It is clear from past mission studies that a manned Mars mission, as well as deep space planetary orbiters will require aerobraking and aerocapture which use aerodynamic drag forces to slow the spacecraft. Aerocapture would enable long term studies of the outer planets and their moons that would not be possible with existing braking technologies. While utilizing planetary atmospheres to slow down and capture spacecraft would dramatically reduce the cost, launch mass, and travel time, current technologies require significant additional spacecraft mass and risk, as the spacecraft must descend deep into a planetary atmosphere that is not well characterized in order to produce significant drag on a relatively small, fixed dimension aeroshell or temperature and structurally sensitive inflatable ballute.

The Magnetoshell deploys a simple dipole magnetic field containing a magnetized plasma. It is interaction of the atmosphere with this magnetized plasma that supplies a significant impediment to atmospheric flow past the spacecraft, and thereby producing the desired drag for braking. Frictional heating would no longer be of concern as the energy dissipation required to slow the spacecraft would be deposited into the plasma ions helping to maintain the Magnetoshell plasma while at the same time shielding the spacecraft itself from frictional heating. With the aeroshell now being composed of massless magnetic field, the transverse scale of the magnetic barrier can be as large as 100 meters while requiring no more than a gram of plasma. With the ability to rapidly and precisely modify the drag in varying atmospheric conditions, much larger forces can now be achieved at low risk, enabling very aggressive aerocapture maneuvers. By providing power in a pulsed manner, the thermal and power processing requirements can be kept modest and with conventional technologies.

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Spiny Norman said:

It is clear from past mission studies that a manned Mars mission, as well as deep space planetary orbiters will require aerobraking and aerocapture which use aerodynamic drag forces to slow the spacecraft. Aerocapture would enable long term studies of the outer planets and their moons that would not be possible with existing braking technologies. While utilizing planetary atmospheres to slow down and capture spacecraft would dramatically reduce the cost, launch mass, and travel time, current technologies require significant additional spacecraft mass and risk, as the spacecraft must descend deep into a planetary atmosphere that is not well characterized in order to produce significant drag on a relatively small, fixed dimension aeroshell or temperature and structurally sensitive inflatable ballute.

The Magnetoshell deploys a simple dipole magnetic field containing a magnetized plasma. It is interaction of the atmosphere with this magnetized plasma that supplies a significant impediment to atmospheric flow past the spacecraft, and thereby producing the desired drag for braking. Frictional heating would no longer be of concern as the energy dissipation required to slow the spacecraft would be deposited into the plasma ions helping to maintain the Magnetoshell plasma while at the same time shielding the spacecraft itself from frictional heating. With the aeroshell now being composed of massless magnetic field, the transverse scale of the magnetic barrier can be as large as 100 meters while requiring no more than a gram of plasma. With the ability to rapidly and precisely modify the drag in varying atmospheric conditions, much larger forces can now be achieved at low risk, enabling very aggressive aerocapture maneuvers. By providing power in a pulsed manner, the thermal and power processing requirements can be kept modest and with conventional technologies.

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I’ve no complaints about the first paragraph, except to note that aerobraking would only work with one moon, Titan. None of the other moons have enough atmosphere. Nor Pluto or Eris.

The second paragraph I can complain about. The magnetic field would have to be impossibly large. The contained plasma would be more of a threat to the spacecraft than the atmospheric drag would. And the braking drag from the plasma in this magnetic field wouldn’t be enough to slow anything.

But otherwise interesting.

The best protection against the heat and violence of aerobraking, I’m not sure of.
I’ve had a brief look into three possibilities:

• tungsten aerogel
• carbon nanobubbles
• a three (or four) layer shield where the outer layer is carbon/tungsten and the second layer is molybdenum

mollwollfumble said:

Spiny Norman said:

It is clear from past mission studies that a manned Mars mission, as well as deep space planetary orbiters will require aerobraking and aerocapture which use aerodynamic drag forces to slow the spacecraft. Aerocapture would enable long term studies of the outer planets and their moons that would not be possible with existing braking technologies. While utilizing planetary atmospheres to slow down and capture spacecraft would dramatically reduce the cost, launch mass, and travel time, current technologies require significant additional spacecraft mass and risk, as the spacecraft must descend deep into a planetary atmosphere that is not well characterized in order to produce significant drag on a relatively small, fixed dimension aeroshell or temperature and structurally sensitive inflatable ballute.

