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SpaceX Lands Falcon 9 Rocket At Cape Canaveral (planetary.org)
Rei writes: At 8:40 PM today, SpaceX successfully launched and relanded the first stage of its Falcon 9 rocket at Cape Canaveral, as well as delivering to orbit the last portion of ORBCOMM's communication satellite constellation. This also marks SpaceX's return to flight and the first launch of the "Full Thrust" Falcon 9 v1.1 with densified (extremely chilled) propellants. The company will now shift its efforts toward catching up on its backlog, investigating and refurbishing its landed first stage, and preparing for the maiden flight of the Falcon Heavy rocket this spring. Congratulations to everyone at SpaceX!
I actually cheered out loud. I've been a space fan since the shuttle program began. This is great news, and great progress.
--Brandon / Split Infinity Music
*drinks beer*
How many times can they reuse the rocket?
I wonder how much of this was due to learning from the past misses and updating to version 1.1, and how much was from deciding to land on the ground and not on a barge at sea. Hell, learning from past misses and deciding not to land on a barge might be the same thing.
You were critically hit for no damage. The bruise will look nice, and maybe the scars will make good party talk.
Hats off to you guys, I was cheering so loud my kids thought something was wrong with me haha.
I came to the datacenter drunk with a fake ID, don't you want to be just like me?
That'll teach Blue Origin not to get cocky...
Or not: http://mashable.com/2015/04/30/penis-rocket-bezos/#SRDCQNhZ9SqH
Everybody knows you wait until the first service pack comes out before launching.
You are welcome on my lawn.
Great job SpaceX! My wife and I kept the kids up to watch and we were cheering like we won the Super Bowl! Awesome!!!
Look, I just made you read my signature.
If you'd been paying attention... There was a live video feed of the attempt. Here's a recording:
https://www.youtube.com/watch?...
Wow, what a sight to behold. It was pretty hard to stay quiet while watching that streak of light come down with everybody cheering. Probably the first "USA! USA!" chant I've ever heard that was both entirely well-deserved and not even a little bit sarcastic. An historic occasion indeed. :-)
Congratulations SpaceX, this is like that 4th launch where everyone suddenly went from doubt to astonishment.
[SHOW SOME LENIENCY TOWARDS
With airplanes, a carrier landing is quite a bit more difficult than landing on land. You can land with a stuck rudder OR with a stuck elevator OR you can land on an aircraft carrier. I wouldn't want to try to land on an aircraft carrier with a stuck rudder.
I don't know the details of the SpaceX controls, but I suppose it's possible that a glitch like a stuck valve would be easier to work around with a larger landing zone, and one that's not moving. In theory, with the stuck valve they might have had the option of manipulating the controls differently to land 300 yards away and upright.
"There is no joy like nerd joy!"
Here's a video: https://www.youtube.com/watch?...
Better known as 318230.
I've watched it land 4-5 times now and every time it's just as fantastic, I get all giddy inside. YEAAAAAAAAAAAAAAA!!!!!!!!!!!!!!!!!!!!!
Actually SpaceX's Grasshopper accomplished what Blue Origin only just did back in 2013. Try again.
You were critically hit for no damage. The bruise will look nice, and maybe the scars will make good party talk.
Congratulations to Elon and co. A feat of engineering!
U-S-A! U-S-A! A reminder that space travel is 10% science and 90% nationalism. Take that, foreigners!
Um, actually, DC-X accomplished that in 1993-1995.
Hopefully it will be one of many such successful launches and recoveries in the year(s) to come, It'll be nice to get some video of day landings as well as while I'm sure a night launch/landing is great for those actually witnessing it on the ground you can't really see much on video. I'm also curious as to how closely to center it landed on its pad, would it have been successful if they had gone for a ocean platform landing or did a larger pad make all the difference.
And congrats to SpaceX, this is a very important step in the right direction!
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Ah, yes. If you US people keep at it, then in a few years you may again have a reliable launch vehicle. You know, like ESA and the Russians have and a few other countries are working up to.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Yes, and if you read about that, you'd see some of Blue Origin's personnel came from that project. So Bezos only just did the same thing his people were capable of 20 years ago.
Musk's SpaceX just put a rocket into orbit, delivered a payload, and brought it back down safely. That's never been done before. That's an order of magnitude more difficult than what we've been discussing. This is the biggest advancement in space flight since the first shuttle landed.
You were critically hit for no damage. The bruise will look nice, and maybe the scars will make good party talk.
Refresh my memory... when was it that the ESA launched humans into space, again?
Because the USA has never been without a "reliable launch vehicle" since the 1960's.
Bezos's launcher only reaches 62km altitude, at mach 3. It's less than half the height of Falcon 9 stage 1. It does not do a gravity turn due to the fact that it doesn't get to orbit. All of these make sticking a landing much much easier. If you want Space X to just go up, back down, and land it (like bezos did), then look at 2013, when they did that. Now they've also beaten Bezos to landing the launcher for an orbital space craft.
Note, things like the launcher being twice as tall as Bezos' isn't a case of "well, Space X made a poor design choice to make it that tall"... Instead, it's a case of "if you want to reach orbit, you need low drag, so you need a long thin space craft".
1. How Native American lands in Florida were used without permission to
2. Help elites leave the planet to create a poor-free utopia while
3. Destroying the environment as they leave.
Won't SOMEONE think of the children!!
Dance like you're hurt, Love like you need money, and work when somebody's watching.
