Subject: Space Technology

 

In the news

• MethaneSAT, the latest addition to the space technology arsenal, promises to revolutionize the tracking and measurement of methane emissions globally.
• Launched aboard a SpaceX Falcon9 rocket, this innovative satellite is set to provide unparalleled insights into methane emissions, aiding in the fight against climate change.

Methane Emissions   Methane, organic compound composed of carbon and four hydrogen atoms (CH4). Second-biggest anthropogenic contributor to global warming after carbon dioxide, 80 times more potent. Global Warming Potential (GWP) measures warming caused by substance relative to carbon dioxide over a century. Methane GWP100: 28, nitrous oxide 265, sulphur hexafluoride 23,500. Short-lived climate pollutant, breaks down in a few years unlike carbon dioxide. Sources: Cattle-farming, landfills, wastewater treatment, rice cultivation, industrial processes. Energy, agriculture, waste sectors primary emitters, responsible for 30% of global warming. Livestock emissions, including manure and gastroenteric releases, account for 32% of human-caused emissions. Global Methane Pledge: Launched at UN COP26 climate conference in Glasgow. Over 90 countries signed, led by United States and European Union (India not signed up).

 Unraveling MethaneSAT

• MethaneSAT is an initiative of the Environmental Defense Fund (EDF), in collaboration with Harvard University, the Smithsonian Astrophysical Observatory, and the New Zealand Space Agency.
• Equipped with a high–resolution infrared sensor and a spectrometer, MethaneSAT can detect methane concentrations as small as three parts per billion.
• With a wide-camera view of about 200 km by 200 km, MethaneSAT can identify both small and large emitters, filling critical data gaps.

Key Features

• Data Accessibility: MethaneSAT will provide its data for free in near real-time, empowering stakeholders and regulators to take timely action to curb methane emissions.
• Cloud Computing and AI: Google’s cloud-computing and AI technology will be used to analyze the vast amount of data collected by MethaneSAT, ensuring efficient processing and interpretation.

Significance of Methane Emission Monitoring

• Greenhouse Gas Impact: Methane, though invisible, is a potent greenhouse gas and a major contributor to global warming, second only to carbon dioxide.
• Health Hazards: Methane emissions also contribute to the formation of ground-level ozone, posing serious health risks and causing premature deaths.
• Fossil Fuel Operations: The bulk of human-caused methane emissions stem from fossil fuel operations, making it imperative to monitor and reduce these emissions.

Implications  

• Global Impact: The launch of MethaneSAT aligns with the growing momentum for stringent methane management policies worldwide.
• Transparency: Publicly available data from MethaneSAT will hold governments and corporations accountable for their methane emission reduction commitments.
• Behavioral Change Challenges: While the data from MethaneSAT can drive awareness, behavioral changes among polluters are not guaranteed, highlighting the need for complementary regulatory measures.

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Try this PYQ from CSE Prelims 2019:

Q.Consider the following:

1. Carbon monoxide
2. Methane
3. Ozone
4. Sulphur dioxide

Which of the above are released into atmosphere due to the burning of crop/biomass residue?

(a) 1 and 2 only

(b) 2, 3 and 4 only

(c) 1 and 4 only

(d) 1, 2, 3 and 4

[wpdiscuz-feedback id=”pty7uzivfd” question=”Please leave a feedback on this” opened=”1″]Post your answers here.[/wpdiscuz-feedback]

In the news

• Recently, the National Aeronautics and Space Administration (NASA) shared mesmerizing images of Cavum clouds, also known as “hole-punch clouds” or “fallstreak holes,” as observed from space.

What are Cavum Clouds?

• Formation Process: Cavum clouds are formed when airplanes traverse through layers of altocumulus clouds, which are mid-level clouds containing supercooled water droplets (water below freezing temperature but still in liquid form).
• Adiabatic Expansion: As the aircraft moves through, a phenomenon called adiabatic expansion can occur, causing the water droplets to freeze into ice crystals.
• Creation of Holes: These ice crystals eventually become too heavy and fall out of the cloud layer, resulting in the formation of a hole in the clouds.
• Steep Angle Formation: Cavum clouds are typically formed when planes pass through at a relatively steep angle.

