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Hydrogen Properties for Energy Research (HYPER) Lab Elijah Shoemake

Cryo-cycling in place – Styrofoam cups and Silly Putty to the rescue!

In this past post, we discussed using cryo-cycling  to identify and fix possible cold leaks before installing equipment in the cryostat. This prevents a lot of problems before they can happen, often saving days of cool-down and warm-up if a test has to be called off. What happens, however, when the leak opens up cold? Your experiment is happily running along at cryogenic temperatures and, all of a sudden, that last temperature cycle proves too much. A crack is allowed to widen through an epoxy joint until you have a little leak and the test has to be called off. When you warm up, the expansion of the epoxy seals the crack and the leak is gone! One option in this situation would be to disassemble the entire system, testing each possible leak location as previously discussed. If your system isn’t a simple one, this could be a serious time investment, and opens up a lot of opportunity for you to break something else, improperly re-install a component, or otherwise mess up something that was already working fine. It was for this reason we developed a system for cryo-cycling in place – using nothing more than a Styrofoam cup and some Silly Putty!

Cryo-cycling in place – Instructions based off ASTM E499/E499M – 11 Test Method A:

  • Take a Styrofoam cup and cut a hole in the bottom or side of the cup just big enough to snugly fit around the test specimen.

    Styrofoam cup photo
    A Styrofoam cup with hole cut in the bottom.
  • Wrap a thin ring of Silly Putty around the test specimen where the cup will seal against the specimen.
  • Slide the Styrofoam cup onto the test specimen, the Silly putty should extrude into the cup a little bit and form a good seal against the cup and the test specimen.

    Styrofoam cup fit around hotwire plug image.
    Styrofoam cup in place. Notice the Silly Putty sticking through at the seal.
  • Apply more Silly Putty, wrapping it around the test specimen and the inside of the cup to completely seal the bottom of the cup.

    Image of cup fitted around hotwire sensor with Silly Putty seal.
    Filling in the Silly Putty for a complete seal.
  • Fill the cup with liquid nitrogen (LN2) to start cooling down the cup and test specimen. As it cools, the Silly Putty will quickly transition through it’s glass transition temperature, first turning rubbery and then becoming a hard plastic that will be a sturdy seal.

    Image of LN2 in the Styrofoam cup
    Sealed Styrofoam cup filled with LN2
  • Sniff all fittings, welds, and solder joints with mass spectrometer by passing the sniffer probe over likely leak points. Start at the bottom of the assembly and work your way up, holding the probe on or not more than 1mm from the surface. Do not move the probe faster than 20mm/s.
  • Continue sniffing in an orderly procedure from bottom to top. Mark any leaks so they can be remedied. Be aware that helium will rise, so a leak above a previously found leak may not actually exist. It is also important to be aware of the airflow in the room, as helium can be blown around the experiment and produce small “leaks” that don’t actually exist.
  • If any leaks are identified, take corrective action and restart this procedure. You may have to let the Silly Putty warm up a while before it is soft enough to be removed.


The HYPER lab tube fitting guide

This post summarizes the use of Swagelok® Tube Fittings, which are used extensively in the HYPER lab. If you’re already familiar with tube fittings, you may want to skip to the best practices at the bottom. Most of this guide is pulled directly from “An Installer’s Pocket Guide for Swagelok® Tube Fittings.” If you haven’t read this already, you should! We have several physical copies around the lab.


Table of Contents

What is a tube fitting?

Swagelok® Tube Fittings are also referred to as Swagelok Fittings, Tube Fittings, or Compression Fittings. You’ll see similar fittings at the local hardware store, but beware – they aren’t the same! While both the hardware store variety of compression fitting, and the Swagelok fitting operate by swaging, or forming the tube around hard metal ferrules, the Swagelok fitting is a robust, double ferrule design whereas the hardware store variety is almost always a single ferrule design. In the above picture, you see a female nut with the two hard metal ferrules installed correctly to a male fitting body (in this case, an NPT adapter). The bends in the tubing around the ferrules signify the seal locations between the ferrules and the tubing.

