ROOM
11
Special Report
manufactured on-orbit) and here we examine
the potential implications of on-orbit assembly
of science, exploration and commercial
communication spacecraft for science and
exploration and, and review the state of the art
and future trends in the area.
Benefits of on-orbit assembly
At a conceptual level, on-orbit assembly offers
a number of advantages that may enable and
enhance various types of space missions:
• An ability to deploy structures that
cannot be launched from Earth because
size, volume and design of payloads that can
be accommodated within the fairing of a single
launch vehicle, the largest of which is less than six
metres in diameter.
In particular, fairing diameter limitations
restrict the size and number of instruments that
can be fielded in orbit for science and national
security missions which, in turn, constrain data
that can be obtained from space-borne payloads.
Design of ground built spacecraft also requires
components to undergo ‘ruggedization’ to
withstand the harsh launch environment - severe
vibration, acoustics, acceleration and thermal
loads - which imposes mass and size penalties
that ultimately limit payload capabilities and
increase launch costs.
These are further compounded by the need
for inclusion of redundant systems to provide
contingency against damage during launch.
Communication satellites have similar
constraints that limit flexibility and operations,
and Figure 1 illustrates how these affect
profitability and revenues.
On-orbit assembly can be defined as the
aggregation onto an orbiting platform of
ready-made structures that are manufactured
on the ground (although they could also be
Artist conception of the
James Webb Space
Telescope.
The 18-segment gold
mirror of the James
Webb Space Telescope is
specially designed to
capture infrared light
from the first galaxies
that formed in the early
universe.
NASA
NASA
