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> There is probably plenty of scope to optimize space radiators. It was never a priority until now and is "just" an engineering problem. Well, it's a physics p

> There is probably plenty of scope to optimize space radiators. It was never a priority until now and is "just" an engineering problem. Well, it's a physics problem. The engineering solution is possibly not cost efficient. I'd put a lot of money that it isn't.

bborud 9mo ago
That bit reminded me of someone who wanted us to design a patch the size of a small postage stamp, at most 0.2mm thick, so you could stick on products. It was to deliver power for two years of operation, run an LTE modem, a GNSS receiver, an MCU, temperature and humidity sensor and would cost $0.10. And it would send back telemetry twice per day.
- jacquesm 9mo ago
  'A mere matter of engineering'.
  - verzali 9mo ago
    All you need to do is make use of a higher dimension to pack stuff into. And then mass produce to bring costs down. How hard can that be?
    - bborud 9mo ago
      Skippy the Magnificent will solve this for us. (reference to a character in the Expiditionary Force series by Craig Alanson Only a very small portion of his physical presence is in local spacetime, with the rest in higher spacetime. He can expand his physical presence from the size of an oil drum or shrink to the size of a lipstick tube. He can’t maintain that for long without risking catastrophic effects. If he did, he would lose containment, fully materialize in local spacetime and occupy local space equal to one quarter the size of Paradise. The resulting explosion would eventually be seen in the Andromeda Galaxy.)
  - bborud 9mo ago
    The conversation went something like this (from memory): - We can't do that - Why not? - Well, physics for one. - What do you mean? - Well, at the very least we need to be able to emit enough RF-energy for a mobile base station to be able to detect it and allow itself to be convinced it is seeing valid signaling. - Yes? - The battery technology that fits within your constraints doesn't exist. Nevermind the electronics or antenna. - Can't you do something creative? We heard you were clever. I distinctly remember that last line. But I can't remember what my response was. It was probably something along the lines of "if I were that clever I'd be at home polishing my Nobel medal in physics". Even the sales guy who dragged me into this meeting couldn't keep it together. He spent the whole one hour drive back to the office muttering "can't you do something creative" and then laughing hysterically. I think the solution they went for was irreversible freeze and moisture indication stickers. Which was what I suggested they go for in the first 5 minutes of the meeting since that a) solved their problem, and b) is on the market, and c) can be had for the price point in bulk.
    - jacquesm 9mo ago
      That's so hilarious. I've had a couple that went in that direction but nothing to come close. To be fair though, there is a lot of tech that to me seems like complete magic and yet it exists. SDR for instance, still has me baffled. Who ever thought you'd simply digitize the antenna signal and call it a day, hardware wise, the rest is just math, after all. When you get used to enough miracles like that without actually understanding any of it and suddenly the impossible might just sound reasonable. > Can't you do something creative? We heard you were clever. Should be chiseled in marble.
      - bborud 9mo ago
        The purely digital neighborhood of the SDRs is much easier to explain than the analog rat droppings between the DAC/ADC and the antenna. That part belongs to dark wizards with costly instruments that draw unsettling polar plots, and whose only consistent output is a request for even pricier gear from companies whose names sound an awful lot like European folk duos. The digital end of SDRs are simple. Sample it, then once you have trapped the signal in digital form beat the signal into submission with the stick labeled "linear algebra". (Nevermind that the math may be demanding. Math books are nowhere near as scary as the Sacred Texts Of The Dark Wizards) "Rohde & Schwarz — live at the VNA, 96 dB dynamic range, one night only."
Ajedi32 9mo ago
What makes you so sure? SpaceX already has thousands of 6 kW networking racks flying around in LEO and they dissipate their heat just fine, and are plenty cost-effective. You think they can't do any better than that with a new design specifically optimized for computing rather than networking?
- verzali 9mo ago
  Probably, but they likely can't do better than we can do on Earth. Networking in space offers specific advantages that are not easy to replicate on Earth. Data centers in space don't have clear advantages beyond easily debunked ideas about cooling and power.
  - Ajedi32 9mo ago
    I'm not talking about the whole idea, just the heat dissipation part. So many people in this thread seem so sure this is impossible because you can't radiate heat in space, completely ignorant to the fact that SpaceX is already dissipating over 20 MW of solar power in LEO in a reasonably cost-effective manner. The advantage of 24/7 solar power is clear, obvious, and undeniable, it's just a question of whether that's outweighed by the other disadvantages.
- undersuit 9mo ago
  The solar panels on the newest satellites can deliver 6kW but the power that satellite actually uses is less. The satellite is only using 300W[1] during the dark phase of it's orbit when it can use it's entire mass to cool down. Is that limit because of the battery or is it because the satellite needs to radiate all the heat it acquired from the other half of the time in the sun? [1] https://lilibots.blogspot.com/2020/04/starlink-satellite-dimension-estimates.html https://lilibots.blogspot.com/2020/04/starlink-satellite-dim...
  - Ajedi32 9mo ago
    Looks like that's a purely speculative assumption the blog author made, not a fact. I'm not sure why he made that assumption given that Starlink doesn't actually stop working at night. Fair point that in SSO you'd need 2-3x the radiator area (and half the solar panels, and minimal/no batteries). I don't think that invalidates my point though.
drtz 9mo ago
Not only is it not cost-effective, it's pointless (in this context). Radiators works almost just as well on Earth. Convection and conduction more than make up the difference.

