What is the Black Knight Satellite

What if you learned that years before the human race shot an object into orbit, there were already manufactured objects circling around the Earth? It's the unbelievable tale of the Black Knight Satellite.

The object was first known in early to mid 20th Century when astronomers began tracking the skies in preparation for the launch of men into orbit from both the United States and Soviet Union.

Officially the Black Knight is considered a piece of space debris. But from what?

The object has been observed by manned missions to space including space shuttle crews and from the International Space Station.

From an article about the Black Knight form Skeptoid:

Like so many stories of weird phenomena, the Black Knight satellite legend starts with Nicola Tesla. It's said that he picked up a repeating radio signal in 1899, that he believed was coming from space, and said so publicly at a conference. In the 1920s, amateur HAM radio operators were able to receive this same signal. Next, scientists in Oslo, Norway experimenting with short wave transmissions into space in 1928, began picking up Long Delay Echoes (LDEs), a not fully understood phenomenon in which they received echoes several seconds after transmission. The apparent explanation finally came in 1954 when newspapers (including the St. Louis Post Dispatch and the San Francisco Examiner) reported an announcement from the US Air Force that two satellites were found to be orbiting the Earth, at a time when no nation yet had the ability to launch them. It appeared that Black Knight had been detected by multiple lines of evidence, and was confirmed by the US Air Force.

Below are YouTube videos that contain conjecture about the Black Knight Satellite. Watch them, form your conclusion and let us know in the comments below exactly what you think this is.