I think gods aren't the same as laws of nature. The god in question is Gond the wonder bringer, he is the god of technology. he can make technology work or not work. The problem is if the spaceship crosses the boundary at 800,000 miles and all high technology ceases to function then everybody dies, that's not going to work. I would say that the 800,000 mile boundary is where most magic ceases to function, with the exception of a few individuals and goddesses of magic named Mystra. If a high technology spaceship crosses the boundary going the other direction, nothing immediate happens, everything continues to function.
Gond realizes that if he kills all the high technology on an incoming spaceship, he's going to kill everybody onboard, and if they don't die immediately, they are either going to run out of oxygen or they'll burn up in the atmosphere.
Another option is killing the high technology of the spaceship when it enters Toril's atmosphere, and that's no good either, because then the ship either burns up in the upper atmosphere or crashes into the surface, and Gond is not going with that either, as he is not an evil deity.
So the third option he'll exercise is that the technology of the spaceship ceases to function upon contact with the ground, the ship goes dark! But then the ship has already landed, and the hatches and doors of the spaceship open manually, so getting out of the spaceship is not a problem.
Of course there is the problem of unmanned landers going dead upon contact with the ground, this would tip off NASA that this planet has a problem if all of its probes go dead upon contact with the surface, so they don't. The landers and rovers don't go dead immediately upon contact with the ground because Gond doesn't notice them, as those things don't have a soul. Machines are soulless, though they may be intelligent, but as a god, Gond doesn't notice soulless creations unless something with a soul touches them, then their tech ceases to function.
So here is what NASA sees, then send a probe to land on Toril, the probe is a rover, it takes samples and pictures returning data to Earth, if an animal (intelligence 1 or less walks by or touches it, nothing happens, but if a creature with an intelligence score of 2 or greater touches it, the probe ceases to function. So the scientists back on Earth assume the creature destroyed the probe and that is why it ceased to return data. Well it is an active planet, unlike Mars or the Moon for instance, so on the manned mission, they ought to send the Marines with the scientists just to keep them safe from all those dangerous animals and creatures moving about.
So the ship with 100 people onboard lands, and as soon as contact with the ground occurs, the ship goes dark. Mission control loses contact with the ship, and assumes a mishap occured such as the ship exploding, and reasons that everybody is lost. This has the effect of discouraging further missions to the planet, and those 20 scientists and 80 Marines are on their own, their guns don't work, and their radios don't work, they can't contact Earth, so they are on their own, there is no rescue coming. The Marines are fighters however, they know how to fight with their combat knives, that know unarmed combat as part of their training, they can navigate by the stars, and they have star charts and maps better than any native of Toril. Purely mechanical devices work, a mechanical wrist watch works for instance. One can tell the time with a telescope, and the Marines and scientists have one. There is a clock called "Jupiter" all one has to do is look at the planet Jupiter through a telescope, and look at the positions of Jupiter's moons, examine a printed chart and they know what time it is, and then they can measure the altitude of the Sun, and they know what longitude they are at, and by measuring the altitude of the star Polaris, they know what Latitude they are at, then they can look at their satellite maps and they can place their position on the World's surface by looking at those, all without electronics, or GPS, as Toril's north pole points at Polaris just as Earth's does. (This fact does mean however that when its winter in Earth's Northern Hemisphere it is Summer in Toril's and so on.