Chip Scale Atomic Clock Contact Info: Captain Ruiz Perez (281) John Merk (617) Paige McClung (281)

2 Overview  Payload Objectives  Payload Hardware Overview  Crew Operations Overview  Safety  Acronyms

3 Payload Objectives  Install a new Expansion Port onto the three SPHERES Satellites  Requires use of MWA CS and Soldering Iron  Soldering Iron as heat source only, no soldering required  New Expansion Port will allow for the Atomic Clock Modules to be attached to SPHERES Satellites  Operate the Atomic Clocks to characterize the microgravity performance of new small form-factor and low-power atomic clocks  Two Atomic Clocks will be synchronized with the Reference Clock (a third larger, highly accurate atomic clock).  During a SPHERES test session, the Atomic Clocks are attached to the Satellites via the new Expansion Ports.  At the end of the session, the Atomic Clocks are re-synced to the Reference Clock to determine/measure any drift.

4 Hardware Overview Expansion Port Install  Expansion Ports are an upgrade to the SPHERES Satellites  Creates a physical location for attaching external payloads  Provides Power and Data buses from satellite to attached hardware Current SPHERES Expansion Connector Upgraded SPHERES Expansion Port (Cover not shown) Assembled View All Expansion Port hardware is captive Exploded View of Expansion Port

5  Two Atomic Clock Modules (one per satellite)  One Reference ClockTwo Synchronization cables Top View Bottom View (Battery Cover Installed) Bottom View (Battery Cover Removed) Chip Scale Atomic Clock Module Hardware Overview Test Session

6 Operations, Timeline Launch 45 P SPHERES Upgrade Permanent modification occurs sometime during Increment Reference Clock & Atomic Clock Modules Powered 2 wks prior to Test Session Ref Clock & Atomic Clock Modules powered up to allow for timing stabilization Disconnect Atomic Clock Modules from Ref Clock & attach to SPHERES Satellites During Test Session Setup Atomic Clock Modules Calibrated with Reference Clock via Atomic Clock Cables Connected to Ref Clock for ~15 minutes SPHERES Test Session is run Atomic Clock Modules operate in background Atomic Clock Modules are recalibrated with Reference Clock Micro Gravity Drift is recorded ~4 hrs ~30 min Typical SPHERES Test Session, ~4 hrs All Atomic Clock data is transmitted along with a typical SPHERES Test Session data and is intended to be run in parallel with other SPHERES Investigations Crew Time DoD Science complete after Test Sessions

7 1.Setup the MWA CS 2.Setup the Soldering Iron 3.Secure the SPHERES Satellite in the MWA CS 4.Heat an Expansion Port Cover Plate screw with the Soldering Iron 5.Use the torque screwdriver to attempt to loosen the heated screw 6.Perform steps 4&5 on the remaining 3 screws 7.Remove all screws holding the cover plate. Trash screws and plate 8.Install new Expansion Port and torque fasteners 9.Install new Expansion Port Circuit Board and torque fasteners 10.Install new Expansion Port Cover Plate Crew Operations Overview Expansion Port Install

8 Step 1: Locate expansion port cover plate and 4 retaining screws Step 2: Heat screw #1 with soldering iron Step 3: Set torque wrench and attempt to turn screw #1 two turns Repeat Steps 2 & 3 for all screws Step 4: After loosening and cooling time, remove screws to expose expansion connector Step 5: Set new Expansion Port adapter in place Step 6: Set torque wrench and secure captive screw #1 Repeat Step 6 for all 4 screws Step 7: Mate the Expansion Port Circuit Board with expansion connector Step 8: Set torque wrench and secure captive screw #1 New Expansion interface is fully installed (Cover not shown) Repeat step 8 for all 4 screws Crew Operations Overview Expansion Port Install

9 1.2 weeks prior to Test Session, power up Reference Clock 2.Connect Atomic Clock Modules to Ref Clock 3.On Test Session day, begin normal SPHERES setup 4.During setup, disconnect Modules from Ref Clock and connect them to their satellites 5.Reconnect Modules to Ref Clock via Atomic Clock Cables for ~15 minutes 6.Disconnect cables from Modules and proceed with normal Test Session 7.After Test Session complete, reconnect the Modules to the Ref Clock via Atomic Clock cables for final calibration 8.After final calibration, disconnect Modules from Ref Clock and the satellites 9.Proceed with normal SPHERES experiment shutdown. Crew Operations Overview Test Session

10 Safety Hazard Reports: STD-CSAC-F01 Flight Payload Standard Hazard Report. The mating/demating of powered connectors is controlled by crew procedures: SPHERES REFERENCE CLOCK SETUP SPHERES RUN TEST SESSION WITH ATOMIC CLOCK CSAC-F02 – 1.1 ISS SPHERES Expansion Port Access Cover Heated Fasteners could cause injury if touched. Appropriate cautions and warnings incorporated into procedure: SPHERES EXPANSION PORT INSTALLATION. CSAC-F02 – 1.3 The ISS SPHERES Expansion Port Access Cover requires a one minute cool down following turning off the ISS Soldering Iron before completely removing the fastener SPHERES EXPANSION PORT INSTALLATION CSAC-F02 – 1.4 Soldering Iron must be positioned such that it’s easily accessible without reaching over hot Soldering Iron SPHERES EXPANSION PORT INSTALLATION CSAC-F02 – 1.5 The ISS Vacuum Cleaner must be connected to the MWA Containment System for dispersion of potential byproducts of solder left on the soldering tip from a previous operation SPHERES EXPANSION PORT INSTALLATION

11 Acronyms CSContainment System MWAMaintenance Work Area SPHERESSynchronized Position Hold, Engage, and Reorient Experimental Satellites