-Scott Adams
The US already has a reliable launch vehicle called the X37-B. It can reach orbit, stay in orbit for extended missions, change it's orbital positioning, and when the mission is complete it can land back on earth for re-use. The US is also developing the Space Launch System (SLS). A heavy-lift booster that can carry humans farther than they've ever been, to an asteroid, Mars, and beyond. Why waste money and resources on rockets whose sole purpose is to launch satellites into orbit or play taxi for the ISS?
I'm sure they could have done this by the 70's if that were their goal. The essentially did the same type of control landing the LEM on the moon (controlled flight of a balanced rocket). In fact it's more difficult to control something short like the LEM where the CP and CM are close together than a long cylinder. At least mathematically, they each have their problems. But they opted for wings which may or may not have been a correct decision based on expected missions.
NASA is a contracting organization, not an engineering and production organization. Rockets, space probes, they contract them out to private companies. That has been true since the moon landing days. Their new SLS is being designed and built by Boeing, ULA, and Rocketdyne.
In that way NASA "can do" whatever they pay other people to do, so they could do this if they wanted to just by contracting out to SpaceX to do it for them.
Refresh my memory... when was it that the ESA launched humans into space, again?
There was the Hermes spacecraft that was going to fly on the Ariane 5 rocket, but it never actually launched. That said, ESA astronauts have flown on both Soyuz and the US Space Shuttle over the years and have definitely gone into space.... and the ESA still maintains an astronaut corps to this day. If it was necessary, the Hermes could be restarted again even though the ESA doesn't see the point of doing that right now.
Because the USA has never been without a "reliable launch vehicle" since the 1960's.
There has been two times in the USA without a reliable crew launch vehicle though. Once after the Saturn V was retired (about 1975-1980 when the Space Shuttle started to fly) and the current hiatus now that the Shuttle has been retired. There was also the return to flight times with the loss of the Challenger and Columbia where crewed launch vehicles didn't exist.
For sending satellites and other stuff into space though, you are spot on: America has never been without some sort of reliable launch vehicle since about the late 1950's. The EELV program is certainly alive and well right now and has been going for a couple decades so far.
No, both of those are re-entry vehicles that used first stage and second stage rockets to get into space (which they later ditched). This was a first stage rocket returning to Earth by itself after delivering its payload. Massive difference. This is unprecedented.
If you can't wrap your head around that...I don't even know how to explain it down to your level.
You were critically hit for no damage. The bruise will look nice, and maybe the scars will make good party talk.
It's a big development, but the space shuttle did re-use everything except the fuel tank. The solid rocket boosters were recovered and reused, and the expensive bits (the main engines and support equipment) were mounted on the orbiter itself.
I think that the main promise of the SpaceX recovery is that the simpler, more reliable, and cheaper traditional rocket stack can now be used in a way that is much more reusable - making it even cheaper than it already was.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
Ah, yes. Ignorance of the facts is a side-effect of patriotism.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Wrong even for non-crewed launches. The key-term here is "reliable". Of course, that gets downplayed by the media and is never repeated later. "Patriotism" (a.k.a. targeted stupidity) at work.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
You are right that the return of a Falcon first stage is a lot more impressive than what Bezos managed. But the part of Falcon that returned is not the part that attained orbit. I believe it did not even reach 5000 m/s, which would not be enough to reach orbit.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
Okay, "recovered" (ejected then deployed parachutes, to be picked up in the ocean by a crew later), but didn't make it up into orbit. Making it into orbit is the key for what makes this rocket different than anything in the past.
You were critically hit for no damage. The bruise will look nice, and maybe the scars will make good party talk.
Okay, "recovered" (ejected then deployed parachutes, to be picked up in the ocean by a crew later), but didn't make it up into orbit. Making it into orbit is the key for what makes this rocket different than anything in the past.
Upon further looking, the part of the Falcon9 that came back didn't make it into orbit, either. But delivering a payload of 10 satellites into orbit and making it back in one piece is still astounding for one rocket to do. Splitting hairs at this point...
You were critically hit for no damage. The bruise will look nice, and maybe the scars will make good party talk.
It's not hard to explain simply. The space-shuttle equivalent would be if the big orange liquid fuel tank and if the white segmented solid rocket boosters successfully soft-landed on land after a launch, instead of falling into the sea and being recovered as no more than scrap.
Comparing the shuttle itself to the Falcon 9 first stage, the Shuttle needed extensive refurbishment work after every single flight, much more than the initial project concepts called for. Until SpaceX does more testing or test flights we won't know how much refurb work this will need, but given the lack of re-entry forces, hopefully quite a bit less.
Do not look into laser with remaining eye.
...electric cars nobody can afford...
I see a half-dozen Teslas a week these days. They're not cheap, and they're out of the price range of most people, but so is your average BMW or Mercedes Benz or even Cadillac.
Do not look into laser with remaining eye.
I'm sure they could have done this by the 70's if that were their goal.
I think the thing is that never would have been their goal. I'm not speaking of corruption (nor suggesting anything like it) but the thing with NASA is that their pockets have always been very deep. Thus they kind of just looked at discarding a stage 1 rocket a necessary cost of doing what they do and figured the funding would just be there anyways. The problem though is a high cost means that something is impractical, even if you can do it (such as the moon landing in the 60's.)
This is exactly where the private sector has an advantage: It seeks to become more practical, and it's a good time for the private sector to begin taking over at least when it comes to near earth missions, and I think it's time for governments to begin focusing more on deep space rather than fucking around with ISS.
It appears you've never landed an aircraft. You did mention ome of three major challenges, though.
> The reason that a carrier landing is harder
There are at least three reasons that a carrier landing is harder .
1. The runway has been relocated, so you have no approach landmarks. The first thing is that you actually start lining up for landing many miles from where you intend to touch down. To land in Baltimore, you might learn that you need take a right at Atlantic City, NJ. With a carrier, your turns and altitude changes are never in the same place. This one doesn't apply so much to the rocket.
