In terms of mission, technical capabilities, anything: how is Rover Spirit different from the Viking Mars landings in the '70s?
Did viking actually land on Mars?
I thought i was more of a probe rather than an actual landed mission.
Spirit is an actual radio controlled style vehicle that let the sceintists explore the immediate envrionment and go to specific objects where as viking i think was largely pre-programmed.
dont know if that helps that just what i thought.
Zaphod
How soon they forget.
The two Viking landers of the mid-70s were pretty good for their time, but the capabilities (not to mention the mobility) of the current rovers are lightyears ahead.
Details of the Viking project can be found here
http://nssdc.gsfc.nasa.gov/planetary/viking.html
The Viking landers were nuclear powered (by radioisotope thermal generators, the same thing that our deep space probes have used), which meant they were designed to last for a long while, and they both did. Viking 1 was active from 1976 until 1982…but it only failed because a bad command sent from Earth. Viking 2 lasted until 1980 when its batteries failed. The Rovers, being solar powered are expected to have a lifespan of about 3 months or so. The effectiveness of the panels will probably slowly degrade as dust starts to cover them. If the dust doesn’t kill them, the cold of winter surely will.
The Vikings spent years looking at the exact same rocks and scenery. By the time 1978 rolled around, I guess that there probably wasn’t anything new for Viking to do or see except to send back weather reports. Being mobile, and able to travel for miles (not just the yards the Pathfinder rover went) I imagine that the Rovers will eventually expand our knowledge of Mars by 100 fold (especially if Opportunity lands safely next week) because they’ll be able to see lots of different things before they do die.
A general rule that I’ve heard about spacecraft is that they are about ten years behind the normal technology curve, because space requires the use of extremely well tested and conservatively constructed components.
Really?! Do you have a cite for this because I’d never heard that before.
The two Viking missions consisted of an orbiter and a lander each. The orbiters, well, orbited and the landers landed (Viking 2 I believe, nearer the north pole). They soft-landed via a totally self-controlled descent engine burn (no silly airbags back then!) Quite a feat for its time (and still is, NASA’s failed at it on Mars everytime since). The landers didn’t move, but did collect soil samples via an extendable arm.
Its not quite correct to call it ‘radio-controlled’ like an RC toy. Commands are sent to go a certain direction and distance, but the probe itself navigates via its onboard cameras & sensors (again, no small feat).
Seems to me that the poles would be more interesting to study anyway but these new cheap craft need solar power and so need to stay near the equator.
There IS water on Mars, right? The poles are all water in ice form, right?
Here’s a NASA page that mentions it:
http://www.hq.nasa.gov/office/pao/History/marschro.htm
There’s surprisingly little mention of this oopsie on the web. Here’s a JPL/NASA press release from April 1982 which says that they were planning to keep the Viking 1 lander active until 1994 (!), “barring any critical hardware failures”. Oh well. That would have been cool.
For some reason, I remembered Viking as being mobile; apparently, I mis-remembered.
You may be confusing Viking with Mars Pathfinder and the Sojourner Rover.
Not all water (they’re also dry ice, frozen CO[sub]2[/sub]), but there is a significant amount of water at the poles, and lesser amounts in permafrost all over the planet. And the poles are interesting, but we want to study a variety of different terrains. The Spirit rover’s landing site, for instance, may have once been a lake bed.
Hopefully they find stratified sediment layers.