After setting foot on the Moon, the next destination for humankind is Mars, which presents a whole new set of challenges in speedy, long-distance space travel.
Venus is significantly more hostile than Mars, so while we definitely want to do more with Venus, Luna and Mars are clear next-ups for manned landings.
While all of Mars is hostile to human life, Venus is also incredibly hostile to equipment, and thus requires a different approach to even unmanned launches.
Current maximum lifetime for any unmanned craft in the Venusian atmosphere (to say nothing of the ground) is only about 2 hours.
That’s true about their upper atmosphere, but we’re nowhere close to being able to capitalize on it (as in, no missions even planned). Closest we’ve got on paper is an orbiter by the early 30s.
Hopefully in my lifetime we see an upper atmosphere balloon or something. That alone would be unbelievably cool.
Dude what’s neat about this is Oxygen on Venus is like Helium on Earth (less dense than most of the atmosphere, so rises naturally) so your balloon doesn’t even need to be hot, just really sturdy.
Venus is interesting. While the surface is extremely hostile, the upper atmosphere is maybe the most similar to Earth-like environment out there in the solar system. At about 50km up in the air, the air pressure is about 1 Earth atmosphere, and the ambient temperature is about 20C. A 80/20% nitrogen-oxygen gas mixture is buoyant too at that depth, so a balloon filled with breathable air will just float. A rupture won’t cause explosive decompression like it would on Mars either. In addition, the gravity one would experience is only very slightly less than that of Earth, and the large atmosphere also provides some shielding against radiation.
Mars doesn’t have these perks. Mars is cold, really cold, with only 1/3rd of the gravity of Earth, has practically no radiation shielding, and any breach would cause explosive decompression and almost instant unconsciousness. On top of that, regular solar panels really don’t work that well on Mars because of the extra distance from the Sun, while solar panels would actually work better in the upper atmosphere of Venus.
I’m sorry to be a stickler, but it’s not an SI unit.
Have a look at p. 145 and “Non-SI units that are accepted for use with the SI”, if you want to know more: bipm.org/…/fcf090b2-04e6-88cc-1149-c3e029ad8232?v…
Hey, no need to be sorry. I appreciate the search for correctness and especially the reference document.
Here’s what I’ve found.
There is no mention of km/h in section 4, “Non-SI units that are accepted for use with the SI”. It does mention h, making it a “non-SI unit that’s accepted for use with the SI.”
km/h is its own unit separate from h. It’s a unit of speed, derived from km and h.
My gut feel at this point is that km/hcould be an SI unit since it’s a unit of speed derived from an SI unit for distance and a non-SI unit accepted for use with the SI for time.
Furthermore, searching the document for mentions of km/h, there’s this bit on page 127, section 2.1, “Defining the unit of a quantity”:
For a particular quantity different units may be used. For example, the value of the speed v of a particle may be expressed as v = 25 m/s or v = 90 km/h, where metre per second and kilometre per hour are alternative units for the same value of the quantity speed.
This paragraph suggests (even though it doesn’t outright say it) that km/h is indeed an SI unit.
I haven’t found anything clearly saying whether km/h is an SI unit or not. Not on that document, not by searching the web. The research above makes me lean towards the idea that it is one.
If you found otherwise, I’d love to compare notes and learn further.
I see it quite simplistic: if it isn’t listed as SI unit by the BIPM it isn’t one.
Lending a helping hand on how to deal with derived units (e.g. km/h) doesn’t mean those derived units are endorsed as SI units.
But that’s just my point of view.
What makes the RDRE so revolutionary is that it makes use of a sustained detonation circling around a ring-shaped channel, fed by a mix of fuel and oxygen which is ignited by each passing explosion.
Crucially, the RDRE uses less propellant fuel than conventional rocket engines, and is simpler in terms of its machinery and mechanisms. That means going into space becomes cheaper, and traveling further distances becomes possible.
We don’t have unlimited fuel, rockets cost too much fuel. It’s not even normal fuel either, it’s rare chemistry rocket technology that takes a while to develop.
Alright so nobody’s going to stop launching rockets realistically, there’s too much potential in space to just ignore, rdre are a way to do the same with less.
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