What makes you so certain it will fail spectacularly? It hasn't
so far ...
ALL of the experiments that have not been totally refuted have
completely and utterly failed to demonstrate a consistent and a
repeatable signal that is higher than the noise threshold. Being
unable to track down all sources of noise is not the same thing
as getting a reliable signal that can be replicated in other
experiments. When we look at all of the experimental evidence
taken together it is completely consistent with zero signal
and only noise.
If you are measuring this as performance art, then sure, it has
been a rip-roaring success but if you are measuring it in terms
of science and engineering then all the experiments have totally
failed to demonstrate that the effect is real.
Just because all of the experiments thus far have either failed
or been refuted, with some experiments getting a signal in the
opposite direction of the one expected, and others getting as much
signal when vital parts of the apparatus are missing, and yet
other early experiments claiming a signal many orders of magnitude
greater than anything seen in the more controlled experiments,
doesn't mean the effect does not exist. It just means that no
matter how carefully they look, somehow, by some miracle, the
signal is always buried in the noise. When you reduce the noise
by a factor of 1,000, that darned signal also gets reduced by a
factor of 1,000.
There is absolutely no coherent theoretical explanation for why
this should work. That doesn't mean it can't work but the fact
that this "new force of nature" with numbers that were pulled out
of a hat just happens to always require an apparatus that creates
enough noise to mask the effect is highly suspicious. Basically
they need to pipe in and dissipate 1,000 Watts of microwaves in
order to create enough thrust to keep a single snowflake from
falling. Certainly it would be great if this worked but so far
there is no theoretical explanation and no experiment evidence to
indicate it does actually work. None. Zero. Zip. Nada.
The signal they are looking for is so darned small, it is almost
impossible to account for all the possible sources of noise.
Claiming that what is left over after all known sources of noise
have been eliminated must be the real signal is ridiculous. This
is why they see the signal in the wrong direction or see a signal
1,000 times greater in the earlier experiments when the noise
floor was 1,000 time greater.
The reaction to the EMDrive is very similar to the reaction to
the "face on Mars" which was also a signal that was down at the
noise threshold. Scientists who tried to explain this to the
public got castigated and got sent tons of hate mail and some may
have lost their jobs over it. When higher resolutions photos
were eventually taken, the doubting, cautious scientists were
right and the wisher and dreamers were wrong.