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Why people make temperature in space a big deal? It's mostly vacuum and has no heat capacity. Sun radiation is the real threat, but the concept of temperature c
by ivanjermakov 2y ago
Why people make temperature in space a big deal? It's mostly vacuum and has no heat capacity. Sun radiation is the real threat, but the concept of temperature can't even be applied to vacuum.
- rtkwe 2y agoThe ground it's laying on though does though.
- elzbardico 2y agoThe space surrounding you may not have a temperature but your spacecraft does, and it will lose heat via radiation, batteries and electronics will stop working after your temperature reaches a certain low.
- kortilla 2y agoAny moderately active satellite has far more issues with excess heat
- snewman 2y agoThe article clearly states that providing enough power to run the heaters was one of the challenges that led to the death of the probe. Satellites are rarely in the shade for an extended period.
- verzali 2y agoIt depends on the size of the satellite and its power use. Small spacecraft often don't use enough power to generate enough heat to warm themselves. The problem then is batteries get cold (which is one of the places you need heaters) and become inefficient and then you end up in death spiral. Here the probe likely wasn't generating enough power anyway, so that would almost certainly kill it before the cold.
- dredmorbius 2y agoThe problem is less the quantity of heat generated than of shedding that heat. Even modest electronics emit several watts of thermal waste heat, and given that the entire satellite is in a highly-insulating vacuum, as well as subject to solar insolation (at 1 kW/m²), it's easy to exceed thermal budgets.
- verzali 2y agoYou can do the sums. Spacecraft lose heat by radiation and if you do the sums for a small spacecraft you can see the equilibrium temperature is low enough that you don't need to take any special measures to shed the heat.
- elzbardico 2y agoIt does, but here we are talking about a spacecraft not exposed to sun radiation and without significant amounts of stored energy to generate heat to overcome the heat losses due.
- NL807 2y ago>The space surrounding you may not have a temperature Just to be pedantic, it actually does, which is the microwave background radiation. But that doesn't detract anything from your point.
- winwang 2y agoIs that really "space" as opposed to "the lingering effects of the big bang"? (or less interestingly, the temperature of the CMB photon gas)
- danwills 2y agoI don't think a photon can exist outside of space, but I'd be very interested to hear of any alternate points of view on that!
- winwang 2y agoWhat I mean is that isn't the temperature of "space" -- if we're being pedantic. Such a temperature would presumably be measured by the blackbody radiation of... space, if space were a blackbody.
- rtkwe 2y agoThere's also ~80,000 molecules per cubic centimeter on the moon. It's extremely thin but there's still stuff out there it's just a VERY slow transfer because there are so few collisions compared to what you'd get on Earth.
- dredmorbius 2y agoAnd: if one designed ones spacecraft / lander with a presumption of being exposed to solar radiation, which peaks around 120°C (250°F), then the temperature-management problem is one of excess heat, not insufficient heat, and would feature radiators and foil insulation to avoid acquiring more heat. Designing for a wide range of temperatures in space where shedding heat is a challenge and running heaters (during dark/cold periods) is necessary, and where at the best of times re-deploying radiators and heat shields is difficult, let alone when the craft is lying on its side. So ambient temperature matters. As another comment notes, in most cases, the problem is excess heat and the shedding of it. Particularly for Earth-orbiting satellites, which are subject to 1kW/m² solar radiation and are in shadow for only a small portion of their orbit (less with higher altitudes).
- Dylan16807 2y agoIt's small enough to lose plenty of heat without conduction.
- humanfromearth9 2y agoBecause it's lethal
- TimByte 2y agoThe problem here isn't the vacuum itself, but that surfaces facing away from the sun radiate heat rapidly into space, causing extremely low temperatures on lander components. That's why temperature still matters practically, even if it's a bit counterintuitive.
- ivanjermakov 2y agoDoes it matter, if vacuum does not conduct heat? Lander would not experience conductive heat unless it has a great contact with the ground.
- deleted 2y ago[deleted]