Watch this space: The Moon, the Sun and getting parcels from space

But Aditya L1 will be impressive in its own regard if ISRO manages to place it in a halo orbit around the first Lagrange point. But what is the Lagrange point? To put it simply, if you put something in these points in space, the thing will tend to stay there. At these points, the gravitational pull of two large masses will be equal to the centripetal force required for a small object to move along with them.

The first Lagrange point, L1, is convenient for the Aditya mission because it falls in between the Sun and the Earth. For missions like the James Webb Space Telescope, the second Lagrange point (L2) would be more convenient because the Earth will shield its instruments from the glare of the Sun, allowing it to peer into the distant universe unobstructed.

L1 is a difficult place to get to. To reach there, a spacecraft will need a complex transfer manoeuvre and since it is one of the “unstable” Lagrange points, the spacecraft will still have to make some manoeuvres to maintain a halo orbit around it after reaching there.

If operators here on Earth want to make the sort of precise manoevures needed for such missions, they will need to know the exact location of the spacecraft at the present, and in the future. This can be worked out using a mathematical process called “orbit determination.”

The Indian space agency developed a new software to do the orbit determination for Aditya L1. But the problem with doing something like that unilaterally is that there is next to no room for error when operating an L1 mission. So, the Aditya L1 team at ISRO decided to enlist the help of an organisation that has already completed an L1 mission—the European Space Agency. (ESA). “The results of the exercise were valuable for ESA and ISRO and both teams are confident in the capabilities of ISRO’s software,” said ESA in a statement.

ISRO and ESA are among two of the biggest and most capable space agencies in the world. But teams at numero uno—NASA—are working on something arguably a more impressive than a solar probe and even a soft lunar landing. The American space agency is preparing to receive a sample of an asteroid collected by its spacecraft.

The OSIRIS-REx mission collected a sample of the asteroid Bennu in 2020, and the spacecraft is going to “drop” the sample to Earth on September 24. Yes, drop. OSIRIS-REx will send a capsule containing the sample hurtling towards Earth as it makes a flyby. And if all goes well, the parcel drop will be so precise that it will land exactly at a drop zone in the Department of Defense’s Utah Test and Training Range in the desert outside Salt Lake City.