A thought on the mobile lunar lander is that the crew does not need to depressurize the air lock to exit the lander as often. Exiting the air lock is a waste of energy to remove the air before exiting the chamber not to mention the value of the air that could be lost.

If this lander is capable of some partial mining then being mobile is also a plus for the processing of the mined ore. Much of which can be used for fueling operations or for building onto a more permanent base structure.

Mike Kahn, Vice President of Reusable Solid Rocket Motor Program, ATK Thiokol
http://www.spacecongress.org/2004/Panel-4/4Kahn.pd
http://www.atk.com/thiokol/

Another ability of mobile lander, is that you can now land in a given area and link them together to form a larger base.

Mobile bases do seem a very good idea. I wonder if someone will think to remember the tri-star wheel concept developed in the 1960's. From what's available online it seems capable of taking a lunar habitat most places you would want to take a lunar habitat. As a bonus it should be possible to design the drive assembly so that changing out wheels (and secondary motors) can be done without jacking the vehicle off the ground.

The page http://www.visi.com/~dc/tristar/bkground.htm has a lot of background on the concept.

However, I do think there is a role for a fixed lunar base in addition to mobile bases. If nothing else, it would include the landing pad for heavy cargo landers and the assembly shop for the mobile bases. It would also be the logical place for a supply dump and LOX generating facility. That way you can use your big landers to ship in cargo in 'bulk' and then maybe distribute it with smaller 'hoppers' to habitats roaming the moon. If nothing else it will probably save shipping container mass.

Cheers,
ErikM

Other thought on mobile landers is that they can be grouped together into a large colony or base to share resources.

More mobile lunar base articles, page has a great picture of the rover and extra links at the bottom of the page.
http://www.universetoday.com/am/publish/mobile_lunar_bases.html?3062004

While mobility is imprtant to lunar or Mars exploration making the base mobile adds a level of complexity and cost that I don't think would be worth what ever benefit that may be gained.
What may be benefical would be a movable base. This would include semi-perminent structures that can be packed up and trasported, either by rover or lander, to another aria of interest.

A mobile lunar base could be operated remotely to move it from one location to another between crew visits. This would allow one base to support multiple missions to widely dispersed locations on the moon. The base, or more likely a small rover it deployed, could also conduct a preliminary survey of a site prior to the crew's arrival. Finally, it could select a safe landing site, set up a landing beacon, get out of the way, then roll up to the crew's lander.

I was reading an article on the florida today site about all the hardware that was left behind from the Apollo visits. Lunars rovers, seimic monitors, reflectors and the lower part of the landers. If we ever do get back to the moon the most likely landing sites should be those of the past.