Dynamics Testing 101 Implementing Dynamics Testing in the ETL

1. Dynamics Testing 101Implementing Dynamics Testing in the ETL Tim Werner Environmental Test Laboratory 357F

2. How To Use The ETL Dynamics Laboratory The cog E is ultimately responsible for all phases of the test program, but ETL personnel will help you get through the effort. Get us on board as early as possible in order to find out the surprises before they impact cost and schedule. Dynamics: Tim Werner – 3-1502 timothy.j.werner@jpl.nasa.gov Instrumentation: Sandro Torres – 3-3956 sandro.l.torres@jpl.nasa.gov

3. Training Objectives • At the conclusion of this course you will be able to: • Have an understanding of what needs to be accomplished by the Cog E to successfully conduct a Dynamics test • Identify who you need to work with to accomplish your tests • Identify the facilities where tests will be performed • Plan for successful Dynamics tests • Explain the reasons for performing Dynamics testing

4. Why do you have to subject your hardware to Dynamics testing? • This section could probably benefit from closer coordination between Ben and me • Verify hardware will survive dynamic environments expected to be encountered during mission. • Simulating Liftoff • Sine vibration • Swept frequency runs, typically from 5 to 2000 Hertz. Can establish discrete resonance frequencies for your hardware. Does not simulate actual vibration environments. At JPL, we only perform sine vibration when we are partnered internationally, or sometimes when other NASA centers want the specific data from sine testing. • Random vibration • Full bandwidth vibration testing, typically from 20-2000 Hertz. Provides a more realistic vibration environment which includes interaction between different resonant frequencies that can result in mechanical interaction between different components of the hardware. • Acoustic Noise • Full bandwidth vibration testing, typically from 31.5-10000 Hertz. In contrast to vibration testing, the hardware is not attached to the source of the vibration. The sound environment is introduced by blowing gas (GN2) through an air stream modulator, which is controlled by the control computer, and a horn into the acoustic noise test cell where the hardware is mounted. Acoustic noise tests thin structures with large surface areas such as solar panels.

5. Why do you have to subject your hardware to Dynamics testing? • This section could probably benefit from closer coordination between Ben and me • Simulating Pyrotechnic Events • SRS (Shock Response Spectrum) Shock • Is achieved by introducing a shock event to the hardware and transforming the time history response into a frequency vs. amplitude spectrum. It is used to simulate pyrotechnic events expected during the mission, such as separation events and cable cutting. Based on the distance from the actual event, the response at the component can be termed “near field”, “mid field” and “far field”. • SRS Shock on the Tunable Beam Shock Machine • Can achieve the amplitudes that JPL has required with response to 10000 Hertz. Because it is not computer controlled, a high fidelity mass model is required to establish the test conditions necessary to accomplish the specified shock before the flight hardware is mounted to the beam. • SRS Shock simulated on a shaker • Due to shaker limitations, the amplitude achievable is quite low and decreases rapidly with higher mass hardware. Also, shakers cannot transmit frequencies higher than 2500 Hertz. This was considered adequate when JPL was building Cassini sized spacecraft, as all of the events would be considered “far field”. But as we are building smaller spacecraft and the hardware is closer to the pyrotechnic event, we needed a method to achieve higher levels with a higher frequency response. We almost never use shakers for shock testing any more.

6. Why do you have to subject your hardware to Dynamics testing? • This section could probably benefit from closer coordination between Ben and me • Simulating Pyrotechnic Events • Live firing of pyrotechnic devices • Having said all that about simulating pyrotechnic shocks, the most reliable method for performing shock testing is to mount your test article to an engineering buss model and firing off actual pyrotechnic devices. All of the methods for simulating shock testing do include the danger of overtesting the hardware, even though the data collected may accomplish the specified requirements, due to various limitations of the various test equipment involved. • We do not perform live pyrotechnic firings in the ETL. Rich Webster (3-4179 / Richard.G.Webster@jpl.nasa.gov) is in charge of handling live explosives on the lab. The test may occur in an ETL facility or it may occur somewhere else on lab. Instrumentation will be involved to collect the data generated by the test. • Typically, live firing of pyrotechnic devices only occurs on higher level assemblies. For most component level testing, one of the simulated methods will be applied, although this will be discussed with your project people and your dynamicist.

