Robert Lemos

Ion Propulsion Helps Spacecraft Cruise Solar System on the Cheap

The Dawn mission to the asteroid belt passed a critical test last weekend, exercising its gentle, yet reliable, ion-propulsion system to accelerate its mission to two destinations during an eight-year voyage through our solar system.

The key: Ion propulsion only needs a tenth of the fuel of a chemical rocket system to reach the same destination, and that means a smaller rocket -- and a lot less fuel -- is needed to launch missions, such as the Dawn probe. The miserly use of propellant will allow the Dawn probe to become the first to orbit two separate objects -- in this case, the asteroid Vesta in 2011 and the dwarf planet Ceres, where it's expected to arrive in 2015.

Wired.com

Sputnik Stunned the World, and Its Rocket Scared the Pentagon

The standard Sputnik story goes like this: It was the launch of this metal ball that forced the United States to elevate the pursuit of science. But that's not quite true.

Technically speaking, Sputnik was no more sophisticated than a cheap transmitter from Radio Shack attached to 120 pounds of batteries. It was the R-7 launch vehicle that scared the pants off the U.S. military. The Soviets proved they not only had a rocket with precise guidance systems, but one that could launch a heavier payload than anything the Americans had.

The launch system on Oct. 4, 1957, was a one-shot deal. It was preset before takeoff and its trajectory could not be changed during flight. The Russians had to fire and pray. Despite its apparent simplicity, the impact of the R-7 rocket cannot be overstated. Sputnik was the first satellite humans launched into orbit, and it stunned the world.

Wired.com