About Altocumulus Clouds

	Details
Appearance	Altocumulus clouds are mid-level clouds characterized by white or gray patches or layers.
Formation	They form between 2,000 to 7,000 meters (6,500 to 23,000 feet) above sea level.
Composition	Composed of water droplets and occasionally ice crystals.
Shape	Usually appear as rounded masses or rolls.
Weather Patterns	Often indicate fair weather, but can also precede thunderstorms or cold fronts.
Optical Effects	They can create a halo effect around the sun or moon when thin enough.
Classification	Altocumulus clouds are classified as “middle-level clouds” (based on their altitude in the atmosphere).
Associated Types	Altocumulus castellanus: Towering altocumulus clouds indicating instability and potential storminess.

Introduction

• The formation of planets within protostellar discs, swirling reservoirs of gas and dust, remains a captivating field in astrophysics.
• Recent advancements in computer simulations have unveiled the unexpected flattened shapes of nascent gas planets within these discs, providing critical understanding of planetary genesis.

What are Circumstellar Discs?

• Protoplanetary Discs: These discs, comprised of dust, gas, and other celestial objects, orbit newly formed stars and serve as the birthplace of planets.
• Composition and Evolution: Initially predominantly gas, protoplanetary discs evolve, hosting various materials including asteroids, comets, and planets.
• Findings: Hubble Space Telescope offers detailed views of these regions, aiding astronomers in studying planet formation dynamics.

Distinctive Shape of Protoplanets

• Unique Structure: Protoplanets exhibit oblate spheroid shapes, highly flattened, resembling discs with up to 90% flattening.
• Growth Dynamics: Gas accumulation primarily occurs through poles rather than equators, impacting observed properties and interpretation of observations.

Formation Mechanisms

• Core Accretion vs. Disc Instability: These two prominent theories offer models for planet formation, emphasizing diverse mechanisms contributing to planetary systems’ complexity.
• Role of Disc Instability: This mechanism, explaining rapid gas giant formation, aligns with observations of certain exoplanetary systems, highlighting the interplay of formation processes.

Challenges in Observation

• Limited Detection: Observing nascent protoplanets within these discs poses challenges, with only a few detected to date, such as within the PDS 70 system.
• Temporal Constraints: The short duration of planetary formation phases necessitates precise timing for observational opportunities.

Insights from Simulations

• Computational Studies: High-resolution simulations elucidate thermal conditions influencing gas protoplanet properties within the discs, offering invaluable insights into their formation.
• Resolution and Analysis: These simulations, computationally demanding, trace protoplanet evolution from condensation to provide a deeper understanding.

Introduction

• In Christopher Nolan’s 2014 sci-fi masterpiece Interstellar, three planets (aside from Earth) captivate viewers with their extreme environments.
• Surprisingly, these worlds, technically termed Blanets, may not be purely fictional and could exist in reality.

What are Blanets?

• Formation Theory: In 2019, Japanese scientists proposed a theory suggesting that planets could form within massive dust and gas clouds surrounding supermassive black holes.
• Unique Characteristics: Blanets, unlike Earth, are not expected to resemble habitable worlds due to their formation near black holes.
• Surrounding Environment: Black holes are encircled by colossal discs of gas and dust, influenced by the black hole’s gravitational pull and heating effects.
• Galactic Presence: Nearly every galaxy is believed to harbor a supermassive black hole at its center, acting as a gravitational nucleus around which stars organize.

Formation Process

• Similar Mechanism: Planets near young stars form from the collision and aggregation of dust and gas particles in swirling disks. A comparable process could occur near supermassive black holes.
• Blanet Characteristics: Blanets are anticipated to be approximately 3,000 times larger than Earth and must orbit the black hole at a distance of about 100 trillion km to avoid gravitational disruption during their formation.

Implications and Speculations

• Extreme Environments: Blanets represent worlds of extremes, vastly different from habitable planets like Earth.
• Scientific Inquiry: The study of blanets offers insights into the dynamic interactions between black holes and their surrounding environments, pushing the boundaries of astrophysical understanding.

Introduction

• India’s pioneering solar mission, Aditya-L1, has achieved a significant milestone as advanced sensors onboard successfully detected the impact of coronal mass ejections (CMEs), marking a leap forward in space exploration.

