What is the largest man-made object to be lost in space ? ?
The largest would still be the massive S-IVB stage, which is still out there in solar orbit again, practically lost because we still can’t tell when it returns and where it is now. The next biggest would be the SOHO sun probe, a bit over ten year ago. After a massive attitude control failure, caused by wrong ground commands, and the resulting loss of power and telemetry, it got lost and required a concentrated search mission by all large radio telescopes available to find it again. Finally, it was using the 300m dish in Arecibo as huge radar which allowed finding it again and measure it’s orientation and rotation rates. Later the DSN was able to get a weak signal from SOHO every time the solar arrays had been producing a bit of energy for the systems to operate. During these short phases, it was possible to send commands to SOHO and make it recharge it’s batteries and finally communicate with Earth. The reactivation of SOHO is still considered a master piece of mission operations, beca
