Exomars orbiter and aerobraking

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In summary, the exomars orbiter will initially have an elliptical orbit and will use aerobraking to circularize it. This will result in a significant fuel savings, but the orbiter will only last for a short time due to the atmospheric drag.
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sophiecentaur

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I heard a talk from a fairly well informed guy about the exomars mission. He was saying that the orbiter will, initially have a very elliptical orbit and that it would be using aerobraking to make it circular (saving a lot of fuel). I have a problem understanding that because aerobraking can only remove energy and the resulting orbital height would (I reckon) bring the orbiter below the fringe of the Martian atmosphere. That would mean it would 'fall down' fairly soon.
I have to conclude that the aerobraking would only reduce the highest orbital distance to what was required and that some fuel would be used to raise the minimum distance out of the atmosphere. (Perigee and apogee terms only apply on Earth?). Someone here must have definitive answer to this. Am I right?
 
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Something like this? - MGS Aerobraking.

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Yes. Thank you. That shows a series of orbits with decreasing energy and I understand that process. However, if aerobraking can take place at that height, the drag (with or without the effect of the solar panels) will surely continue to take significant energy. So the lifetime of an orbit at that height will be limited. Is there a way to extract energy by aerobraking that will raise the minimum height as well as lowering the maximum height - away from the drag of the atmosphere?
 
  • #4
Once it's at the lowest point, they use the rockets to add some kinetic energy and push it into a higher orbit away from the atmosphere. It's still a significant fuel savings.

The atmosphere itself can also be used to push it into a higher orbit. During one of the low passes, if the ship is oriented correctly and hit the atmosphere at the right angle, it can bounce off of it like a stone skipping off of the water. This can also be used to increase altitude.
 
  • #5
newjerseyrunner said:
Once it's at the lowest point, they use the rockets to add some kinetic energy and push it into a higher orbit away from the atmosphere. It's still a significant fuel savings.

The atmosphere itself can also be used to push it into a higher orbit. During one of the low passes, if the ship is oriented correctly and hit the atmosphere at the right angle, it can bounce off of it like a stone skipping off of the water. This can also be used to increase altitude.
Thanks. Two good answers that I had wondered about.
Hope it all works as it seems like a bit of a shoestring project, compared with Curiosity.
 

1. What is the Exomars orbiter?

The Exomars orbiter is a spacecraft that was launched by the European Space Agency and Roscosmos in 2016. Its main mission is to search for evidence of past or present life on Mars, as well as to serve as a communication relay for future missions to the planet.

2. What is aerobraking?

Aerobraking is a technique used by spacecraft to slow down and enter orbit around a planet by using the friction of the planet's atmosphere. In the case of the Exomars orbiter, it will use the thin Martian atmosphere to gradually slow down and enter its final orbit around the planet.

3. How does the Exomars orbiter use aerobraking?

The Exomars orbiter will use its solar panels to create drag and slow down as it enters the Martian atmosphere. This will help the spacecraft reduce its velocity and enter a circular orbit around Mars.

4. Why is aerobraking necessary for the Exomars orbiter?

Aerobraking is necessary for the Exomars orbiter because it allows the spacecraft to conserve fuel and reduce the risk of damaging its instruments. It is also a more cost-effective method of entering orbit compared to using rockets to slow down.

5. How long will the aerobraking process take for the Exomars orbiter?

The aerobraking process for the Exomars orbiter is expected to take approximately 12 months. This includes multiple passes through the Martian atmosphere, gradually adjusting the spacecraft's orbit until it reaches its final science orbit.

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