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SuitSat2 as box SuitSat2 as flat box –One SMEX Lite solar panel per 4 sides of box –One SMEX Lite solar panel per top/bottom allows considerable surface.

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Presentation on theme: "SuitSat2 as box SuitSat2 as flat box –One SMEX Lite solar panel per 4 sides of box –One SMEX Lite solar panel per top/bottom allows considerable surface."— Presentation transcript:

1 SuitSat2 as box SuitSat2 as flat box –One SMEX Lite solar panel per 4 sides of box –One SMEX Lite solar panel per top/bottom allows considerable surface area for switches, connectors, antennas, handle, etc. –Two SMEX Lite solar panels per top/bottom generates more power (except spin Beta 0°) but leaves no unused area. –External dims rounded from 17.2x8.2 inches to 18x9 inches –For now, I assume everything inside will fit in say 16x16x7 inches –Max inertia axis suggests spinning as coin (stable) Individual covers for solar panels –Highly discouraged. Double CTB (NOMEX soft-wall container) –Exterior 502x425x502 mm (19.76x16.73x19.76 in) –Interior 486x410x460 mm (19.13x16.14x18.11 in) Ejection Box –Probably bigger than interior of Double CTB (but it’s close…) –Hard-wall to protect solar panels –Lid flips open to allow satellite (with handle) to slide out –Similar in concept to CalPoly’s P-POD launcher for CubeSats, except: No ejection springs. Glove-friendly handles. No mechanisms. Manual latch for lid. CalPoly sliding surfaces are silicone-impregnated aluminum with tight tolerances. With 4” CubeSats, CalPoly’s concerns are minimal of shrinkage induced friction. Scaling up to 18”, we should consider a better approach to sliding. –Shallow depth for sliding rails is better, though all sliding mechanisms are inferior due to concerns of variable friction. –In ejection views to right, sliding surfaces are RED. –Consider redesigning sliding surfaces to approach statically determinant (which helps prevent “sticking” due to thermal effects, etc). –Alternatively to Double CTB, could be sized to fit a 19” electronics rack. SuitSat2 or SuitSat2 Ejection Box KF4KSS July 9, 2009 AM Latching Lid Latching Lid Spin axis and antennas

2 Expanding on Ejection Box Requirements –Provide minimal impact resistance to prevent damage to solar cells due to rough handling –No tools required for opening/deployment –No tools required for optional repacking/closure –Additional access to a safe/arm port without opening for deployment. –Vents (does not hold pressure) –Provide adequate structural stability for mounting/stacking/strapping. Desirements –Compatible interface Double CTB, 19” rack, or TBD Handles, loops, velcro Integral instructions? Manual latch Which is easier: –Is there a human factors difference between lids? 19”x19” versus 19”x9” Could thermal expansion/contraction lead to friction? –See next page If the big Lid is broken into two separately latching lids, then one could serve as access port to Safe/Arm, battery charge, etc, while the second lid prevents SuitSat2 from exiting the Ejection Box and protects the SMEX panel. SuitSat2 or SuitSat2 Ejection Box KF4KSS July 9, 2009 PM Latching Lid Latching Lid or Separately Latching Lids

3 Thermal Shrinkage of Ejection Box? Could thermal expansion/contraction lead to friction? –My thought is SuitSat2 may be room temperature, but the Ejection Box may cool, causing it to shrink. This would add to friction. It may be worth making the rails “statically determinant” (or close), meaning that if the Ejection Box shrinks, it imparts no additional force on SuitSat2. Read “no additional force” to mean “no additional friction”. –Sketch on right also has advantage of tolerances from assembly of SuitSat2 and Ejection Box don’t immediately stack as friction resisting deployment. If Ejection Box is covered in NOMEX or other blanket, maybe this shrinkage concern of mine disappears. KF4KSS July 9, 2009 PM SuitSat2 (there would also be non-determinant forces in and out of plane) Ejection Box SuitSat2 This bar on edge of satellite constrains forces in one direction, but allows Ejection Box shrinkage. This bar on edge of satellite constrains forces in two directions. No contact. Satellite interface in this notch may “slide” left and right to allow for expansion/contraction. Satellite interface in this notch is fully constrained, except for deployment direction.

