Huxley wrote Brave New World amid a significant number of influences regarding science, fiction and social commentary. Huxley himself was known for his social commentaries, and intended the novel to be both a sort of ironic counter-commentary to the more utopian science fiction novels of the time, and a social critique of what he envisioned the modern, science-driven world might devolve into.
The main emphasis and impact of science in the story is not science or the scientific method itself, but the hallmarks of the Industrial Revolution, such as mechanization, assembly-line production and uniformity, as they might be applied to people and societies. Thus it is important that we distinguish between science as a procedure, philosophy and academic domain, and technology, as an application of science to human needs and desires. Most of the things we critique in Brave New World are technologies. This is even suggested by John when he considers his own limited knowledge; that science is something you "made helicopters with".
Mustapha Mond elaborates at length about the true role of science in society in Chapter 16.
"Yes," Mustapha Mond was saying, "that's another item in the cost of stability. It isn't only art that's incompatible with happiness; it's also science. Science is dangerous; we have to keep it most carefully chained and muzzled."
There are several concepts key to the New World Order that are discussed in this section. Science, far from being the true solution to the world's problems and a replacement for religion, is really just a means to an end itself. The real dichotomy is between truth and happiness. While art and science can be made to serve truth, they can also diminish happiness. The only means of achieving happiness is control; thus this society controls all things, in order to ensure happiness, and does so in whatever ways will serve it best, such as by eliminating art. Science is no more or less helpful than anything else, and is surely dangerous if left "pure" as Mond suggests.
Thus, science is valuable when it can discover or create control and happiness; it is not valuable when it diminishes these things. Science is "muzzled" so that it is really more of a funnel toward specific technologies, which results in the sort of implements we see impacting daily life, like birth control and other hormonal manipulations. The science of Brave New World is not science as we commonly discuss or understand the subject.