12
$\begingroup$

How were the Soviet Lunochod rovers during the 1970s controlled from Earth? Did they take images on the fly and a guy with a joystick steared it around to reach targets of opportunity? Well, probably not, but did they take advantage of the near real time radio communication?

Rovers on Mars are given a single batch of commands once a day. So while the roundtrip travel of light delay is no more than 8 to 48 minutes, a rover would be remotely operated at exactly the same pace even if it were on a moon of Neptune 4 light hours away. But the Moon is so close that the 2-3 second delay would be at most irritating until gotten used to.

Here's a lecture by Dr. Jeff Norris at JPL from 12 sep 2013. I really recommend it, a potentially easy solution on a seemingly unfixable problem:

https://www.youtube.com/watch?v=EeSGuGw4aJU

He describes how time delays can be handled by human psychology by simulating and visualizing in real time what would happen if the given commands give the expected results. While he focuses speculative on using this on Mars, eliminating the 2-3 seconds delay on the Moon in a virtual way certainly seems very doable.

$\endgroup$
  • $\begingroup$ Do you have a reference for the description "at most irritating"? $\endgroup$ – DJohnM Jul 15 '14 at 18:07
  • 1
    $\begingroup$ Yes, my own lagged online modem multiplayer gaming in the 1990s ;-) But check out the youtube link I just edited into my Q post. $\endgroup$ – LocalFluff Jul 15 '14 at 19:17
18
$\begingroup$

The Lunokhods were controlled in real-time from Earth (long article well worth reading), exactly as you say. A camera relayed images to Earth (one image every 7-20 seconds) and a five-man team (driver, commander, navigator, radio antenna operator, and the flight engineer) would control the rover.

You can imagine this was difficult: the driver has to anticipate massively due to the communications delay and the image delay. The cameras had a dead zone right in front of the rover, so the driver would also have to remember previous images (and with 1970s technology, no easy way to recall the previous image on screen).
Each team worked a two-hour stretch before being relieved.

The control room looked like this:
Lunokhod control room
Yup, a guy with a joystick.

$\endgroup$
  • 4
    $\begingroup$ Space travel was was more fun in the old times. $\endgroup$ – LocalFluff Jul 15 '14 at 19:28
2
$\begingroup$

This is really an add-on to above, but joined just to mention it and accordingly don't have enough rep to make a comment; I think its important to point out that the low resolution of the Lunokhod B/W cameras (I believe <100 lines, but cant find a reference) combined with large delay between frames meant the first rover had to be brought to a stop for about 3 days around each lunar noon because with the moon being essentially monochrome to begin with, there were not enough shadows to navigate safely with the sun ~overhead.

And the politics of the time cause them to focus on covering distance, which was announced to the press every day, at the expense of stopping to take "high-res" images or do other science.

Video was better with L-2 than L-1 of course due to improvements in technology over time, but it still lead to the loss of the second rover due to misunderstanding the terrain they were driving through causing them to drive into a crater and then covering the solar panels in dust trying to back out, which doomed the mission.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.