Space Week 2019: After Chandrayaan 2, ISRO's upcoming interplanetary missions to Mars, Venus, the Sun

The Vikram lander and Pragyan rover, part of India's first attempt to land on the moon with the Chandrayaan 2 mission, appear to be incommunicado on the moon's surface after a failed 7 September crash landing. But the Indian Space Research Organisation's (ISRO's) has a packed couple of years ahead, with a string of interesting (and interplanetary) projects on its to-do list in the near-future.The Chandrayaan 2 mission (and the Gaganyaan manned mission planned for 2022 are two of the better-known, bigger-budget missions, but far from the only ones for which work is underway. The agency is also working on a total of seven interplanetary missions in the coming decade. Among the destinations are Mars, the Moon, Venus, the Sun's corona and interplanetary space to study space.The first of these will be in April 2020, with the Aditya-L1 mission to the Sun.

April 2020 (estimated): Aditya-L1 mission

The Aditya-L1 mission is ISRO's first planned probe to study the Sun's corona and its atmosphere. The corona is the outer layer of the Sun, which extends thousands of km above the visible disc around it.

Interestingly, it has temperatures over a million degree Kelvin — far higher than the surface of the Sun (6000 degrees Kelvin). How the corona gets heated to such high temperatures is still an unanswered question in solar physics, and something NASA's Parker probe is currently exploring.ISRO's Aditya L-1 will also soon follow suit and study this astrophysical mystery.  The probe is expected to launch in April 2020 on a PSLV rocket from Sriharikota, according to ISRO's website.(Also read: All about the Aditya-L1: ISRO's upcoming satellite to unveil secrets of the Sun)

December 2021/January 2022: Gaganyaan mission

In his 2018 Independence Day address, the Prime Minister Narendra Modi announced that India will attempt to send astronauts to space on a spacecraft called the 'Gaganyaan' by 2022.The mission will make India only the fourth nation in the world to accomplish the feat if successful, he added. At Rs 10,000 crore, Gaganyaan is slated to be India's biggest, boldest space mission so far.

The Gaganyaan’s crew module to house astronauts, its life support systems to keep them alive in space, and the spacecraft's environmental control systems have already been developed, and are being tested at a new facility opened by ISRO for human spaceflight missions.The mission is "highest priority" for ISRO in 2019, the space agency announced, with plans to have the first unmanned tests for the mission in December 2020 and second in July 2021. If these tests are successful, the manned mission will happen as planned in December 2021.

2022-2023: Mangalyaan-2 (or the Mars Orbiter Mission-2)

India's second mission to Mars, the Mars Orbiter-2, is another planned mission by the Indian Space Research Organisation (ISRO) between 2022 and 2023. The Mangalyaan-2 orbiter will use aerobraking to lower its initial apoapsis and enter into an orbit more suitable for observations. This mission, much like the Mangalyaan-1 mission has been planned as an orbiter-alone mission, and won't feature a lander or rover.

India's ISRO and French CNES space agencies were intended as partners building the MOM-2 module by 2020, but by April 2018, France was not yet involved in the mission.In a sign of encouragement, the Indian government-funded the MOM-2 mission in its 2017 budget proposal, leaving ISRO mulling over whether the best path is a MOM mission with an orbiter, lander and rover will be feasible or an orbiter alone with instruments more sophisticated than those on MOM-1 would be the way to go.

Late 2020s: Chandrayaan-3 mission

While the second mission in the Chandrayaan (India's lunar exploration) programme is still currently underway, K Sivan announced in January this year that the third mission in the series will also be carried out in the coming decade. The Chandrayaan program was always intended as a multi-mission space programme.

"The Moon is a good candidate as a staging point for carrying out our deep space human spaceflight missions, and Chandrayaan-2 will assess the suitability of the Moon for such activities," Chairman K Sivan said in an interview to Current Science. ISRO will also soon initiate a space robotics programme to look at the possibility of an Indian robot on the Moon, he added. With the first mission in the program featuring an Orbiter and the second featuring a soft lander and rover, it sure is interesting to consider what India's third lunar mission might bring to the table. Could Chandrayaan-3 be the mission to put an Indian robot on the Moon?

2023-2025: Shukrayaan mission to Venus

Our neighbouring planet Venus is often described as Earth's 'twin sister' due to similarities in their sizes, densities, composition and gravity. Some theories suggest both planets share a common origin, forming at the same time from the same condensing swirl of gas and dust all those 4.5 billion years ago. Being 30 percent closer to the Sun than the Earth, Venus has a much higher exposure to solar radiation, effects of solar flares and other solar phenomena, which makes it an object of interest for ISRO to study.

ISRO intends to send an orbiter mission to study the atmosphere of Venus, which is made up primarily of carbon dioxide. The Shukrayaan mission will study the dense, hot atmosphere of Venus and the planet's surface using a probe.The satellite configuration and payloads on Shukrayaan-1 are yet to be finalised. But the science objectives that will feed the design of the spacecraft are  The "super-rotation" of the Venusian atmosphere and how it interacts with solar radiation and solar wind are also among the mission's science objectives, according to an ISRO release.

Late 2020s: EXPOSat Planetary exploration

The EXPOSat mission appears to be a follow-up to the AstroSAT mission, ISRO's multi-wavelength X-ray astronomy observatory studying X-ray sources in the universe. Considering the great success of AstroSAT, the EXPOSat mission will further explore X-rays in the universe — specifically, the polarisation of bright X-ray sources in our universe.

These objects could be neutron stars, supernova remnants, pulsars and regions around black holes that could give scientists information about the electromagnetic nature of space radiation. Understanding space radiation better could be used to protect spacecraft and astronauts in the future, but also pave the way for space technology to better understand happenings in the universe.These, K Sivan said at the briefing, are only some of the planned interplanetary missions ISRO has in mind for the decade to come.

2023: India's Space Station

Another plan in the pipeline is a space station that will be built by India. Currently, the International Space Station is the only functioning one but it is supposed to be winding up by 2028. The proposed station will weigh 15-20 tonnes and will be able to host people for 15-20 days. It will be used to conduct microgravity tests said Kailasavadivoo Sivan the chairperson of ISRO to Business Standard.The space station according to Sivan is a logical extension of the RS 10,000 crore Gaganyaan mission that will be sending human beings to space in 2022.The timeline for the mission is five to seven years which should be a challenge but ISRO has been developing the necessary technologies like the space docking technology that should keep it on track said Ajay Lele, a senior fellow at the Institute for Defence Studies and Analyses.(Also read: India plans to have an orbiting space station by 2030 — here's what we can expect)