Dr Reed's proposal is for a barbed spear about 30cm in length. It would be mounted on a "chaser satellite" that would edge to within 100m of a junk object.

Pictures sent to the ground would then be used to assess the target, before the chaser was moved to within perhaps 20m to take a shot.

Once the harpoon is hooked through the skin of the rogue satellite or rocket stage, the chaser could either pull on a trailing polymer cord itself or deploy a separate thruster unit to do the job of dragging the aimless drifter towards Earth.

(Space harpoon diagram)

Another new method has been suggested by Boeing. The Boeing engineers suggest hastening orbital decay of space debris by creating a transient gaseous cloud with enough density to slow debris enough to make it fall into Earth's atmosphere.

Boeing has applied for a patent for its idea:

SUMMARY

[0004] According to an aspect herein, a method comprises removing space debris having a relatively low ballistic coefficient by hastening orbital decay of the debris. A transient gaseous cloud is created at an altitude of at least 100 km above Earth. The cloud has a density sufficient to slow the debris so the debris falls into Earth's atmosphere.

[0005] According to another aspect herein, a method for removing space debris having a relatively low ballistic coefficient comprises performing a Prandtl-Meyer expansion of gas into a gaseous cloud at an altitude of at least 100 km above Earth. The cloud has a density sufficient to slow the space debris so the debris falls into Earth's atmosphere. The cloud does not target any specific debris.

[0006] According to another aspect herein, an apparatus for creating a transient gaseous cloud comprises an expellant including at least one of the following: a burn metal of higher atomic weight than aluminum fuel; a cryogenic noble gas; a heavy molecular fluid having a low isentropic exponent; and high-atomic-weight elements and halogens. The apparatus further comprises a gas generator for generating a gas from the expellant, and a nozzle for expanding the gas into a gaseous cloud.

Science fiction writers of all sorts, in a variety of media, have been sounding the warning about space debris for generations, and placing the solutions into popular culture where they can be part of the lives of engineers and policymakers.

For example, consider the 1977 television series Quark. This comedy, created by legendary writer Buck Henry, described the activities of the United Galaxies Sanitation Patrol Cruiser, an interstellar garbage scow.

(Richard Benjamin and the Barnstable twins)

Richard Benjamin played Adam Quark, who worked to clean up trash in space. He is ably assisted by the Bettys, played by the Doublemint twins (Cyb and Patricia Barnstable).

In his 1978 novel The Fountains of Paradise, Arthur C. Clarke uses Operation Cleanup to make sure that low earth orbit is clear of debris for the newly constructed space elevator.

Fortunately, the old orbital forts were superbly equipped for this task. Their radars - designed to locate oncoming missles at extreme ranges with no advance warning - could easily pinpoint the debris of the early Space Age. Then their lasers vaporized the smaller satellites, while the larger ones were nudged into higher and harmless orbits.

Fans may also recall Planetes, an anime series published by Makoto Yakimura in Japan starting in 1999. The series follows a team of debris cleaners who clear space junk from flight paths.

Planetes cover art

Update 03-Mar-2017: See also the helix gun used to gather meteors from Salvage in Space (1933) by Jack Williamson.