The Ethical Use of Outer Space - Ethical Engineering for International Development and Environmental Sustainability - page 120

that companies sponsoring the research can often then determine the conditions of
release of results and therefore block the publication of fi ndings that might harm
their business. As universities become more and more commercialised, research
scientists seeking funds to keep going will need to be increasingly careful about the
ethical implications of the contracts they sign or that are signed on their behalf.

4.2 The Ozone Layer

Given the importance of the ozone layer in protecting living organisms from harm-
ful ultraviolet radiation, it is important to understand how rockets passing through
might affect it. For example, although it is not known how liquid-fuel rockets affect
the upper atmosphere, it is known that solid-fuel rockets release chlorine gas directly
into the stratosphere, where the chlorine can react with oxygen to form ozone-
destroying chlorine oxides. Ross et al. ( 2009 ) have estimated the extent of the dam-
age as a function of payload launch rate and a mix of solid and liquid rocket
emissions. They found that global rocket launches deplete the ozone layer by only
about 0.03%, which is an insignifi cant fraction of the depletion caused by other
ozone depletion substances. However, they point out that as the space industry
(including military activity and new ventures such as space tourism) grows and CFC
substances fade from the stratosphere, depletion from rockets could become more
signifi cant, perhaps even requiring some level of regulation. They suggest it may
even become necessary to limit launches to as little as several tens of kilotons per
year. However, they also emphasise that new studies are needed to help guide any
possible future restrictions on commercial and state rocket launches. Nevertheless,
it is also clear that it should be the responsibility of those involved in space technol-
ogy to ensure that we are not removing one danger to the protective ozone layer,
only to replace it with another.

4.3 Space Situational Awareness

Space Situational Awareness refers to the knowledge of location and function of
natural and artifi cial space objects and the space environment. The increasing utili-
sation of space is presenting us with a growing problem - space debris. As activities
in space increase, so does the amount of junk - burnt out rocket stages, defunct
satellites and wreckage from collisions, explosions, antisatellite tests, etc. All these
have contributed to the tens of thousands of fragments that have formed a cloud
about the Earth.
Travelling at orbital speeds of around 8 km/s, a collision with the smallest piece
of space junk could breach the walls of a satellite or spacecraft and damage it. Initial
thoughts about the Columbia disaster in February 2003 were that it had been struck
by debris. Two of the worst debris-creating events in history occurred in the fi rst 6