161–170 of 279 posts
Can someone explain what the rocket was trying to do? Was it trying to correct itself to land vertically thrusters-first? I also don't understand how it got in that particular trajectory either from this vine.
https://www.youtube.com/watch?v=NoxiK7K28PU
The video's a few years old, so the hardware's changed a bit since then, but I think you'll get the idea. :)
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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.
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> I'm not saying he can do no wrong, but I'm just flabbergasted that there are still so many armchair critics and naysayers when it comes to Elon Musk. That's why you're a fanboy. Nobody is perfect, and Elon Musk likes to make fun of the competition quite publicly when they have an issue, while ignoring his project's own failures. It is hard to even discuss the man on HN as anything that could even be taken as critic…
Amen. It's also kind of insulting how much HN has bought into this "Great Man" theory of engineering and development. Sure, Elon Musk is a smart guy and seems to be a good leader who sets bold goals, but the real geniuses that make SpaceX possible are the brilliant engineers working there--who you've never heard of. Watching the way HN reacts to SpaceX, in contrast to say, NASA, or the ESA makes me think those organi…
The SpaceX Falcon 9/Dragon was designed by SpaceX, driven by Elon Musk's requirements. The part where the design matched what NASA wanted for the COTS program was a happy coincidence, but NASA were not driving the original design specifications.
Of course, the F9/Dragon was adapted to NASA standards, and is also an effective satellite launch vehicle.
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> I'm not saying he can do no wrong, but I'm just flabbergasted that there are still so many armchair critics and naysayers when it comes to Elon Musk. That's why you're a fanboy. Nobody is perfect, and Elon Musk likes to make fun of the competition quite publicly when they have an issue, while ignoring his project's own failures. It is hard to even discuss the man on HN as anything that could even be taken as critic…
Not sure what you're saying reflects reality. When Orbital Science's rocket recently exploded, Elon's words were nothing but polite: https://twitter.com/elonmusk/status/527247155954610176 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. It is upsetting, but still not as surprising that they suffered catastrophic failure having such an…
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 - with tests like throwing metal chips (nuts?) into pumps, or running uninterrupted for ~4 hours (!) . Technical capabilities are also quite formidable - ok, Merlin-D has better thrust-to-weight, but worse Isp, and that's with the hindsight of ~40 years. Throttleable... relatively modest pressure by today's standards... And they were stored in Volga region, which is firmly Europe.
So, Musk's comment - intentionally or not - painted OSC's decision in less-than-objective color. Well, Elon is known for exagerrating... and sometimes quite grossly. We'll know the scale.
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.
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Cheaper to use drones / cruise missiles / HE carried by a flock of small robot helicoptors; many simpler schemes that are less traceable, unless developing a reputation is your intent. There are uncountable ways to kill people without needing to invoke Hollywood class exotica. [NB: I thought about not posting this, because people who are paid to not have a sense of humor about these things almost certainly read HN, b…
Hard to make any of those work across intercontinental differences. Drones, cruise missiles and small robot helicopters need to be launched from a location relatively close to the target.
http://www.popsci.com/article/technology/solar-powered-drone...
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Not sure what you're saying reflects reality. When Orbital Science's rocket recently exploded, Elon's words were nothing but polite: https://twitter.com/elonmusk/status/527247155954610176 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. It is upsetting, but still not as surprising that they suffered catastrophic failure having such an…
One example of his being polite doesn't mean he doesn't also make fun of competition publicly. Look at the interview where the interviewer asks him about a competitor's electric car (BMW I think) and he just laughs for a not-insignificant amount of time followed by something like "have you seen the thing?"
I feel if the 1st stage booster had an attitude control system toward the top like the BRAHMOS missile [1], the lean could've been corrected to at least have the rocket be upright when it impacted the platform. Although the choice to add an attitude control system would probably take up more space and add mass which is critical for a stage rocket. [1] http://i.imgur.com/5RWkvem.gif
It does ( https://www.youtube.com/watch?v=DgLBIdVg3EM ), it just ran out of hydraulic fluid in this case.
If I kick the rocket over those fins won't do any thing because they can't correct the force I applied to kick the rocket over. An active thruster (an attitude control system) can recorrect the force of my kick and reorient the rocket vertically.
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And my response is the same: See those sections.
Sure, let's go over it together. Tlb is many things, but "rarely wrong" is probably near the top of the list. He certainly read those sections before making that comment, so there must be something here which made him as an engineering expert say that it doesn't properly address thermal expansion. I'll try to run an emulator of tlb's mind, but mine is far less sharp. The tube will be supported by pillars which constr…
For instance, you could have periodic sleeves that can slide over one another so you don't end up with the expansion on the final endpoints accumulated, the trajectory could be adjusted to allow for translation of some end-to-end expansion into a sideways expansion (much like what you see in long runs of heating tubing where they throw in the occasional U or loop to make sure the tubing stays put on the longer stretches) and so on.
There are a lot of really hard technical challenges involved in the hyper loop concept, I'm not sure why you'd focus on the thermal expansion as the major one, it's trivial in comparison to some of the others.
Btw, in railroads (that other long distance transportation method) the expansion is dealt with by putting a small gap between two adjacent rails. That's obviously not possible with the hyper loop as it is currently envisioned but I think that the answer is in there: don't allow the differences to accumulate over long stretches. We already have plenty of long pipelines, this one is just a big bigger in circumference.
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ICBM Delivery service? sign me up
Okay. That 1oz letter will be $150 at current Falcon 9 prices. You know, that started as a joke, but cut it in half with reusable stages and that's really not too far off for intercontinental overnight delivery.
Scene: ten miles over a major metropolitan city, an ICBM is racing in. Seconds later the nose cone is jettisoned and a cluster of small cones begin pouring out. Little grid fins pop out and they scatter out like dandylion seeds to the wind. Zooming on one, we watch it hurtle towards an enormous skyscraper. The cone's nose begins blinking from green to red, blinking faster as it approaches its target. Screaming closer and closer, we see the tower suddenly open a panel showing a large tank and the cone slams into it with an enormous splash. As it settles a platform gently captures it and raises it up to a crew of people with mail carts ready to distribute the packages.