Space Simulation Tutorials
Monday, October 17, 2022

8:00 a.m. Introduction

8:05 - 10 a.m.
Practical Considerations for Force Limited Vibration Testing
Bill Zwolinski (Kistler Instruments), Dale Schick (m+p international), and Martin Betschart (Kistler Instruments)  

Space payloads are ground tested to ensure they are mission ready after launch. Conventional vibration testing using response accelerometers and hard mounting to a shaker can overtest the payload resulting in damage or destruction of expensive technological or scientific equipment.

This is why nowadays FLVT (Force Limited Vibration Testing) is often performed on Space payloads. Force limited automatically notches the acceleration at a test item’s resonances,  by measuring and limiting the reaction force between the test item and the shaker table, where overtesting risks and costly damage can be eliminated.

This Tutorial will review basic principles of Piezoelectric measurements including typical properties and Quasistatic/Dynamic Operation. Other topics to be covered include Multicomponent Piezoelectric force sensor principal of operation, dynamometers  and practical considerations for mounting, installation and use. In particular, topics include preloading, calibration, use of  force sensors and force links and frequency response. These concepts will be extended to typical FLVT measuring chains with various geometries to resolve forces and moments. 

A practical demonstration of FLVT will be provided using a 1U model Cubesat while employing various techniques for vibration control including Sine and Random notching, summed force, calculated moment, control weighting, and vector RSS.

 

10:15 a.m. - 12:00 p.m.
Best Practices in Space Simulation Testing
Tom Foley (Dynavac)

Thermal vacuum systems play a crucial role in qualifying flight hardware for the extreme environments of space.   Systems are used for a variety of applications including thermal vacuum, cycling, balancing, and bakeout.   The tutorial focuses on the fundamentals of thermal vacuum system configurations and the various testing methods.   Design criteria for thermal vacuum systems will be discussed including considerations when specifying vacuum pumping systems, thermal control methods, control systems, and ancillary equipment. 
 

1:00 - 3:00 p.m.
Thermal Vacuum Bake-Out Workshop
Glenn Rosecrans (KBR, Inc., contractor at NASA-GSFC), John Canham (Peraton, contractor at NASA-GSFC), and Therese Errigo (civil servant with NASA-GSFC)

Spacecraft hardware thermal vacuum exposures and bakeouts have been used for years to reduce molecular outgassing to limit contamination to critical optics and sensors on-ground and in orbit.  This presentation will discuss lessons learned and vacuum procedural techniques to make the most of your vacuum time.  Quartz Crystal Microbalances (QCMs) and Residue Gas Analyzers (RGA) are 2 devices that help track molecular outgassing and examples will be shown on how to use them for your analytical benefit.

3:15 - 5:00 p.m.
Fundamentals of Classic Shock and SRS Shaker Testing
Chris Sensor (Siemens PLM Software) and Melissa Maze (PCB Piezotronics)

This tutorial will cover the fundamental concepts of shaker shock testing, from field data acquisition to Classic Shock and Shock Response Spectrum (SRS) wavelet synthesis in a vibration controller. The tutorial will cover shock data acquisition and analysis, classic shock pulses, SRS concepts, SRS and Pseudo Velocity Shock Spectrum (PVSS) data analysis, Fatigue Damage Spectrum, a review of Classic Shock and SRS test methods in MIL-STD-810H (including the “new” method of Te and TE), shock test tailoring and SRS wavelet synthesis for shaker SRS testing.  A segment covering specialty shock sensors and instrumentation will also be presented. Subjects will be accompanied by live demos of data acquisition and shaker tests, with opportunities for hands on participation by attendees.