7. Dangers Inherent in Dynamics Testing • Ben gives a very comprehensive presentation on this subject • Resonance • All parts resonate. • This is not usually considered during design; compared to functionality of hardware it really does need to be a secondary concern. • Where a resonant frequency is activated is where the hardware will most likely be damaged. • Try to design resonant frequencies as high as possible, but obviously the hardware needs to be designed to perform the required function. • Overtest • Force Limiting • Force limiting is applied to limit resonances in the force at the base of the hardware. It is the preferred method as it utilizes the mass of the entire structure. • Force limiting is implemented by your dynamicist. After each test run, the dynamicist will review the data collected during the run and, in concurrence with the cog E and any stress analysts present, decide what limit profile to have programmed into the control computer to accomplish the necessary limiting of the input vibration. • Response Limiting • Response limiting is applied to limit resonances at specific locations on the hardware. It’s application is limited by the size of accelerometers available to install on the hardware. At times an accelerometer may alter the mass of a given component structure or even be heavier than that structure. • Response limiting is also implemented by your dynamicist. After each test run, the dynamicist will review the data collected during the run and, in concurrence with the cog E and any stress analysts present, decide what limit profile to have programmed into the control computer to accomplish the necessary limiting of the input vibration. • Control Peak Limiting for Independent Overtest Protection • Each Control Channel has separate independent overtest protection circuitry added to prevent runaway vibration. If either Control Channel gets a peak signal over 5 sigma of the nominal full scale grms level, the test will be aborted.

8. Tour • Room 104 / Control and Instrumentation room • M+P 1 & 2 for vibration control • M+P for acoustic noise control • Instrumentation • Perform live test run to demonstrate what a test actually looks like and how long (or short) it actually lasts • Instrumentation begins recording. • The Fields are brought up. The DC coils in the body of the shaker create a DC magnetic field. A test run is defined from “Fields up” to “Fields down”. • The Power Amplifier is brought up. This powers the AC coils in the armature that create a variable magnetic field that works against the DC magnetic field from the body of the shaker to excite vibratory motion. The AC coils are controlled by the Vibration Control Computer to provide the specified vibration test level. • The Amplifier Gain is brought up. The gain is brought to a level that was determined to work and documented during the verification runs. • The self check is initiated. The control computer sends a known low level drive signal to the shaker, receives the responses back from the shaker and, based on the specified input curve programmed to run, calculates the drive signal necessary to perform the test. This is known as a self check. • The measured results of the self check come up on a screen and the measurements of the two individual control accelerometers and the independent monitor accelerometer are checked to verify that sufficient signal voltage is present on each channel and that the three channels give comparable readings. • The calculated drive signal is compared to the drive signal that was used during the verification run, which has been pasted to the computer screen. If the two signals are comparable, the test may proceed. • The test run is initiated. The run proceeds as was formerly instructed by the test conductor and is then completed. • The Amplifier Gain is turned down to the off detent. • The Power Amplifier is turned off. • The Fields are turned off. The run is over. • Instrumentation turns off the recorders.

9. Tour • Room 102 / Small Shaker room • 964 #1 & 964 #2 shakers / 20,000 force pounds • 335B shaker / 17,000 force pounds • Room 101 / Acoustic Noise Test Cell • 10,900 cubic foot reverberant test cell • Room 100 / Large Shaker and Tunable Beam Shock Machine Room • 994 shaker / 60,000 force pounds • Tunable Beam Shock Machine • Perform live test run to demonstrate what a test actually looks like and how quickly it actually occurs

10. ETL Vibration Equipment:Small Shakers • Vibration and mechanical shock • Two 20,000 force pound vibration exciters with a displacement of 1.5-inch double amplitude • One 17,000 force pound vibration exciter with a displacement of 0.75-inch double amplitude • Computer control of vibration equalization • 32 channels available for control • Force limiting capability • Simulated SRS Shock up to 1,000 g’s Electrodynamic Exciters Building 144

11. ETL Vibration Equipment (cont.)Large Shaker MER Spacecraft • Vibration building 144 Hi-Bay • One 60,000 force pound vibration exciter located in a cleanroom • 2600 ft2 Class 10,000 (ISO 7) cleanroom Electrodynamic Exciters Building 144 Aquarius Instrument

12. ETL Equipment (cont.)Acoustic Noise Test Cell Acoustic Reverberation Chamber Building 144 Hi-Bay • 10,900-cubic-foot chamber capable of up to 153 dB • 22 feet wide, 18 feet deep, 26 feet high • Class 10,000 (ISO 7) clean room

