Is nuclear fusion easier to exploit in space than on Earth? Surprisingly, harnessing the power that drives the Sun may be a simpler challenge in propulsion terms than creating clean, safe power supplies for our planet. So says Brian Wang, whose NextBigFuture site speculates on fusion development (and, I should add, also hosts this week’s Carnival of Space). Wang, who has been following fusion development for years, notes key differences between space and planet-side technologies, one of them being that dealing with stray neutrons is easier when you can vent them directly to space, rather than developing reactor materials that can both exploit their energy and ensure maximum safety.

We know that a fusion power plant on Earth must operate for many years, working with steady state fusion that affords low maintenance and maximum reliability. Space, however, offers a different set of goals, with duty cycles in months before major overhauls, and the possibility of interesting pulsed fusion options as well. In terms of creating a clean, high vacuum, space is obviously a simpler environment than a planetary surface. Brian’s conclusion: Generating propulsion is a lesser challenge than producing electricity, while other non-electric uses of fusion, such as creating relatively inexpensive PET isotopes for use in cancer diagnosis, are equally promising offshoots of the search for fusion power.

Also of note in this week’s carnival is Dave Mosher’s post on dark energy, which offers up links to Discovery News stories covering the topic in some detail, with discussion of how dark energy is studied, where the research is headed, and why it has drawn its share of skeptics. It’s a useful package, one highlighted by James Williams’ quick video overview of the question and the ever-reliable Ray Villard’s look at the ultimate fate of the cosmos. For still more on dark energy, have a look at the video below, put together by Alexey Vikhlinin of the Smithsonian Astrophysical Observatory, describing the latest results in this new and compelling science.

The monastic plainchant in the background is a nice touch. And why not — we’re talking about principles that have shaped the growth of matter in the cosmos at the largest scales and over immense periods of time. A certain sense of awe is both welcome and inescapable.