Starship Asterisk*

[img3="This artist concept shows Comet Hitchhiker, an idea for traveling
between asteroids and comets using a harpoon and tether system.
(Credit: NASA/JPL-Caltech/Cornelius Dammrich)"]http://www.jpl.nasa.gov/images/asteroid ... 150901.jpg[/img3][hr][/hr]

Catching a ride from one solar system body to another isn't easy. You have to figure out how to land your spacecraft safely and then get it on its way to the next destination. The landing part is especially tricky for asteroids and comets, which have low gravitational pull.

A concept called Comet Hitchhiker, developed at NASA's Jet Propulsion Laboratory, Pasadena, California, puts forth a new way to get into orbit and land on comets and asteroids, using the kinetic energy -- the energy of motion -- of these small bodies. Masahiro Ono, the principal investigator based at JPL, had "Hitchhiker's Guide to the Galaxy" in mind when dreaming up the idea.

"Hitchhiking a celestial body is not as simple as sticking out your thumb, because it flies at an astronomical speed and it won't stop to pick you up. Instead of a thumb, our idea is to use a harpoon and a tether," Ono said. Ono is presenting results about the concept at the American Institute of Aeronautics and Astronautics SPACE conference on September 1.

A reusable tether system would replace the need for propellant for entering orbit and landing, so running out wouldn't be an issue, according to the concept design. ...