India Shoots for the Sun — ISRO’s Aditya L1 on its Way to Create History
After the successful landing of Chandrayaan-3, India’s first solar expedition, Aditya-L1 is all set to create history with its launch on 2nd September
Chandrayaan-3 represents India’s third lunar exploration mission within the Indian Space Research Organisation’s (ISRO) Chandrayaan program. It features a lander named Vikram and a rover named Pragyan, akin to those utilized in the Chandrayaan-2 mission. The propulsion module transported the combined lander and rover setup into lunar orbit, priming it for a controlled descent by the lander.
The launch of Chandrayaan-3 took place on July 14, 2023. Subsequently, the spacecraft successfully entered lunar orbit by August 5. Notably, on August 23, 2023, at 12:32 UTC, the lander successfully made a touchdown in the lunar south pole area.
This achievement marked India as the fourth country to effectively land on the Moon and notably, the first nation to achieve this feat in proximity to the lunar south pole.
Isro announced on Tuesday evening that a laser detector carried onboard had conducted groundbreaking “in-situ” measurements of the elemental composition of the lunar surface near the south pole. The findings revealed a variety of substances, among them sulphur and oxygen, present in the lunar soil.
The data from the instrument provides unequivocal confirmation of sulphur’s presence. Moreover, initial analysis has revealed the existence of several other elements, including aluminium, calcium, iron, chromium, titanium, manganese, silicon, and oxygen. This development signifies a significant step forward in our understanding of the lunar surface’s composition.
History of Solar Expedition
The Parker Solar Probe (PSP), formerly known as Solar Probe, Solar Probe Plus, or Solar Probe+, is a NASA spacecraft launched in 2018 with the primary objective of observing the outer corona of the Sun. The spacecraft is designed to approach within an impressive 9.86 solar radii (equivalent to around 6.9 million kilometres or 4.3 million miles) from the Sun’s centre. As it reaches its closest points, it will achieve speeds of up to 690,000 km/h (430,000 mph), approximately 0.064% of the speed of light (about 191 km/s). Notably, the Parker Solar Probe holds the distinction of being the fastest human-made object ever constructed.
The initiative was introduced during the fiscal year 2009 budget cycle, with a total project cost of $1.5 billion. The spacecraft itself was developed by the Johns Hopkins University Applied Physics Laboratory and was launched on August 12, 2018. Remarkably, it was the first NASA spacecraft to be named after a living individual, honouring physicist Eugene Newman Parker, a distinguished professor at the University of Chicago.
An interesting addition was a memory card affixed to a plaque and positioned beneath the spacecraft’s high-gain antenna on May 18, 2018. This card contained the names of over 1.1 million individuals, alongside pictures of Parker himself and a copy of his groundbreaking 1958 scientific paper, which predicted significant facets of solar physics.
On October 29, 2018, at approximately 18:04 UTC, the Parker Solar Probe achieved the record for the closest distance to the Sun by any artificial object.
This feat surpassed the previous record held by the Helios 2 spacecraft, which came within 42.73 million kilometres (26.55 million miles) of the Sun’s surface in April 1976. As of its closest approach on November 21, 2021, the Parker Solar Probe reached a distance of 8.5 million kilometres (5.3 million miles) from the Sun. This proximity will be surpassed with the upcoming flybys of Venus.
India’s first solar mission — Aditya L1
Aditya L1 marks India’s inaugural space-based mission dedicated to Sun observation. The spacecraft is poised to occupy a strategic halo orbit encircling the Lagrange point 1 (L1) within the Sun-Earth system, situated roughly 1.5 million kilometres away from Earth. The distinct advantage of placing a satellite in this halo orbit around the L1 point is its continuous, unobstructed view of the Sun, free from any instances of occultation or eclipses. This unique perspective facilitates real-time observation of solar activities and their consequential impact on space weather.
Equipped with seven payloads, the spacecraft is engineered to examine various layers of the Sun, encompassing the photosphere, chromosphere, and the outermost corona, by leveraging electromagnetic, particle, and magnetic field detectors. The utilization of the L1 vantage point allows four of these payloads to directly observe the Sun, while the remaining three payloads undertake in-situ analyses of particles and fields at the Lagrange point L1. Consequently, these capabilities enable significant scientific investigations into the propagation effects of solar dynamics within the interplanetary medium.