13. ETL Equipment (cont.) Tunable Beam Shock Machine Pyro Shock Simulation Typical SRS Shock Requirement:Frequency Hz Peak SRS (Q=10)100 30g – 50g100-(1000-1600) +10 dB/Oct(1000-1600)-10,000 1000g – 4000g+/- 3 dB spectrum tolerance • JPL’s Tunable Beam is based on the Tunable Beam concept developed by Sandia Laboratory • Excitation is provided by a projectile driven by gas pressure • Knee frequency of SRS is adjusted by varying the beam span • Damping material used to tune high frequency content

14. Data Acquisition • Three, Digital Data Acquisition Systems • One, 32 and two, 64 Channel recorders • Integral Electronics or Voltage Input • Sample Rates of 1k - 100kHz • All Standard Analysis Programs. PSD, Sine Sweep, SRS, 1/n Octave, & Time History • Two, 32 Channel PCM Tape Recorders • 40 Channels of Charge Amplifiers • 72 Channels of Integral Electronic Signal Conditioning • Large Selection of General Purpose Accelerometers • Force Gages and Signal Conditioning

15. Planning • Cost and schedule for testing should be part of the initial funding proposal for all test articles, including allocating other resources for testing. • Cost Estimates • Dynamic testing • Call Tim Werner, ext. 3-1502 • Vibration test: $12K/day, typically two to three days to complete a vibration test on the small shakers & acoustic noise chamber. Tests on the large shaker typically require five to six days to complete. • SRS Shock test: $4K/day, typically three to four days shock testing. Need to provide a high fidelity mass model in advance. • Instrumentation • Call Sandro Torres ext. 3-3956 • $179 per hour for support • While Dynamic and Thermal Vacuum test cost estimates typically include Instrumentation, sometimes, especially on higher level assemblies, you may require Instrumentation to begin transducer installation before the test article is actually completely assembled. Sometimes this may occur many weeks before the test article is transported to the ETL. This will typically require a separate job to be opened to cover this work. Please call the ETL for a cost estimatewhen doing initial planning!

16. Planning (cont.)Schedule a Test by Using the TFM ToolGet on the schedule as soon as you know that you require testing. It’s better to slip schedule while communicating with ETL than to have problems because we didn’t know you were coming. Type TFM in Web-Browser. Normal log-in with JPL password. Click on “New Reservation”. Fill in the required information. Submit your request. You will be contacted by Glenn Putnam within five days. Div 37 Scheduling Glenn Putnam 3-5030 Standing Meeting to gather all cog Es with upcoming tests to discuss priorities of scheduling conflicts: Wednesdays @ 11:00am in 321-128 Its ok if your test slips the schedule!

17. Responsibilities • Cognizant Engineer • Is responsible for documenting test item progress with an AIDS. • Is responsible for documenting test requirements with an ETAS • Is responsible for all phases of the test article test program. This includes communicating the test requirements to the ETL and scheduling the test. The cog E consults with the dynamicist to get input on the design of the test adapter fixture and mass model. The cog E gives the design to the machine shop to have the test adapter fixture and mass model fabricated. The cog E provides all of the hardware necessary to attach the test article to the test equipment which includes all of the fasteners and tools to attach the fasteners to the test adapter fixture and mass model. The cog E arranges for all personnel required to perform the test, including the cog E, a dynamicist, QA, safety, a flight tech for handling the test article and all personnel required to monitor the test article during test. The cog E is also responsible for transporting the test article to and from the test facility. Communicate with the ETL dynamics test engineer for all technical and logistical issues and for access to the lab. • QA • Is responsible to witness testing and verify that all steps are completed as specified in the test plan, test procedure and that all protocols for handling and testing flight hardware are correctly followed. • Dynamics Environments Engineer (Dynamicist) • Is responsible for communicating the correct test specifications to the cog E and ETL dynamics test engineer. Also, will help cog E design an adequate test fixture and mass model as required. Will act as the test conductor when the test is being performed, including analyzing response data after each test run to verify that the next test level will be performed in a safe manner.

