Engage The X Drive: Ten Ways To Traverse Deep Space

The VASIMR ion engine could - if powered by an onboard nuclear reactor - take astronauts to Mars in just 39 days (Illustration: Ad Astra Rocket Company)

From New Scientist:

In 1961, Yuri Gagarin became the first human being to reach outer space. Eight years later, Neil Armstrong and Buzz Aldrin made it to the surface of the moon. And that is as far as any of us has ventured.

Apart from the mundane problems of budgets and political will, the major roadblock is that our dominant space-flight technology – chemically fuelled rockets – just isn't up to the distances involved. We can send robot probes to the outer planets, but they take years to get there.

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