2. Wave motion (AGL keeps moving). The magic to a smooth landing is to make it so that you reach EXACTLY zero altitude at precisely the same moment when your forward motion puts you at the beginning of the runway, at the same instant that your lateral adjustment, with wind, puts you in the middle of the runway, while at the same instant you have ceased lateral motion against the wind and brought the yaw exactly parallel to the runway, at the same time roll goes to zero, while maintaining proper flare (pitch). In other words, the craft is moving in six dimensions* and you try to hit just the right mark in all six dimensions at precisely the same time. It's awfully tough to hit zero AGL at exactly the right time when the ground is moving up towards you, then down away from you. Too difficult for me to try in real life. SpaceX has had much trouble with this. They had the rocket perfectly vertical, and they were able to reach 0 AGL, but they couldn't do both at the same time - touch down while the vehicle was vertical. It's much easier to do that of zero AGL remains constant, rather than having the ocean move the barge up and down.
3. The landing area is much smaller. Factors 1 and 2 can easily cause the landing to occur 40 feet to far to the right, or 400 feet to far down the runway. An ocean-going landing area isn't big enough to allow any margin of error.
> The reason that a carrier landing is harder is because the runway is shorter. With a vertical landing vehicle, it's a non-issue.
The best way to really understand this is to try landing a model helicopter smoothly. Not a drone that flies itself when you let go of the stick, but an old-fashioned model heli. If you can't try that, imagine a perfect, frictionless air-hockey table - the puck glides absolutely perfectly across the table. The lightest feather touch will send it to the other side of the table because there is no friction. That's hover - there is no friction keeping you in the same spot over the ground. Your job is to position the puck at an exact spot on the table and keep in there by tossing pebbles at it.
For anyone that read that and was confused by "moving in six dimensions", consider that an aircraft can MOVE to the left, it LEAN to the left, or it can be POINTED to the left. Aircraft don't have tires in contact with the ground, so with a crosswind you can be pointing to the left while moving to the right. It can GO up or it can POINT up. So the six dimensions of movement are:
X
Y
Z
Yaw
Pitch
Roll
If your goal is reducing launch costs, it's hardly unnecessary.
The shuttle program showed that the shuttle was impractical. A large part of that impracticality was due to Congressional meddling.
A rocket that either burns up or lands in the water is a rocket that is no longer reusable.
>Musk's SpaceX just...
Eh... not quite. The rocket they brought down safely never got anywhere near orbit (1.6km/s = 4% of LEO kinetic energy). But, while their first stage rocket didn't get dramatically closer to orbit than Blue Origin's did, it did so while carrying a second stage that DID make it to orbit. That extra ~80 tonnes of payload is the difference between a useful first stage rocket and a proof of concept flight.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
The Shuttle program showed that it is impractical.
What precisely did the shuttle show is impractical? I think comparing this to the shuttle seems like an apples to oranges comparison.
Imagine you drive to work, arrive safely, but your car is completely destroyed during the trip. But the seat is reusable! That's kinda how the space shuttle worked. With Falcon 9, the entire car is re-usable.
When I was a kid, I thought the "shuttle" launched into space and the "shuttle" landed. So it was re-usable right? Not really. The space shuttle was mostly the passenger compartment. The part that got it up into space was a pair of solid rocket boosters. Those were essentially destroyed each time a shuttle was sent up. They did parachute down into the ocean, and parts of them were salvaged, but it sounds more like re-using the wood from a sunken boat to build a new boat, than really being re-used.
The US already has a reliable launch vehicle called the X37-B. It can reach orbit (...) The US is also developing the Space Launch System (SLS). (...) Why waste money and resources on rockets whose sole purpose is to launch satellites into orbit or play taxi for the ISS?
Not sure if troll or serious, but since your posting history looks rather sincere... The X37-B is not a launch vehicle, it launches on top of an Atlas rocket. As for the SLS program it will cost $20-35 billion to fully develop and hideously expensive to launch, just throwing away four RD-25 engines will cost around $900 million alone. Given the extremely few launches that are planned, estimates for the amortized cost has been as high as $5 billion/launch. When you compare that to SpaceX's fixed $60-130 million per launch that also covers their R&D expenses it's a bargain.
When the Falcon Heavy launches you get 70% of a SLS Block 1 for a small fraction of the cost and you can assemble 50+ ton modules in LEO if you need to. Like you could launch the whole Apollo mission (CSM+LEM) in one go, then add engines, then add fuel and break orbit for TLI. Looking at delta-v charts there doesn't seem to be any significant penalty for doing so and docking in space we've done many, many times now with the ISS. The only downside is if you genuinely need an even larger monolithic module due to structural integrity or something.
Live today, because you never know what tomorrow brings
The key-term here is "reliable".
Name a specific time era when reliable vehicles weren't available for launch from America. Cheap and/or affordable might not be the proper term to use here, but I can't think of a time period after the Explorer I satellite was actually launched when America didn't have some extremely reliable launch vehicle for putting stuff into orbit.... and that reliability only got better over time. The Delta and Atlas series of rockets in particular have been available that whole time, not to mention other rockets that were developed and used as well.
For that matter, name a year since 1960 when America didn't send something into space. I dare you to find that mystery year. If the key is "reliable", what was unreliable since 1960 yet used for one of those thousands of vehicles sent up by American launch providers?
> What precisely did the shuttle show is impractical? I think comparing this to the shuttle seems like an apples to oranges comparison.
Two factors.
