Andrew Nowicki wrote:

All satellites and space telescopes should
be modular and compatible with telerobots
so that they can be upgraded frequently
and repaired.

Christopher M. Jones" wrote:

If we require compatability with non-existent entities
then we might as well require that the device work by
magic, or be compatable with leprechaun-based maintenance
work or what-have-you.

Dextre already exists.

Besides which, maintenance compatability does not come
cheap, nor does the maintenance, with or without robots.

Most compatibility issues are just common sense rules.
They are described in:

AIAA Guide for Berthing/Docking/Grasping Interfaces for
Serviceable Spacecraft, 1992, AIAA, ISBN 1-56347-052-7.

AIAA Guide for Utility Connector Interfaces for Serviceable
Spacecraft, 1995, AIAA, ISBN 1-56347-134-5.

Dextre cannot handle very small bolts/screws so all the
connectors have to be rather large. This is not a big
issue because we are talking about modular design --
all Dextre has to do is to replace modules. Another
little problem is that modular design takes up more
space that the monolithic, throwaway design. This means
that the modular satellite/telescope is longer than
the monolithic one.

Realistically, you save very little, if anything,
from maintenance compatability. Indeed, sometimes you
lose because you spend money fixing up obsolete hardware
rather than putting the effort into completely new systems.
For the money we've spent on HST upgrades already we
could have had another HST-class telescope on orbit
*right now* (maybe more than one), and it wouldn't be
15 years old with bits that use 20+ year old technology.

Using the shuttle to service the HST and ISS did not
make economic sense, but it "proved" that the shuttle
was not a complete waste of money. Dextre is much
cheaper because it can service a plethora of satellites
and telescopes 24 hours a day, 365 days a year. It
does not ask for a raise, does not rape female astronauts,
and does not need expensive funeral when it dies while
on duty. When all the satellites have been fixed Dextre
will be removing space junk.

PS. Space cadets hate Dextre because it seems to replace
heroic astronauts conquering the universe. Actually, the
opposite is true. Dextre and its ilk are necessary to
build the infrastructure that will make outer space
safe and affordable for us. People belong to orbital
greenhouses, telerobots belong to dangerous environments.