Why in News:

• The Defence Ministry placed ₹7,523-crore order for 118 indigenous Arjun Mk-1A tanks.

About Main Battle Tank (MBT) Arjun 

• It has been developed under a multi-laboratory programme of DRDO mainly at the Combat Vehicles Research & Development Establishment (CVRDE) facility.
• The Arjun tanks stand out for their ‘Fin Stabilised Armour Piercing Discarding Sabot (FSAPDS)’ ammunition and 120-mm calibre rifled gun. 
• It also has a computer-controlled integrated fire control system with stabilised sighting that works in all lighting conditions. 
• The secondary weapons include a co-axial 7.62-mm machine gun for anti-personnel and a 12.7-mm machine gun for anti-aircraft and ground targets.
• Due to the high power-to-weight ratio and low specific ground pressure, MBT is fast, highly manoeuvrable and extremely mobile to cross the most difficult terrain with ease. 
• High acceleration rapid braking capabilities with excellent steering characteristics make MBT agile in the battlefield. Adequate fuel storage capacity and relatively low fuel consumption allow for an optimal operational range.
  • The development of Arjun Mk1 was followed by improved variants Mk1A and MkII. 
  • The Arjun MkII variant is a light-weight futuristic main battle tank (FMBT) with electro-optical sensors and high-power lasers.

What is new in the Mk-1A variant?

• The Mk-1A version has 14 major upgrades on the earlier version.
• Accurate and fast target acquisition capability during day and night and in all types of weather.
• Shortest possible reaction time during combat engagements.
• Ability to accurately engage targets on move.
• Capability to destroy all possible enemy armour at maximum battle ranges.
• It was supposed to have missile firing capability as per the design, but The Mk1A will be without missile firing capability and will be incorporated as and when the development is complete.
• Improved firepower and transmission systems
• 54.3 percent indeginous content against the 41 per cent in the earlier model.

References:

1. https://indianexpress.com/article/explained/explained-what-is-the-arjun-main-battle-tank-mk-1a-7188226/
2. https://www.thehindu.com/news/national/defence-ministry-places-7523-crore-order-for-118-indigenous-arjun-mk-1a-tanks/article36632889.ece
3. https://www.drdo.gov.in/mbt-arjun-tank