1. Excessive cost of $/kg to orbit.
2. Design flaw making it inherently unsafe (the foam pieces falling during launch).
The situation with the SRBs wasn't that bad. They are very simple devices so no wonder after burn-off there was very little left to recover. The solid, hard shell was recovered and it was fully reusable. The rest had to be restored, because it was actually all "consumables". No big deal, they were the cheapest part anyway.
The huge LF tank was lost. It wasn't exactly cheap, but not terribly expensive.
The shuttle, though, had to be refurbished after each flight. And being an incredibly complex device, it took excessive time and cost to perform the inspection and repairs.
And then most of the fuel burned, most of the construction to carry that fuel, most of infrastructure to support that huge construction - was there to lift the cargo bay, the landing gear, the wings, the heat shields on all that, and there was relatively little left for the actual cargo.
For the Shuttle the reusability was a liability, not a boon.
SpaceX still loses the whole second stage. That's not a small loss. But it seems they actually save up a lot on the reuse of the first stage - the cost of preparing it for another launch is nowhere near to the cost of rebuilding it from scratch - and the cost of building it from scratch is nowhere near the cost of preparing the Shuttle for another launch.
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A destructive test means something like cutting the finished part open, chemically etching the metal and examining it under a magnifying glass. It is simply 'testing that destroys the part, the opposite to non-destructive testing like ultrasound.
Prediction for end of Universe #42: Fencepost error in Quantum_bogosort.cpp
To fly to the orbit the energy is needed. No way around it. But there is a lot of available energy to land. It is provided by the gravity.
Landing a rocket full of fuel is dangerous for the civilians on the ground, for the crew on board. Besides, it makes the whole flight even more damaging for the environment, because a rocket burns fuel (i.e. emits CO2) also while landing, not just at the take off.
A parachute could be further developed. It could also be reusable, ultralight, built from composite materials, etc. A descent with a parachute could as well be controled.
I guess it is just difficult to fly to a space in a vehicle, which principal concept (ascent in a rocket, descent with a parachute) was developed not in the USA, and not even in the Western Europe.
This payload was light enough, and the upgraded F9 grunty enough, that it could do it, but larger payloads will require an ocean landing.
A barge landing can use the atmosphere for braking, but that means that you re-enter halfway across the Atlantic. Returning to the launch site takes a honking great boost-back maneuver. The booster accelerated to 6000 km/h (1 mile per second) before staging. While some part of that is vertical and gravity will help, for orbital insertion the majority is lateral, and the booster has to cancel all of that velocity propulsively before it can start backtracking to the launch site.
The fundamental job of a rocket is to supply kinetic energy to a payload. Energy consumed in boost-back is not delivered to the payload.
As Elon Musk explains, return to launch site is much more expensive than return to barge. F9 can deliver 300 GJ of energy to the second stage and return to a barge. Or it can deliver 120 GJ to the second stage and return to the launch site. That's 40%. Return to launch site is throwing away 60% of the booster.
Notice how much they talked about the performance increases. Higher engine thrust, densified LOX to fix more fuel into the first stage, a stretched second stage. Even though the net payload mass is one third of the Dragon capsule on CRS-7.
(Dragon has 6000 kg payload capacity, plus the pressurized capsule and orbital maneuvering system isn't light. 12×172 kg of Orbcomm satellites is 2064 kg, plus a fairing and deployment bus.)
Although it's >90% of the weight, the cost of kerlox rocket fuel is so tiny compared to the rest that it's worth burning more fuel for a higher-probability of recovery. But not all payloads give you that option.
Six degrees of freedom, not six dimensions. Still only the boring old 3 dimensions.
Oolite: Elite-like game. For Mac, Linux and Windows
take a right at Atlantic City, NJ
I'm not putting you in charge of navigation. You're supposed to take a left toin at Albuquerque.
systemd is Roko's Basilisk.
Actually, the rocket could just as well burn H2, creating water vapor. Though Falcon 9 uses kerosene.
The problem with "a lot of available energy" is when "a lot" becomes "too much". Soyuz needs to dissipate around 0.2 gigawatt of energy during peak-Q of reentry.
Some big problems with parachutes: - they work only in certain velocity range: they will be ripped apart at very high speeds and they will never slow you down below a couple m/s. And they need fairly thick atmosphere. And they are unsteerable.
But a hybrid system could work (like in Soyuz which launches small SRBs last 3 meters above the ground). It could be that - in case of Earth surface landing - a modestly sized parachute could be deployed on some last kilometer or so, It's not viable for the barge landing though.
The principal concept was actually developed in [Germany](https://en.wikipedia.org/wiki/Wernher_von_Braun) but Russians perfected it enough to reach space, and later enter orbit.
Actually, the *concept* is quite simple. It's the mind-boggling numbers pushing the envelope on material science and engineering that make it so difficult. Eight kilometers per second. 32 megajoules of kinetic energy per every kilogram in orbit. Dissipating that energy on reentry and ascent. Tsiolkovski's rocket equation and its tyranny that boils down to taking many times the weight of the vehicle in fuel. Managing extreme energy density cryofuels - extremely corrosive liquid oxygen and explosive liquid hydrogen. Working with temperatures between 70 and 3500 Kelvin. Void, cosmic radiation, extreme temperature differences, lack of convective cooling. Attitude monitoring and control.
Each of these problems taken alone is a moderately difficult engineering challenge. But if you put them all together this becomes a byzantine puzzle.
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Linux is a complete re-write and many of the contributors live overseas.
This is an irrelevant side conversation. SpaceX's use of Linux is tactical, not strategic, and they could just as easily used many other OS's in place of Linux, so long as they were capable of getting the job done.