18. Responsibilities • ETL Dynamics Test Engineer • Is responsible for communicating with the cog E about technical and logistical issues in preparation for the test. Implements the correct test specifications received from the dynamicist. Responsible for performing the test as specified and following protocols for flight hardware testing. Also, responsible for maintenance for test equipment and that all test equipment is in current calibration. • Safety • Will witness all crane lift operations • Will perform Operational Safety Survey

19. CommunicationWho to call • Dynamics Test Engineer • Call Tim Werner ( 3-1502) for information on making your test happen. He will either directly accomplish your needs or give you the information concerning who you need to call. • Dynamic Environments Group (352G) • Dennis Kern ( 4-3158) is the Group Supervisor. • 352G works with your Project to specify test requirements. • Will assist in designing your test fixture and mass model. • Will write the Test Plan which will specify the levels to be accomplished during the vibration test. The Test Procedure is written from the information in the Test Plan. • Will act as the Test Director during the vibration test. The Test Director will be the single source of instruction to the Test Operators during the test. • Will calculate levels required to accomplish Force Limiting necessary during the test. • Quality Assurance • Will oversee all phases of testing to ensure proper procedures are followed. • Will already be involved with the fabrication and handling of your hardware.

20. Communication (cont.) • Safety • Cami Vongsouthy ( 4-6317) is the Section Manager. • Will perform Safety Survey to ensure that all aspects of the upcoming test are discussed ahead of time to give a better opportunity to eliminate surprises during the test. • Instrumentation • Call Sandro Torres ( 3-3956) when you know what your instrumentation needs are going to be. Arrangements may need to be made to assure that the instrumentation you need will be available when you need it. • Also call when you are ready to have response instrumentation installed on your hardware. This often happens before the hardware is transported to the ETL. • Will install instrumentation according to the Test Plan written by the Dynamics Environments Group (352G). • During the test, will operate the Data Acquisition System and provide data to the Test Director and Cog E. for perusal after each test run. • Flight Technician • Jim Pearson ( 4-6447) is the Group Supervisor. • Will perform all handling of the test hardware in conjunction with the Cog E., including installation of the hardware to the test equipment prior to test and removal of the hardware from the test equipment after the test.

21. Paperwork • Ben gives a lot more detail here • AIDS - Prepared by cog E. What is an AIDS? Who to call • ETL does not use the AIDS for performance of test, but the TAE may require it to document the installation and other handling of the test item • ETAS - Prepared by cog E. What is an ETAS? Who to call • Systems Safety Survey - Prepared by Systems Safety Engineer • Test Plan - Prepared by Dynamicist to specify test levels and sequence. • Test Procedure - Prepared by Dynamics Test Engineer from Test Plan.

22. Meetings • Ben gives a good presentation of this, but I’m not sure but that repeating this ad infinitum isn’t a bad idea • Annual: • Facility Safety Survey - Systems Safety and ETL representative • ESD Survey - ESD Engineer from QA • Prior to test: • Informal meetings with Dynamics Test Engineer to discuss preparation for the test. • Schedule a time to bring your adapter plate to the ETL to perform a fit check to the test equipment before the test. • Weekly meetings on Wednesday at 11:00 am in 321-128 to discuss schedule issues. • Test Readiness Review - Cog E, Project Managers, QA, Dynamicist , ETL representative. • TRR will typically happen within a month before the test is scheduled, although this can be modified by specific project requirements • Operational Safety Survey - Systems Safety, Cog E, QA, Dynamicist and ETL representative. • OSR will typically happen within a week before the test is scheduled, although this can be modified by specific project requirements • Pretest meeting, the morning of the test, to discuss test conduct and sign the Test Procedure. • Discussion prior to every test run, to verify safety to continue test as Test Conductor directs and to fill out and witness checkoff sheet.

23. What a cog E needs to plan a test • As soon as you know that you’re building hardware, you should include costs for testing in your initial proposal planning. • Communicate with your Project to find out your testing requirements. • You may be communicating with the Dynamics Environments Group (352G, Dennis Kern, Group Supervisor <4-3158>) • Call Tim Werner (3-1502) for cost estimates for the Dynamics tests you need. • Call the Dynamics Environments Group (352G, Dennis Kern, Group Supervisor @ 4-3158) • A Dynamicist will be assigned to your hardware. This Dynamicist will help you: • Select the proper test requirements for your hardware. • Write a Test Plan which will communicate the test level requirements and sequence of steps for the conduct of the test. • The Test Plan will also specify the Instrumentation requirements including number and location of response accelerometers and force transducers. • Design the mass model to accomplish verification testing prior to mounting your flight hardware to the test set up, as necessary. • Design the test adapter fixture used to attach your hardware to the test equipment. • Act as Test Conductor. The test conductor will be the sole source of instruction to the test operators. Also, the test conductor will analyze the test data after each test run and calculate the necessary limit profiles to proceed with the test, safely.

