2004 ASTRONOMY & ASTROPHYSICS - Indian Academy of Sciences

CHAPTER 9
It will also clarify whether we should,
instead, be participating in an
international project.
6. New Initiatives in Astronomy from Space
• Solar Coronograph
Space Observatories tend to be very
versatile and ambitious, and therefore very
expensive. The more ambitious a mission is,
the more is the lead time and greater the
possibility that when it is finally launched the
technology is too outdated to cope with the
current questions! Freeman Dyson has argued
about this very eloquently. In the 1980s, the
Japanese astronomy community broke away
from this tradition by launching small satellites,
with specific objectives. The rest is history.
They are now among the leaders in the
exploration of the Universe from space in
the X-ray band.
India has developed considerable capability
in building satellites and launch vehicles.
Soon after the successful flight of the first
PSLV possibilities opened up for small
payloads to be flown on various PSLV
launches. The highly successful Indian X-ray
Astronomy Experiment onboard IRS P3 is an
example. Recently a Solar X-ray Spectrometer
was integrated into GSAT 2, and launched by
the GSLV. ISRO has also successfully
demonstrated its capability to launch several
payloads with a single launch. This opens
up exciting possibilities for the Indian space
science community.
The committee strongly endorses the
suggestion from the solar physics
community to launch a small
coronograph of approximately 10 cm
aperture. Although quite modest, the
science returns will be very substantial.
There are substantial number of scientists in
India who are interested in the subject of
SPACE WEATHER. Mass ejections from the
corona of the Sun are intimately related to
space weather. Even a small coronograph
can track such mass ejections up to 50 solar
radii. Such observations combined with
simultaneous observations in the radio
wavelengths using the GMRT and the low
frequency telescope at Gauribidanur can be
very rewarding.
• Near Infrared Spectrometer
The design and fabrication of the various
telescopes that will be on the dedicated
Indian astronomy satellite, the ASTROSAT, is
well under way. Once the flight models are
delivered to ISRO, one should start planning
for the next facility. A Near Infrared
Spectro–Photometer is an attractive project.
If one focuses on the wavelength region
between 1.8 and 3 microns, then one will
occupy a niche that is difficult to study with
ground based telescopes, and which is not
covered by the recently launched SIRTF
mission. But such an instrument will require
cooling to about 80 K. Fortuitously, ISRO
has plans of developing a mechanical cooler
for space applications. Among other
uncertainties is the availability of the
detector array.
Despite these difficulties one must start
planning for the next missions. If space
sciences have to flourish in India, then it is
very important to attract young people. And
in order to do that, ASTROSAT has to be a
beginning of a new era, rather than a oneshot
mission. On the other side, such new
scientific projects will pose the required
technological challenges to ISRO to enable it
to enhance its capabilities.
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