Rockets and spacecrafts cannot fly: why?

Question

Building up from this question, let's say that we have a lighter situation where:

1. The Earth has lost its magnetic field
2. Solar winds are interacting with the atmosphere
3. Molecules are split up due to this situation, and hydrogen has left to space escaping the gravity well, causing the loss of water over time
4. Still, oxygen is still in atmosphere, maybe leaking a little bit over time, but human survival is guaranteed for now (although, generally speaking, the population is doomed, with less oxygen in the air and less water to drink)

In this ok-but-not-so-great situation, I am looking for scientific or pseudo-scientific explanations for saying that

• NASA rockets and spacecrafts that used to fly in normal situation (normal atmosphere, normal magnetic field, solar winds at bay etc) do not fly correctly anymore
• NASA scientists can try to keep up, to modify their rockets in a new quest to conquer space
• if they do not do it fast enough, the overall situation changes again (less water, less hydrogen, more gases escaping the gravity well etc) and they have to redo their math from scratch, in this continuous modifications to their spacecrafts and Earth laws understanding

Which could be a plausible (even if not super-sound) explanation to support this narrative?

Note. I am fine even with solutions that suppose this degrading process of the planet and its atmosphere (which would take millions of years to undergo) is somehow compressed in a shorter timespan.

Answer 1

A meteorite impact broke the earth's magnetic field, and made space uninhabitable.

Meteorite impacts can reverse the earth's magnetic field. A large collision could do this, and also leave enough debris in space that travel up was very complicated. In addition, the meteorite could have enough mass and enough oxidixable material that it notably depleted the Earth's oxygen reserves as it interacted with oxygen.

Rockets have internal fuel supplies. They don't need atmospheric air, and can fly without it just fine. They can even fly in space. Whatever is happening in the atmosphere matters very little to them. They can't fly up through solids.

This would require more and more effort to adapt to the very unpleasant and rock filled satellites of the earth.

Answer 2

I have a few comments.

One)

Rockets operate more efficiently in a vacuum than in an atmosphere.

Two)

Without a magnetnosphere the solar wind would strip away air particles from Earth's atmopshere. But very slowly, over millions and billions of years, a time span much longer than the time span of your story. The planet Venus has a very weak magnetosphere and is losing air particles to the solar wind, but still retains a very dense atmosphere after billions of years, for example.

Three)

Without an atmosphere, everyone on Earth would die, except for the ones who quickly enough build airtight self enclosed ecosystems, like moon bases or space habitats, on the Earth or in outer space. So if Earth was rapidly losing its atmosphere, people would be more concerned with survival than with using rockets or how well those rockets functioned, unless they planned to use rockets to construct moon bases or space habitats to live in.

Four)

The ultimate airtight self enclosed habitat would be to build a roof over the entire Earth to hold in the air and prevent it from escaping. It would take a very long time by human standards to complete such a vast project, but it would be a mere instant of time compared to the time it would take for Earth to lose its atmosphere.

Five)

The only thing I can think of which might case Earth to lose its atmosphere rapidly would be some terrible collision with a large asteroid creating a gigantic explosion. A gigantic explosion powerful enough to make Earth lose its atmosphere quckly would probably also cause all life on Earth to be cooked to death and probably turn the upper few miles of Earth's crust into hot lava.

So maybe you should think of another reason why rockets become harder to use in your story.

Answer 3

If the atmosphere sudden changed, I don't think NASA would use actual rockets without adapting them to the new scenario

In this popsci.com, you can find the reason why NASA could scrub a launch. Basically, strong winds, risk of lightnings and cold temperatures, or high levels of high energy particles in near-orbit.

In this new situation, it is not implausible that some of the conditions that prevent NASA from launching a rocket could become permanent, for instance high energy particles, since we are no more shielded by Earth's magnetic field.
Honestly, I don't know if an increase of the other features (like lightning) would be compatible with the new atmospheric conditions without some handwavium.

Of course this situation wouldn't be permanent, but would surely need scientists to stop new launches and re-evaluate the reliability of the existing hardware, which could take some years (even because I suspect that whatever caused this scenario would also become a more short-term priority than space launches...).

Answer 4

A partial answer: A very large quantity of helium was dumped on the Earth (to the point it's mostly helium.) The atmosphere now extends out far enough to render current rockets unable to attain orbit. Note that this does not prohibit making new designs that can put something in orbit.

The issue is atmospheric drag. You lose more energy to the thicker atmosphere and you have to wait longer to jettison the fairings. A redesign for more fuel, less payload and carrying the fairings longer could be done, there's no way to make the atmosphere so deep as to preclude that.