Environmental Test Verification

1
Environmental Test Verification
2
Test Philosophy

• Verification testing will be of the spacecraft as
  a whole to demonstrate that no structural changes
  occur as a result of environmental influences and
  that all components function as required
  afterward.

3
Tests

• Vibration
• Sine Sweep
• Random Vibration
• Mass Properties
• Mass, Moments of Inertia, CG
• Thermal Vacuum
• Payloads/Vital Systems Functionality Tests in
  Space Environment

4
Vibration

• Test Facility NRL in Washington, DC
• Horizontal/Vertical Vibration Table
  Configurations
• Will provide Mechanical Interface to Vibration
  Table
• Adequate GSE

5
Test Models

• Two series of tests
• TU-1 Flight hardware load-bearing structure
  with aluminum mass models to simulate
  payloads/vital systems
• Protoflight testing of MidSTAR-1
• Verification Levels
• TU-1 4.14 dB MEFL
• MidSTAR-1 .969 dB MEFL

6
Static Loads Determination

• Current Ideas
• Static Loads Test
• Sine Sweep
• Advantage simultaneously obtain fundamental
  modes and frequencies while performing static
  loads test
• Advantage already using facilities for random
  vibration test
• Centrifuge
• Advantage educational experience for Midshipmen
  Test Team

7
Random Vibration Test

• Objective to verify the capability of the
  satellite structure and components to withstand
  stresses introduced during sustained launch
  vibrations.
• Success Criteria the spacecraft structure and
  components shall not yield fasteners shall not
  lose more than 20 of original torque.

8
Mass Properties

• Spacecraft mass is measured to determine launch
  weight and demonstrate conformity to launch
  vehicle requirements (120 kg /- 10 kg).
• Current estimate 118.28 kg
• CG must be 20 inches from the origin of the
  spacecraft coordinate system, offset from the
  x-axis.

9
Thermal Vacuum Testing

• Facility NRL
• Ports to the spacecraft will be required for
  electrical power, a user interface terminal
  (serial), and radio frequency communications via
  coaxial cabling.

10
Thermal Vacuum Testing (Cont.)

• During the TVAC cycle, a day-in-the-life test
  will take place which will exercise the
  spacecraft electronics in such a way as to
  simulate on-orbit operations.
• 4 TVAC cycles will be performed.
• Pressure under vacuum shall be no greater than 1
  x 10-4 Torr.
• Temperature limits will will be derived from
  predicted flight temperatures at the solar panels
  with a 5C margin