Is an indefinite lifespan, i.e. eternal life/immortality, possible?

Immortality (or eternal life) is the concept of living in a physical or spiritual form for an inconceivably vast length of time. Aging and death are two enemies of the human race that have eluded the grasps of the human mind making it incapable of them being defeated by resources we know of today. But recent advances of mankind in the fields of technology and medicine have shed a glimmer of light on ways to conquer these adversaries to human life or at least further elongate the chances of our survival against them. The establishment of new technologies and sciences such as: Telomerase, Transhumanism, Cryonics, Mind uploading, and Cyborgology; are some of the many ways that mankind is waging war on death and aging. So the Question arises: Is an indefinite lifespan, i.e. eternal life/immortality, possible? -Conrad James, HS Sopre