The suite of Aditya L1 payloads is anticipated to furnish pivotal insights to decode intricate phenomena such as coronal heating, coronal mass ejections, pre-flare and flare activities, along with their inherent characteristics. Furthermore, the mission endeavours to comprehend the dynamics of space weather and unravel the intricate propagation of particles and fields.
The major science objectives of Aditya-L1’s mission are:
- Study of Solar upper atmospheric (chromosphere and corona) dynamics.
- Study of chromospheric and coronal heating, physics of the partially ionized plasma, initiation of the coronal mass ejections, and flares
- Observe the in-situ particle and plasma environment providing data for the study of particle dynamics from the Sun.
- Physics of solar corona and its heating mechanism.
- Diagnostics of the coronal and coronal loops plasma: Temperature, velocity and density.
- Development, dynamics and origin of CMEs.
- Identify the sequence of processes that occur at multiple layers (chromosphere, base and extended corona) which eventually leads to solar eruptive events.
- Magnetic field topology and magnetic field measurements in the solar corona.
- Drivers for space weather (origin, composition and dynamics of solar wind.
The inception of Aditya dates back to January 2008 when the Advisory Committee for Space Research introduced the concept. Initially envisioned as a compact satellite weighing 400 kg (880 lb) and operating within Low Earth Orbit (LEO) at 800 km altitude, the satellite was designed to incorporate a coronagraph for studying the solar corona. For the fiscal year 2016–2017, an initial experimental budget of 3 crore INR was earmarked for the project. Subsequently, the mission’s scope underwent substantial expansion, leading to its transformation into a comprehensive solar and space environment observatory intended for placement at the Lagrange point L1. This prompted the mission’s renaming to “Aditya-L1.” By July 2019, the project had been allocated a budget of ₹378.53 crore, exclusive of launch expenditures.
Following its launch, the Aditya-L1 mission is projected to traverse approximately 109 Earth days before attaining its desired halo orbit encircling the L1 point, positioned at a distance of approximately 1,500,000 km (930,000 mi) from Earth. The satellite, weighing 1,500 kg (3,300 lb), boasts a payload of seven distinct scientific instruments, each with its own specific objectives.
These objectives encompass a wide array of scientific goals, including but not limited to investigating phenomena such as coronal heating, the acceleration of solar wind, magnetometry of the solar corona, and the origin and monitoring of near-UV solar radiation. This radiation, in turn, plays a pivotal role in driving the dynamics of Earth’s upper atmosphere and influencing the global climate. Additionally, the mission aims to delve into the coupling mechanisms between the solar photosphere, chromosphere, and corona. Moreover, the satellite is equipped to carry out in-situ characterizations of the space environment surrounding Earth. This involves the measurement of energetic particle fluxes and magnetic fields emanating from the solar wind. These measurements are crucial in understanding and mitigating the adverse effects of solar magnetic storms on both space-based and ground-based technologies.
Aditya-L1 is primed to deliver comprehensive observations of the Sun’s key layers: the photosphere, chromosphere, and corona. Furthermore, a designated instrument will meticulously analyze the influx of solar energetic particles at the L1 orbit, while an accompanying magnetometer payload is geared towards quantifying fluctuations in magnetic field strength within the halo orbit encircling L1. The choice of placing these payloads beyond the influence of Earth’s magnetic field is crucial, rendering them less suitable for the original Aditya mission concept within low Earth orbit.
An enigma that continues to challenge solar physics pertains to the stark contrast in temperature between the Sun’s upper atmosphere, blazing at 1,000,000 K (1,000,000 °C; 1,800,000 °F), and its lower atmosphere, maintained at a mere 6,000 K (5,730 °C; 10,340 °F). Moreover, the intricate ways through which the Sun’s radiation impacts Earth’s atmospheric dynamics across both short and long timescales remain largely unresolved.
Aditya-L1’s significance lies in its capacity to capture nearly simultaneous images of distinct atmospheric layers, thereby unveiling the intricate pathways through which energy is channelled and transferred from one layer to another. By doing so, the mission holds the potential to foster a comprehensive comprehension of the Sun’s dynamic processes. Consequently, Aditya-L1 is poised to address longstanding questions in the realms of solar physics and heliophysics, thus contributing significantly to the advancement of our understanding of the Sun’s intricate dynamics.