First Installation: Swaging

Before Installing for the first time, ensure that the tubing and fitting are in good order. The tubing should be clean and free of scratches at the ends. The tubing should already be bent into the desired shape, and you should check  for sizing to ensure proper fit (this insures we don’t waste nuts and ferrules by swaging onto the tubing before measuring). If you cut the tubing, be sure to clean the tubing with a burr-removal tool. The tubing end should be completely round and clear of burrs or dents.

The above steps point you through the process of swaging the nut ferrule onto a fitting. Be aware! While most of our fittings require 1-1/4 turns to swage, smaller fittings may require 3/4 turn. Make sure your tubing is all the way into the fitting body – you will not get a good seal if you don’t properly seat the tubing.

After your first installation (swaging the ferrules on the tubing) you can ensure proper tightening by using the gauging tool. HYPER lab has a gauging tool that can test our most commonly used fitting sizes. Try to insert the correct side of the gauging tool into the gap between the nut and fitting body. If you are able to insert the gauging tool into the gap, the fitting must be tightened further. If you cannot, the fitting is properly tightened. BEWARE: The gauging tool only works on the initial installation of the fitting. If you remove the tubing from the fitting and reseal, you are not guaranteed proper tightening with the gauging tool.

Reinstallation: When you have to disconnect and reconnect lines.

Before you disconnect a tube fitting, ensure that the system is depressurized. It is not recommended that you depressurize any system by loosening any fitting, including tubing fittings. Doing so could potentially shoot fittings and/or tubing across the room. Mark the fitting as indicated in the instructions below before taking the fitting apart.


Again, as stated above, the gauging tool will not help you to determine if a fitting you have resealed is correctly tightened.

Best Practices

The following list are best practices developed by members of the lab for working with tubing fittings.

Marking fittings

Always mark fittings before tightening (or loosening) the fittings. It will ensure that fittings are properly tightened, and will prevent over-tightening. This will increase the lifespan of our fittings and tubing. Clean fittings after finishing so your markings don’t get in the way for next time.

Hard to reach fittings

If the fitting body you’re trying to attach tubing to is in a hard to reach area, use a different fitting body to swage the tubing, then remove the tube from the fitting and install in location. In this case, you will not be able to use markings to help you reseal the fitting – tighten the fitting until hand tight, then tighten 1/4 turn more with wrenches.

Correct tubing thicknesses

The recommended tubing thickness for using fractional tubing fittings for stainless steel and copper tubing are given below. For gas service, it is recommended that you use a tubing thickness outside the shaded areas in the charts.

Stainless Steel Tubing Sizing Chart for Tube Fittings
Stainless Steel Tubing Sizing Chart for Tube Fittings
Copper Tubing Sizing Chart for Tube Fittings

For other materials, or metric recommendations, please consult “An Installer’s Pocket Guide for Swagelok® Tube Fittings.”

Surplus: What, Why, and How

Sometimes it’s necessary to remove the junk, and here’s how we do it:

  1. #1Log in to myFacilities with your WSU Network ID
  2. #2In the list, select the link for Work Request
  3. #3 Select “Request pick-up or drop-off of Surplus items”
  4. #4 Fill out the items to be surplused, and then choose “Landeen, Gayle” in the dropdown menu for approval authority.
  5. Submit the form, and you’re done!


Saving money (and time!) with HYPER’s wiring system – Vacuum Feedthroughs

Due to the very cold nature of our work, we find ourselves needing to design (and redesign) vacuum chambers on a regular basis. In order to do useful research, this usually means trying to pass electrical signals through a high vacuum seal, which as you may expect, takes time and money. However, we’ve come up with a few tricks to reduce our time and dollar expenditures.

