1. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design CRaTER and the Electronics Assembly Matthew Smith Mechanical Engineer (617)-252-1736 matt@space.mit.edu June 27,2005

2. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design CRaTER Telescope Assembly Electronics Assembly SIM Table NADIR +Z (Moon) ZENITH -Z (Space) Crater integrates two sub-assemblies: the Telescope Assembly and the Electronics Assembly. –The Telescope Assembly is being designed and built by The Aerospace Corporation –The Electronics Assembly is being designed and built by MIT. –MIT will integrate the two sub-assemblies and perform all functional, environmental and acceptance testing.

3. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design CRaTER Mechanical Interface Drawing 32-02003.02

4. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design CRaTER Electrical/Mechanical Interface Interface Connectors J1 9 Pin D-Sub Male 311409-1P-B-12 J2 9 Pin D-sub Female 311409-1S-B-12 J3 1553, BJ3150 J4 1553, BJ3150 PART OF MID DRAWING NUMBER 32-02003.02 Mounting Hardware - Six #10-32 SHCS Surface roughness of 63 micro inches or better for interface surfaces. Mounting surfaces have Electrically Conductive finish (MIL-C-5541 Cl 3)

5. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design CRaTER Design Requirements for Protoflight Hardware from the NASA Mechanical Environments and Verification Requirements Document # 431-RQMT-000012 –Must demonstrate that we meet the performance requirements after being subjected to the net C.G. limit load of 12 g’s in any direction –Must demonstrate that we meet the performance requirements after being subjected to sine vibration of 8 g’s, Protoflight level, from 5-100 Hz., (Level=1.25 X Limit Level, sweep rate= 4 Octaves/Minute/Axis.) –Must demonstrate that we meet the performance requirements after being subjected Random Vibration environment of 14.1 grms for Protoflight Hardware (Level=Limit Level +3dB, Duration= 1 Minute/Axis) –Demonstrate the ability to meet performance requirements after subjected to Protoflight acoustic environment. (OAPL=143, Level= Limit Level +3dB, Duration = 1 minute) –Natural frequency Stowed- >35Hz required. >50Hz is recommended. Deployed- >3Hz in the deployed configuration when hard mounted at the spacecraft interface. –Factors of Safety (FS) Demonstrate positive Margins of Safety (MS) for all Yield and Ultimate Failures (MS= Allowable Stress(or Load)/(applied Limit Stress(Load)x FS-1) FS for metallic Flight structures is: 1.25 for Yield and 1.4 for Ultimate Keep mass below 5.6kg. –Excludes mounting hardware and Thermal Protection System

6. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design CRaTER Mechanical Testing –Sinusoidal Vibration 5-100Hz at 8g’s (Protoflight) 4 Octaves/minute/axis. –Random Vibration 14.1 grms (Protoflight) 60 sec/ axis. –Will perform low level sine sweep, up to 2000 Hz. Frequencies shall be verified and reported up to 200 Hz. –Acoustics testing will not be done at the instrument level. –Shock testing to be done at the Observatory Level. CRaTER has no self induced shock.

7. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design CRaTER Mass Properties Estimate Summary ORIGINAL PROPOSAL TIM (April 2005) PDR (June 2005) grams CBE: CRaTER (Electronics and Telescope Assembly) 430043224997 Reserve 1300 (30%) 1288 (30%)640 (12%) Proposal Allocation5600 Extra requested allocation 400 MLI/TPS and Hardwaren/a 290 30 % Reserven/a 87 MLI and TPS Total 377 Requested Allocation6377

8. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design CRaTER Mechanical Analysis, CRaTER –The fundamental frequency is estimated to be 564 Hz. –Not required to produce an FEM since our predicted first frequency is >75 Hz. –No fracture critical Items. –Will meet all Factors of Safety requirements. More analysis to be performed.

9. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design of Electronics Assembly Top Cover Analog Board Electronics Enclosure Digital Board (Bottom Cover Not Shown)

10. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design Electronics Assembly Electronics Assembly Requirements (Internal) –Have proper contact area to support Thermal and Mechanical needs –Provide safe structure to support Telescope Assembly. –Provide for mounting 2 Circuit Card Assemblies. The Analog Board must be shielded from the Digital Board. The Analog Board to provide direct linear path for electronics from the telescope interface to the Digital Board interface to reduce noise. Provide adequate surface area for electrical components. –Interface to the Spacecraft to be on one side of the Electronics Enclosure. The interface connectors to be on the Digital side of the Electronics Enclosure (separate from the Analog side) –Provide GN2 purge interface inlet and outlet ports. The Electronics Assembly will meet all these requirements.

11. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design Electronics Assembly Preliminary Natural Frequency Estimates –Based from Steinberg Vibration Analysis for Electronic Equipment- (Simply supported on 4 sides.) Top Cover~ 160Hz Analog Board~ 99 Hz Digital Board~ 114 Hz Bottom Cover ~ 138 Hz –Further frequency, stress, and loads analysis will be performed

12. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design CRaTER NEAR TERM TASKS –Further develop analysis on natural frequencies and stresses using SOLID WORKS and COSMOS –Continue to work the weight issue to maintain margin. –Finalize interface between Telescope Assembly and Electronics Assembly.

13. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design Backup slides

14. C osmic R Ay T elescope for the E ffects of R adiation MECHANCIAL DESIGN ORIGINAL PROPOSED WEIGHTS Component/subsystemweight kg,(lbs) mechanical structure2.35.06 Electronics1.53.30 Sensors0.40.88 Fasteners0.10.22 Crater sub-total4.39.46 mass reserve 30%1.32.84 Crater grand total mass max.5.612.30

15. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design Mass Properties MASS PROPERTIES (FROM TIM in APRIL) gramslbs Electronics Assembly Analog board 7501.7 Digital board11002.4..interconnect cables A/D 300.1 Mechanical enclosure11502.5 interconnect cables 240 0.5 Sub-Total3270 7.2 Detector Assembly Detector Board (3 total)1800.4 TEP Package (2 total)1720.4 Detector Mechanical enclosure7001.5 Sub-Total10522.3 Crater Total43229.5 Reserve 30%1296 2.8 Total Max 5618 12.4

16. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design CRaTER Mass Properties CURRENT MASS PROPERTY ESTIMATES Electronics Assembly gramslbs Analog CCA4801.05 Digital CCA5401.19 Interconnect Cable, A/D520.11 Internal E-box Cables1220.27 Mechanical Enclosure18003.96 Top Cover2500.55 Bottom Cover2250.49 Hardware1660.36 Purge system1500.33 Electronics Assembly Sub-Total37858.32 Detector Assembly Detector Board (3 total)1800.40 TEP Package (2 total)1720.38 Detector Mechanical Enclosure8601.89 Detector Assembly Sub- Total12122.7 Crater Total499711.02

17. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design Mass Properties Miscellaneous Estimates GSFC Supplied Material grams lbs MLI and TPS2500.55 Mounting Hardware400.09 Misc. total2900.64 30% reserve870.19 Misc. Grand Total3770.832

18. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design Drawing List Drawing NumberDrawing TitleRevqtylayout completedrawing createdcheckedReleased 32-10200Electronics Assembly-n/a0% 32-10201Digital Electronics, PWA02125% 32-10202Analog Electronics PWA02125 32-10203Electronics Enclosure 01175% 32-10204 Cover, Top Electronics Enclosure 01175% 32-10205 Cover, Bottom Electronics Enclosure -175%

19. C osmic R Ay T elescope for the E ffects of R adiation Mechanical Design Electronics Box Assembly PolyimideTop coverBottom Cover ModulusE(lb/in^2)8.7E+51.00E+07 heighth(inches)0.0620.080.06 Poison ratiou0.450.12 lengtha (in)4.037.66 widthb (in)7.0610.129 weightW (lb)0.41.20.4 gin/sec^2386 pi3.14 D=E*h^3/(12(1-u^2)D=21.66432.90182.62 density pmass/area=W/gab2.73E-054.01E-051.50E-05 for a a simply supported board on 4 sides f=pi/2((D/p)^.5)(1/a^ 2+1/b^2))^.5frequency=114138.4160.9 This is from an example by Steinberg, vibration analysis for electronic equipment page 149