ISRO PSLV-C51 🚀🛰

       PSLV-C51 is scheduled to launch Amazonia-1 and 20 Co-passenger satellites on February 28, 2021 from Satish Dhawan Space Centre SHAR. 

     
       PSLV-C51, which is the 53rd mission of PSLV,    will launch Amazonia-1 of Brazil as primary         satellite and 20 Co-passenger satellites from     Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota. The launch is tentatively scheduled at 1023 Hrs IST on February 28, 2021 subject to weather conditions.

PSLV-C51/Amazonia-1 is the first dedicated commercial mission of NewSpace India Limited (NSIL), a Government of India company under Department of Space. NSIL is undertaking this mission under a commercial arrangement with Spaceflight Inc. USA.

      Amazonia-1 is the optical earth observation    satellite of National Institute for Space Research (INPE). This satellite would further strengthen the existing structure by providing remote sensing data to users for monitoring deforestation in the Amazon region and analysis of diversified agriculture across the Brazilian territory.

The 20 co-passenger satellites include one from ISRO (INS-2TD), four from IN-SPACe (three UNITYsats from consortium of three Indian academic institutes and One Satish Dhawan Sat from Space Kidz India) and 15 from NSIL.

What is Mach Number ?

 What is Mach Number?

The Mach number is the ratio of flow velocity after a certain limit of the sounds speed. In simple words it is the the ratio of the speed of a body to the speed of sound in the surrounding medium.

Mach Number Formula

The formula of Mach Number is:

M = u/c

Where,

• The Mach number is M
• Based on the limits the local flow velocity is u
• The speed of sound in that medium is c

To explain it simply, the speed of sound can be equated to Mach 1 speed. Thus, Mach 0.75 will be 75% of the speed of sound that is also called subsonic and Mach 1.65 will be 65% faster than the speed of light which is also called supersonic.

           The Mach number due to the local speed of sound is dependent on the surrounding mediums in specific temperature and pressure. A flow can be determined as an incompressible flow with the help of Mach number. The medium can either be a liquid or a gas. The medium can be flowing whereas the boundary may be stable or the boundary may be traveling in a medium which is at rest. The medium and boundary both may be traveling with certain speed but their velocities in respect to each other are what matters. The medium may be channeled through several devices such as wind tunnels or may be immersed in the medium. The Mach number is termed as a dimensionless number because it is a ratio of two speeds.

Mach Number Classification

Speed below the speed of sound is termed as subsonic whereas speed above the speed of sound is termed as supersonic, although scientists practicing aerodynamics most of the time use these terms to describe a particular range of Mach Number. 

Subsonic:

Commercial aircraft with aerodynamic features such as the rounded nose and leading edges. The mach is below 0.8.

Transonic:

Aircraft that are built with swept wings. The mach value is between 0.8-2.1.

Supersonic:

The aircraft created to go supersonic have a definite design it has complete movement of the canards, thin aerofoil sections, and sharp edges. The mach levels are between 1.2 and 5.0.

Hypersonic:

These planes have several distinctive features such as nickel-titanium skin that is cooled and small wings. The mach values are between 5.0 and 10.0. The U.S. plane X-15 created the world record of flying at Mach 6.72.

High-Hypersonic:

The mach levels are between 10.0 -25.0. When flying at such huge speeds thermal controls becomes an integral portion of the design. The hotness of the surface must be considered beforehand.