First, we reduce the cost of our vacuum feedthrough components. An example of a prebuilt solution is $551 for 7 connection pins, but we can build a 26 pin passthrough for around $120. To reduce the cost of the hermetic connecter itself, we use a very common military hermetic specification, the MIL-DTL-26482 Series I MS3113 (Male) with matching a female connector MS3116F16-26S. The cheapest we’ve found this so far is through Detoronics. We will also order a KF blank through Ideal Vacuum Products or McMaster-Carr. By soldering the connector together, we save a significant amount of money.

Male side installed on a KF flange
MIL-DTL-26482 Series I MS3113 installed on a KF flange
MS3116F16-26S with installed leads

Secondly, and most importantly, when we set up a vacuum feedthrough, we never solder connections directly to the hermetic connector. By putting a second, non-hermetic connector between sensors and the passthrough, we can avoid having to replace the expensive vacuum feedthrough, and instead just replace the inexpensive standard plug. For this second connector, the HYPER lab uses another inexpensive common connector, the 25 pin D-sub.

A 25 pin D sub connector installed inside CHEF
A 25 pin D sub connector installed inside CHEF

Instructions and pinout as follows:

Needed: 2 female 25 pin D-sub connectors, 1 MS3113M16-26S, 1 MS3116F16-26S, 1 KF blank (we usually use KF40, KF25 if a more compact application is required.)

25 pin D-sub to MS3113/MS3116F16-26S to 25 pin D-sub

  1. Attach MIL-DTL-26482 Series I to KF flange, as shown in the post above.
  2. Starting at Pin 25, follow pinout to connect D-sub to Hermetic
    26 pin MIL-SPEC connector pinout
    26 pin MIL-SPEC connector pinout
    25 pin D Sub pinout
    25 pin D Sub pinout
    1. Pin 25 – Pin c
    2. Pin 24 – Pin b
    3. Pin 23 – Pin a
    4. Pin 22 – Pin Z
    5. Pin 21 – Pin Y
    6. Pin 20 – Pin X
    7. Pin 19 – Pin W
    8. Pin 18 – Pin V
    9. Pin 17 – Pin U
    10. Pin 16 – Pin T
    11. Pin 15 – Pin S
    12. Pin 14 – Pin R
    13. Pin 13 – Pin P
    14. Pin 12 – Pin N
    15. Pin 11 – Pin M
    16. Pin 10 – Pin L
    17. Pin 9 – Pin K
    18. Pin 8 – Pin J
    19. Pin 7 – Pin H
    20. Pin 6 – Pin G
    21. Pin 5 – Pin F
    22. Pin 4 – Pin E
    23. Pin 3 – Pin D
    24. Pin 2 – Pin C
    25. Pin 1 – Pin B

Note: Pin A on the hermetic connector should be free.

3. Starting again at Pin 25, connect the D-Sub to the other side of the hermetic using the same pinout.

Your completed passthrough!
Your completed passthrough!

Finding Cryogenic Material Propeties

Many people don’t consider from day to day how we know properties of any given material for use in design. It seems to be common knowledge that water freezes at 0°C, and it’s easy enough to look up thermal conductivities or heat capacity of common metals, gasses, and building materials. What happens, however, when your operating conditions are hundreds of degrees below room temperature? You can’t assume the same, easily found values anymore – you have to find someone who has taken the measurements at those extreme temperatures. So where do you go? Here’s a list of some good options we’ve used in the past to find data.