Since most of the time is spent in user space running the applications they need the platform to run, and not in the system calls, it's really quite irrelevant what software platform is implementing those system calls, just like the speed, overhead, or number of system calls a second, and other benchmarks on which Linux prides itself, are largely irrelevant.
Sorry to burst your bubble.
To be fair, a Green Card is not the same as being "from the USA" and Elon Musk himself is from South Africa. So it was a bit strange to me too to hear "USA - USA" when SpaceX is really competing mostly with other US companies...
Not really splitting hairs. Both the Shuttle and Falcon 9 discard and lose a good part of their spacecraft - the Shuttle loses the whole (huge) LF tank, F9 loses the whole (big and pretty complex) second stage. Apples to apples, Falcon 9 loses more, "percentage-wise".
The real difference though is in cost of refurbishing of what is recovered.
Refurbishing the shuttle and preparing it for a launch (800mln) costs about 10x more than building the Falcon 9, both stages, from scratch (80mln)!
And then recovery of Falcon 9 first stage about halves these costs.
So, the real difference isn't really in what, how much is recovered, how it flies and lands. The real difference is the absolutely vast reduction of costs. 80mln was already something very competetive. Halving it is a total game-changer!
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The space shuttle was mostly the passenger compartment. The part that got it up into space was a pair of solid rocket boosters.
Uh, what? No. The space shuttle was mostly the cargo bay. Its size was determined by the military. But by mass, the biggest component of the shuttle, maybe after the airframe itself, was the main engine. You know, the reason for that big orange tank?
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I'm sure they could have done this by the 70's if that were their goal. The essentially did the same type of control landing the LEM on the moon (controlled flight of a balanced rocket). In fact it's more difficult to control something short like the LEM where the CP and CM are close together than a long cylinder.
It's easier to land on the moon than to land on the planet because you only need 1/6 as much vertical thrust, while your orientation rockets still work just as well as ever. I'd think that overall it would still be an easier job.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
And yet it had a slightly better safety record than Soyuz.
Do be aware that there were 135 Shuttle launches, of which two were failures. At that time, there had been ~120 Soyuz launches, of which two were failures....
Biggest problem with Shuttle wasn't really a problem with the Shuttle so much as a problem with Congress and NASA. They should have built a dozen or so of the things, and launched every other week doing things that only that honking big booster could do - like life space station parts or Moon/Mars rocket parts.
Then it might have been worthwhile...
Yeah, I know.."space nutter"...deal.
"I do not agree with what you say, but I will defend to the death your right to say it"
If you want to make space access more practical you need to recover your craft somehow. Imagine if we shipped cargo from warehouse to store in trucks & trailers that disintegrated after their trip, a can of beans alone would probably cost a hundred dollars. This is the method SpaceX is using, probably has its issues but so does every method. If you're interested in parachute recovery ULA is supposedly going to be trying that in the "near" future with a system they've named Vulcan.
I see a half-dozen Teslas a week these days. They're not cheap, and they're out of the price range of most people, but so is your average BMW or Mercedes Benz or even Cadillac.
I drive a 1982 Mercedes-Benz 300SD. Originally it cost around $33k, which with inflation puts it over $85k. Tesla money. I am replacing it with a 1997 Audi A8 Quattro. Also originally into the Tesla money. Expensive cars ain't even new. And eventually, the middle class can afford them, if they're willing to turn a wrench. Remember when wrenching used to be an American pastime? And I'm not even talking about because you had to, I'm talking about because you wanted to. My 1960 Dodge Dart was as reliable as the day is long. Sure, it was designed to spew lead out its arse (it had 12:1 compression, no less) and it would be completely unsafe by modern standards but it needed very little attention, probably less than almost anything modern with a shitload of sensors and gewgaws to fail. And the relatively small-displacement big-block engines (of which the original 318 was one) were just big rocks. That one had 240hp and 340 ft-lb out of 5.2 liters though, which would not be bad today for a naturally aspirated engine. Not great, but okay. But now people don't seem to want to know anything.
That, naturally, fits great with an EV, since there's so much less to go wrong. People who have never taken off their plastic engine cover don't seem to get how much complexity is involved in a combustion engine. For each cylinder you've got a piston with a bearing and a wrist pin, and two or more cylinder rings; a conn rod (probably powder metal, but if not, then very possibly forged) with two caps (cracked if PM, machined if forged) and four bolts; the bearing at the crank; typically two intake and two exhaust valves (maybe another valve in there someplace) and for each valve a spring, a two- to four-piece lifter or follower, probably a butterfly flap or another second-stage intake valve which is held to an actuator rod by two to four screws, a set of hardware to hold the cam near that cylinder comprised of a cover, two nuts, and a bearing, a valve guide, a valve guide seal, and possibly a pressed valve seat, and maybe a valve retainer clip, and possibly a rocker arm and a whole bunch more hardware for that; two head bolts or two studs and two nuts, probably with washers; a fuel injector itself usually composed of one to two dozen parts, usually at least two O-rings and/or quad seals and maybe a rubber isolator for the fuel injector as well, if you are lucky you will get a retention clip or other device which holds the injector to the fuel rail; the electrical connector which attaches to the injector is itself made up of a housing, two pins, a gasket, a retention clip wire and a cover; these days right atop the spark plug for that cylinder (which is itself made up of a body, center electrode, isolator, and a washer, and which has fancy-pants metal coatings applied with vapor deposition) you get an ignition coil pack potted with epoxy in a plastic body (about a dozen parts including the igniter transistor) and usually two bolts to hold it down; the coil pack has a rubber extension unit to reach the plug, itself with a center electrode, a contact spring, and a retention clip; the coil pack has three wires so its connector has one more pin than that of the injector. *breathe* Wait, there's more! Your air-shrouded fuel injector has a air feed line! Where are you going? Come back!
