In another milestone for the Indian Space
Research Organisation or ISRO, the Aditya Solar wind Particle Experiment-ASPEX
payload onboard Bharat’s Aditya-L1 satellite began its operations and started
performing normally on Saturday.
ISRO stated the ASPEX has two
instruments – the Solar wind Ion Spectrometer (Swis) and the SupraThermal and
Energetic Particle Spectrometer (Steps).
While the Steps instrument started functioning
on September 10, the Swis instrument was activated on November 2, and has
exhibited optimal performance.
Swis, utilising two sensor units with a
360-degree field of view each, operates in planes perpendicular to one another.
The instrument has successfully measured solar wind ions, primarily protons and
alpha particles.
A sample energy histogram acquired from
one of the sensors over two days in November 2023 illustrates variations in
proton (H+) and alpha particle (doubly ionised helium, He2+) counts.
These variations were recorded with
nominal integration time, providing a comprehensive snapshot of solar wind
behaviour.
The directional capabilities of the Swis
enable precise measurements of solar wind protons and alphas, contributing
significantly to addressing longstanding questions about solar wind properties,
underlying processes, and their impact on the Earth.
As per ISRO, the change in the proton
and alpha particle number ratio, as noticed by Swis, holds the potential to
provide indirect information about the arrival of Coronal Mass Ejections (CMEs)
at the Sun-Earth Lagrange Point L1.
An enhanced alpha-to-proton ratio is
often regarded as one of the sensitive markers of the passage of interplanetary
coronal mass ejections (ICMEs) at the L1 and hence is considered significant for
space weather studies.
Notably, Aditya-L1, Bharat’s first
dedicated solar mission, was launched into space on September 2 from the Satish
Dhawan Space Centre in Andhra Pradesh’s Sriharikota island.
The spacecraft, after travelling about
1.5 million km from Earth over 125 days, is likely to be placed in a Halo orbit
around the Lagrangian point L1, regarded closest to the Sun.
Last week, ISRO chief S Somnath said the
Aditya L1 spacecraft is nearing its final phase, and manoeuvres to enter the L1
point are expected to be completed by January 7, 2024.
NE Watch Desk