  1. Engineering Equation Solver (EES)
    • The lab uses EES for much of the thermodynamic calculations we do, and one reason is that it has standard curves for thermodynamic properties of many materials across a wide range of operating conditions. Through available function calls, you can get accurate thermodynamic properties for the most common real and ideal fluids, even at cryogenic temperatures. EES also has a selection of commonly used incompressible substances. Whenever using a material for the first time, make sure you look at the substance properties and references to ensure you understand the valid operating conditions and assumptions the substance is using.
  2. NIST Cryogenic Materials Database
    • NIST has data for several common structural materials at cryogenic materials. Some of these are referenced as incompressible substances in EES, some are not. The specific properties given varies for the different substances.
  3. / Jack Ekin’s Experimental Techniques for Low-temperature Measurements: Cryostat Design, Materials Properties, and Superconductor Critical-Current Testing
    • This site provides supplemental information and updates for the book Experimental Techniques for Low-temperature Measurements: Cryostat Design, Materials Properties, and Superconductor Critical-Current Testing, published by Oxford University Press in 2006, 2007, and 2011. The book is a handy guide we often use for reference in building our cryogenic systems. The site has many figures and data tables from the book, including many on the varies properties of materials commonly used in cryogenic design. The book provides much further insight into design that is not available on the website, and the lab owns several copies for reference.

These are the sources we’ve used the most in the lab – please let us know if you have a favorite we haven’t listed!

Cryogenic Seals using Indium

Finding a way to seal small, mobile molecules such as hydrogen and helium at cryogenic temperatures can be quite difficult. Most common seals break down at such cold temperatures, and even a tiny leak path can be catastrophic when working with flammable gasses and temperatures that can freeze the oxygen right out of the air. Luckily, we have wonder element 49: Indium. High purity indium has a lower melting point, and hardness than lead, making it malleable enough to be an effective sealing material. In addition, at high purities, indium readily pressure welds to itself, and bonds to other metals, glass, and ceramics.

Lab member Casey Evans installing a cryogenic indium seal.
Lab member Casey Evans installing a cryogenic indium seal.

In the HYPER lab, we’re set up to extrude 0.0625 inch (1.5875 mm) and 0.1 inch (2.54 mm) diameter wire, and therefore use this wire size most often. For most seals we create, this is a usable size, and allows us to standardize seal design and indium extrusion. Although much of our wire is recycled and re-extruded, we will occasionally buy new indium wire from Indium Wire Extrusion, currently priced at $150 /oz.

A good indium vacuum seal is designed to fill a small gap around the sealed volume with pure indium through an even application of pressure, usually using a bolted flange. Making things easier for us, Indium Wire Extrusion has some helpful guidelines for proper indium seal design. Indium Wire Extrusion recommends three types of indium seals:

  1. A semicircular indium seal. This seal is created by using a ball end mill to machine out a rounded ring in one side of the sealing flange. The other side of the sealing flange should be polished smooth to provide a good sealing surface. Recommended geometry is to use a ball end mill the same diameter as the wire you’re using and machine to a depth equal to half the wire diameter.
  2. A rectangular groove seal with mating surface. This seal is created by machining a rectangular step groove into one side of the flange, and a smaller rectangular step protrusion on the other side of the flange. This geometry has the advantage of not only providing a secure effective seal, but also self aligning the flanges so the seal occurs in the same place every time. Recommended geometry is a groove the same width as the the wire being used to seal and a gap area equal to ~80% of the wire cross sectional area. The protruded step should be chamfered to allow the indium to easily flow into the gap to the sides of the protrusion.
  3. Similar to the first sealing method, you can use a single seal on the flange, but with a square step groove. This can be machined with a standard flat nosed end mill. Again, the gap area of the seal should be 80% or slightly less of the cross sectional area of the wire.

Some other general suggestions when creating / using indium seals:

  1. While HYPER lab hasn’t done this extensively in the past, it can be very helpful to include a jack screw in the flange design. Indium seals after compression and cryo-cycling can be very difficult to pull apart and a jack screw will ensure that you can get the flange back apart for the next run!
  2. When creating the indium o-ring, cut the ends at as shallow an angle as possible. Ensure these ends are overlapping, so that one end of the indium wire will crush on the other to seal the ring together. A straight 90° cut will leave a gap between the ends of the indium wire in the ring, which can allow a leak path through the seal.

