The Sweden Solar System (SSS) is the world’s largest model of our planetary system. The Sun is represented by the Globe in Stockholm, the largest spherical building in the world, and the planets are lined up in direction north from here.

Distances and sizes are scaled according to 1:20 million, and the inner planets are all in the Stockholm area. The outer planets follow in the same direction with for instance Neptune in Söderhamn and the dwarf planet Pluto in Delsbo, 300 km from the Globe. A number of minor planets and comets also populate SSS, which now extends from the very south to the very north of Sweden. There is a host institution for each model. SSS is a pedagogical instrument and conveys a direct feeling of the enormous distances in space, and how small the planets are compared to the Sun. Art, mythology and science merge in this project, and SSS connects to different places and activities in Sweden.

A nuclear salt-water rocket (NSWR) is a theoretical type of nuclear thermal rocket which was designed by Robert Zubrin. In place of traditional chemical propellant, such as that in a chemical rocket, the rocket would be fueled by salts of plutonium or 20 percent enriched uranium. The solution would be contained in a bundle of pipes coated in boron carbide (for its properties of neutron absorption). Through a combination of the coating and space between the pipes, the contents would not reach critical mass until the solution is pumped into a reaction chamber, thus reaching a critical mass, and being expelled through a nozzle to generate thrust.

There is a good reason for colonizing another planet, which is to avoid extinction if the Earth is hit by a 10km or larger asteroid, as has happened many times in the Earth's history. Colonization of Mercury appears to be a very real and practical possibility, whereas colonization of Mars or the other planets, moons or asteroids is really more in the realm of fantasy.

But if Breakthrough Starshot succeeds, we could get snapshots of the Alpha Centauri solar system 4 light-years away — roughly the same as 6,800 trips to Pluto — 30 to 40 years from now. And maybe we'll get a better idea about just how rare life is in the universe.

/

After all, there are 100-mile impact craters on our planet’s surface from the last billion years, but no 600-mile craters. But, of course, there couldn’t be scars this big. On worlds where such craters exist, there is no one around afterward to ponder them.

The soil, which was developed by NASA to be as close as possible to what space travelers would be working with on Mars, was mixed with pig manure and then "seeded" with adult earthworms. Overcoming several potential dangers, the worms managed just fine, and soon the scientists discovered baby worms which had been born in the soil simulant.

In the spring of 1958, after President Dwight Eisenhower called to create a civilian space agency, the US Air Force assumed it would lead any national spaceflight effort. As such, the service prepared a detailed, multi-stage plan called Man in Space with the goal of landing a man on the Moon by the mid 1960s.

Most of the really wrong design decisions in the Shuttle system — the side-mounted orbiter, solid rocket boosters, lack of air-breathing engines, no escape system, fragile heat protection — were the direct fallout of this design phase, when tight budgets and onerous Air Force requirements forced engineers to improvise solutions to problems that had as much to do to do with the mechanics of Congressional funding as the mechanics of flight. In a pattern that would recur repeatedly in the years to come, NASA managers decided that they were better off making spending cuts on initial design even if they resulted in much higher operating costs over the lifetime of the program.

It turns out that if all the stars and all the planets in all the galaxies were before you in a terrifying, brilliant, impossible box, the color would you see (while no doubt experiencing a transcendent feeling of oneness) is the most boring color in the world.

Pick your favorite travel mode—big, small, light, dark, or twisted.