From what I have read and from what I have heard from people who have taken a spacecraft through from design to flight, qualification testing is very expensive and time consuming, and cite this as the reason parts and systems don't evolve quickly in the space industry. However, I've never gotten a clear detailed answer as to why qualification tests are so expensive (and time consuming). Is it because of the need to operate at high vacuum, and those vacuum chambers/vacuum pumps require a lot of maintenance to keep working properly? Or is it because a person needs to be involved to place sensors in the proper locations and interpret the data coming from the sensor?

If this is the case, why can't qualification testing be automated?

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    $\begingroup$ This is really too broad, you could write a book on this topic. $\endgroup$
    – GdD
    Commented Dec 11, 2015 at 8:51
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    $\begingroup$ Testing for space flight hardware is expensive and demanding simply because it needs to be so much more robust and complete compared to any other industry (including things like aircraft and nuclear power). The reason for that is because you can't exactly go fix something in space -- Hubble and ISS are exceptions but in general you don't have much of a chance for repair and servicing (for now). $\endgroup$ Commented Dec 11, 2015 at 18:15
  • $\begingroup$ How should I edit the question to make it more specific? Maybe ask about a certain class of spacecraft like cubesats? Or rockets below a certain payload lift to LEO? $\endgroup$
    – user11377
    Commented Dec 11, 2015 at 21:57
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    $\begingroup$ To add to Brian's comment, space vehicles & launch vehicles tend to be one-off items that take time & a lot of money to assemble - there is no mass production assembly line making them. When everything associated with space vehicles is expensive, rigorous testing is required to minimize the chances of equipment failure & financial loss. Rigorous testing just costs lots of money. Also people are always pushing the envelope to achieve higher productivities. It all adds to the costs. $\endgroup$
    – Fred
    Commented Dec 12, 2015 at 6:13
  • $\begingroup$ Here's a couple of problems that are not issues in labs on Earth: a) you cannot cool things with a fan in space; and b) there is no electric ground to connect to so your spacecraft will charge up (positive and negative, depending on location, etc.). It is incredibly difficult to make things work well and fast without running into problems relating to these two issues alone... $\endgroup$ Commented Dec 12, 2015 at 15:51

1 Answer 1


This answer addresses the last part of the question: "why can't qualification testing be automated". You have a good point, but we need to clarify some terminology.

As an aside, the earlier parts of the question have some inevitable overlap with this question here by the same OP.

Back to automation. There are two distinct concepts in testing for satellites. There is Qualification testing and Acceptance testing. Where a piece of equipment will have a "large" production run, i.e. hundreds (thrusters, amplifiers) or thousands (solar cells) then acceptance testing is a much more intuitive candidate for automation than qualification.

There are probably others who could make this distinction more formally though this is it in human terms:

  • The aim of qualification is to demonstrate that the design works and has sufficient margin to be tolerant of allowable build variations. It is usually done on just one or a small number of flight-standard production items.
  • The aim of acceptance is to demonstrate that there are no workmanship errors in each item in the production run.

Loosely, qualification testing is more severe and intrusive than acceptance testing and the tested item would usually be considered to be degraded by the qualification experience, e.g. already having suffered a lifetime of use, and would not subsequently be used for flight.

There is a relatively commonly understood range of names given to different levels in the integration process: piece part, tray, sub-assembly, equipment, subsystem, spacecraft and the concepts of qualification and acceptance can be found at every level. Whole spacecraft are often (not exclusively) subject to a middle ground in test-severity terms, called proto-flight testing, which reflects the customer's risk-tolerance and agreement that it would cost too much to build an entire satellite, test it and then never use it.


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