Cleaning Helium Compressors

The helium compressor that drives a cryocooler has to effectively reject the heat it’s removing from the helium stream to prevent itself from overheating, and keep the cryocooler cooling efficiently. In most cases, this means running a heat exchanger with a cooled water loop to keep everything cool. This can be very effective when you’re running high purity, clean water through the heat exchanger, but dirty, rusty, or impure water can reduce performance and foul the heat exchanger tubes. In the lab, we use a cooling loop independent from the building water paired with a water filter to help keep water as clean as possible in the loop. Unfortunately, our water pump in the loop had a cast iron casing and impeller, which began to rust and dirty the water. During the process of cleaning out the water and rebuilding the system, we’ve learned a few things about our cryocoolers and keeping them clean.

Sumitomo (SHI) Cryogenics:

The heat exchanger built into the SHI HE-4 cryocooler is a 1/2″ flattened copper tube, and pretty robust. It’s unlikely for anything to get stuck in the tube, although fouling on the surface is possible. Calling Sumitomo, they recommended reversing the water flow through the heat exchanger while the compressor is off to ensure the heat exchanger is free of obstruction. Running vinegar solution through the lines will help remove fouling.

Cryomech Compressors:

Similar to the Sunitomo cryocooler above, the Cryomech cryocoolers also use copper tube in their heat exchangers. The technical representative from Cryomech recommends reversing the flow on the heat exchanger and to flush the system with a standard strength Calcium, Lime, and Rust (CLR) Remover solution. In the event of sludge build up, a 50 wt. % solution of hydrogen peroxide (H2O2) is a viable option in extreme cases.

ME 527: Lesson 14 – All About Gibbs!

Discovery and Origins – J. Willard Gibbs

Josiah_Willard_GibbsJosiah Willard Gibbs, born in 1839, was deemed by Einstein as “the greatest mind in American history.” Gibbs primarily focused on physical chemistry and its chemical reaction relationship with thermodynamics. During the years 1876-1878, he published the famous “On the Equilibrium of Heterogeneous Substances” in the Transactions of the Connecticut Academy of Arts and Sciences. He will later earn the most prestigious international science award in its time, the “Copley Medal of the British Royal Society” in 1901. Within the publication, the discovery of free energy emerged; now known as Gibbs free energy1. Gibbs described this energy as:

“The greatest amount mechanical work which can be obtained from a given quantity of a certain substance in a given initial state, without increasing its total volume or allowing heat to pass to or from external bodies, except such as at the close of the processes are left in their initial condition.”

This “mechanical work” or energy can be thought of as the maximum amount of non-expansion work extracted from a closed system. The work done is at the expense of the internal energy of the system and any portion of the work not extracted is lost to the environment in the form of heat.

His discovery led to the development of quantum mechanics, further discoveries in theoretical physics, and in statistical mechanics.



Gibbs Free Energy

Gibbs free energy is usually expressed as:

gibbs_equationThe fundamental property relation can then be expressed as:

Where h is the enthalpy, T is the temperature, and s is the entropy, P is the pressure, and v is the specific volume.

The Gibbs fundamental property relation equation (dg) shows the most commonly used form of the Gibbs Free Energy Equation. Gibbs is most useful being in terms of temperature and pressure. This is because the ability to quantify entropy and -enthalpy pose to be a much more complicated task.

Although the Helmholtz Free Energy Equation is the most used fundamental property relation, Gibbs’ equation is still used primarily by chemists and physicists. Its primarily uses are to determine:

  1. The chemical potential
  2. Electrochemical properties of fluids
  3. Excess enthalpies of fluid mixtures
  4. Equilibrium properties of fluids when the temperature and pressure of the system is known

The dg predicts the direction of the chemical reaction and tells whether the reaction is spontaneous or nonspontaneous; meaning, whether the reaction may occur with or without applied external energy to the system. Note that a negative dg between two phases does not guarantee that a phase change will happen quickly, or even at all! At atmospheric temperature and pressure a diamond is NOT the lowest Gibbs energy state, however metastability means that it will take a time that is comparable with the duration of the universe before it will turn back into its Carbon form. The same can be seen in supercooled liquids below the freezing point, where an impurity or energy inputs can cause it to rapidly freeze. The use of a catalyst, impurities, or seed crystals can significantly lower the dg necessary to instigate a phase change. This is an important concept in interfacial phenomena where one can decrease, or even increase the energy barrier necessary to casue a phase change.