4 Expanding on SuitSat2 structure Can all the Hammond boxes mount to the bottom floor of a open box, 16x16x7 inches? Paired with my favored Ejection Box design, then the SuitSat2 floor is the only “structural” panel. The rest of the structure could be angles and a non-structural AL panel as required. KF4KSS July 9, 2009 PM Whip antenna Structural floor w/ 4 AL angles Frame of 8 AL angles 4X sides On bottom Handle 2 angles are heavier and have “rails” for Ejection Box On top

5 Issues List Russians wouldn’t want a container that couldn’t be collapsed. That’s why original thought was to have covers (stackable when it’s all said and done). Russians are proposing a pencil (not a pancake), where the sides are long and narrow, not wide and short. I guess that’s easier to get through a small hatch. It would likely be stable in a “flat spin”, not through axis of symmetry. Interface to the Russians… Fit through Progress hatch? What’s the size? Is one handle going to work? Excessive friction towards one side + one centered handle = binding? –Does orientation of handle matter? If you have to put SuitSat2 back into the Ejection Box, is it a huge pain? –Should we do something besides flare the rails open at the entry end? Is one SMEX panel in each of 6 directions enough power? Do we passively/actively induce spin similar to AO-51? Assume it will be released with a minor tumble. KF4KSS July 9, 2009 PM

6 Collapsible Container (not really an idea) 1.Remove top 2.Sides are spring loaded to pop outward 3.Release satellite (springs?) 4.Top can be temporarily velcro’ed to either either side of container base 5.Once indoors, the top can be attached to collapsed container base. KF4KSS July 9, 2009 PM 1 & 2 5 Lid Base Lid Base No rails!

7 Radical thoughts I Send 6x SMEX covers with satellite. –Stack them all on empty underside opposite the “Safe/Arm” panel using velcro. KF4KSS July 9, 2009 PM Thickness exaggerated

8 Radical thoughts II Eliminate covers altogether by “flipping” the solar panel backsides out for storage. Other (more useful) hinge lines may be possible. KF4KSS July 9, 2009 PM Velcro to flat position cells blank backside blank backside Hinges backside blank cells Hinges cells Hinges Velcro to flat position blank backside

9 Incorporating experiments It sounds like a couple more inches of thickness would be appropriate to handle side-looking cameras, etc. This is not because interior volume is needed, but the ability to look around the SMEX solar panels on the sides. So, I added a notional 2”. Just a conversation starter. It’s not clear to me how much of Kursk protrudes from the spacecraft. Obviously significant protrusion next to a solar array would increase the occurrence of shadowing. And if Kursk can’t fit in the same general area as “safe/arm” and “camera” on top surface, then it blows away the previously mentioned idea of flying the satellite with its solar panel covers velcro’ed to the bottom (Radical thoughts I, sheet 7). I thought it was a good idea also because it eliminates junk going back into Station after deployment. KF4KSS July 10, 2009 AM Top Iso View Bottom Iso View

10 Lou’s clamshell concept This is my attempt to document Lou’s concept I’m not convinced this is a good idea mechanically. 2 (nearly) identical welded assemblies: 3 panels each, with bolts at interface Arrange electronics primarily to one set, to minimize harness complications Top/Bottom SMEX panels are opposite each other so top/bottom antennas are near opposite corners of satellite. KF4KSS July 13, 2009 PM Top Iso View + = Likely: 3 SMEX Control Box All 3 cameras Handle One antenna Likely: 3 SMEX Kursk One antenna Screws along red lines (welded)

11 I’d prefer… Top Iso View KF4KSS July 13, 2009 PM Box with removable Lid OR Box with removable Lid and 1 side Top Iso View Maybe these components are down here instead. (welded)

12 SuitSat-2 as Box July 15 Update Exterior views showing component placements Approx 19”x19”x11” excluding –Antennas –Kursk –Two handles –Switches of Control Box –Panel/experiment covers Design methodology is quick but sound mechanical packaging. Top Iso View Bottom Iso View Kursk Cameras on 2 sides, top, and bottom KF4KSS July 15, 2009 PM 2meter 70cm

13 SuitSat-2 as Box July 19 Update Structure still 19” x 19” x 11” plus protrusions Still considering how best to assemble (Lou’s split or my split) Kursk same side as 2meter Whip w/ Collar Opposite side as 70cm Whip w/ Collar Most Boxes mounted to Bottom Plate Remaining Boxes mounted to Top Plate Slight tweaking of camera positions since Orlando mockup Reminder: all exposed edges must be rounded to 1/16” to protect gloves Top Iso View Bottom Iso View Kursk Cameras on 2 sides, top, and bottom KF4KSS July 19, 2009 PM 2meter 70cm XY Z XY Z

14 Top & Bottom (close to scale) KF4KSS July 19, 2009 PM Handle Control Box 2m Whip & Collar Kursk SMEX Border for Panel Cover SMEX Border for Panel Cover Cam Hidden lines are inside satellite Cam Battery Handle IHU RF stack Power stack 70cm Whip & Collar Spare Exp. Spare Exp. cutout 19 inches (480 mm) Hat section

