) and an EXP (on the ISS zenith outboard attach site)
is approximately 9 inches. See Figure 2.

![](media/image3.png){width="6.604166666666667in" height="4.9375in"}

Figure 2: Clearance Between the AMS and the EXP is approximately 9
Inches

![](media/image4.png){width="6.604166666666667in" height="4.9375in"}

Figure 3: Clearance Between the AMS and the S1 outboard upper camera is
approximately 12 inches

![](media/image5.png){width="6.604166666666667in" height="4.9375in"}

Figure 4: Clearance Between the AMS Keel Structure and the S3 Truss is
12 inches

This analysis also looked at the removal/replacement of a payload ORU on
the EXP, specifically, the inboard, center ORU (closest to the AMS),
which is the most difficult to remove of the six EXP payload ORU
locations. See Figure 5 for an overall view of the AMS, EXP, SSRMS and
SPDM configuration from an ISS front view. The stabilization point used
by the SPDM is not visible in this view as it is located on the ISS back
face of the EXP structure. This view shows the left SPDM arm at an
approach point 17 inches from payload ORU grapple fixture. Figure 6
shows the left SPDM arm at grapple and Figure 7 shows the payload ORU
being removed. The only violation shown is a clearance violation between
the SPDM LEE and one of the EXP payload ORUs. This violation is shown in
Figures 6 and 7 and is due to a combination of the relative placement of
the stabilization point to grasp fixture and the limited reach of the
SPDM arms. This violation is somewhat a generic issue with the Express
Pallet and not necessarily a direct result of the AMS design. The
Express Pallet designers are investigating options for decreasing the
relative distance between these fixtures which would alleviate this
violation.

![](media/image6.png){width="6.604166666666667in" height="4.9375in"}

Figure 5: ISS Front View of the AMS, the EXP and the SPDM with the Left
Arm at Approach

![](media/image7.png){width="6.604166666666667in" height="4.9375in"}

Figure 6: ISS Front View of the AMS, the EXP and the SPDM with the Left
Arm at Grapple

![](media/image8.png){width="6.604166666666667in" height="4.9375in"}

Figure 7: ISS Front View of the AMS, the EXP and the SPDM with the Left
Arm at ORU Unberth

Reanalyzing Action Item \# 1110 with an updated EXP location is shown in
the following Figures. This analysis investigated the AMS on both the
inboard and outboard PAS with the EXP located on the opposite upper PAS.
It is found that the clearances between the AMS and the EXP are less
than when the AMS is in a rolled orientation. Figure 8 shows the AMS
inboard and the EXP outboard with a clearance of 6 inches. The assembly
for this case can be completed as documented in the DAC 8 Assembly.
Figure 9 shows the AMS outboard and the EXP inboard with a clearance of
21 inches. The assembly for this case would require that the EXP not be
present during the AMS installation operations. Either the AMS would
need to be installed first or the EXP would need to be moved to a
temporary location during the AMS installation. If this option is
considered, it could be beneficial if the install grapple is moved so
that it would lie on the ISS forward debris shielding. This would allow
the installation operations to be completed with or without the EXP
present.

![](media/image9.png){width="6.708333333333333in"
height="5.114583333333333in"}

Figure 8: AMS Inboard, EXP Outboard with 6" of Clearance

![](media/image10.png){width="6.708333333333333in"
height="5.114583333333333in"}

Figure 9: AMS Outboard, EXP Inboard with 21" of Clearance

The maintenance operations obviously show, see Figures 10 and 11, that
these cases are not desirable due to SPDM to AMS interference when the
SPDM arm tries to reach the inboard, center payload ORU. Both cases show
a hard interference when the SPDM is grappled or at the approach to
grapple position for this ORU grapple fixture.

![](media/image11.png){width="6.708333333333333in"
height="5.114583333333333in"}

Figure 10: AMS Inboard, EXP Outboard - Showing SPDM Interference

![](media/image12.png){width="6.708333333333333in"
height="5.114583333333333in"}

Figure 11: AMS Outboard, EXP Inboard -- Showing SPDM Clearance