IAS Gyan

Daily News Analysis


9th October, 2023 Science and Technology

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  • NASA has unveiled plans for a ‘sounding rocket mission’ set to launch three rockets during this year's solar eclipse on October 14.


  • The APEP (Atmospheric Perturbations around the Eclipse Path) mission, spearheaded by NASA, is set to launch three rockets during the solar eclipse on October 14, 2023.
  • The project, aimed at studying the impact of the sudden reduction in sunlight on the Earth's atmosphere, is led by Aroh Barjatya, an engineering physics professor of Indian origin at Embry-Riddle Aeronautical University.

Mission Overview

  • The APEP mission focuses on studying how the sudden reduction in sunlight during a solar eclipse affects the Earth's atmosphere, specifically the ionosphere.
  • The ionosphere is a region of the Earth's upper atmosphere that plays a crucial role in various aspects, including satellite communications.

Rocket Launches

  • The APEP team plans to execute a sequence of three rocket launches during the solar eclipse.
  • The first rocket launch is scheduled to occur 35 minutes prior to the local peak of the eclipse.
  • The second rocket will be launched during the eclipse itself.
  • The third rocket will be launched 35 minutes after the eclipse.
  • These launches will take place at the White Sands Missile Range in New Mexico, with a specific focus on studying the ionosphere.

Focus on the Ionosphere

  • The ionosphere's temperature and density are expected to decrease during the eclipse, causing a wave-like disturbance.
  • This disturbance has the potential to disrupt GPS and other satellite communications, making it essential to understand and model these perturbations.

Importance of the Ionosphere

  • The ionosphere plays a critical role in satellite communications, as all satellite signals pass through it before reaching Earth.
  • As our reliance on space-based assets and satellite communications grows, understanding and predicting ionospheric disturbances becomes increasingly crucial.

Future Plans

  • The APEP project extends beyond the 2023 mission, with plans to retrieve and relaunch rockets from NASA's Wallops Flight Facility in Virginia on April 8, 2024, during a total solar eclipse sweeping across the United States.
  • This subsequent launch will provide an opportunity to assess the broader effects of an eclipse, even though it will be positioned farther from the eclipse's path compared to the October annular eclipse.

Rocket Instruments and Data Collection

  • Each rocket will deploy four small scientific instruments designed to record changes in electric and magnetic fields, density, and temperature.
  • The goal is to achieve the first-ever simultaneous measurements from multiple locations in the ionosphere during a solar eclipse.
  • Rockets are chosen for this mission due to their precision and ability to investigate lower altitudes that may be inaccessible to satellites.
  • Rockets can collect data at altitudes ranging from 45 to 200 miles (70 to 325 kilometers) above the Earth's surface along their flight path.

Ring of Fire Eclipse

  • A "Ring of Fire" eclipse, also known as an annular solar eclipse, is a remarkable celestial event that occurs when the Moon partially covers the Sun, leaving a brilliant ring-like appearance of sunlight around the edges of the Moon.
  • This phenomenon takes place when the Moon is at a relatively distant point in its elliptical orbit around Earth, causing it to appear smaller than the Sun's disk.
  • As a result, during the eclipse, the Sun is not entirely obscured, and a radiant ring of sunlight encircles the Moon.

Key characteristics of a Ring of Fire Eclipse include:

  • Annularity: The term "annular" is derived from the Latin word "annulus," which means "ring." During this eclipse, the Moon covers the central portion of the Sun, creating the appearance of a fiery ring, or "ring of fire," around the Moon's silhouette.
  • Unique Visual Spectacle: A Ring of Fire Eclipse is a captivating visual spectacle, attracting skywatchers and astronomers from around the world. It offers a breathtaking view of the solar corona—a faint, outer layer of the Sun's atmosphere—that is typically visible only during total solar eclipses.
  • Safety Precautions: Just like during a total solar eclipse, it is essential to use proper eye protection when observing a Ring of Fire Eclipse. Staring directly at the Sun, even when partially covered by the Moon, can cause serious eye damage.
  • Geographical Variation: The visibility of a Ring of Fire Eclipse depends on the observer's location. It is typically visible from a specific region on Earth, and its path may vary during each occurrence.
  • Scientific Significance: Solar eclipses, including Ring of Fire Eclipses, offer valuable opportunities for scientific research. They allow scientists to study the Sun's outer atmosphere, magnetic fields, and other phenomena.
  • Cultural and Historical Significance: Throughout history, solar eclipses have held cultural and spiritual significance in various societies. Many cultures have developed myths, legends, and rituals associated with eclipses.

Sounding Rocket

  • A sounding rocket is a specialized suborbital rocket designed for scientific research and data collection in Earth's upper atmosphere and beyond.
  • These rockets are valuable tools for conducting experiments in space and gathering data on various atmospheric and cosmic phenomena.

Here are key features and uses of sounding rockets:

  • Suborbital Flight: Sounding rockets are not designed to achieve orbit around Earth. Instead, they follow a suborbital trajectory, reaching altitudes that may range from tens to hundreds of miles above the Earth's surface.
  • Research Payload: Sounding rockets carry scientific instruments and experiments, known as payloads, into space. These payloads are carefully designed to collect data on factors such as atmospheric conditions, cosmic rays, radiation, and electromagnetic phenomena.
  • Brief Flight Duration: Sounding rocket flights are relatively short-lived, typically lasting a few minutes. This limited duration allows researchers to gather data during specific phases of a mission, such as during a solar eclipse or in the ionosphere.
  • Precise Launch Timing: Sounding rockets offer researchers precise control over when and where their experiments are conducted. This flexibility is particularly valuable for studying time-sensitive events like solar eclipses.
  • Multiple Launch Sites: Launch facilities for sounding rockets are located around the world to accommodate diverse research needs and access various regions of the Earth's atmosphere and space.
  • International Collaboration: Sounding rocket missions often involve international collaboration, with scientists and organizations from different countries working together to conduct experiments and gather data.
  • Applications: Sounding rockets have a wide range of applications, including atmospheric research, space weather monitoring, and studies of cosmic phenomena. They provide critical data for understanding Earth's atmosphere and the space environment.


The APEP mission represents a significant effort to better understand the complex interactions in the Earth's atmosphere during a solar eclipse and their potential impact on vital communication systems.


Q.   Discuss the significance of sounding rockets in scientific research and data collection. Elaborate on the role they play in advancing our understanding of Earth's atmosphere and space. (250 Words)