There is so much less to know with an EV it's not even goddamned comical. It fits perfectly with Millenials' waning interest in the car as a status symbol.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
"Landing a rocket full of fuel is dangerous"
The rocket uses up virtually all of its fuel getting the second stage up to speed and altitude, after ejecting that payload it returns to the launch site on a comparatively insignificant amount of fuel. And at least for the Falcon 9 a crew will never ride the first stage back to the pad, they continue on to orbit on the second stage. I highly doubt that SpaceX will even reuse a first stage to launch "precious cargo" (people, expensive satellites, etc) for the foreseeable future. I imagine their intent is to use newly built stages to launch such cargo, and then reuse the first stage launching cheaper satellites for a discount (new first stage ~$50 million launch, reused first stage ~$30 million launch).
> instead of falling into the sea and being recovered as no more than scrap.
They were originally designed for re-use. The abandonment of plans to use the external liquid tank as building materials in orbit, and the poor re-usability of the solid rocket boosters were parts of the tremendous expense and overall failure of the space shuttle program to provide "trucks to space".
Last Soyuz fatality was in 1971. The Shuttle program began in 1977. So, "at that time" there were no fatal Soyuz failures.
To date there's been over 940 successful launches of Soyuz with a total of 2 fatal accidents involving 4 astronauts. The Shuttles over their two accidents killed 14 astronauts.
There were 9 total (fatal or nonfatal) dangerous accidents on Soyuz missions over its 940+ launches, so below 1%.
There were 10 total dangerous accidents involving the Shuttles. So above 13%. (source: https://en.wikipedia.org/wiki/...)
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This is what I thought the 21st century was going to be like. Rockets taking off and landing again. I can see a passenger version of this in a few years where you can fly from New York to Australia in 30 minutes. The same vertical landing tech can be used to land on Mars. Refuel and return to Earth. Now if we can just perfect flying cars.
Today's vices may be tomorrow's virtues.
I agree with everything you said, except the final 80 million number. The first stage costs about $16 million, and around $200,000 of that is fuel. So this may cut the $16 million in half, not the $80 million . Still, $72 million per launch is pretty darned good.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
Oy, not $16 million - $60 million. Just forget I was here. :)
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
I saw different articles citing different numbers. I saw 16mln too.
I believe the sum of 80mln is including their commercial mark-up - the price for the customer. And while recovery will drop the cost by 16mln, the "price" will be halved, firstly because the expensive development can slow down, and besides because Musk wants space travel to become more accessible, more ubiquitous, and above all to force the competition to step up their efforts.
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It's not so much the controlled vertical landing of the rocket, but that they can re-use the rocket engines so many times. NASA never achieved that, for example the SSMEs effectively needed rebuilding after each flight. What SpaceX seem to be shooting for with this is closer to "put the gas in it, go, repeat" without the rebuild between every flight (which made the Space Shuttle so damned expensive).
Oolite: Elite-like game. For Mac, Linux and Windows
Not raining on the parade, but the last two attempts were out in the ocean, so if something went wrong, a very large object with fuel still in it wouldn't fall on someone's minivan on I-95 on the way to grandma's house in Boca Raton.
How come this time around SpaceX had the cajones to return the vehicle to Florida? At the altitude this thing reaches, wouldn't a small ballistic error and motor failure (resulting, say, from a little software error that reboots the controller) send the launcher anywhere from a few feet to multiple miles off target? Like Ft. Lauderdale?
I mean, it's fuck crazy cool what just happened, truly, but I sure hope it's got old-fashioned parachutes as a backup before it lands by accident in a retirement community, because the plan is to launch and land a lot more of them and something is bound to go a little wack.
Take it easy, Charlie, I've got an Angle...
NASA never achieved that
But they never really tried that either. AFAIK, the SSME are the most complex engines, of any type, ever made and also the most efficient. Performance was their goal, not reuseability.
Yes. There is economic disincentive to reuseability if you are a manufacturer. Why build one rocket when you can build 20?
I've seen some concept-art where external tanks are used as space habitats, and it still doesn't make a whole lot of sense to me. Wouldn't it be more cost-effective to use bulk payload launch systems with lightweight, almost passive cowls to protect the payloads, without using the Shuttle as a cargo vessel? The Shuttle seemed like it was better geared as a spacious habitat and workshop for those working in space. The max takeoff weight is 120 tons. The cargo capacity of the shuttle is around 27 tons. Wouldn't it make more sense to lift bulk cargo on the rocket without the presence of the shuttle? Even if the faring weighs 20 tons, that's a hundred tons of cargo and module sizes as large as the shuttle itself, rather than modules small enough to fit within the shuttle cargo bay. The ISS weighs in around 400 tons, that could have been launched in four or five heavy launches if the shuttle hadn't been used to ferry parts.
Do not look into laser with remaining eye.
One more step closer to running away from our problems.
This can be an effective solution when the former group that you were part of didn't have an interest in solving those problems.
I think you're right, though those are probably the "all in" numbers if the booster is going to be thrown away instead of trying to land. My number were for this specific rocket though. It doesn't really change much either way, your'e still nowhere near LEO orbital velocity of 28,000 kph.
According to the on-screen speed indicator in the video they were going about 5800kph, or 1.6km/s, at separation. That was after the engines had already shut down and maximum speed had been reached. That *is* about 20% of LEO velocity, but since klinetic energy is proportional to the square of velocity that translates to only (20%)^2 = 4% of LEO orbital kinetic energy.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
I agree with your analysis of the complexity of an ICE, but I argue that an electric car is no less complex if you look inside the silicon. IGBTs and MOSFETS along with their control networks are quite complex, but they are beyond the mechanics purview. The millions of lines of code in the control systems would certainly be another point of complexity, beyond the ken of the majority of the population. And while the electric motors themselves are simple, their simplicity belies the many thousands of hours that went into designing the field windings and armature to maximize the effectiveness of the generated magnetic flux.
