I still do not see why there is such a focus on NASA. The conspiracy would have needed to be going on for a very long time pre-dating NASA.
I posted a random paper before where they were using models for plate tectonics, Earth tide, tidal loading, tectonics and some others I can not think of right now. The paper was about looking into errors of 5 mm or less in predictions. The point I was trying to make is that using different models from different fields that were based on a RE resulted in errors of less than 5 mm. Pretty accurate IMHO, considering that if the Earth was flat there should be rather large errors when combining different models to make predictions.
As given as evidence above showing scientist looking for an error of less then 5 mm most scientist involved in the Earth scientist are likely involved and publish fabricated papers to keep up the charade. Errors would resonate not only in the scientific field, but others.
HAM radio operators
Sailors and pilots that travel certain routes. Including myself that have sailed to different areas. crossed the Pacific and Atlantic and for some reason the distances all added up.
Navies for a very long time has been training look outs using falsified information or let those look outs in on the secrete.
Navigators would have needed to be in on it, celestial navigation uses math that assumes a RE.
Companies involved in communications would need to be in on it.
Of course different countries from around the world would have needed to get on board, even those that do not get a long so well with the US.
Geodetic surveyors would have needed be one of the first groups that needed to become part of the conspiracy.
I would imagine a semi-competent satellite TV installer would likely notice something odd.
Astronomers including amateurs would have to not notice anything or keep silent about it.
The conspiracy would need enforcers and a group dedicated to keep people silent who figured it out.
Unlike other organizations trying to keep a secrete this group seems to like to release a lot of information and make it readily available for scrutiny. Just look at what NASA makes available beyond just press releases. Live feeds, pictures, documents all available online.
Here is an example:
http://ntrs.nasa.gov/advSearch.jspNow try to find something like that for any organization that is widely accepted as trying to hide something from people. What you will find is limited, lacks details or simply not available.
This conspiracy would have needed to start a rather long time before NASA was even thought of. Then it would have needed to have been able to keep the secret for that time.