Coronal Mass Ejections (CMEs) CMEs were discovered in 1971 and established their importance in solar-terrestrial relations later in the 1980s. It consists of massive clouds of solar plasma and magnetic field lines. It typically accompanies solar flares and filament eruptions. The frequency of CMEs varies with the 11-year solar cycle, with about one a week observed during solar minimum and an average of two to three CMEs per day observed near solar maximum They travel at thousands of km per hour. They can lead to geomagnetic storms, aurorae, and in extreme cases, damage to electrical power grids. They are primarily detected using coronagraphs aboard spacecraft such as SOHO and STEREO. Not all CMEs interact with Earth, but those that do can cause disruptions to satellite communications and power grids. Halo CMEs are Earth-directed CMEs visible as rings in white-light coronagraph observations.

About Plasma Analyser Package for Aditya (PAPA)

• Purpose: PAPA is an energy and mass analyser tailored for in-situ measurements of solar wind electrons and ions within the low energy range.
• Sensor Composition: PAPA comprises two sensors—Solar Wind Electron Energy Probe (SWEEP) and Solar Wind Ion Composition Analyser (SWICAR)—facilitating comprehensive observations of solar phenomena.
• Functionalities: Sensors not only measure electrons and ions’ energy but also ascertain their direction of arrival, enabling a holistic understanding of solar wind dynamics.

CME Detection and Analysis

• Observations: PAPA detected CME events, notably on December 15, 2023, and during February 10-11, 2024.
• December 15, 2023: Single CME event marked by a sudden increase in electron and ion counts, aligning with solar wind parameters and magnetic field measurements.
• February 10-11, 2024: Multiple minor CME events observed, showcasing nuanced variations in electron and ion counts over time.

Performance Evaluation and Continuous Observations

• PAPA sensors are currently operational in default mode, demonstrating adherence to design specifications across all operational modes.
• Continuous observations underscore PAPA’s efficacy in monitoring space weather conditions and its adeptness in detecting and analyzing solar phenomena.

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Back2Basics: Aditya-L1

• Launched successfully by ISRO on September 2.
• Orbits around the Lagrangian Point 1 (L1), maintaining a stable position 1.5 million km from Earth in the direction of the Sun.
• Hosts seven payloads dedicated to studying various aspects of the Sun, encompassing both remote observations and in-situ measurements.

Introduction

• Astronomers have triumphantly uncovered a rare class of stars, known as helium stars, after a decade-long quest.
• Led by Dr. Maria Drout from the University of Toronto, astronomers embarked on a collaborative mission to decipher the mysteries of these elusive cosmic entities

Helium Stars: An Overview

• Helium stars, also known as helium-burning stars, are a stage in the evolution of certain types of stars.
• These stars are typically more massive than the Sun and have exhausted the hydrogen fuel in their cores, leading to a contraction and subsequent heating of the core.
• As a result, helium fusion begins in the core, where helium nuclei fuse to form heavier elements such as carbon and oxygen.
• This fusion process releases energy, causing the star to expand and become more luminous.
• Helium stars represent an intermediate stage in stellar evolution between main-sequence stars and later stages such as red giants or supernovae.

Key Findings and Insights

• Spectral Analysis: Rigorous spectral analysis conducted from 2017 to 2024 unveiled distinct classes of helium stars based on hydrogen content, providing profound insights into their evolutionary trajectories.
• Computational Modeling: Advanced computational modelling techniques yielded crucial data on surface temperatures and gravitational forces, enriching our understanding of helium stars’ properties.
• Surface Conditions of Class 1 Stars: Further investigations into Class 1 helium stars revealed intriguing surface conditions. The team utilized computer modelling to determine surface temperature and gravity, finding them to be approximately 20 times hotter than the Sun and possessing surface gravity about 1,000 times stronger than Earth’s.

Significance of the Findings

• Hydrogen-Deficient Supernovae: A pivotal breakthrough in the discovery of helium stars was the elucidation of hydrogen-deficient supernovae, perplexing phenomena that puzzled scientists for decades.
• Binary-Star Interactions: Gravitational interactions within binary star systems played a crucial role in unmasking the helium-rich surfaces of these stellar anomalies.

Implications for Astrophysics

• Cosmic Laboratories: Helium stars serve as invaluable cosmic laboratories, offering unprecedented opportunities to explore the intricacies of stellar evolution and binary star dynamics.
• Frontiers of Research: Their discovery opens new frontiers in astrophysical research, unraveling mysteries surrounding heavy element formation and gravitational wave generation.

