3 ms·

Actually, I found that it is not as drastic as 5x on this site. https://space.stackexchange.com/questions/2156/does-a-mission-to-venus-orbit-require-less-propel

Actually, I found that it is not as drastic as 5x on this site. https://space.stackexchange.com/questions/2156/does-a-mission-to-venus-orbit-require-less-propellant-than-a-similar-mission-to https://space.stackexchange.com/questions/2156/does-a-missio...

JumpCrisscross 7y ago
> it is not as drastic as 5x on this site Those are deltas-v from low-Earth orbit to low-Venus and low-Mars orbits, respectively. Going from low-Venus orbit to the Venusian surface costs as much as getting from Earth to low-Venus orbit plus getting from Earth to Mars almost 3x over [1]. [1] https://www.dailymail.co.uk/sciencetech/article-2679107/Mind-interplanetary-gap-Space-subway-map-reveals-travel-planets-moons-solar-Tube.html https://www.dailymail.co.uk/sciencetech/article-2679107/Mind...
- Retric 7y ago
  Only if the atmosphere was non existent. In practice getting to the surface is free, launching again is the problem. This becomes more pronounced as you simply don’t need to enter orbit. Even if that’s the goal, bouncing off the atmosphere is still useful.
- Mirioron 7y ago
  Wait, what? The article mentions that the delta-v on the chart is required to go from the surface of Venus to a low Venusian orbit, not the other way around. I don't see why it would cost the same to go down from orbit to the surface. In fact, I'm pretty sure that a probe in a low Venusian orbit would decay on its own just like they do in low Earth orbit. I really don't see how going from a low Venusian orbit to the surface would be costly.
  - JumpCrisscross 7y ago
    > The article mentions that the delta-v on the chart is required to go from the surface of Venus to a low Venusian orbit, not the other way around Delta-v is symmetrical. Putting something in orbit is mostly about accelerating tangentially to the surface, not about going up. Taking something out of orbit is mostly about accelerating tangentially to the surface, not about falling down. > I'm pretty sure that a probe in a low Venusian orbit would decay on its own just like they do in low Earth orbit Orbital decay for small objects is slow aerobraking. It is slow, requires a heat shield, and is structurally stressful.

JumpCrisscross 7y ago

> it is not as drastic as 5x on this site Those are deltas-v from low-Earth orbit to low-Venus and low-Mars orbits, respectively. Going from low-Venus orbit to the Venusian surface costs as much as getting from Earth to low-Venus orbit plus getting from Earth to Mars almost 3x over [1]. [1] https://www.dailymail.co.uk/sciencetech/article-2679107/Mind-interplanetary-gap-Space-subway-map-reveals-travel-planets-moons-solar-Tube.html https://www.dailymail.co.uk/sciencetech/article-2679107/Mind...

Retric 7y ago
Only if the atmosphere was non existent. In practice getting to the surface is free, launching again is the problem. This becomes more pronounced as you simply don’t need to enter orbit. Even if that’s the goal, bouncing off the atmosphere is still useful.
Mirioron 7y ago
Wait, what? The article mentions that the delta-v on the chart is required to go from the surface of Venus to a low Venusian orbit, not the other way around. I don't see why it would cost the same to go down from orbit to the surface. In fact, I'm pretty sure that a probe in a low Venusian orbit would decay on its own just like they do in low Earth orbit. I really don't see how going from a low Venusian orbit to the surface would be costly.
- JumpCrisscross 7y ago
  > The article mentions that the delta-v on the chart is required to go from the surface of Venus to a low Venusian orbit, not the other way around Delta-v is symmetrical. Putting something in orbit is mostly about accelerating tangentially to the surface, not about going up. Taking something out of orbit is mostly about accelerating tangentially to the surface, not about falling down. > I'm pretty sure that a probe in a low Venusian orbit would decay on its own just like they do in low Earth orbit Orbital decay for small objects is slow aerobraking. It is slow, requires a heat shield, and is structurally stressful.