Smart Industry 1/2019

Smart Communications Low-earth-orbit satellites
Low-Earth-Orbit Satellites
The Next Space
Revolution
source ©: The Wave Magazine Online / Jacksonville University
Over the past few decades, small satellites have dramatically changed the future
of humans in space. The big money is now on business and space
exploration has moved from one-of-a-kind systems performing specific missions
to satellite constellations working in concert to achieve a larger purpose.
Like the industrial revolution, when new manufacturing processes marked a historic
turning point, low-Earth-orbit satellites (LEOs) are poised to transform
our relationship with outer space.
n By Gordon Feller
While mass production of
small satellites conjures
up thoughts of large
factories with assembly
lines rolling out standardized products,
it may not be that simple. Highvolume
production would be necessary
to achieve the global coverage
sought by commercial and government
stakeholders. In that business,
new problems must be solved in
quality control, standards, and in designing
for manufacturability, as well
as the challenges of automated assembly,
integration, and testing – all
of which must be balanced with cost
considerations that are critical to the
success of starting up. The development
and launch of tens, hundreds,
or even thousands of small satellites
is starting to happen and it will almost
certainly produce revolutionary
effects.
The first low-Earth-orbit satellites
were launched many decades ago.
48
Those “birds” were owned and operated
by national governments
– at a huge cost to taxpayers. Despite
the cost, over the past two
or three years the LEO industry
has been growing exponentially in
the private sector, which raises the
question of what is attracting this
interest.
The major purpose of these groups of
thousands of small satellites (constellations)
is to have connectivity that
gives 100 percent global coverage.
The world is currently comprised of
approximately four billion active Internet
users, which means there are
approximately 3.5 billion additional
people who currently lack access.
Once in orbit and fully operational,
each new constellation brings total
coverage closer but, at the same time,
they will also provide 100 percent
coverage in other domains – such as
constant worldwide surveillance and
imaging.
Two definitions might help here:
• When it’s in a geosynchronous orbit
(GSO), a satellite has an orbital
period that matches the Earth’s
axial rotation period of approximately
23 hours 56 minutes and
4 seconds (one “sidereal day”).
Variously called a geostationary
orbit, geostationary Earth orbit
or geosynchronous equatorial orbit
(GEO), the path taken forms a
circle round the equator at around
35,786 kilometers above the equator
and following the direction of
the planet’s rotation.
• Low Earth orbit is classed as an altitude
of 2,000 kilometers above
the Earth’s surface, with an orbital
period that stays between 84 minutes
and 127 minutes. Any objects
below a threshold of approximately
160 kilometers will experience very
rapid orbital decay and altitude
loss, so LEO satellites fly well above
this danger zone.