Explained: The Payloads That Are Being Carried By Aditya-L1

India launched its maiden solar mission, Aditya-L1, from Andhra Pradesh's Sriharikota today at 11:50 am. The mission is aimed at observing solar activities and how they affect the space weather in real time. Aditya-L1 is carrying several payloads that will send crucial information and help achieve the objectives of the mission.

According to the Indian Space Research Organisation (ISRO), the Aditya-L1 spacecraft will be placed in a halo orbit around the Lagrange point 1 (L1) of the Sun-Earth system. The point is about 1.5 million km from the Earth and will allow the spacecraft to continuously observe the Sun without any interruption.  

The major objectives of the Aditya-L1 mission are to study coronal heating, solar wind acceleration, Coronal Mass Ejections (CME), dynamics of the solar atmosphere, and temperature anisotropy.

Payloads Onboard Aditya-L1

Aditya-L1 is carrying a total of seven payloads that will observe the chromosphere, photosphere, and the corona, or the outermost layer of the Sun, using electromagnetic particle, and magnetic field detectors.

The seven payloads include four Remote Sensing Payloads that will directly view the Sun and record data and three in-situ Payloads that will conduct in-situ studies of particles and fields at the Lagrange point L1.

Remote Sensing Payloads

The four remote sensing payloads include the Visible Emission Line Coronagraph (VELC), which is “the prime payload designed as a reflective coronagraph with a multi-slit spectrograph”. The payload will send 1,440 images of the Sun every day to the ground station on Earth for analysis and research of the intended orbit.

Solar Ultraviolet Imaging Telescope (SUIT) is another payload whose objective is to picture the “solar disk in the near ultra-violet wavelength range”.

The third payload or instrument is the Solar Low Energy X-ray Spectrometer (SoLEXS) which has been designed to “measure the solar soft X-ray flux to study solar flares”.

The High Energy L1 Orbiting X-ray Spectrometer (HEL1OS) is another instrument that will observe the Sun and study solar flares in the high-energy X-rays.

In-Situ Payloads

The Aditya Solar Wind Particle Experiment (ASPEX) is an in-situ payload onboard Aditya-L1 which consists of two subsystems – Solar Wind Ion Spectrometer (SWIS) and Suprathermal and Energetic Particle Spectrometer (STEPS). While SWIS is a low-energy spectrometer that will measure the proton and particles of the solar wind, STEPS is a high-energy version of it tasked with measuring high-energy ions of the solar wind.

The Plasma Analyser Package For Aditya (PAPA) instrument will help scientists understand the solar winds and their composition. It will also carry out mass analysis of solar wind ions.

The Advanced Tri-axial High-Resolution Digital Magnetometers will measure the “low intensity interplanetary magnetic field in space”. The instrument has two sets of magnetic sensors – one at the tip of a 6-meter deployable boom and the other in the middle of the boom, around three meters away from the spacecraft.