Actually, I wasn't being a pendantic jackass, I was correcting something that was wrong. Period. Not just a subtle, technical issue that will only appear on an exam; plain wrong.
You can have net heat transfer from an object even with a hotter object nearby via radiation. A radiator will lose heat (via radiation) to space regardless of what it is near. It's ability to absorb/reflect will determine if there is any heat transfer the other way. You can't just simply say what the NET direction will be based on temperature. Only for conduction and convection can you say this...not radiation. What would be the purpose of a shield by the way if you couldn't take advantage of this fact?
Not that you will want to know since you seem to "know" it all ready... the orbital plane of the Earth about the Sun that you are referring to is called the ecliptic. Since I wasn't trying to be pedantic or overly technical, I just said that it was near-equatorial. There is really no need for it to be exactly in the ecliptic for simply for thermal reasons--it would be determined based on other constraints.
As for why drag is an issue here, the radiators needed are huge, as in on the order of 500 m^2. Not that it will slow it down, but it does make attitude control an issue if you try to fly it sideways.
Okay, I see where the misconception lies now. The temperature difference between the radiator and the surrounding does not "cause" radiative heat transfer. As I mentioned before, a medium is not required for this type of heat transfer (hence the reason it is used in spacecraft). Even if the spacecraft was close to the sun it would radiate heat. The problem then would be that the radiative heat from the Sun would more than make up for that.
The main problem with flying with big radiators near-Earth will be drag, therefore, they will be nearly edge-on relative to the velocity vector. Then to avoid a big hit from solar radiation all that is required is a near-equatorial orbit. This type of orbit is almost certainly going to be used. A shield would only be needed if the main body of the spacecraft was going to take on a lot of heat--not really an issue unless the spacecraft will be going closer to the sun, say to Venus orbit.
I believe that you are confusing conductive heat transfer with radiative heat transfer. Conduction does care about the medium (and the temperature of the medium) that surrounds it. Radiation does not. Since there isn't much of a medium to go around in space, conduction is practically non-existent and there is no need to take into account the average temperature of deep space.
Also, it might seem to make sense to point the radiators edge on to the Sun, but then why do you have radiators in the first place? Radiators of this size are required to dump the heat from a reactor. The reactor is there because solar cells can't be used. In other words you are too far from the Sun to have a significant amount of solar radiation input. A shield in this case would be extra weight and money for no real benefit.
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You can have net heat transfer from an object even with a hotter object nearby via radiation. A radiator will lose heat (via radiation) to space regardless of what it is near. It's ability to absorb/reflect will determine if there is any heat transfer the other way. You can't just simply say what the NET direction will be based on temperature. Only for conduction and convection can you say this...not radiation. What would be the purpose of a shield by the way if you couldn't take advantage of this fact?
Not that you will want to know since you seem to "know" it all ready... the orbital plane of the Earth about the Sun that you are referring to is called the ecliptic. Since I wasn't trying to be pedantic or overly technical, I just said that it was near-equatorial. There is really no need for it to be exactly in the ecliptic for simply for thermal reasons--it would be determined based on other constraints.
As for why drag is an issue here, the radiators needed are huge, as in on the order of 500 m^2. Not that it will slow it down, but it does make attitude control an issue if you try to fly it sideways.
Okay, I see where the misconception lies now. The temperature difference between the radiator and the surrounding does not "cause" radiative heat transfer. As I mentioned before, a medium is not required for this type of heat transfer (hence the reason it is used in spacecraft). Even if the spacecraft was close to the sun it would radiate heat. The problem then would be that the radiative heat from the Sun would more than make up for that.
The main problem with flying with big radiators near-Earth will be drag, therefore, they will be nearly edge-on relative to the velocity vector. Then to avoid a big hit from solar radiation all that is required is a near-equatorial orbit. This type of orbit is almost certainly going to be used. A shield would only be needed if the main body of the spacecraft was going to take on a lot of heat--not really an issue unless the spacecraft will be going closer to the sun, say to Venus orbit.
Also, it might seem to make sense to point the radiators edge on to the Sun, but then why do you have radiators in the first place? Radiators of this size are required to dump the heat from a reactor. The reactor is there because solar cells can't be used. In other words you are too far from the Sun to have a significant amount of solar radiation input. A shield in this case would be extra weight and money for no real benefit.