24. What a cog E needs to plan a test • As soon as you have an idea when your test will need to occur, get on the schedule. • It’s OK for your test to slip schedule. You’ll be in good company. Your test schedule can be edited in the TFM Tool. • Go online to use the TFM Tool. • Type tfm in the address bar. • Sign in with your normal password. • Follow the prompts to schedule your test. • If you have problems with the TFM Tool, call Glenn Putnam (3-5030) and he can help you get on the schedule. • When the time to perform your tests get closer, you will be invited to the weekly scheduling meeting • This is why it’s important to get on the schedule so that we know to speak with you when your test is imminent. • When you understand your Instrumentation requirements, call Instrumentation to arrange for the accelerometers and force transducers you will need for the test. • Call Sandro Torres (3-3956). • Will arrange for the installation of the instrumentation to your hardware according to the specifications delineated in the Test Plan. Sometimes, this occurs before the hardware is transported to the Dynamics Lab. • During the test, will operate the Data Acquisition System and make the data available to the Test Conductor and Cog E for analysis after each test run.

25. What a cog E needs to plan a test • Safety • Cami Vongsouthy (4-6317 ) is the Section Manager. • Safety will preside over Operational Safety Survey to discuss all aspects of the upcoming test in order to have fewer surprises during the test effort. • Will witness all crane lifts involving your hardware. • Will oversee all other Safety requirements connected to your testing (eg: Laser set up) • QA • QA is required to be in attendance of every phase of Dynamics testing. • Will already be involved with your hardware from the beginning. • Will attend the Safety Survey. • Will verify adherence to ESD requirements for your hardware. • Will witness all steps of the AIDS are followed. • Will verify ETAS, Test Plan and Test Procedure are complete and approved. • Will verify that installation of all instrumentation is correct. • Will witness all handling, lifting, torquing and mate-demate steps of hardware installation to and removal from the test equipment. • Will witness the checkoff sheet that is filled out prior to each test run. This sheet verifies that the setup of the run about to be performed is correct.

26. What a cog E needs to plan a test • Sometime before you bring your test article to the Dynamics Lab: • Come to the Dynamics Lab to make some measurements to verify that your GSE will fit the floor spacing available or figure out how to work with the available space. • Verify that requisite power is available to accommodate your GSE or work out what needs to happen to accomplish that accommodation. • Arrange your software scripts so that you can perform required power measurements during a 30 second test run. • Bring your test fixture to the Dynamics Lab and perform a fit check to verify that it will fit to the test equipment. • When you come to the Dynamics Lab to perform your test: • You must bring the equipment and tools you need to mount your hardware. None of our tools are certified for use on flight hardware. • You must provide the fasteners to attach your hardware to your adapter plate. ETL will provide the bolts to attach your adapter plate to our test equipment. • You must bring the tools you need to attach your hardware to your adapter plate. We have some torque wrenches, but often we don’t have the range you need to mount your hardware. • You must bring the all the smocks, hats, booties and gloves you will need to keep your hardware clean. • You must bring the ESD equipment you need, including wrist straps and wrist strap checker. QA will perform any ESD survey you require prior to test. • You will need to bring the GSE you need to monitor your hardware during test runs and to perform any functional tests necessary for your test effort. • Don’t forget your hardware and adapter plate.

27. What happens in the Dynamics Lab: • If hardware monitoring will occur during vibration, the coordination between the test operators and hardware personnel needs to be worked out before any vibration occurs. • Prior to the first run of your test: • All action items from the Safety Survey must be completed. QA will verify. • Test procedure must be signed off by the ETL Test Operators, the Test Conductor (Dynamicist), the cog E and QA. • Prior to mounting the test hardware, verification runs must be completed. This can be done before your arrival and does not require QA witness. QA will be witnessing the transportation of your hardware. • Once the verification runs are complete, the hardware can be mounted to the shaker. • Instrumentation can then complete the installation of all required response accelerometers and force transducers. • A setup photo is to be taken of the hardware set up on the shaker in each axis. • Once everybody is ready to begin the test, there will be a discussion involving the particular requirements of your specific test. This discussion will occur prior to every test run. • The Test Conductor will be the single source of instruction to the test operators. A consensus between the test conductor and cog E needs to be discussed prior to every test run. • The test conductor will instruct the test operators which test level is to be performed for the next test run. • QA will witness and verify the filling out of the Test Procedure check off sheet prior to every test run. • If hardware monitoring will occur during vibration, the coordination between the test operators and hardware personnel needs to be worked out before any vibration occurs. This coordination is independent of the selection of test level as the monitoring will occur at every test level. • Discussion of whether someone needs to operate the kill switch in the shaker room during the test run. If no one is to be in the room during vibration, the switch need not be tested. If someone is to be in the room during vibration, the kill switch needs to be tested prior to every test run. The person assigned to the switch will activate the switch and demonstrate that the control computer is indeed shut down. • Any other activity that needs to occur during the test run should be discussed and coordinated prior to any vibration. • Anybody, at any time, can stop vibration during any test run by calling out “STOP!”

