How close are we to unraveling aging?

I have heard something along the lines of something that stops telomere DNA from becoming shorter and in effect stops the aging process. I have not done a lot of research into this topic but from what I understand the problem is that it causes cancer. Researchers believe that cancer cells are creating an enzyme called telomerase, which prevents telomere shortening. This is also why cancer cells can live forever. Aging however is not completely understood. Researchers also think that environment plays an important role in aging. I think that sometime within the next century we will have ways that greatly extend the life of humans, but I have no idea as to when, if ever, we will find a way for humans to live forever.