(Archived 2019) - ARGUMENT XI: Sending Materials to Mars vs. Sending Materials to Venus.

Having written this in 2019, and originally published in 2021.. when I was 15 and 17, there would be inaccuracies that I would correct here. Having removed it, I'm publishing  again, for sake of completion so that the efforts wouldn't have gone to vain: Most of this still stands true 

Extraterrestrial colonies don’t often begin as self-sufficient; self-sufficiency is something that could only be achieved through adequate production and export of surplus. Thus, we as the motherworld, have to send a constant supply of essential materials; this is especially critical during the infancy of an alien colony. Similarly, when one of our extraterrestrial colonies was to be safely self-sufficient; they’d have to do two-way trade with the Earth – this is because mere self-sufficiency is dangerous, as it could fall any time. Either for feeding an extraterrestrial colony in its infancy, or trading for the good of the colony; sending materials to such colonies is quite important – The same would be true for our Martian and Venusian colonies.

When considering Venus and Martian colonies; supplies would most likely arrive in aeroshells, which travel the interplanetary seas with rockets. It is expensive for now, but it’s the best we’ve got. Let’s first probe into how it’s done on Venus: When I said aeroshells for Venus, I didn’t meant the classical aeroshell – it would likely not reach the cloud-cities during entry, as a slight change in trajectory could lead to it falling to the surface, where it could never be retrieved from. Instead of the classical aeroshell, it’d be better to use hollow Titanium spheres filled with the right gas. When filled with the right gas at the right buoyancy, the hollow Titanium sphere would float like a balloon at the level of the cloud-cities. It could even float indefinitely if the sphere isn’t to be punctured, but the cloud-cities would likely retrieve it. Even if the supplies were to land hundreds of miles off-course, they would just float around there with the wind – The cloud-cities would have plenty of time to retrieve them, with the guarantee that it would always flat at a retrievable altitude!

Still, during the atmospheric entry of any object, the kinetic energy of the object gets dissipated as heat, due to air-resistance. It sometimes gets hot enough to melt the object. Would the hollow spheres be able to withstand it? Yes, yes it can: detailed calculations reveal that “large-diameter hollow spheres of titanium have no difficulty surviving atmospheric entry. It is in fact experimentally demonstrated that a titanium sphere can enter the atmosphere burning through” ^[40].

Retrieved from: - Landis, G.A. (2010, January). Low-altitude Exploration of the Venus atmosphere by Balloon. [Paper available online and for download at https://ntrs.gov/search.jsp?R=20110016033].

We have our own practical example of it: the Titanium tank, used for storing helium of Salyut 7, was still intact after re-entry in 1991 ^[40].  Since the atmosphere above the cloud-cities are equivalent to that of the Earth, it is proof that the alleged Titanium spheres could serve its purpose. As depicted by the above diagram; a standard Titanium-balloon would have a shell of only 2mm thickness and a corrosion barrier of 2µm. The balloon will carry a payload and filled with an inert gas, ideally moist Nitrogen ^[40].

However, atmospheric entry in Mars is a different story – a worse one too. The Martian atmosphere is so thin, that its air resistance is much lower than on Earth and Venus. It is also with an atmospheric ceiling, which is low in altitude. That is, a typical aeroshell would meet the Martian surfaced with a bang, with the possibility of scattering the supplies everywhere.

Therefore, in order to prevent impact; heavily ballooned landings with much wider parachutes are required. This is much more complex than a simple floating sphere, and it could bounce from its impact zone to astray, leaving the Martians to scavenge for it. Such precautions are also more expensive to implement than probable simple parachutes for the Venusian supplies.  

Other than the rocket needed for both Venusian and Martian supplies; (1) Venusian supply would only require a buoyant Titanium sphere. (2) Martian supply would be more complex with large parachutes and ballooned landing. (3) Precautions needed for safe Martian supply is expensive. Therefore, supplying materials to the Venus is much harder than that for Mars.

[40] Landis, G.A. (2010, January). Low-altitude Exploration of the Venus atmosphere by Balloon. [Paper available online and for download at https://ntrs.gov/search.jsp?R=20110016033].

Achinthya Nanayakkara (30.03.2025)

Originally published - 2021 (now removed)

Originally written - 2019