The Magnetoshell deploys a simple dipole magnetic field containing a magnetized plasma. It is interaction of the atmosphere with this magnetized plasma that supplies a significant impediment to atmospheric flow past the spacecraft, and thereby producing the desired drag for braking. Frictional heating would no longer be of concern as the energy dissipation required to slow the spacecraft would be deposited into the plasma ions helping to maintain the Magnetoshell plasma while at the same time shielding the spacecraft itself from frictional heating. With the aeroshell now being composed of massless magnetic field, the transverse scale of the magnetic barrier can be as large as 100 meters while requiring no more than a gram of plasma. With the ability to rapidly and precisely modify the drag in varying atmospheric conditions, much larger forces can now be achieved at low risk, enabling very aggressive aerocapture maneuvers. By providing power in a pulsed manner, the thermal and power processing requirements can be kept modest and with conventional technologies.

More

I’ve no complaints about the first paragraph, except to note that aerobraking would only work with one moon, Titan. None of the other moons have enough atmosphere. Nor Pluto or Eris.

The second paragraph I can complain about. The magnetic field would have to be impossibly large. The contained plasma would be more of a threat to the spacecraft than the atmospheric drag would. And the braking drag from the plasma in this magnetic field wouldn’t be enough to slow anything.

But otherwise interesting.

The best protection against the heat and violence of aerobraking, I’m not sure of.
I’ve had a brief look into three possibilities:

• tungsten aerogel
• carbon nanobubbles
• a three (or four) layer shield where the outer layer is carbon/tungsten and the second layer is molybdenum
  

> a three (or four) layer shield where the outer layer is carbon/tungsten and the second layer is molybdenum

Yes. First layer outer side tungsten and inner side carbon (ideally vantablack or similar). Second layer outer side molybdenum and inner side carbon. Third layer outer side chromium and inner side carbon.

The shiny outer side reflects heat back to outside the spacecraft. The black inner side absorbs heat radiated from the spacecraft.

mollwollfumble said:

mollwollfumble said:

Spiny Norman said:

It is clear from past mission studies that a manned Mars mission, as well as deep space planetary orbiters will require aerobraking and aerocapture which use aerodynamic drag forces to slow the spacecraft. Aerocapture would enable long term studies of the outer planets and their moons that would not be possible with existing braking technologies. While utilizing planetary atmospheres to slow down and capture spacecraft would dramatically reduce the cost, launch mass, and travel time, current technologies require significant additional spacecraft mass and risk, as the spacecraft must descend deep into a planetary atmosphere that is not well characterized in order to produce significant drag on a relatively small, fixed dimension aeroshell or temperature and structurally sensitive inflatable ballute.

The Magnetoshell deploys a simple dipole magnetic field containing a magnetized plasma. It is interaction of the atmosphere with this magnetized plasma that supplies a significant impediment to atmospheric flow past the spacecraft, and thereby producing the desired drag for braking. Frictional heating would no longer be of concern as the energy dissipation required to slow the spacecraft would be deposited into the plasma ions helping to maintain the Magnetoshell plasma while at the same time shielding the spacecraft itself from frictional heating. With the aeroshell now being composed of massless magnetic field, the transverse scale of the magnetic barrier can be as large as 100 meters while requiring no more than a gram of plasma. With the ability to rapidly and precisely modify the drag in varying atmospheric conditions, much larger forces can now be achieved at low risk, enabling very aggressive aerocapture maneuvers. By providing power in a pulsed manner, the thermal and power processing requirements can be kept modest and with conventional technologies.

More

I’ve no complaints about the first paragraph, except to note that aerobraking would only work with one moon, Titan. None of the other moons have enough atmosphere. Nor Pluto or Eris.

The second paragraph I can complain about. The magnetic field would have to be impossibly large. The contained plasma would be more of a threat to the spacecraft than the atmospheric drag would. And the braking drag from the plasma in this magnetic field wouldn’t be enough to slow anything.

But otherwise interesting.

The best protection against the heat and violence of aerobraking, I’m not sure of.
I’ve had a brief look into three possibilities:

• tungsten aerogel
• carbon nanobubbles
• a three (or four) layer shield where the outer layer is carbon/tungsten and the second layer is molybdenum
  

> a three (or four) layer shield where the outer layer is carbon/tungsten and the second layer is molybdenum

Yes. First layer outer side tungsten and inner side carbon (ideally vantablack or similar). Second layer outer side molybdenum and inner side carbon. Third layer outer side chromium and inner side carbon.

The shiny outer side reflects heat back to outside the spacecraft. The black inner side absorbs heat radiated from the spacecraft.

The only problem with that is tungsten is very heavy, I’d guess it’d be better to use a more conventional material that ablates but weighs quite a lot less.