Welcome to brain Stuff from how Stuff Works, Hey, brain Stuff, Lauren vocal bomb here. Since humans began putting satellites into orbit in the nineteen fifties, we've relied upon big, powerful rockets to escape Earth's gravity and get into space. But big rockets have a major downside in that they make space launches expensive. For example, NASA's Space Launch System Heavy Lift rocket, which is scheduled for its maiden flight in December of twenty nineteen, will cost an estimated one billion
dollars per launch. Costs for space X is far more economical. Falcon Heavy, which took off successfully from Kennedy Space Center in February, still range from between ninety million and a hundred and fifty million dollars per launch. For decades, however, visionaries have looked for ways to get into space without relying, at least not primarily upon rocket power. One such alternative approach is air to orbit launches, and it seems to
be the verge of becoming a reality. Strato Launch, the private space launch company started by Microsoft co founder Paul Allen in eleven, has an ambitious plan to fly the world's biggest airplane with its three five foot that's a hundred and seventeen meter wingspan to an altitude of thirty five thousand feet or about eleven thousand meters. There it will serve as a high altitude launch platform for smaller
rocket powered vehicles. Once released from the airplane, those vehicles won't have to overcome the drag caused by the thickness of the lower atmosphere as a ground launched rocket would, and they'll be able to get into orbit without having to burn as much fuel. In August eighteen, the company announced its lineup for four different types of launch vehicles, one vehicle that's still in the design study phase, a reusable space plane could transport either cargo or a human crew.
Strato Launch plans to begin offering regular service in It's chief executive officer, Gene Floyd, said in a media release that the company as mission is to make access to space quote more convenient, affordable, and routine, and that scheduling a satellite launch eventually will be as easy as booking
an airline flight. Meanwhile, another air to orbit outfit, Virgin Orbit, plans to use a modified Bowing seven hundred as a platform for its Launcher one rocket, which will propel satellites into orbit, but several other, even more exotic concepts still remain on the drawing board. James R. Powell, who co invented superconducting maglev propulsion for trains back in the mid nineteen sixties, has been advocating for years that the technology
be used for launching spacecraft as well. Instead of a launching pad, this solution, called the Star Tram project, would use a massive elevated launch tube, Powell explained via email. Think of a magnetically levitated maglev train and a vacuum tunnel, with no air drags slowing the vehicle down, and with no need to carry large amounts of onboard propellant as is the case with rockets. It's relatively easy to reach orbital velocity of eighteen thousand miles per hour that's two
thousand nine kilometers per hour or greater. When the vehicle exits the tunnel at high altitude, for example, at the summit of a high mountain, the vehicle would be going so fast that it basically coasts up to orbital altitude, where a small rocket is used to circularize the orbit. We've also designed several mechanisms to keep the vacuum in the tunnel intact when the vehicle exits the tunnel, so that the tunnel can be quickly reused to launch the
next vehicle. All the major components of the star trans system exist already and are well understood. Powell first started contemplating the use of super conducting maglev for launching spacecraft at the suggestion of a colleague from NASA. Initially, he and his engineering partner, George Mazie developed a concept for a hundred billion dollar system suitable for manned space launches, in which a tube would be levitated with massive super
conducting cables. They also designed a scaled down cargo only tube system that would stretch up the slope of a tall mouth town. They estimate that this cargo only system could be built for just twenty billion dollars, less than the cost of developing NASA's new heavy launch rocket. Once built, star Tram could transport one hundred thousand tons of cargo into space each year, many times what rocket launches currently carry, and would put equipment into low Earth orbit for a
cost of about fifty dollars a pound. Powell says that once built, star Tram could transport one hundred thousand tons of cargo into space each year, many times what rocket launches currently carry and put equipment into low Earth orbit, for a cost of about fifty dollars a pound. That would be a fraction of the thousands of dollars per pound that it currently costs to get cargo into space. Another idea that's been around for decades is construction of
a space elevator. A tall base tower near Earth's equator would be attached by a cable to a satellite in geosynchronous Earth orbit twenty two thousand miles that's thirty five kilometers above sea level, which would act as a counterbalance. Four to six elevator tracks would extend up the tower and cable structure, going to platforms at various levels. Electromagnetic powered vehicles would rise on the tracks, making the trip
into orbital space in about five hours. The concept dates back to when Russian scientist Konstantine Silkovski suggested building a celestial castle that would be attached to a similar structure to the Eiffel Tower in Paris, and the concept was first popularized by science fiction author Arthur C. Clark in
his nineteen seventy nine novel the Fountains of Paradise. Since then, space elevator adherents have continued to tout the concept, but the feasibility of a space elevator took a hit in twenty sixteen when Chinese researchers published a paper detailing their findings that carbon nanotubes, the material earmarked for use in creating that enormously long cable, are vulnerable to a flaw that could reduce their strength significantly. Today's episode was written
by Patrick J. Kaiger and produced by Tyler Klang. Visit our onlin in store it public dot com, slash brain stuff to find braining gear every purchase supports is directly and of course, for more on this and other far reaching topics, visit our home planet, how stuff Works dot com.