I don't know if NASA themselves do, but Zero-G does. I want to get the money for it one day.. but I'm terrified of heights, not sure how it would work.. 
This would not be a problem I think. The zero-g airplanes don't even have passenger windows, which is important to create this perfect illusion of floating through space. So you can't look outside and you don't have any perception of heights. Basically you are in that long big tube-shaped room which is illuminated quite brightly, but with no opportunity to look outside to check your position relative to earth. Maybe this would be more of a problem for people suffering from claustrophobia, but not if you are "just" scared of heights...
If you have been flying before and did not have any problems in that regard, you would be okay on a zero G flight as well.
So: Go ahead and give it a try! At least start saving some money for it...
And in reference to your flight... You're lucky as heck. I would love to try this. What did it feel like, just floating?
I know I was VERY lucky, not only because I got invited, but in the first place because I got the chance to participate in such a flight with the guys who usually train the real cosmonauts. It was one of my biggest dreams that came true.
So, being aware that I was very lucky, I always like to share some of that experience with people who are interested (like you and maybe some other users here):
So what did it feel like:
It is actually very hard, almost impossible, to describe this feeling of weightlessness, as it is completely incomparable to anything I have done in my life (including flying in all kinds of aircraft, fast and slow). Some people say it is like floating underwater, but well... it is NOT. In the water you still have the resistance of the water that helps you control your movements, and you are still in one G, although this is balanced by the buoyancy of your body in the water ("neutral buoyancy").
So, being weightless under real zero G conditions just feels like that: weightless...
Everything that is not safely attached to the airplane floats around, people included. A slight push with your hand or your foot against the cabin walls will send you floating across the cabin in the exact opposite direction of your push. (No better way to prove Newton's law that "action equals reaction"
)
As the IL-76 was originally built as a cargo plane, its cabin is rather big, about 3 meters high, 4 meters wide and 24 meters long. So, if you are floating in the middle of the cabin, with no possibility to touch the walls, the floor or the ceiling, you would just hang there with no chance to get anywhere. If you can't manage to get hold of one of the railing bars along the cabin walls before the pilot pulls the plane out of its parabolic dive, you would crash to the padded floor with a force of 2 G! Of course there were instructors on board that watched over us and helped us to get a hold each time before a parabola ended. There was also a flight surgeon on board who had the authority to stop the parabolas immediately and end the flight if somebody developed an unforseen medical problem.
The day before the flight we had to attend a thorough briefing and a medical check. Another short medical check was done immediately before the flight as well as a safety briefing.
After the flight I received a certificate (in Russian of course!
), signed by the director of the Cosmonaut Training Center, veteran cosmonaut Vasiliy Tsibliyev.
The Russian crewmembers were all very nice and helpful despite the fact not everybody was speaking English and me not speaking Russian. Anyway we had a good party that evening after the flight...
I also had a nice and very interesting chat with Yuri Gidzenko after the flight. He seemed to be quite surprised that I knew who he was and that I was interested to hear from him about his experiences aboard Mir and ISS. He had a lot of storys to tell, of course.
The most easiest and cheapest way to experience zero-g is to have a friend who has a PPL (Private Pilot Licence)
Of course a parabola flight with a Cessna is rather short, but nevertheless it's zero-g
I have done this before also. It can be exciting, but it can hardly compare to a "real" zero G flight. In a small plane you usually wear your seat belts and therefore are attached to the plane. The cabin is very small and you can not float anywhere, even if you unbuckle. Also, you have those big windows where you can see the outside world and instinctively check your position in relation to earth. This would destroy the illusion of floating weightless in a space, because your eyes see what your body feels: you are falling towards earth. In this case your reference is the outside world, not the cabin.
On a zero G flight you have no windows. So, the only reference you have is the inside of the cabin: Your eyes see that you are not moving but your body feels no gravity, like you were falling. This creats that perfect illusion of weightless floating.
Tried -4G on a C152 and did not like it that much - LOL! I prefer +G any day (for as long as itis belo 9G of course).
/Admin
-4 G? Ouh, that's bad! About the preference: I have had some high G experience before, both with and without G-suit. Believe me, I would prefer 25 seconds of 0 G over 25 seconds of 5 G (or even 3 G) anytime...
(Oops, just noticed this is quite a long post which may be somewhat off topic. So, Admin, may want to split the thread and create a new one, together with the 5 or so preceding posts?)
