71–80 of 121 posts
I know it's the year 2020 and we're capable of some amazing technical feats, but for some reasons the fact that we can have bidirectional communication with something so old and so far away is astounding to me.
It's amazing, and it makes me happy every time.
I know it's the year 2020 and we're capable of some amazing technical feats, but for some reasons the fact that we can have bidirectional communication with something so old and so far away is astounding to me.
"The probe launched on August 20th 1977, but is still just seventeen light-hours away" 43 years for 0.00194 light years... makes me feel :( huh ... and nearest star Proxima Centauri is 4.2441 light years away ... :/
That's funny, I had exactly the opposite reaction. Almost 20 light hours sounds far for something we basically strapped on the top of a big firecracker, which probably provided propulsion for at most a few dozen minutes... The fact that it was even possible to make that thing fly over several planets before exiting the orbital plane on a predictable course, and that one can still communicate with it as it exits the h…
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Our hacks are nothing compared to the hacks of these old school nasa programmers :) The amazing thing (to me) is that they developed the Voyager spacecraft in an era when space flight wasn't hugely popular and the budgets at NASA were being cut regularly. NASA went from a peak of $6bn a year in the mid-sixties under Johnson to almost half that under Ford and Nixon. The engineers were well-respected and they clearly f…
It's great, but hardly amazing. Most academic research is done by underpaid PhD and postdoc students for the love of science, and most of that is far less glamorous than SPACE.
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If the actuator broke down the 351st time, would you've commented 'they didn't even spin something 400 times...'? What would be a number you'd be comfortable with instead?
I would have thought they would run every part until it died so they know roughly what it's lifespan is. It's good if the parts lifespan is twice as long as you need. However, it's even better if you could make it four times the amount you think you need, as long as it isn't horribly expensive. I would tend to assume they've thought of that though, and stuck with this part for reasons. Maybe there werent other space-…
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Project Orion is kind of ludicrously inefficient, making it largely useless for interstellar travel. A nuclear powered ION engine can achieve a much higher exhaust velocity and replace that giant pusher plate with useful propellant. It’s one of those designs that trades something considered largely meaningless, total engine weight, for something considered far more important exhaust velocity. This always ends up bein…
What good does a high exhaust velocity if your fuel stays all inside the ship?
Project Orion is detonating nuclear weapons which consist of far more than just fuel, they also need high explosives etc, however much of the fuels energy is wasted both from low yield bombs being less efficient but also simply radiating energy in all directions. Nuclear powered ION engines however would be ejecting far more of their reaction mass of say xenon per KG of fuel that leftover fuel is basically irrelevant. In other words it’s a more efficient nuclear reaction, a vastly more efficient engine, and a much lower mass fraction spent on the physical engine.
This gets more extreme when you consider a crewed mission would need lots of power during the trip so they would want/need to build redundant nuclear reactors anyway.
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It's great, but hardly amazing. Most academic research is done by underpaid PhD and postdoc students for the love of science, and most of that is far less glamorous than SPACE.
> Most academic research is done by underpaid PhD and postdoc students for the love of science I’d hardly call the graduate papers coming out of academia equivalent to the level of innovation & creativity of what the engineers above described. Perhaps they’re both underpaid, but one is certainly more amazing. Hardly the same.
I was just reading the pale blue dot and he mentions that Voyager 2’s scan platform jammed after its encounter with Saturn. Voyager 2 emerged from behind Saturn (as seen from the Earth) in August 1981. The scan platform had been moving feverishly—pointing here and there among the rings, moons, and the planet itself during the all-too-brief moments of close approach. Suddenly, the platform jammed. A stuck scan platfor…
I found out that usually happens when you have some constraints. The more constraints the more clever ways people find to achieve their goal.
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Our hacks are nothing compared to the hacks of these old school nasa programmers :) The amazing thing (to me) is that they developed the Voyager spacecraft in an era when space flight wasn't hugely popular and the budgets at NASA were being cut regularly. NASA went from a peak of $6bn a year in the mid-sixties under Johnson to almost half that under Ford and Nixon. The engineers were well-respected and they clearly f…
We spent more money under Nixon and Ford than we do now. You’re not familiar with how much money as a percentage of GDP we spent in the 1960s? It’s noteworthy. https://en.m.wikipedia.org/wiki/Budget_of_NASA#Annual_budget We were building the Space Shuttle and exploring the planets. I wish we could spend money on NASA like we did in the 1970’s
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They didn't even spin something 350 times before launching it out of the solar system?
What you say is just common sense but as you can see from the downvotes, average people do not like smart people. And the exact same thing happened before the launch, I bet. But the exceptional engineer was simply “downvoted”. Things are tested all the time in factories. For how long? Till destruction.
When it comes to space missions, common sense starts bad and rapidly gets worse — there is no down, there is no “now”, metals can contact-weld without any supply of energy, exposed fluids boil until they freeze, radiation pressure is relevant, ionising radiation doses can be enough to break things, impact damage is radically different, launch times are prescribed by orbital dynamics, engines are more efficient when they are moving faster, fuel use is exponential with regard to change in velocity and nothing to do with distance, and the launch mass is heavily constrained. And that’s just the stuff I know from following Scott Manley and similar on YouTube — I’m a very long way from being a rocket engineer.