The exploration missions to the red planet were started in 1960 by the Soviet Union, since then the planet has gain attention of all the scientists and explorers worldwide. Several exploration missions have been launched by the space organizations and nations to explore the Martian surface. NASA launched its first exploration mission to Mars in 1964 in the form of Mariner 3. After that, the series of robotic exploration missions have been launched to understand the red planet intensely. The Mars Exploration Program (MEP) was also formed in 1993 to explore the possibilities of the presence of life, climate and natural resources on Mars. The MEP uses the spacecraft, orbiters, landers and rovers to explore the Martian soil. As of present, NASA has launched twenty-five missions to the red planet out of which only five missions were unsuccessful. Some of the significant discoveries have been made in recent years with missions such as Pathfinder, Spirit, Opportunity, Curiosity, MAVEN and InSight. Currently, NASA is making plans to send more robotic explorers on the Martian soil in the upcoming years to make more discoveries and gain scientific information. These robotic missions are the first steps towards the human-crewed missions to Mars. The present paper provides a quick overview of NASA's past, present and future robotic exploration missions to the red planet.

The Moon has always been the center of attention for mankind, more than any other heavenly body in the night sky. With the early history of the solar system etched on it, the Moon challenges mankind from time immemorial to discover its secrets and admire its marvels. Understanding the Moon will provide us a pathway to unravel the early evolution of the solar system and that of planet Earth. Almost twelve years after its first lunar exploration mission, India bounced back towards Moon with Chandrayaan-2. India's most advanced engineering marvel Chandrayaan-2 is on a mission unlike any before. Leveraging nearly a decade of scientific research and engineering development, India's second lunar expedition will shed light on a completely unexplored region of the Moon, its South Polar Region. The indigenously built Chandrayaan-2 consists of an orbiter, a lander (Vikram) along with a rover (Pragyan). With the payload of completely home-grown technologies, it will help us to gain a better understanding of the origin and evolution of the Moon by conducting detailed topographical studies, comprehensive mineralogical analysis and a host of other experiments. The Chandrayaan-2 is India's first robotic exploration mission to attempt a soft landing on the South Polar Region of the Moon. With the success of this mission, India became the fifth country ever to attempt a soft landing on the lunar surface. This paper provides an insight into the Chandrayaan-2 Mission. Additionally, an overview of the mission profile, challenges involved, launch vehicle architecture, spacecraft configuration and scientific payloads are also presented.

The Mission Shakti, also called as Project XSV-1 was India's first Anti-Satellite Test (ASAT) conducted successfully on 27 March 2019. The PDV-MK II interceptor missile designed and developed by Defence Research and Development Organisation (DRDO) was launched from Dr A.P.J. Abdul Kalam Island to intercept the Microsat-R satellite. The Microsat-R satellite, which acts as a prime target for the mission was India's imaging satellite manufactured by DRDO and launched into the orbit eight weeks before the test by Indian Space Research Organisation (ISRO). The Project XSV-1 had been under planning since 2016. As India's space programme is rapidly growing, its nation's responsibility to safeguard the country's assets present in outer space. Also, the nation is concerned about the threats it faces in outer space; the ASAT test was conducted to examine the capability of the nation to defend itself in space. The mission was planned at the lowest possible altitude to avoid any risk to the operational space assets. India has demonstrated its capability to legitimate deterrence against increasing threats to nations emerging space assets from various kinds of missiles. With this particular successful test, India becomes the fourth country among an exclusive group of space-faring nations to perform ASAT. The paper provides an overview of the overall Mission Shakti, aka Project XSV-1.

After the successful completion of robotic expeditions on Mars, an ultimate goal was set for space fairing nations and agencies around the world to send astronauts to Mars by 2030. Unfortunately, a mission to Mars would last upwards for years meanwhile several asteroids fly close to the Earth. A manned trip to an asteroid would be a valuable stepping stone towards a manned mission to Mars, as the mission time can be reduced to a few months round-trip. In addition to gaining experience with manned travel through deep space, a mission to an asteroid would provide experience overcoming a unique challenge of rendezvousing with a foreign object in microgravity. Since most of the known asteroids that are close enough to Earth to be viable targets are less than 300 m in diameter, chances are the selected asteroid will not have a significant gravitational field. Near Earth Asteroids (NEAs) have orbits that bring them into close proximity with Earth's orbit making them both a unique hazard to life on Earth and a unique opportunity for science and exploration. A specific case study was therefore undertaken to shortlist such NEAs that are accessible for round-trip human missions using heavy lift launch architecture. A fully parameterized, highly efficient algorithm is developed using MATLAB to accomplish this. Using this algorithm a family of NEA is reviewed, several candidate asteroids are shortlisted for potential exploration and a final selection of asteroid 1999 AO10 is made followed by a specific mission trajectory design and selection to this asteroid, accounting for mission requirements and constraints. The astrodynamic components of a manned mission to NEA 1999 AO10 are also described in this study. Beginning with a launch, we will walk through preliminary trajectory optimization using Lambert's problem and patched conics. Once the ideal trajectory is designed, the study will be extended to include abort scenarios.

For several decades orbital debris has been identified as a serious concern by all space-faring agencies and nations as it potentially threatens the current and future space endeavors. The Indian Space Research Organization (ISRO) is well aware of the present space debris scenario and is aimed towards achieving the goal of preserving outer-space for humanity. ISRO works on different aspects to effectively manage the threats due to space debris. This paper provides an overview of past activities carried out in ISRO towards the implementation of space debris mitigation guidelines. One of the significant step taken is the implementation of end of life passivation of the cryogenic upper stage of ISRO's Geosynchronous Satellite Launch Vehicle (GSLV). Another one is the successful design and development of propellant venting system for the upper stage of ISRO's Polar Satellite Launch Vehicle (PSLV). ISRO's constellation of communication and navigation satellites orbiting in GSO's are designed with adequate propellant so that it can re-orbit to the higher graveyard orbit at the end of their operational lifetime. A typical successful re-orbiting and decommissioning operation of INSAT-3E is described in detail. ISRO has successfully designed and developed the models and software to predict the atmospheric re-entry of satellites and launch vehicle upper stages, and also to compute the collision risk between the debris and the operational satellites. ISRO has also developed models to study the evolution of the space debris environment in LEO and GEO region. ISRO enthusiastically works with the United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS) and Inter-Agency Space Debris Coordination Committee (IADC) to further improve the space debris mitigation guidelines.