bborud 9mo ago

That bit reminded me of someone who wanted us to design a patch the size of a small postage stamp, at most 0.2mm thick, so you could stick on products. It was to deliver power for two years of operation, run an LTE modem, a GNSS receiver, an MCU, temperature and humidity sensor and would cost $0.10. And it would send back telemetry twice per day.

jacquesm 9mo ago
'A mere matter of engineering'.
- verzali 9mo ago
  All you need to do is make use of a higher dimension to pack stuff into. And then mass produce to bring costs down. How hard can that be?
  - bborud 9mo ago
    Skippy the Magnificent will solve this for us. (reference to a character in the Expiditionary Force series by Craig Alanson Only a very small portion of his physical presence is in local spacetime, with the rest in higher spacetime. He can expand his physical presence from the size of an oil drum or shrink to the size of a lipstick tube. He can’t maintain that for long without risking catastrophic effects. If he did, he would lose containment, fully materialize in local spacetime and occupy local space equal to one quarter the size of Paradise. The resulting explosion would eventually be seen in the Andromeda Galaxy.)
- bborud 9mo ago
  The conversation went something like this (from memory): - We can't do that - Why not? - Well, physics for one. - What do you mean? - Well, at the very least we need to be able to emit enough RF-energy for a mobile base station to be able to detect it and allow itself to be convinced it is seeing valid signaling. - Yes? - The battery technology that fits within your constraints doesn't exist. Nevermind the electronics or antenna. - Can't you do something creative? We heard you were clever. I distinctly remember that last line. But I can't remember what my response was. It was probably something along the lines of "if I were that clever I'd be at home polishing my Nobel medal in physics". Even the sales guy who dragged me into this meeting couldn't keep it together. He spent the whole one hour drive back to the office muttering "can't you do something creative" and then laughing hysterically. I think the solution they went for was irreversible freeze and moisture indication stickers. Which was what I suggested they go for in the first 5 minutes of the meeting since that a) solved their problem, and b) is on the market, and c) can be had for the price point in bulk.
  - jacquesm 9mo ago
    That's so hilarious. I've had a couple that went in that direction but nothing to come close. To be fair though, there is a lot of tech that to me seems like complete magic and yet it exists. SDR for instance, still has me baffled. Who ever thought you'd simply digitize the antenna signal and call it a day, hardware wise, the rest is just math, after all. When you get used to enough miracles like that without actually understanding any of it and suddenly the impossible might just sound reasonable. > Can't you do something creative? We heard you were clever. Should be chiseled in marble.
    - bborud 9mo ago
      The purely digital neighborhood of the SDRs is much easier to explain than the analog rat droppings between the DAC/ADC and the antenna. That part belongs to dark wizards with costly instruments that draw unsettling polar plots, and whose only consistent output is a request for even pricier gear from companies whose names sound an awful lot like European folk duos. The digital end of SDRs are simple. Sample it, then once you have trapped the signal in digital form beat the signal into submission with the stick labeled "linear algebra". (Nevermind that the math may be demanding. Math books are nowhere near as scary as the Sacred Texts Of The Dark Wizards) "Rohde & Schwarz — live at the VNA, 96 dB dynamic range, one night only."

Ajedi32 9mo ago

What makes you so sure? SpaceX already has thousands of 6 kW networking racks flying around in LEO and they dissipate their heat just fine, and are plenty cost-effective. You think they can't do any better than that with a new design specifically optimized for computing rather than networking?

verzali 9mo ago
Probably, but they likely can't do better than we can do on Earth. Networking in space offers specific advantages that are not easy to replicate on Earth. Data centers in space don't have clear advantages beyond easily debunked ideas about cooling and power.
- Ajedi32 9mo ago
  I'm not talking about the whole idea, just the heat dissipation part. So many people in this thread seem so sure this is impossible because you can't radiate heat in space, completely ignorant to the fact that SpaceX is already dissipating over 20 MW of solar power in LEO in a reasonably cost-effective manner. The advantage of 24/7 solar power is clear, obvious, and undeniable, it's just a question of whether that's outweighed by the other disadvantages.
undersuit 9mo ago
The solar panels on the newest satellites can deliver 6kW but the power that satellite actually uses is less. The satellite is only using 300W[1] during the dark phase of it's orbit when it can use it's entire mass to cool down. Is that limit because of the battery or is it because the satellite needs to radiate all the heat it acquired from the other half of the time in the sun? [1] https://lilibots.blogspot.com/2020/04/starlink-satellite-dimension-estimates.html https://lilibots.blogspot.com/2020/04/starlink-satellite-dim...
- Ajedi32 9mo ago
  Looks like that's a purely speculative assumption the blog author made, not a fact. I'm not sure why he made that assumption given that Starlink doesn't actually stop working at night. Fair point that in SSO you'd need 2-3x the radiator area (and half the solar panels, and minimal/no batteries). I don't think that invalidates my point though.

drtz 9mo ago

Not only is it not cost-effective, it's pointless (in this context). Radiators works almost just as well on Earth. Convection and conduction more than make up the difference.