6 upvotes, 1 direct replies (showing 1)
View submission: xkcd: Quantum Vacuum Virtual Plasma
No, there were **3** test articles. One was the properly configured test - which produced thrust. The second was a test article that was changed in a way that was intended to make it not work *if a specific theory on how the reaction worked was correct* - which produced thrust, but less than the proper configuration (meaning that theory was wrong). The last was an RF load capable of accepting the power from the inputs to test the sensors to see if there were anomaly in the system's sensitivity - that one produced no thrust.
Comment by djimbob at 06/08/2014 at 19:32 UTC
2 upvotes, 1 direct replies
I can't find non-paywalled access to the actual PDF describing the tests (and can't even find the cost without creating an account -- even at a research university's network) [1] only the brief summary[2].
1: http://arc.aiaa.org/doi/abs/10.2514/6.2014-4029
2: http://ntrs.nasa.gov/search.jsp?R=20140006052
Describing it as just "two drives/test articles" is accurate - as well as your description tests of a third test with just an RF load (which in the summary they don't call a drive or a test article). From the summary:
**Several different test configurations were used, including two different test articles as well as a reversal of the test article orientation. In addition, the test article was replaced by an RF load to verify that the force was not being generated by effects not associated with the test article. The two test articles were designed by Cannae LLC of Doylestown, Pennsylvania.**
...
Approximately six days of test integration were required, followed by two days of test operations, during which, technical issues were discovered and resolved. Integration of the two test articles and their supporting equipment was performed in an iterative fashion between the test bench and the vacuum chamber. In other words, the test article was tested on the bench, then moved to the chamber, then moved back as needed to resolve issues. Manual frequency control was required throughout the test. **Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the “null” test article).**
There were more than two tests and you describe a third test that wasn't an EmDrive, but an RF load (a simple RF terminator[3]).
3: http://en.wikipedia.org/wiki/Dummy_load#Radio
The fact that their "null" test article found significant thrust (even if smaller in magnitude in the null configuration) is to me a big flag to view their results very skeptically.