I agree with your analysis of the complexity of an ICE, but I argue that an electric car is no less complex if you look inside the silicon.
All modern cars have traction control. Most of them have torque measurement, let alone estimation. So they have just as much complexity hiding in their silicon...
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The shuttle program has nothing to do with this... virtually every design decision for the shuttle was different from the falcon 9.
The shuttle carried a huge non-reusable external fuel tank and the SRBs (which produced 70% of takeoff thrust) were also non-reusable. The 'main' engines were not really designed for re-use and had to be completely rebuilt after each flight. The decision to use heat tiles instead of an ablative coating meant the risk of heat tiles falling off and required very expensive refurb after each flight. The weird shape of the shuttle meant that the aerodynamics were complicated and hard to understand; Columbia was destroyed partly due to aerodynamic forces. There was no escape system in the event of failure. Much of the design was literally based on "let's get the initial program cost down so that it can be approved by congress and let people pay for our mistakes later."
The shuttle proved zip about re-usable spacecraft. It did, however, prove just how much can go wrong when you have a flawed design process based on impossible and conflicting design requirements and a manufacturing process based on pork and congressional approval.
A fool and his hard drive are soon parted.
I think the idea is that you have to take the tanks with you anyway, you're not getting very far without a gas tank after all. And, once you've got the tank almost to orbit, it's relatively cheap to nudge it the rest of the way there. At which point you have a great big air-tight tank floating in orbit, just waiting for you to move in.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
>But now people don't seem to want to know anything.
I assume you're referring to people not wanting to work on their cars today. But really, things have changed dramatically - a cars guts used to be an engine, transmission, and a few auxilliary gew-gaws. Now it's a rats-nest of finicky emission control systems that happen to have a car attached. And in many places you can't register your car unless the ECS is working correctly (or the car is old enough to not have one and be grandfathered in). So, what was once a straightforward mechanical system that anyone who could spin a wrench could tinker with is now encased in a byzantine mess of electronics and computers.
One of the things I'm really looking forward to with EVs is the return to a straightforward drive system that will make things easy for tinkerers once again. Of course autonomous driving is going to add a whole slew of new complexity, but its mostly complexity that can be isolated from the drive system both physically and conceptually. I would hope any autonomous system worth its salt will be analyzing and adapting to actual vehicle performance rather than just assuming the motor and brakes work within factory-specified tolerances. Otherwise we're going to have a real problem as they begin to age.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Umm, maybe not. Even if your maneuvering thrusters can provide a lot more thrust with that tall moment arm, dynamic stability is much lower. It's like trying to balance a pencil on the eraser as compared to balancing just the eraser.
Plus there's the fact that you're operating under lunar gravity, which is 1/6th that of Earth. That buys you roughly six times as long to correct any thrust imbalances - essentially everything is moving at 1/6th speed compared to an Earth landing. Which is a big deal considering the actual landing was done under direct human control because software of the era wasn't up to the challenge. You just can't overclock humans to deal with things that much more rapidly.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
I'm not sure a hybrid system would make practical sense though. If you can use the existing rockets to do the final landing, then the million-dollar question becomes, "How does the mass of the necessary parachute compare to the mass of the fuel needed to do the same job?". You also need to compare reliability, price, and engineering overhead. It's possible that a huge super-light parachute could come out ahead, but I suspect it would be by a narrow enough margin that it wouldn't be worth the headache.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Q: "How does the mass of the necessary parachute compare to the mass of the fuel needed to do the same job?".
A: Quadratically, vs linearly.
In the range of speeds where the parachute works at all, its efficiency is proportional to square of airspeed. The engine provides deceleration directly proportional to the speed change needed.
That means that even a very modestly sized parachute could adequately replace the middle burn and a major part of the final burn. It can do wonders at high airspeeds, but it's lousy for the last several m/s that make the difference between a crash and a landing.
But it also really sucks for precision of the landing. If the landing pad was a dry salt lake, it would be a no-brainer solution. But for a barge landing it would be rather risky.
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That said, ESA astronauts have flown on both Soyuz and the US Space Shuttle over the years and have definitely gone into space
Right, but his question wasn't whether the ESA had astronauts...
No it wasn't. The question which you refuse too answer because it embarrasses you was:
Refresh my memory... when was it that the ESA launched humans into space, again?
Democracy is a sheep and two wolves deciding what to have for lunch. Freedom is a well armed sheep contesting the issue
It all has to do with gain margins (from control theory) and not gravity or moment arms. To be sable (controllable), the center of mass has to be ahead of the center of pressure. The problem with the lem is than it's squat with a heavy bottom and not a lot of high up mass. There was only 15" between the two.
In my opinion such a landing add an unnecessary complexity. The Shuttle program showed that it is impractical.
.
I think it is just one more attempt to do it differently, not with a parachute, not as it was done originally in 1957 and 1961. Kind of its own, an US way.
So how would the Shuttle show that a different way is impractical? Isn't part of the point of the SpaceX approach being different so that they aren't repeating the economic failure of the Space Shuttle?
The purpose seems to be to save several million dollars per launch. We'll see if they can do that in the long run, but if they can, then that sounds practical to me even with the extra complexity of the system.
NASA never achieved that
But they never really tried that either. AFAIK, the SSME are the most complex engines, of any type, ever made and also the most efficient. Performance was their goal, not reuseability.
