It could be enclosed in a spherical ablative shield filled with cryogenic material. When it is gasified, maybe it could be ejected to get rid of heat and provide propulsion to shorten the high temperature exposure time. There's quite an Oberth effect.What science could be done without exposing any sensors? I suppose that the temperature and magnetic field can be measured. And if it can be well located, maybe by an orbiting spacecraft, its movements might reveal the density of the plasma.
The transition zone between the chromosphere and the corona is "only" 6000 degrees hot and seems to be key to understanding the corona. Could a probe fly through it and generate valuable science data?It could be enclosed in a spherical ablative shield filled with cryogenic material. When it is gasified, maybe it could be ejected to get rid of heat and provide propulsion to shorten the high temperature exposure time. There's quite an Oberth effect.What science could be done without exposing any sensors? I suppose that the temperature and magnetic field can be measured. And if it can be well located, maybe by an orbiting spacecraft, its movements might reveal the density of the plasma.
Not really basing this on any concrete computations but I think any such maneuvers would take too long (hours/days) for the kind of trajectories we can realistically send the probe on with current technology. So all of the ablator would likely be gone long before the closest approach concludes.But I might as well be just forgetting something and one of our trajectory gurus might fix me.
Quote from: TakeOff on 10/03/2017 10:15 pmIt could be enclosed in a spherical ablative shield filled with cryogenic material. When it is gasified, maybe it could be ejected to get rid of heat and provide propulsion to shorten the high temperature exposure time. There's quite an Oberth effect.What science could be done without exposing any sensors? I suppose that the temperature and magnetic field can be measured. And if it can be well located, maybe by an orbiting spacecraft, its movements might reveal the density of the plasma. How is the cryogen going to be stored for the years it is going to take to get there?How is temp is going to be measured if no exposed sensors. how is magnetic field going to be measured in an enclosed case?
Quote from: Martin.cz on 10/03/2017 10:30 pmNot really basing this on any concrete computations but I think any such maneuvers would take too long (hours/days) for the kind of trajectories we can realistically send the probe on with current technology. So all of the ablator would likely be gone long before the closest approach concludes.But I might as well be just forgetting something and one of our trajectory gurus might fix me. The Parker Solar Probe, at 10 Solar radii from the Sun as closest, will achieve a speed of 200 km/s pass the Sun. It then takes it two hours to pass one diameter of the Sun's disk. A flyby probe ten times closer, well, I better ask someone else here to estimate what its highest speed would be. And what the Oberth bonus then would be if heat exhaust can be used for propulsion.I suppose that a Krafft-Ericke type trajectory to Jupiter is the best option for a one time Solar flyby. PSP uses Venus to gradually narrow its orbit, while a flyby would want to get it over with asap.
Quote from: Jim on 10/04/2017 01:31 amQuote from: TakeOff on 10/03/2017 10:15 pmIt could be enclosed in a spherical ablative shield filled with cryogenic material. When it is gasified, maybe it could be ejected to get rid of heat and provide propulsion to shorten the high temperature exposure time. There's quite an Oberth effect.What science could be done without exposing any sensors? I suppose that the temperature and magnetic field can be measured. And if it can be well located, maybe by an orbiting spacecraft, its movements might reveal the density of the plasma. How is the cryogen going to be stored for the years it is going to take to get there?How is temp is going to be measured if no exposed sensors. how is magnetic field going to be measured in an enclosed case?Can't a spacecraft be cryocooled in space for half a dozen years? Aren't several telescopes?If there are radial sensors in the shield, it should be possible to estimate the temperature from the rate of ablation and the heating of the interior of the spacecraft. The enclosing need not be a Faraday's cage. Carbon materials and ceramics seem popular for heat shields.I wonder if it is physically possible, or if everything is zapped into plasma if it dives through and under the corona.
Tungsten or carbon can go up to about 4000K, but at 6000K everything will vaporize. Rather than using a cryogen for cooling you should consider a large block of ice. The latent heat of water is quite impressive.