28. What happens in the Dynamics Lab: • Anybody, at any time, can stop vibration during any test run by calling out “STOP!” • During a test run: • Instrumentation begins recording. • The Fields are brought up. The DC coils in the body of the shaker create a DC magnetic field. A test run is defined from “Fields up” to “Fields down”. • The Power Amplifier is brought up. This powers the AC coils in the armature that create a variable magnetic field that works against the DC magnetic field from the body of the shaker to excite vibratory motion. The AC coils are controlled by the Vibration Control Computer to provide the specified vibration test level. • The Amplifier Gain is brought up. The gain is brought to a level that was determined to work and documented during the verification runs. • The self check is initiated. The control computer sends a known low level drive signal to the shaker, receives the responses back from the shaker and, based on the specified input curve programmed to run, calculates the drive signal necessary to perform the test. This is known as a self check. • The measured results of the self check come up on a screen and the measurements of the two individual control accelerometers and the independent monitor accelerometer are checked to verify that sufficient signal voltage is present on each channel and that the three channels give comparable readings. • The calculated drive signal is compared to the drive signal that was used during the verification run, which has been digitally pasted to the computer screen. If the two signals are comparable, the test may proceed. • The test run is initiated. The run proceeds as was formerly instructed by the test conductor and is then completed. • The Amplifier Gain is turned down to the off detent. • The Power Amplifier is turned off. • The Fields are turned off. The run is over. • Instrumentation turns off the recorders.

29. What happens in the Dynamics Lab: • After a test run: • The data collected during the run is transferred from the control computer and data acquisition system to the computer in the customer area for the test conductor and cog E to analyze and decide what step should occur next. • The test conductor will calculate any limit profiles that need to be implemented to ensure a safe test and determine at what level the next test run should be performed. This conclusion will be arrived at after discussion with the cog E. • The test conductor will communicate the information for the next test run to the test operators. • The test operators will implement the information from the test conductor and prepare for the next run. • When the test operators are ready for the next run, they will get with QA and go over the check off sheet to verify that the next test run is properly set up. • When everybody is ready for the next test run, there will be an informal discussion to make sure that everybody is prepared to perform the same test.

30. Frequently Asked Questions • What does testing in the Dynamics Lab cost? • Dynamics • Call Tim Werner, ext. 3-1502 • Vibration test: $12K/day, typically two to three days to complete a vibration test on the small shakers & acoustic noise chamber. Tests on the large shaker typically require five to six days to complete. • SRS Shock test: $4K/day, typically three to four days shock testing. Need to provide a high fidelity mass model in advance. • Instrumentation • Call Sandro Torres ext. 3-3956 • $179 per hour for support • Dynamic and Thermal Vacuum test cost estimates typically include Instrumentation Please call the ETL for a cost estimatewhen doing initial planning!

31. Frequently Asked Questions • How do you determine if a test item is tested on the large shaker versus the small shakers? • On the small shakers, we have a head expander that can accommodate a 24”X24” test fixture. If your test item has a footprint that can fit on that fixture, we can perform your test on the small shakers. If your test item has a footprint larger than 24”X24”, we will need to test on the large shaker to avoid butterflying that will occur from shaking a fixture that overhangs the head expander. The overhanging area of the fixture will be shaking unsupported and will introduce unacceptable levels of uncontrolled vibration to your test item.

32. Frequently Asked Questions • What is JCI? • JPL Critical Items (JCI) are project critical hardware, software and test or handling equipment, including fixtures or ground support equipment that if damaged or lost would: • 1. Jeopardize the success of the Project • 2. Increase the Project’s cost substantially, or in any case have an impact of $100,000 or greater • 3. Adversely affect the Project’s schedule • 4. Cause embarrassment to the Laboratory.

