The ISS with its 73m x 108m Integrated truss structure, apparently, is the largest (by dimensions) artificial object in space.

I know about the Krab experiment which produced two self assembly rings of 20m diameter, attached to a Progress spacecraft. That gives 40m x 20m.

Both Space Shuttle orbiter and Mir station were a bit shorter than 40m.

Neither of thin object such as IKAROS solar sail (20m) or Znamya reflector (20m) come even close.

The Inflatable Antenna Experiment's struts were shorter (28m) too.

So the question is: have there been any (other than ISS) artificial objects longer than 40 meters in orbit?


3 Answers 3


That one is easy: http://www-istp.gsfc.nasa.gov/Education/wtether.html

There have been a number of space tether missions, the longest (verified!) was the TSS-1R on February 25, 1996, when the Columbia in the STS-75 flight unrolled the tether to 19.7 km.

Video: http://www.youtube.com/watch?v=pq4brZBqXvU



The satellites are classified, so details are speculative, but it is believed that the Magnum/Orion and Mentor SIGINT satellites have parabolic antennae around 100 m in diameter.


Answering my own question to broaden the context a little bit.

The 60 meter ADAM mast was the larges rigid structure of its time (STS-77, 16 February 2000).

enter image description here

To quote the JPL description:

Unique latches on the diagonal members of the truss allowed the mechanism to deploy bay-by-bay out of the mast canister to a length of 60 meters (200 feet). The canister housed the mast during launch and landing, and it also deployed and retracted the mast.


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