Introduction

• Indian Space Research Organisation (ISRO) has achieved a significant breakthrough in its quest for human spaceflight with the successful human rating of its CE20 cryogenic engine.
• The ground qualification tests, conducted at the High Altitude Test Facility at ISRO Propulsion Complex, Mahendragiri, have been successfully completed, validating the CE20 engine for the Gaganyaan programme.

What is Cryogenic Engine?   It is a type of rocket engine that operates on cryogenic (extremely low-temperature) fuels and oxidizers, typically liquid hydrogen (LH2) and liquid oxygen (LOX). They are highly efficient due to the high energy density of cryogenic fuels. They provide greater thrust compared to traditional rocket engines, making them suitable for launching heavy payloads into space. They are commonly used in the upper stages of space launch vehicles, where they propel payloads from initial launch phases into desired orbits. They operate at extremely low temperatures, typically below -150°C (-238°F) for liquid hydrogen and below -183°C (-297°F) for liquid oxygen.

About CE20 Cryogenic Engine

• It has been designed and developed by the Liquid Propulsion Systems Centre (LPSC), a subsidiary of ISRO.
• It is the first Indian cryogenic engine to feature a gas-generator cycle.
• It is one of the most powerful upper-stage cryogenic engines in the world.
• This engine develops a nominal thrust of 186.36 kN in vacuum.

Key Highlights of Ground Qualification Tests

• Thorough Evaluation: The CE20 engine underwent extensive testing, including evaluation under nominal and off-nominal conditions related to thrust, mixture ratio, and propellant tank pressure.
• Hot Firing Tests: Four engines underwent a total of 39 hot firing tests, accumulating a cumulative duration of 8,810 seconds, surpassing the minimum human rating qualification standard requirement of 6,350 seconds.

Update on First Unmanned Gaganyaan (G1) Mission

• Mission Objectives: The Gaganyaan project aims to demonstrate India’s human spaceflight capabilities by launching a crew of three members into a 400 km orbit for a 3-day mission, followed by a safe return to Earth with a landing in Indian sea waters.
• Acceptance Tests: ISRO has completed the acceptance tests of the flight engine designated for the first unmanned Gaganyaan (G1) mission, scheduled tentatively for the second quarter of 2024.
• Engine Specifications: The flight engine, which will power the upper stage of the human-rated LVM3 vehicle, boasts a thrust capability of 19 to 22 tonnes and a specific impulse of 442.5 seconds.

Introduction

• Recent findings published in the journal Nature suggest that beneath the icy shell of Mimas, there lies a potential liquid ocean, challenging previous assumptions about the moon’s composition and internal dynamics.

About Mimas

	Description
Discovery	Discovered by William Herschel on September 17, 1789.
Characteristics	Smallest and innermost of Saturn’s major moons.
Size	Diameter of about 396 kilometers (246 miles), making it one of the smallest known astronomical bodies that is rounded in shape.
Features	Known for its large Herschel Crater, Called as “Death Star” from the Star Wars films.
Composition	Mostly composed of water ice with a small amount of rock.
Orbit	Orbits Saturn at a distance of about 185,520 km (115,220 miles).
Exploration	Visited by the Cassini spacecraft, which captured detailed images of its surface during its mission to Saturn.

Astronomical Insights

• Potential Liquid Ocean: Scientists analyzed Mimas’s orbital motion using data from NASA’s Cassini spacecraft, concluding that the moon’s oscillations indicate the presence of either an elongated silicate core or a global ocean.
• Librational Model: Calculations based on Mimas’s librations and orbital changes reached a deadlock, prompting consideration of a subsurface ocean. Theoretical models incorporating viscoelastic outer layers and hydrostatic interior interfaces suggested an ice shell thickness of 20-30 km.
• Surface Heat and Eccentricity: Estimates indicate surface heat release of approximately 25 milliwatts per sq. m, expected to reduce Mimas’s eccentricity by half in 4-5 million years. Simulations suggest the ocean may have formed 2-25 million years ago, with potential hydrothermal activity.

Implications and Findings

• Comparative Analysis: Similarities between Mimas and Enceladus, another Saturn moon with a global ocean, hint at potential hydrothermal activity despite surface differences.
• Ice Shell Composition: The viscoelastic nature of Mimas’s outer icy layer and hydrostatic interior interfaces align with observations, supporting the theoretical ice shell thickness determined through calculations.