Colorado Space Grant Consortium

Gateway To SpaceASEN 1400 / ASTR 2500

Class #24

T-16

- Announcements

- Guest Lecture – Spacecraft Structures

- Launch is in 16 days

Today:

4

Announcements…

Propulsion Talk…- What did you think?

Design Document Rev C- Due 11-16-2012 at 12 PM

Launch Readiness Review- Due 11-27-2012 at 7 AM- Presentation order…

> 8, 6, 7, 3, 5, 1, 2, and 4- Template on the website

Test Results (3 minutes)– Prove your project is ready for flight– Heart of your presentation– Show test data (graphs, charts, etc) that are

labeled, with key events indicated– Structural tests should be included but equal

time should be devoted to mission/science tests (present mission/science test first)

– Proof should be shown that you have actually recorded, off-loaded, and analyzed your data

6

Announcements…

Ready for Flight Cards- Don’t lose this only copy- Must turn in on 11/30- Use as a checklist- Follow it exactly- Not fully completed, your

team doesn’t fly

Colorado Space Grant Consortium

Tuesday 11/27…LRR Presentations

Presentations due 7:00 AM4 days to launch

Colorado Space Grant Consortium

Thursday 11/29…Launch LogisticsFriday meeting time sign up

2 days to launch

Colorado Space Grant Consortium

Friday 11/30…BalloonSat Turn inRFF Cards Turn in

30 minute turn in timesCompleted by 3:00 PM1 day to launch

Colorado Space Grant Consortium

Saturday 12/01…Launch!

Leave Boulder at 4:45 AM

Arrive ~5:45 AM

Colorado Space Grant ConsortiumT-16

Mission SimulationsASEN 1400 / ASTR 2500

Class #24

Payload Handlers:

- Bring you payload to the front of the class

- Tell us about

- Demo something with it

- Let them run for until ~10:35

Colorado Space Grant Consortium

Spacecraft StructuresHeather ReedLASP(Laboratory of Atmospheric and Space Physics)

Spacecraft Structures

Heather ReedMechanical Engineering Manager

Laboratory for Atmospheric and Space Structures

reed@lasp.colorado.edu

What is a structure?

Why does a spacecraft need a structure?

PRIMARY or Secondary?

23 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

Lifecycle of a Structure

REQUIREMENTS(NEEDS)

DESIGN

ANALYSIS

BUILD

TEST

INTEGRATION

STUDENT NITRIC OXIDE EXPLORER (SNOE)

24 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

REQUIREMENTS

• What does this spacecraft structure need to do?

• Accessability• Lift points

– Vibe– Acoustic– Shock

» Thermal» Radiation

ROCKET LAUNCH

GROUNDTESTING

ON-ORBITCONDITIO

NS

25 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

DESIGN – What shape will it be?

• SNOE was a “spinner”

26 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

DESIGN – What will it be made out of?

• Materials selection– Stiffness vs. Strength

• Car suspension – STRONG CAR, weak connection to the road– WEIGHT CHEAPEST RIDE TO SPACE = $35,000 per lb– Cleanliness

• Specific plastics only• Materials that can be scrubbed

• Aluminum is a great material

27 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

DESIGN – How will it be built?

• Manufacturability– Strongest structure is all one piece– How easy is it to assemble?

– Primary structure $$ < 1% of SNOE mission budget ($8M)

28 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

SPACECRAFT

ROCKETNOSECONE

ROCKET SECONDARYSTAGE

DESIGN – Will it fit?

• Solid Modeling

29 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

Solid Modeling - SolidWorks

30 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

ANALYSIS - Modal Simulation Results

Mode 2 – 821 Hz – Mode shape plotRocking in the Y-direction

Mode 6 – 1270 Hz – Mode shape plotRocking in the X-direction

• 821 Hz: First predicted high mass participation mode.

• 741 Hz: Lowest frequency mode is a local connector bracket mode.

• Z-axis has very little mass participation below 2000 Hz.

• Two principal mode shapes shown below:

31 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

BUILDING IT – Your best laid plans

• Fabrication – Do 2 planes meet perfectly?

32 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

Why TEST?

• Vibration Testing• Thermal Vacuum Testing• Acoustic Testing• Shock Testing• Strength Testing

NASA Goddard Gold Rules: • TEST AS YOU FLY, FLY AS YOU TEST

33 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

TESTING – Vibration Testing

• Mass model testing – Good practice• Test sensors - Accelerometers

LARGE SPEAKER “VIBE TABLE”

AT BALL AEROSPACE

SNOE SPACECRAFT

34 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

TESTING – Thermal Vacuum

• More heat without air – Electronics• Thermal expansion – Causing binding• More friction without air – Moving parts• HOT/COLD Operational and Survival limits

SNOE SPACECRAFT

LARGE TANK “RAMBO” AT BALL

AEROSPACE

35 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

INTEGRATION to the Pegasus

36 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

Secondary Structure – Solar Arrays

37 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

Heather Reed, CU Mechanical Eng 97’

• Work during Undergrad studies, BS ME in 1995– Space Grant College– NIST, NDE lab– CU football & basketball security– Hart Ranch snack shop

• Work during Grad studies on SNOE, MS ME in 1997– FEA, Solar panel substrate, Nutation damper, Torque rods,

Thermal blankets

• Employed at LASP after graduation• ME Manager in 2001, 8 ME’s then, 23 ME’s now• Current program is MAVEN, mission to MARS• Program Management on grants

The PF Package

Langmuir Probe and Waves (LPW) – LASP / SSLLPW/Extreme Ultra-Violet (LPW-EUV) – LASP

LPW-EUV

39 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

Testing

• Engineering Unit testing – Mechanism Life Testing – Vibe, Life Test cycling– Luxel filter qualification – Vibe, thermal cycles– Light leak testing– Torque margins– Spring force – Magnetic field

• Flight Unit testing– Vibe test

• Random Vibe, response limit• Strength verification = ?

– Mechanism Run-in• Torque margins• Spring force

– Light leak testing

40 Nov 15th, 2012 Spacecraft Structures Heather Reed, ME Manager

Aperture Mechanism Life Test Plan

-40

-20

0

20

40

60

Tem

p (d

egC)

30V

22V30V36V

22V30V36V

22V30V36V

30V

200 Cycles

4280 Cycles

-5°C

-35°C

35°C

50°C