261–270 of 279 posts
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At the relative ranges we are talking about here, those numbers are probably more comparable than many would realize. Consider, Mars at its closest, is over 6700km away. The space station at its furthest is 418km. (Assuming I looked up the correct numbers, of course.)
Mars is 225,000,000 km away, on average.
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Ahh, thanks for the tip, and the wonderful discussion! I agree, that would not work. I was suggesting that motorized rollers move the track longitudinally instead of sideways. Essentially they would take up the slack and actively push it to the end stations, counteracting the friction from the passive rollers. You could use thermometers and position sensors to model the stress on the tube.
Whoops, I see. Sorry for the confusion! That's an interesting idea, but are you sure that thermal expansion imparts enough force against 175 miles of steel in order to push it all the way to the station? 175 miles of steel would be incredibly heavy. It seems like the heating/cooling might even cause the steel to weaken enough such that, rather than rolling the tube towards the station, it would start to scrunch like…
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> And his comment on their rocket being the butt of a joke, using engines literally made in the 1960s and stored in Siberia were true. That was quite misleading on Elon's side. Engines were manufactured in 1970's (I believe in 1973-1974) after quite an extensive RND program - actualy, remake of similar engines, NK-15, which weren't nearly as good. NK-33 engines were tested as perhaps no others of theirs caliber - wit…
The odyssey of the reclaimed NK-33's is intriguing as hell, but I can only imagine that everyone involved in their resurrection knew the odds of failure would be higher than with modern engines. Soviet metallurgy in the 1970's likely didn't have the consistency and precision we have today. So while the NK-33 was (is) a remarkably advanced design, it was likely pushing the limits of the materials of its time and place…
Limits of materials were pushed indeed. Some safety margins for materials were claimed as under 1.0 - i.e., 0.97 - that is, materials were pushed further than their limits. The idea was that since the engine is used once, we can use it in the manner that greatly reduces the life of the engine - and nobody would care, since a stage will be done with in a few short minutes. A lot of things were done quite unconventionally - remember SR-71, for example, or oxygen-rich pre-burners which were considered rather impossible.
NK-33 remains unsurpassed even today by many criteria. Now it includes even the ability to work after 40 years of shelf line - which probably left the trace on engines reliability.
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To have an enjoyable conversation with an interested colleague, rather than someone whose tone is "shut up and listen to your elders." Besides, having a crotchety back-and-forth makes for boring reading, and we should be respectful of the community. Thanks for the pieces you've provided so far. I'll bring up my objections elsewhere. Hopefully anyone who's been having my same concerns will be able to do the same.
Let me try to explain what is going wrong here: You argue that something is impossible but at the same time you outline your ignorance. The normal position for being ignorant is to study the subject, not to argue that something is impossible. It's like saying a moonshot never happened because you couldn't do it yourself. There are lots of things that each of us individually can not do, but collectively we can do amaz…
But no, actually, you smashing huge holes into my logic was exactly what I was hoping for, because that's how ignorance is transcended. I dislike both the peanut gallery and peanuts, so I think I came across wrong. Starting the conversation by vaguely disparaging your merry band of engineers probably wasn't great, but my mind's malleability is play-dough, definitely not steel.
Finding someone who agrees with my viewpoint is the most useless thing, both to me and to anyone that might be reading the conversation. Someone with an ability to point out why I'm wrong and to actually debate with me is both rare and valuable.
Please try to understand that some people find the basics interesting, so even though you're saying you don't, it's important to kindle that spark. (I still don't see how this is basic, since the entire SpaceX engineering team somehow missed your segmentation approach, or considered it and chose not to pursue it for some reason, but you're probably right. And I have other qualms about the approach, but I don't really trust re-opening this debate without some kind of mutual understanding that we'll focus on the ideas in the debate, not on the people involved.)
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This is the tweets by Elon Musk on this "Tks. Turns out we recovered some impact video frames from drone ship. It's kinda begging to be released…" " Before impact, fins lose power and go hardover. Engines fights to restore, but …" "Rocket hits hard at ~45 deg angle, smashing legs and engine section" "Residual fuel and oxygen combine " "Full RUD (rapid unscheduled disassembly) event. Ship is fine minor repairs. Exciti…
I love the acronym RUD (Rapid Unscheduled disassembly) Is there ever a RSD (Rapid Scheduled disassembly) ?
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Put a .5" x .5" cardboard square on a wooden post. Grab a pushpin. Start counting paces away from the post. Stop when you're about four city blocks away. Start running full speed towards the post. Hurl the pin at the post as hard as you can when you're three city blocks away. Pin glances off of one corner of the cardboard square. Crowd yells, "epic fail!"
In contrast, from the HN-featured article about finding the Beagle2 probe on Mars: MRO's data confirms that Beagle landed just 5km from the centre of its targeted touchdown zone. 5km, and it was considered a bulls-eye accurate landing.
I wonder what the cost savings to space there are for buying a trip for a satellite on a "used" booster. Also if SpaceX is recycling the 1st stage, I wonder if they have plans to "Recycle" the 2nd stage in orbit.
Somebody on /r/spacex made the following spreadsheet to demonstrate the effect of savings due to the reusability of the first and potentially second stages: https://docs.google.com/spreadsheet/ccc?key=0AhFJHvEz4SHQdDB...
Sorry for sounding like such a fanboy, but during my 40 years on this earth, I have never been more impressed with a human being. The guy is pushing the envelope on perhaps the most difficult engineering/technological endeavor ever attempted by a private company - and he's making it look cool and futuristic. As if that wasn't enough, he's doing this in two different industries simultaneously. I'm not saying he can do…
... in technology - I would add. Otherwise I agree. But let's not forget that technology is a niche, there area many other achievements of mankind, literature, arts, civil organizations etc.