Tuesday, 19 August 2025

A Comprehensive Overview of Atmospheric and Spaceflight Operation| Chapter 2 | Physical Science: New Insights and Developments Vol. 2

 

The limit of the atmosphere and the beginning of space are considered to be at 100 km altitude. Microgravity is the term used to characterise the very low acceleration level encountered inside a spacecraft in LEO (Low Earth Orbit). The study aims to monitor atmospheric operations and their applications. Chemical composition in the lower layers: 78% of nitrogen, 21% of oxygen, 1% of argon, and < 0.1% others and then a very small amount of other molecules, mainly water vapour and carbon dioxide, are present, which are in fact greenhouse gases, so they are important although they are small in quantity in the atmosphere compared to the other components. In terms of temperature evolution towards the atmosphere, at the level of the ground, with a temperature of 288 K, or 15°C. As one goes up in the mesosphere, about 50 km altitude, the temperature decreases again, and then above 80-90 km altitude it starts to increase again, because of the ionisation of the oxygen, mainly, and somewhat nitrogen atoms in the so-called thermosphere. Microgravity: these are the conditions that one can have in free fall. If someone has pure free fall, they are going to have zero-g or weightlessness, but in fact, there are always perturbing forces. The Hohmann transfer is a special kind of transfer from one circular orbit to another circular orbit. First of all, manoeuvring in orbit is basically <i>ΔV vectorial</i> that, if applied at some point in the orbit of a satellite or spacecraft that one will change the orbit. Here is an example of an initial circular orbit, and if velocity is added in the direction of the circular velocity. At some point,  <i>ΔV</i>, if added, it will change the orbit to an elliptical orbit of high energy. Basically, energy was added to the orbit, kinetic energy was also added, so a larger value of the semi-major axis can be obtained instead of the radius <i>r</i> of the initial circular orbit. An elliptical orbit appears, which has a semi-major axis larger than the radius of the initial circular orbit. Now, only instantaneous <i>ΔV</i> will be considered. This is the simplification. Most of the time, the initial conditions are a spacecraft on the ground, called the chaser, which is active and another spacecraft in orbit, the target, which is passive.

 

Author(s) DetailsP.Sateesh
Department of Physics, St. Peter’s Engineering College, India.

 

A.Rajesh
Department of Physics, St. Peter’s Engineering College, India.

 

Ch.Chakrapani
Department of BS&H, Seshadri Rao Gudlavalleru Engineering College, India.

 

P.Siva Kumar
Department of Physics, Kaveri University, Gowraram, India.

 

Y.Durga Sravanthi
Department of Chemistry, St. Peter’s Engineering College, India.

 

Masma Shaik
Department of Chemistry, St. Peter’s Engineering College, India.

 

Hemanth Kumar Narsetti
Department of Physics, St. Peter’s Engineering College, India.

 

M.Rajesh
Department of Physics, St. Peter’s Engineering College, India.

 

T.Ram Prasad
Department of Physics, St. Peter’s Engineering College, India.

 

K.Gopinath
Department of Chemistry, St. Peter’s Engineering College, India.

 

Please see the book here:- https://doi.org/10.9734/bpi/psniad/v2/5931

 

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