Ikaros was the first space mission to
be propelled by sunlight alone and the the first spacecraft to
successfully demonstrate solar sail technology in interplanetary
space. Ikaros is a Japanese experimental spacecraft and stands for
Interplanetary Kite-craft Accelerated by Radiation of the Sun.
On 21 May 2010, the Japan Aerospace
Exploration Agency (JAXA) launched a new kind of spacecraft. Named
IKAROS, a short for Interplanetary Kite-craft Accelerated by
Radiation of the Sun, this square-shaped craft is propelled through
space using the Sun's energy in two different ways. It is embedded
with thin solar cells that store sunlight as electricity and it also
reflects light particles from the Sun. As the light particles bounce
off the sail, they should provide the bulk of the momentum needed to
propel the spacecraft.
IKAROS was launched on a
from the Tanegashima Island in Japan. The rocket also carried an
unmanned Venus probe called Akatsuki (Venus Climate Orbiter) and
some small satellites. IKAROS will take the same trajectory as
Akatsuki, but will pass by Venus and keep going on its way to the
The solar sail weighs about 315 kilograms in tidal and cost around
£11 million to build and launch. A previous
Japanese space organization, the Institute of Space and
Astronautical Science demonstrated successful deployment of
prototype solar sailed in 2004, but the propulsion system remains
unproven. However, JAXA is confident that IKAROS will reach its
ultimate destination. The challenge will be keeping the solar sail
flat, stable and orientated correctly to take in enough sunlight.
The IKAROS membrane
The sail is made of four trapezoid-shaped panels of polymide, a
light weight material abbot 32 micrometers thick. It is about 20
metros on the diagonal. One side of the sail has an aluminum layer,
which reflects sunlight and provides thrust.
An independent non-profit organization called the Planetary Society
has had its own solar sail project in the works, LightSail-1 is
based on the NanoSail-D, a former NASA project. The Planetary
Society hopes to launch LightSail-1 by the end of 2o10, but the
launch is dependent on funding and whether rockets are available.
The membrane will be made of Mylar and its body will comprise
several tiny satellites called CubeSats.
JAXA hopes IKAROS will deploy and show that power and thrust can be
generated using solar cells. On 10 June 2010 JAXA confirmed the
membrane had deployed. IKAROS took a picture of itself and replayed
it back to mission control. The solar cells are also generating some
Long Term, IKAROS will spend six months travelling to Venus, then
thee years to the far side of the Sun. Spacecraft may one day use
solar power for propulsion, cutting down on expensive fuel and
allowing for exploration. JAXA hopes to send a large sail to Juipter
by 2020. IKAROS will investigate and measure space phenomenon and
gather data on its way past Venus.
Solar Sails: A Novel Approach to Interplanetary
Travel (Hardcover) by Giovanni Vulpetti
(Author), Les Johnson (Author), Gregory L. Matloff
- Starsailing: Solar Sails and
by Louis Friedman from
- Solar Sailing: Technology, Dynamics and Mission
by Colin Robert McInnes
Did you know?
The name is similar to Icarus, a
figure in Greek mythology who melted his wings flying his wings too
close to the Sun.
Solar Sail converts sunlight as a propulsion by means of a large
membrane while a Solar 'Power' Sail gets electricity from thin film
solar cells on the membrane in addition to acceleration by solar
Small Solar Power Sail Demonstrator IKAROS:
Picture of Ikaros: