HeLa cells have gone to the moon to test the effect of zero gravity.

VOA: special.2010.07.21

They have found that lack of gravity has a severe effect on bones.

VOA: special.2009.03.10

Percival Lowell also studied the effect of gravity on the planet Neptune.

VOA: special.2010.07.11

Here, without the gravity effect, we can grow cells very purely and understand the mechanisms by which they are replicating.

WHITEHOUSE: President Obama's call to the International Space Station

Let me start off by saying one of the nice things about where we physically are right now is that we remove the effects of gravity, so we're able to do experiments that involve the effect of gravity basically on Earth as we look at what happens with the absence of it.

WHITEHOUSE: President Obama's call to the International Space Station

Then, of course, there's the small issue of gravity, and the effect it will have on growing vegetation, but we're thinking, at least there'd be fewer bruised apples.

ENGADGET: Alt-week 9.8.12: Moon farming, self powered health monitors and bringing a 50,000 year-old girl to life