Although Gibbs’ equation is classified as an Equation of State, Gibbs’ equation is not the ideal fundamental property relation to use in plotting specific states; such as, density, pressure, temperature, etc.; s discussed in Lesson 10. This is because the Gibbs equation cannot accurately determine specific states when the temperature and pressure are not independent quantities; predominately at phase changes. As Dr. Leachman stated, the “inability of the Gibbs Energy to differentiate phase in the most commonly used temperature and pressure coordinates is why modern EOS are explicit in Helmholtz Energy.2

Below is the correlation between the commonly used form of Gibbs Free Energy and the most used form of the Helmholtz Energy Equation:

The Helmholtz Equation can be represented by:


The most common form of the Helmholtz Equation is in its reduced non-dimensionalized form:


The relation of Gibbs to Helmholtz energy equation can then be represented as:


Where α is the reduced Helmholtz energy and:




where tao is the reduced inverse temperature and delta is the reduced density. Typically, the critical density and temperature are used in place of the the reduced density and temperature. This is done to reduce the density and the inverse temperature.


Cryo-cycling for better leak testing

One of the biggest issues that you will run into working with cryogenic fluid systems is finding and fixing leaks, especially those leaks that open up at low temperature. A helium leak detector and a bottle of soapy water does wonders for finding leaks at room temperature, but in order to get components down to working temperature in the cryostat you have to enclose the entire experiment in a vacuum chamber and cool everything down via cryocooler – not a very easy environment to isolate the location of a leak! An example of this is that in some cases (usually poor joints between multiple different materials), brazed joints will have no leakage at room temperature, but new leaks will open up after getting really cold. We have had this happen anywhere from 80 to 200 Kelvin, and as these temperatures are far below your typical room conditions, they’re very difficult to isolate. To try and speed up the process of checking if leaks would open, our recommended practice for all cold joints and fittings is therefore to test in liquid nitrogen (LN2) before installation on the system.

General Instructions for LN2 Leak Checking, based off ASTM E499/E499M – 11 Test Method A:

  • Cap the test specimen and connect to a helium bottle. Pressurize the test specimen with helium to the working pressure of the specimen.
  • Dip the test specimen into LN2 to cool it down to the LN2 temperature of approximately 77 K.
  • Sniff all fittings, welds, and solder joints with the mass spectrometer by passing the sniffer probe over likely leak points. Start at the bottom of the specimen and work your way up, holding the probe on or not more than 1mm from the surface. Do not move the probe faster than 20mm/s.
  • Continue sniffing in an orderly procedure from bottom to top. Identify any leaks so they can be remedied. Be aware that helium will rise, so a leak above a previously found leak may not actually exist. It is also important to be aware of the airflow in the room, as helium can be blown around the experiment and produce small “leaks” that don’t actually exist. When testing with a short line from the helium bottle, be aware that the regulator connection into the bottle often leaks at a higher rate than is acceptable for our cryo experiments, and can cause false alarms (This can usually be remedied with longer lines to move the specimen farther from the bottle and by keeping the specimen low, well below the bottle).
  • If any leaks are identified, take corrective action and perform this procedure again until leaks are no longer detected.

This is recommended for cryo-rated valves, small pressurized vessels, or any other cold equipment that you don’t mind completely submerging in LN2. It will definitely save yourself a lot of time by doing this every time!

ME 316 Lesson 39: System Ethics – Case Study I

Today we’re going to discuss a complex case with multiple ethical considerations, but first, let’s watch a shuttle launch.

