Your question is phrased a little bit ambiguously. There is not a lack of gravity in space, gravity is present throughout the universe. Are you instead referring to the weightlessness experienced by astronauts in orbit?

hi! you may be interested in these previous discussions

Before the launch of the first satellites, how did scientists know that there was no gravity/oxygen in space?

What did the world think about "walking in space" before humans actually went there? Were there any popular but crazy predictions?