2.
Budgeted at Rs 49 crore, Aditya - 1 will be the first
satellite specifically designed to study the Sun's
corona.
The satellite will help to determine why solar flares
and solar winds disturb the communication network
and electronics on earth.
ISRO plans to use the data from the satellite to better
protect its satellites and space ware from being
damaged by hot winds and flares ejected out of the
corona.
INTRODUCTION
3.
ISRO initially planned to put the 200-kg satellite into an 800 km
orbit in in 2012-13 to coincide with the "solar maxima."
The current plan is to launch the satellite between 2017 to 2020.
ISRO website suggests that current plans envisage placing the
satellite in a halo orbit around L1 Lagranian point of the Sun-
Earth system to facilitate continuous viewing of the sun without
any occultation / eclipses.
Technical studies have established that a PLSV-XL launcher
would be able to place a satellite at a halo orbit around L1
point.
However, in February 2014, ISRO Chairman K Radhakrishnan
told the press, "The mission would be around the Earth. A few
equipment are being planned for that. We hope for the launch
between 2017 and 2020."
MISSION
4.
A spacecraft in a halo orbit moves in a circular path
around the Lagrange point, it does not technically
orbit the actual Lagrange point, because the
Lagrange point is just an equilibrium point with no
gravitational pull but travels in a closed, repeating
path near the Lagrange point.
Halo orbits are the result of a complicated interaction
between the gravitational pull of the two planetary
bodies and the coriolis and centrifugal accelerations
on a spacecraft.
HALO ORBIT
5.
The following six proposals have been short-listed for the mission:
1. Visible Emission Line Coronagraph (VELC), IIA, Bengaluru
2. Solar Ultraviolet Imaging Telescope (SUIT), IUCAA, Pune
3. Plasma Analyser Package for Aditya (PAPA), SPL/VSSC,
Trivandrum
4. Aditya Solar wind Particle Experiment (ASPEX), PRL,
Ahmedabad
5. Solar Low Energy X-ray Spectrometer (SoLEXS), SAG/ISAC,
Bengaluru
6. High Energy L1 Orbiting X-ray Spectrometer (HEL1OS),
SAG/ISAC, Bengaluru
The Aditya-1 mission is expected to last for 3 years.
PAYLOADS
6. In the past it has been reported that the satellite will carry a 20-cm diameter visible
wavelength solar coronagraph developed by the Indian Institute of Astrophysics
(IIA).
A coronagraph is a telescopic attachment that blocks out the direct light from a star
(an artificial eclipse of the star) allowing dimly lit nearby objects, otherwise hidden
in the star's glare, to be viewed.
“Unlike Aditya, most space-based instruments observe the corona at UV
wavelengths and capture images at a relatively low temporal resolution," says
Jagdev Singh, senior professor of the Indian Institute of Astrophysics (IIA) and
principal investigator for the mission.
"Also, there are no such missions planned between 2012 and 2016 [coinciding with a
solar maximum], during which period Aditya will provide important data.”
The coronagraph will observe the solar corona with the help of an artificial eclipse
that will prevent sunlight from directly entering the instrument, revealing to the
telescope only the halo of the corona.
“Our emphasis is to go close to the sun surface and click fast-time resolution images
which may be about three or four images per second. The solar coronagraph will
click the images and send data based on which we will be able to conduct research
and find out why the corona’s temperature rises to more than a million degrees,”
says Singh.
SOLAR CORONAGRAPH
7.
The design of the coronagraph was approved in end
July, 2010 by the Advisory Committee for Space
Research, which comprises ISRO Satellite Centre,
Indian Institute of Astrophysics, Udaipur Solar
Observatory, Radio Astronomy Center and the
National Centre for Radio Astrophysics.
As of July 2010, ISRO was working on the design of
the detectors and the thermal structures.
A prototype of the satellite was to be built in 2011.
PROGRESS
