ROOM
18
Special Report
below one million US dollars. The initialisation and
replenishment will roughly double the number of
launch events, which are currently around 70 per
year. This is in addition to the general increase
in space traffic in LEO mainly fuelled by small
satellites and cubesats as well as nanosats, which
grant cheaper access to space.
Even before these recent trends, space debris
had already emerged as one of the major sources
of risk for spaceflight. Since the first orbital launch
in 1957, the number of artificial objects in Earth
orbit has been growing. The number of on-orbit
objects tracked by the US Strategic Command
(operators of the US Space Surveillance Network)
shows faster growth compared to the number of
operational satellites on-orbit.
This has led to a corresponding increase in
the threat to active satellites from hypervelocity
collisions, putting in jeopardy crucial services that
benefit human society. Some future scenarios
produced by computer models suggest that
the space debris population has reached a
tipping point such that collisions will increase
in frequency even in the absence of new space
traffic. Whilst such an outcome is not certain,
there is growing pressure on space users
to implement mitigation measures aimed at
Credits: ESA HSO-GR
Samsung
Spatial Density
=
[
Number of Objects
]
[
VolumeUnit
]
OneWeb, Boeing
SpaceX
< 1 < 25 < 100 < 1000 > 1000
Orbital Lifetime [years]
Man-made objects > 10cm
Current distribution of
man-made objects
tracked by the
USSTRATCOM in LEO. In
this artist impression the
size of the objects is
exaggerated as compared
to Earth.
Proposed concepts foresee a
global, leak-proof network of
inter-linked small satellites,
accessible at any time from
deployed ground terminals
Current altitude
distribution of man-made
objects greater than 10
cm (according to ESA’s
MASTER-2009 model),
average orbital lifetime of
an average satellite and
operating altitudes of
selected mega-
constellation concepts.
