SOLAR PANELS IN SPACECRAFTS
Solar Panels Observed Significant Developments
Through Their Use In Spacecrafts
The Solar Panels saw developments during the 1960s, at the time of the
Space Race. The researchers were looking for a constant and reliable
source of energy. They considered the option of using solar technology
as it was in continuous supply to the satellites in orbit. The space
industry even made heavy investments in the development of solar panels.
In the fact, the space industry made a serious use of this resource for
the first time.
There were different space programs in which the solar energy was deployed.
From the experiences, the reliability of the Solar Panels was established.
This further brought down the costs of development of the solar cells.
Already by that time, the heavy investments were geared towards the making
of more efficient solar panels, which could be easily created. Spacecrafts
normally depend on the use of photovoltaic Solar Panels for the generation
of electricity from sunlight.
This applies to the spacecrafts operating in the inner solar system and not
to the ones in the outer solar system where there is lack of adequate
sunlight strength to produce electricity. The Vanguard 1 satellite was
the first spacecraft, which made use of the solar panels. The U.S. launched
the satellite in the year 1958. Credit should be given to Dr. Hans Ziegler,
who can be considered as the father of spacecraft solar power.
The power supplied by Solar Panels to a spacecraft is dedicated to main
applications. First of all, power is needed to run the sensors, for active
heating and cooling and for telemetry. Secondly, power is also needed to
support the propulsion of the spacecraft. This motion is also referred to
as the electric propulsion or the solar-electric propulsion. Solar panels
require immense surface area so that enough electricity can be generated.
But there is a limitation as spacecrafts need to be small and so the
amount of solar power that be produced, gets restricted.
Moreover, the Solar Panels used in spacecrafts can be pivoted so that they
always point towards the sunlight irrespective of the movement of the
spacecraft. Higher efficiency has gained the Gallium-Arsenide solar cells
more popularity over the silicon ones. The multi-junctions cells are
expected to come with the promise of greater efficiency. Spacecrafts,
which are operating, near the sun or within the orbit of Mars have
made use of solar power.
Some of the spacecrafts, which have used solar power, are Mars Global
Surveyor, Magellan and Mars Observer. The well-known Hubble Space
Telescope uses the same solar technology. The Rosetta space probe of
March 2, 2004 was to use solar panels as far as Jupiter’s orbit (5.25 AU).
So far, the Stardust spacecraft has used solar panels at
a maximum distance of 2 AU.
The European lunar mission, SMART-1, used solar power for the spacecraft’s
propulsion. Coming up is the Juno mission, which is going to use solar panels
instead of the conventional RTGs in the first journey to Jupiter. Researchers
are now trying to develop space-based solar plants. Solar power satellites
equipped with large arrays of photovoltaic cells would beam the solar energy
to Earth through lasers or microwaves. This can be considered as an
alternative source of power generated without the use of fossil fuels.