XPoSat Mission: Polarimetry of X-rays

X-Ray Polarimeter Satellite (XPoSat)

• ISRO launched the XPoSat polarimetry mission on January 1, 2024.
• The primary goal is to study the polarisation (direction of the electric field of an electromagnetic wave) of astronomical X-rays.
• Aims to understand astronomical X-ray sources like black holes and neutron stars.
• Has two payloads in low Earth orbit.
• POLIX (Polarimeter Instrument in X-rays) is designed for observations in the 8-30 keV energy band and will observe around 40 bright astronomical sources during its five-year mission.
• XPoSat mission complements NASA's IXPE mission, launched in 2021.
• IXPE focuses on the 2-8 keV energy range, while XPoSat extends this spectrum from 8-30 keV.

Understanding Polarization

• Electromagnetic waves, like light, consist of coupled oscillating electric and magnetic fields perpendicular to each other.
• Polarisation refers to the direction of the electric field of an electromagnetic field.

High Altitude Pseudo Satellite (HAPS)

• CSIR-National Aerospace Laboratories (NAL) successfully tested an unmanned High Altitude Pseudo Satellite (HAPS) in Karnataka on February 13, 2024.
• This 5-meter drone, with an 11-meter wingspan, flew at 3 kilometers for 8 hours.
• Advanced uncrewed aircraft designed to operate in the stratosphere, approximately 20 kilometers above ground.
• Functions as aerial base stations, providing internet connectivity and other services at lower costs than satellites.
• Powered by solar energy to stay airborne for months.
• Ground coverage can span very large areas (around 500 km diameter) from a single platform. Advantages over Satellites:
• Lower latency
• Greater two-way transmission speeds
• Easier and less costly to deploy and maintain
• Can take off and land at regular airports, allowing flexible launch and retrieval. Applications:
• Border surveillance in remote terrain
• Wireless hotspots during disasters
• Maritime monitoring
• Bridging digital divides by providing low-cost broadband and IoT access
• Agricultural use with persistent wide-area monitoring
• Compelment India's satellite capacity

Neglected Tropical Diseases (NTD)

• The 74th World Health Assembly declared January 30th as 'World Neglected Tropical Diseases (NTD) Day.'
• Ahead of the 77th World Health Assembly session, the WHO released its Global report on neglected diseases (NTD) of 2024 in May.
• Viral diseases mentioned include Dengue, Chikungunya, Zika, and Rabies.
• Protozoal diseases include African Trypanosomiasis, and Leishmaniasis.
• Bacterial diseases featured are Leprosy and cholera.

CAR-T Cell Therapy

• Involves taking T cells from the patient's blood and modifying them in the laboratory by adding an antibody to a specific cancer cell antigen, creating a Chimeric Antigen Receptor (CAR).
• The CAR T cells are then introduced back to the patient.
• Each CAR is designed for a specific cancer's antigen, such as the CD19 antigen found in leukemia or lymphoma cells.
• CAR T-cell therapies attach to the CD19 antigen and not work for a kind of cancer that does present CD19 angtigen.
• Reduces the cost.

Solar Storms

• Solar flares are emissions of high-energy electromagnetic waves, including x-rays and gamma rays, which travel at the speed of light and take 8 minutes to reach Earth.
• There are five categories of solar flares based on x-ray wavelength and solar radiation (A, B, C, M, and X).
• Solar dynamics captured images of the events which were recorded to have two strong solar flairs on May 10-11 2024 an X5.8, X1.5-class flares and also an M6.6-class flare on May 13th 2024.
• The solar wind is composed of charged particles from the Sun’s atmosphere consisting mostly of electrons protons and alpha particles (kinetic energy between 0.5 and 10 keV).
• Coronal mass injections (CME) are the release of plasma with magnetic field from the sun.
• They takes 1-3 days to reach Earth.
• Geomagnetic stroms are major disturbances due to heliospheric magentic feild, categorised as G1, G2, G3, G4 and G5.

Effects of Solar Storms:

• Solar storms are similar to geomagnetic storms, but generally last a few minutes to several hours while geomagnetic storms last for days to weeks.
• Power Grid disruption where strong geomagnetic stroms induce strong currents in power lines which can damage transformers leading to power outages.
• Satellites: Charged particles damage electronic signals
• GPS and Navigation Systems: Geomagnetic disturbances impact accuracy
• Radio Communications: Storms disrupt systems using HF, VHF and UHF bands
• Aurora formation: Charged particles colliding with Earth
• Pigeons: Internal biological compasses

Historical Geomagnetic Storms

• Notiable geomagnetic storms in history include:
  • The Carrington event of 1859
  • Halloween Storms of 2003
  • The Quebec Blackout in 1989.

PSLV Orbital Experimental Module-3 (POEM-3)

• ISRO reached milestone with re-entry of PLSV which carries two satallites (PSLV-C58 and XPoSat) which elimenated all the old debris.
• The 4th stage helps is the last stage of the mission that faciliates re-entry process.
• The final stage of PLSV, also known as PORM-3 deorbited from an altidue of 650k to 350 km.
• Expected POEM-3 was expected to have reached North Pacific Ocean by March 21st 2024. -Until near reach PORM-3 was tracked by ISRO telemtry, Tracking and Commant.
• All tracked by System for Safe and Sustainable Spacecraft Operation Management to see any altitutde deviations.

Glycemic Index (GI) and Load (GI)

• Glycemic index (GI) of a food refers to the property of the food to increas ethe glucose and is a measure of carbohydrate quality
• Glucose of white bread is uses as the comparator.
• GI is taken as 100 and the ofter other foods are given as a percentage.
• GI catagories include low, medium and high.
• Multipled by thee carbohydrate consumed determins Glycemic Load (GL).
• Hight Gi and Gl diets are linked to type 2 diasbetes.
• Altzeimer is knows us type 3, cause the brain is affectted and causes dymentia.

WHO's Fungal Priority Pathogens List

• There is a list of 19 fungi that pose greatest threat to human health Important catagories include:
• Critcal Priority Group contain Candidia auris The classification is based on public health impact & antifugal risk.
• High Priority Group included Candida family and Mucorales.
• Priority group: Contains Coccidioides species and Crytococcus gattil.

INDIA TEST-FIRES AGNI-V BALLISTIC MISSILE

• Narendra Modi test fired the Agni-5 with Multiple Independently Targetable Re-entry Vehicle (MIRV) technology.
• MIRV missiles design multiple warheads with targeting distint targets spaces out throught a kilometer. Advantages:
• Can released multipe warheads It can reduce missiles because if released more the once.
• The range can reach into various distances.

Key Features of Agni-V :

• Has USA, UK, and France, has intercential Ballistic Missle System
• Weight - 50,000 kilograms
• Height-1.75 meters
• Diameter - 2 meters
• Carries about 1650 kiligrans of solid fuel.
• MIRV Capacity – from 2-12 warheads
• Speed measured as 25 mach
• Agni V system measures as 50 derees Celcuis.

SQUARE KILOMETRE ARRAY OBSERVATORY

• Has array called SKAO
• Initiative too build worlds largest radio telescopes
• Will connect to autstraliia, help probe celstrial phenonmena throught extreme distances.