Indian scientists use Mangalyaan, Mars Orbiter Mission, to look into sun's atmosphere

Indian scientists use Mangalyaan to look into Sun's atmosphere

A team of Indian scientists used the Mars Orbiter Mission, a.k.a Mangalyaan to study the Solar Corona when the Earth and Mars were on the opposite sides of the Sun. Scientists used solar conjunction to look into the atmosphere of the Sun, which remains a complex mystery.

Scientists from Space Physics Laboratory of Vikram Sarabhai Space Centre, Trivandrum; Physical Research Laboratory, Ahmedabad; and ISRO Telemetry Tracking and Command Network (ISTRAC), Bangalore used S-band radio signals coming from Mangalyaan to study the Solar Corona.

Isro scientists used the conjunction event of May-June 2015 a time when the Sun's activity was quite low, to study the turbulence in the solar corona. The findings have been published in the journal Monthly Notices of the Royal Astronomical Society.

The Corona is the outer atmosphere of the Sun, where temperatures are several million degrees Kelvin, making it impossible for in-situ measurements, thereby challenging the experimenters. Scientists from the world over are trying to figure out the reason for such a high temperature of the corona, and study the solar wind that originates here. These winds are responsible for triggering geomagnetic storms on the inner planets, including Earth, creating dangerous conditions for humans to operate in space.


Isro said that the radio signals from MOM spacecraft crossing through the solar corona during the conjunction event (cf. Figure 1) consequently experience dispersive effects. The turbulence in the corona produces fluctuations in plasma density which are registered as fluctuations in the phase of radio waves passing through it.


These radio signals contain the signature of a propagating medium (solar corona) and can be spectrally analyzed to derive the turbulence spectrum of the medium. Isro scientists have obtained coronal turbulence spectrum at heliocentric distances between 4 and 20 R (1 solar radii (R) = 696,340 km). " This is the region where the solar wind primarily gets accelerated to velocities of a few hundreds of kilometers per second. The changes in turbulence regime are well reflected in spectral index values of the temporal frequency fluctuation spectrum," Isro said.

Another intriguing observation is when the results of studies by MOM are compared with similar experiments conducted by the earlier missions which spanned past solar cycles. The work based on MOM data reports an insight into the feeble maxima of solar cycle 24, which is recorded as a peculiar solar cycle in terms of overall lower activity than any other previous solar cycle.

India's maiden mission to Mars was launched in 2013 and reached Martian orbit a year later. "The MOM was planned for a mission lifetime of 6 months, but has successfully surpassed it by a factor of 10 now in Martian orbit for more than 7 years, and is doing well in the extended mission phase," Isro said.

 

Indian spacecraft Mangalyaan completed 7 years in orbit .

Mangalyaan probe completes 7 years in orbit

Bengaluru: India’s Mars Orbiter spacecraft has completed seven years in its orbit, well beyond its designed mission life of six months.

“Indeed, a satisfying feeling,” K Radhakrishnan who as the then Chairman of Indian Space Research Organisation (ISRO) led the Mars Orbiter Mission (Mangalyaan) team said on the milestone.

MOM is the maiden interplanetary mission of ISRO. Launched on November 5, 2013, the probe was successfully inserted into Martian orbit on September 24, 2014 in its first attempt.

MOM is primarily a technology demonstration venture and all the mission objectives were successfully met, according to officials of Bengaluru-headquartered India’s national space agency.

The main lessons learnt were in the field of design and realisation of systems and subsystems, launch for interplanetary mission, insertion into other planet’s orbit, operation of the spacecraft and scientific instruments around Mars orbit, they said.

ISRO has been continuously monitoring the spacecraft and its five scientific instruments, and officials said scientific analysis of the data being received from MOM spacecraft is in progress.

On the health of the spacecraft, M Annadurai, who was the Programme Director of MOM, said the spacecraft’s “moving elements are facing some issues and some of the redundancies we have to switch over”. “The spacecraft’s health is reasonably good considering that we are in the seventh year,” Annadurai said.

He expects the spacecraft to have a mission life of probably another one year.

On the reasons for the long mission life, Annadurai said ISRO had done corrections after learning lessons from the Chandrayaan-1 venture, in terms of reconfiguring the spacecraft and optimisation of fuel management, among others.

Noting that Earth remote-sensing satellites typically have a mission life of seven to nine years, he said it was a very satisfying moment that India could establish that around Mars also, a spacecraft can be in operation for such a long period.