Payloads:
- The Visible Emission Line Coronagraph (VELC) is a sophisticated instrument designed to replicate a controlled total solar eclipse in space through the use of an occultor, which blocks the influx of sunlight. This innovative telescope functions by creating a darkened region akin to an eclipse, enabling the study of the solar corona in visible and infrared wavelengths. VELC serves multifaceted purposes, including spectral imaging of the corona. It employs visible and infrared channels to fulfil its objectives. The primary goals encompass the examination of diagnostic parameters characterizing the solar corona, investigating the dynamics and origins of coronal mass ejections (CMEs) utilizing three visible channels and one infrared channel, and conducting precise measurements of the magnetic field within the solar corona, down to magnitudes of tens of Gauss. In addition to these core objectives, VELC seeks to address pressing questions in solar physics. It endeavours to unravel the mysteries surrounding the elevated temperature of the solar atmosphere, a perplexing phenomenon and aims to elucidate the interplay between changes in the Sun and their impact on both space weather and Earth’s climate. This substantial payload, the Visible Emission Line Coronagraph (VELC), registers an approximate weight of 170 kg (370 lb).
- The Solar Ultraviolet Imaging Telescope (SUIT) is designed with the purpose of observing the Sun within the wavelength range of 200–400 nm. This remarkable instrument will capture full disk images of distinct layers within the solar atmosphere by employing a suite of 11 specialized filters. Of particular significance is the fact that the Sun has never before been observed from space within this specific wavelength range. SUIT’s positioning at the first Lagrange point (L1) offers a compelling advantage: uninterrupted and continuous observation of the Sun. This unique capability will facilitate an in-depth study of solar phenomena over prolonged periods. The development of SUIT is led by A. N. Ramaprakash and Durgesh Tripathi from the Inter-University Centre for Astronomy and Astrophysics (IUCAA) in Pune, in collaboration with ISRO and other affiliated institutions. This cooperative effort aims to bring the SUIT instrument to fruition. Remarkably, the payload weight of the SUIT instrument stands at approximately 35 kg (77 lb).
- The Aditya Solar Wind Particle Experiment (ASPEX) is designated to scrutinize the solar wind’s attributes, fluctuations, distribution, and spectral traits. This instrument plays a pivotal role in delving into the dynamic characteristics of the solar wind and its intricate properties.
- The Plasma Analyser Package for Aditya (PAPA) is employed to decipher the composition of the solar wind and analyze its energy distribution. This essential instrument serves the purpose of unravelling the intricate makeup and energetic profile of the solar wind.
- The Solar Low Energy X-ray Spectrometer (SoLEXS) is a critical instrument tasked with monitoring X-ray flares for the purpose of investigating the perplexing mechanism responsible for the coronal heating of the solar corona. This instrument’s primary objective revolves around unravelling the enigma of how the corona attains its elevated temperatures through the study of X-ray flares.
- The High Energy L1 Orbiting X-ray Spectrometer (HEL1OS) is dedicated to observing dynamic occurrences within the solar corona. It serves a crucial role in estimating the energy required to accelerate solar energetic particles during eruptive events. By studying these phenomena, HEL1OS contributes to a deeper understanding of the mechanisms driving these events and the energy dynamics within the solar corona.
- The Magnetometer payload serves the purpose of quantifying both the magnitude and characteristics of the interplanetary magnetic field. This instrument’s function lies in capturing essential data about the magnetic environment in the interplanetary space.
Probo’s Opinion
Trade on the opinion here
Pointers for the graph:
- Chandrayaan’s rover sends back updates about the presence of sulphur on the south pole of the moon
- The Rover came across a 4-meter diameter crater positioned 3 meters ahead of its location. The Rover was commanded to retrace the path. It then safely headed on a new path.
- ISRO updated Aditya L1 spacecraft is equipped with advanced instruments and sensors, and can withstand extreme space conditions, to carry out precise observations of the Sun
- ISRO said that its Aditya-L1 mission, designed to study the Sun, has completed launch rehearsals and internal checks.
