Returning from Geo-stationery Orbit

  • Thread starter Thread starter Chatterton
  • Start date Start date
  • Tags Tags
    Orbit
AI Thread Summary
When a Soyuz capsule returns from the ISS, it orbits Earth multiple times to manage momentum and reduce speed through atmospheric friction. In contrast, a spacecraft positioned in the Clarke zone, despite having radiation and heat shielding, cannot drop capsules straight down due to its tangential velocity, which would result in an elliptical orbit instead. Effective de-orbiting would require traditional methods, involving several orbits before landing, potentially leading to unpredictable landing zones. Control systems could enhance proximity during re-entry, but the descent duration would vary based on launch velocity and orbit specifics. Additionally, launching from the Earth-Moon Lagrange point 1 is more efficient than from geosynchronous orbit, requiring less velocity for aerobraking, thus presenting a strategic advantage for operations involving capsule deployment or artillery launch.
Chatterton
Messages
34
Reaction score
5
I know when a Soyuz capsule returns from the ISS it has to orbit Earth a few times before re-entry due to all the momentum it borrowed from ISS.

What would happen if your ship was in the Clarke zone? Assuming we have the radiation shielding covered already. Would it be conceivable that a ship parked like that could just drop capsules in a fairly straight down manner? Assuming we have all the heat-shielding worked out.
 
Physics news on Phys.org
Chatterton said:
I know when a Soyuz capsule returns from the ISS it has to orbit Earth a few times before re-entry due to all the momentum it borrowed from ISS.

It's more because they don't want to carry the fuel required to de-orbit in less than a single orbit. Instead, they can break a little bit, fall towards Earth, and then use the air friction to slow them down further and further over successive orbits until the density of the air is high enough that they finally fall back to Earth instead of making another orbit.

Chatterton said:
What would happen if your ship was in the Clarke zone? Assuming we have the radiation shielding covered already. Would it be conceivable that a ship parked like that could just drop capsules in a fairly straight down manner? Assuming we have all the heat-shielding worked out.

No, because the ships would still be moving tangentially "around" the Earth. Firing a capsule straight towards the Earth would just result in an elliptical orbit since the capsule would retain all of the tangential velocity and gain an additional radial component.
 
So, to do it right, my team of commandos will have to de-orbit the old fashioned way, spinning around the globe a few times before hopefully landing in relatively the same area, which would make even clumsier and more random than WWII paratrooper action and oh my God I think that cold be wicked cool. And it would take a while too, right? I think I remember something from Chris Hadfield's book about sleeping on the way down.
 
Chatterton said:
So, to do it right, my team of commandos will have to de-orbit the old fashioned way, spinning around the globe a few times before hopefully landing in relatively the same area, which would make even clumsier and more random than WWII paratrooper action

Not necessarily. They could have control systems designed to keep them in close proximity prior to and during reentry.
Chatterton said:
And it would take a while too, right?

I'm not sure how long it would take. Geostationary orbit is about 22,000 miles above sea level, so I assume it would take a while, with the exact time depending on the velocity the capsules were launched at, the exact orbit, and a few other details.
 
  • Like
Likes Chatterton
Chatterton said:
So, to do it right, my team of commandos will have to de-orbit the old fashioned way, spinning around the globe a few times before hopefully landing in relatively the same area, which would make even clumsier and more random than WWII paratrooper action and oh my God I think that cold be wicked cool. And it would take a while too, right? I think I remember something from Chris Hadfield's book about sleeping on the way down.

Consider a reverse escape from lunar gravity. Then your paratroopers can hang out in a bunker complex in lava tubes. You can also magnetic launch artillery. No need for explosives in the shells. Just crack the heat shield at the altitude you want. Between 2500 and 2600 m/s for Δv. If you give them 3,000 m/s they can launch at multiple angles and all arrive at once.

Dropping from Earth-Moon Lagrange point 1 is easier than dropping to Earth from geosynchronous. That can be done with 750 m/s. Geo requires around 1500 m/s before you can aerobrake. Launchers and fuel tanks sitting in geo are huge targets.
 
  • Like
Likes Chatterton
We've just had an interesting thread about generation ships, but I don't think that that is the most reasonable way to colonize another planet. Fatal problems: - Crew may become chaotic and self destructive. - Crew may become so adapted to space as to be unwilling to return to a planet. - Making the planet habitable may take longer then the trip, so the ship needs to last far longer than just the journey. - Mid-flight malfunction may render the ship unable to decelerate at the destination...
I know this topic is extremely contraversial and debated, but I'm writing a book where an AI attempts to become as human as possible. Would it, eventually, especially in the far future, be possible for an AI to gain a conscious? To be clear, my definition of a consciousness being the ability to possess self-created morals, thoughts, and views, AKA a whole personality. And if this is possible (and let's just say it is for this question), about how long may it take for something to happen...
This is a question for people who know about astrophysics. It's been said that the habitable zones around red dwarf stars are so close to those stars that any planets in the zones would be tidally locked to the stars in question. With one side roasting and another side freezing almost forever, those planets wouldn't be hospitable to life. a) Could there be forms of life--whole ecologies--that first evolve in the planet's twilight zone and then extend their habitat by burrowing...

Similar threads

Back
Top