15 What the holes look like: Top & Bottom (close to scale) KF4KSS July 19, 2009 PM Through holes are white. Threaded holes inside satellite are blue. Threaded holes outside satellite are red. 19 inches (480 mm) cutout for battery patch panel. See Russian integration slide below cutout for SMEX wires cutout for Control Box cutout for Kursk

16 Sides KF4KSS July 19, 2009 PM SMEX Border for Panel Cover Cam Hidden lines are inside satellite. The two cameras were placed on arbitrary sides. SMEX Border for Panel Cover SMEX Border for Panel Cover SMEX Border for Panel Cover Cam +Y +X -X -Y

17 What the holes look like: Sides (close to scale) KF4KSS July 19, 2009 PM Through holes are white. Nutplates inside satellite are red. (the sheetmetal isn’t thick enough to support threaded holes) +Y +X -X -Y cutout for entire rear of SMEX

18 Camera Issues KF4KSS July 19, 2009 PM Cam SMEX Border for Panel Cover Handle Cam Camera FoV is rectangular 90º full angle Top Camera will see –2m ¼ wave Whip Bottom Camera may see –70cm ¼ wave Whip 2x Side cameras –have no obstructions Both handles are fine Kursk is fine Without baffles, all cameras are subject to stray light from objects outside FoV but with clear line of sight to the pin hole edge. Do we need to aim the top camera slightly sideways to clear FoV? How long are the ¼ wave whips including mounting and kapton tape? 11 inches (280 mm) 5.5 in (140 mm) 2.5 in (64 mm) Top Bottom Side View

19 How we might simplify final integration in Russia Avoid opening entire structure in Russia Kursk mounts from outside –Change Kursk flange to thru holes –Threaded holes in Top Plate –Can harness be attached then stuffed inside prior to bolting? Orlan-M Battery mounts from outside –Mount battery and Handle to patch panel, which then mounts to outside of Bottom Plate –Bottom Plate has cutout for battery and threaded holes for mounting patch plate –Can harness be attached then stuffed inside prior to bolting? Top Iso View Bottom Iso View Kursk KF4KSS July 19, 2009 PM XY Z XY Z Battery Handle Side View

20 MGSE holes All 6 sides have 4 corner threads Handles shown blue Legs (standoffs) shown red Legs on upper surface could be replaced by lifting eyes for use with a crane (not sure that is needed, but is possible) Covers and Handles/Legs are independent –None have to be removed/installed for the installation/removal of others Allows satellite to be lifted and rotated onto any of 6 surfaces without damaging flight hardware. MGSE Handles and Legs removed prior to launch to ISS Sketch below would be milled vertical angles, not extrusion as originally envisioned (still just an idea) Would we use four of these holes for attaching to vibration table for workmanship vibration test? Top Iso View Bottom Iso View KF4KSS July 19, 2009 PM XY Z XY Z Handle Leg Side sheetmetal and SMEX solar panel Cover Side sheetmetal and SMEX solar panel Cover Vertical corner, perhaps machined but was originally envisioned as extrusion

21 A note about strength & testing KF4KSS July 19, 2009 PM Will look to Goddard’s Environmental Verification Specification (GEVS) for –Minimum static loading –Factors of Safety –Workmanship vibration levels Until superseded by a requirement from Progress launch vehicle –Lou is working to get a Progress payloads requirements document Based on previous guidance from KSC (unrelated project) –Minimum natural frequency is 50 Hz –Desired natural frequencies above 100 Hz –Doubtful that Progress would use different numbers Panels for which natural frequency should be predicted –Bottom Plate with its heavy components, some machined ribs, and mid-line stiffener –Top Plate with its lighter components, some machined ribs, but no mid-line stiffener –Generic Side Panel sheetmetal with camera, no ribs, no stiffener –Panel covers sheetmetal with perimeter spacer to provide gap verify that out of phase deflections still have adequate gap to solar cells

22 Concept still lacks significant details KF4KSS July 19, 2009 PM Weld vs screws How to break open for integration How to attach panel covers How to address CTE mismatch of SMEX carbon facesheet vs aluminum structure Camera FoV Despite that, I will estimate structure mass next –Top and Bottom are aluminum plates Thick enough to prevent drum modes and provide threaded holes SMEX panels must be raised since cutouts can’t clear all components on back Bottom will have hat section to split 19”x19” into two 19”x9” areas –4x Sides are aluminum sheetmetal Thin, only through holes SMEX panels can be flush since cutouts can clear all components on back –Corner angles are aluminum (robust verticals and minimal horizontals) –SMEX panel covers will be sheetmetal with strip spacer perimeter Fastening TBD (perhaps mix of captured thumb screw & velcro) Clearly I’m just about ready for CAD too


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