33. Frequently Asked Questions • What do the different “Test Levels” mean? • Developmental • Levels conducted on non-flight hardware to determine functional capabilities of a design concept • Test duration as needed. Often testing performed to Qualification levels. • Qualification • Levels conducted on non-flight hardware to determine if the hardware can perform and survive at levels which exceed the conditions expected to be encountered during the mission, typically to qualify hardware design. Levels are typically Flight Acceptance levels plus 3 dB, performed for twice the duration. • Test duration 120 seconds per axis. • Flight Acceptance • Levels conducted on flight hardware at levels selected to simulate the expected conditions during the mission. • Test duration 60 seconds per axis. • Protoflight • Levels conducted on flight hardware as a compromise between Qualification and Flight Acceptance test levels. Levels are typically Flight Acceptance levels plus 3 dB.. • Test duration 60 seconds per axis.

34. Frequently Asked Questions • What’s the difference between a Test Plan and a Test Procedure? • Test Plan • Is written by the Dynamics Environments Engineer (Dynamicist) • Specifies test levels • Specifies response accelerometer and force transducer locations • Specifies intended conduct of the test • Test Procedure • Is written by the Dynamics Test Engineer based on the information from the Test Plan • Specifies test levels • Specifies how to operate the test equipment The actual conduct of the test, as it occurs, is documented on a Test Log Sheet and will be part of the job package.

35. Frequently Asked Questions • What do I need to do in case of an anomaly during test ? • Stop the test with the kill switch or have test operators abort the test. • Notify your Dynamicist and QA of the nature of the anomaly. • Secure facility from operation and ensure that the test item is not at risk. • QA to document the steps that lead to the anomaly with the concurrence of all participants of the test operation. • You need to call your Project Delivery Manager and discuss what conclusions should be drawn from the anomaly and what course of action should be followed. • This could involve a teleconference with any number of Project, Safety and Stress Analysis personnel. (to be determined real time, depending on the extant situation). Your Dynamicist and QA will already be present and will participate in this discussion. • If the anomaly can be resolved reasonably by the hardware test team, testing may continue IF no member of the team has any doubt about proceeding with the test. • Prior to the start of any troubleshooting, ALL test items will be removed from the test equipment.

36. Frequently Asked Questions • What do I need to do in case of an anomaly during test ? (Continued) • Prior to the start of any troubleshooting, ALL test items will be removed from the test equipment. (It bears repeating.) • If any test team member has a concern about the restart of the test or the cause of the anomaly, the Dynamics Test Engineer will secure the test facility and contact the following personnel: • ETL Supervisor. • Section 376 Section Manager • Instrumentation Engineer to ensure data has been secured • Anomalies shall be documented within one working day of the incident/observation by the QA representative in an Inspection Report or by the Cognizant Engineer in a PFR.

37. Frequently Asked Questions • What do I need to do in case of a mishap during test? • Stop the test with the kill switch or have test operators abort the test if the equipment is still operating. Immediately secure facility from operation. • Instrumentation Engineer to ensure data has been secured. • Notify your Dynamicist and QA of the nature of the mishap. • QA to document the steps that lead to the mishap with the concurrence of all participants of the test operation. • You need to call your Project Delivery Manager, Safety and Mission Assurance to report the mishap. • Based on the discussion with the above personnel, you will write a PFR.

38. Frequently Asked Questions • If the ETL Technicians have had Flight Hardware Safety training, why are Flight Technicians required to install my hardware? A.Since the Flight Technicians are more familiar with your hardware they are less likely to mishandle it. The ETL does not want to assume the risk of handling delicate hardware that we are not be familiar with.

39. Frequently Asked Questions • What documents control the conduct of Dynamics testing? • JPL Rules 34880 (D-560), JPL Standard for Systems Safety • JPL Rules 35492 (900-434), Standard Environmental Testing Facilities and Practices • JPL Rules 35515 (CD503620), Detail Specification for Evaluation and Acceptance of Dynamic Test fixtures Used in Vibration and Shock Environmental Tests (Assembly Level) • JPL Rules 33472, Environmental Laboratory Services Policy • JPL Rules 33832, Environmental Testing Procedure • Note: The ETL Users’ Guide is available on-line at https://jpl-web.jpl.nasa.gov/etl/documents/D-63875%20ETL%20Facilities%20Guide_030810.pdf