The Challenger disaster came at a time where NASA was trying to deal with the harsh reality of space, for the first time, was becoming “old-hat.” Media attention had dropped significantly from the Apollo moon missions, and Challenger was an attempt to rekindle some interest in the space – largely through the inclusion of Christa McAuliffe, who was to be the first teacher in space. NASA relied on it’s popularity to rationalize the amount of funding it received, and was facing criticism that shuttles were flawed design and never live up to their expense. This, combined with “every day” concerns of operating an expensive, complex system like the Space Shuttle (cost of launch abort, several previous delays, cost of personnel and maintenance already dedicated to launching on time, etc.) put a great deal of pressure on NASA to launch without further delay. The communications structure internal to NASA, as well as between NASA and it’s suppliers, passed this pressure on to suppliers such as Morton-Thiokol, the manufacturer of the Solid Rocket Boosters (SRBs). What resulted was a series of ethical issues, before and after the accident, which in some cases were handled properly, and in some cases, were not. See below:

Sections of the Code of Ethics pertaining to this case:

I. Introduction

1. Hold paramount the safety, health, and welfare of the public.

3. Issue public statements only in an objective and truthful manner.

5. Avoid deceptive acts.

6. Conduct themselves honorably, responsibly, ethically, and lawfully so as to enhance the honor, reputation, and usefulness of the profession.

II. Rules of Conduct

1. Engineers shall hold paramount the safety, health, and welfare of the public.

a. If engineers’ judgment is overruled under circumstances that endanger life or property, they shall notify their employer or client and such other authority as may be appropriate.

e. Engineers shall not aid or abet the unlawful practice of engineering by a person or firm.

3. Engineers shall issue public statements only in an objective and truthful manner.

a. Engineers shall be objective and truthful in professional reports, statements, or testimony. They shall include all relevant and pertinent information in such reports, statements, or testimony, which should bear the date indicating when it was current.

b. Engineers may express publicly technical opinions that are founded upon knowledge of the facts and competence in the subject matter.

5. Engineers shall avoid deceptive acts.

III. Professional Obligations

1. Engineers shall be guided in all their relations by the highest standards of honesty and integrity.

a. Engineers shall acknowledge their errors and shall not distort or alter the facts.

b. Engineers shall advise their clients or employers when they believe a project will not be successful.

2. Engineers shall at all times strive to serve the public interest

b. Engineers shall not complete, sign, or seal plans and/or specifications that are not in conformity with applicable engineering standards. If the client or employer insists on such unprofessional conduct, they shall notify the proper authorities and withdraw from further service on the project.

3. Engineers shall avoid all conduct or practice that deceives the public.

a. Engineers shall avoid the use of statements containing a material misrepresentation of fact or omitting a material fact.

5. Engineers shall not be influenced in their professional duties by conflicting interests.


A few further considerations on the ethical design and operation of the Space Shuttle:

It is believed that the crew of the shuttle survived until impact with the surface of the ocean, and possible that they may have been conscious. Emergency air supplies had been turned on, and several safety switches on the pilot’s electrical console were moved from launch positions. Despite this, there was no way for the crew to survive the disaster. Ejection seats had been implemented on earlier test flights, but, as the Roger’s Report states, “Other options for “operational” flights carrying crews of five or more astronauts were considered, but were not implemented because of limited utility, technical complexity and excessive cost in dollars, weight or schedule delays.”
Was it ethical to design a system where the users had no chance of surviving such a catastrophic failure?

Christa McAuliffe was a civilian teacher, put on the shuttle largely as a PR stunt for NASA and the Regan administration. She was not a member of the astronaut corps and had only 4 months of training before launch, rather than the extensive 20 month training given to astronauts. Was it ethical to include her in such a high risk situation, and was she properly informed and prepared for the risk?


Further Information:

Remembering the mistakes of Challenger at





Washington State University