Exciting stuff, but the question inevitably arises, why do it? The Buddha already noted the ultimate futility of such travel in the Rohitissa Sutta;
In other words, the end of suffering is here-and-now and we will not move any closer to that goal even by crossing the galaxy.
"In times past, I was a seer, Rohitassa by name, ... gifted so, that I could fly through the air. And so swift, was my speed that I could fly just as quickly as a master of archery, .. armed with a strong bow could, without difficulty, send a light shaft .... And so great was my stride that I could step from the eastern to the western sea.
"In me, arose such a wish as this: 'I will arrive at the end of the world by walking.' And though such was my speed, and such my stride, and though, with a life-span of a century, living for hundred years I walked continuously for a hundred years, save the while I spent in eating, drinking, chewing or tasting, or in answering calls of nature, save the while I gave way to sleep or fatigue, yet I died on the way without reaching the end of the world."But neither do I say, friend, that without having reached the end of the world there could be an ending of ill. It is in this very fathom-long physical frame with its perceptions and mind, that, I declare, lies the world, and the arising of the world, and the cessation of the world, and the path leading to the cessation of the world.
However, the same could be said for all mundane pursuits. The affairs and doings of samsara are ultimately futile; "rearranging the deck chairs on the Titanic" as someone said. Space missions are no more, and no less, valid than any other karma.
Leaving the ultimate question of spiritual transcendence aside, even within the strictly conventional plane of conditionality, space exploration may seem useless or a waste of resources better used elsewhere. Certainly, from a strict economic view-point, it is very hard to see how any space travel beyond earth orbit could ever repay the investment, at least for a very long time.
(Unless you buy the Helium-3 hype)
Sometimes the argument against space exploration is framed in terms of how the money could better be used to deal with poverty and disease on earth. But it's really a false argument. It would be valid if that's where the resources really would go, but there would already be plenty available to help the poor and sick if that were a priority. Sadly, it isn't. There are trillions to spend on war, and hundreds of billions to give to the financiers to help them out of their folly, but thousands still sleep on the streets of our cities.
Realistically, nations will compete, one way or the other. Human beings are territorial primates. I would much rather see money and research go into a vigorous competition to be the first on Mars than to see the same resources go into building warships and bombs. Besides, aren't we all curious?
I say good on the Indians, the Chinese, the Yanks and the rest of them. First one there wins. Ready, steady, go!
Nerdy note - Assuming the air-speed velocity of an arrow to be about 200 feet per second, and allowing Rohitissa twelve hours of travel a day, in one hundred years he would have gotten about 60 million miles, somewhat more than the closest approach of Mars to Earth.