That Nasa never attempted to develop cheap & reliable engines/launch systems, preferring to tweak & complexify everything is damning in and of itself.
Democracy is a sheep and two wolves deciding what to have for lunch. Freedom is a well armed sheep contesting the issue
I was on my high school's electric car team. We had a Porsche 914 that had been donated with a blown motor that was converted to electric. It had its share of problems, but the drivetrain was never among them.
I look at electric cars as a way for the car to much more quickly approach appliance-like maintenance and use compared to gasoline and diesel cars. Sure, there will be consumables to change, but the chemical-aspect of the car will not require as much owner involvement as it currently does. No gasoline, no oil change invervals a 3000, 5000, or 7500 miles depending on the manufacturer's penchant. With the end of the need for frequent fluids service I could see on-board tire pressure monitoring evolving into a central tire inflation system so that the less frequent maintenance cycles do not mean tires go underinflated for an extended period of time. That would mean possibly chassis/bearing lubes, tires, brakes (which would probably last longer with regenerative braking), and windshield washer fluid being the most common maintenance. Hell, carwashes might add a couple of services and thus meet 90% of the needs of the car within its first 100,000 miles, and it's conceivable that the cars could go far more than the ~200,000 miles we reasonably expect out of them now.
Do not look into laser with remaining eye.
The biggest difference of the electric versus the ICE will be the nature of how maintenance and repair is handled. I expect a lot more component-level repair of circuit boards and power systems, along the lines of how Prius owners have been replacing or repairing bad battery contacts to extend the lives of the battery packs, as opposed to the very greasy, fluid-mess job that maintaining a water cooled reciprocating piston engine with hydraulic systems that we currently face.
Do not look into laser with remaining eye.
I was not clear. The previous post said that the US doesn't have a reliable launch vehicle when in fact they do. They have a reliable launch vehicle that is responsible for delivering the X-37B into orbit. The US also uses the Delta IV Heavy and the configurable Delta IV Medium-Plus launch vehicles. There are a lot of people who seem to think the US is not currently capable of putting things into space but that perception is wrong.
I assume you're referring to people not wanting to work on their cars today. But really, things have changed dramatically - a cars guts used to be an engine, transmission, and a few auxilliary gew-gaws. Now it's a rats-nest of finicky emission control systems that happen to have a car attached.
While that is completely true, it does come with benefits, and not just better emissions. Once the tuner familiarizes themselves with the systems, they can accomplish a great deal just by punching keys. My A8 has a Motronic 5.3, which is broken wide open. Not only can I clone PCMs, but I can also supposedly tune. The Motronic 5.3 is basically the same hardware as the Bosch MS4 (motorsport?) and you can use the documentation for that to understand the M5.3. But even when you can't do that, you can yank out your PCM and drop in a Haltech, or a VEMS.
And in many places you can't register your car unless the ECS is working correctly
Sure, you don't want to be chopping your harness...
I would hope any autonomous system worth its salt will be analyzing and adapting to actual vehicle performance rather than just assuming the motor and brakes work within factory-specified tolerances. Otherwise we're going to have a real problem as they begin to age.
The systems we have now are already adaptive, so I don't see why they wouldn't be.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I expect a lot more component-level repair of circuit boards and power systems,
The actual motor control boards are very expensive, and not all their phases will fizzle at once, so they will be repaired more than most automotive electronics are now. But I've sat through a whole video of a Bosch ABS controller being refurbished, including cracking off the case and milling away the old adhesive. Then a robot resolders all the contacts, because Bosch used some fancy-pants flexible cable bonding technology that didn't pan out. People are definitely refurbing a lot of control units for which no official replacement is available. I'm collecting replacements for all the modules in my Audi, which is basically a goddamned rolling NOC...
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
...if they were, there could be no boost-back burn.
(But I get your meaning; they are nearly empty.)
That that is is that that that that is not is not.
> think the idea is that you have to take the tanks with you anyway
Exactly. Custom designing a "bulk payload launch systems with lightweight, almost passive cowl" system would seem to be unnecessary when these large shells nearly reach orbital velocity, anyway. Also note that it's very difficult to design something from scratch that will very leightweight but survive the launch to orbit. If it's light, even hollow, that can add a great deal of drag to the launch system.
"I’m nauseatingly pro-American. It is where great things are possible."
That that is is that that that that is not is not.
estimates for the amortized cost has been as high as $5 billion/launch. When you compare that to SpaceX's fixed $60-130 million per launch that also covers their R&D expenses it's a bargain.
Given facts like this, how does anyone claim with a straight face that government can do things about as efficiently as private-sector efforts can?
That that is is that that that that is not is not.
You answered the wrong question. It doesn't matter what the BigO of the formula is, only the actual value for the specifc situation under examination. I'll refer to http://i.imgur.com/D9BdO86.png to be sure we're on the same page. After separation we have
1 - The boostback burn, which obviously can't be aided by parachutes since we still need to navigate. That's probably going to be the bulk of the fuel consumption too, since it's pretty much in vacuum and has to cancel the 5800kph lateral speed and then accelerate back to a sizable fraction of that speed in the opposite direction to return home (probably at least half the average speed based on the time between launch, boostback, and landing.)
No parachute, but not strictly necessary with the right launch and landing sites.
2 - The rentry burn. Which is going to happen in near vacuum (45-25 km), at speeds in the thousands of kph (presumably to avoid damaging or destabilizing the rocket by flying it cone-first into hypersonic winds at higher pressure.)
That's going to have to be one hell of a parachute for most of the job
3 - The final approach, the last 30 seconds before landing.
*This* I could see being replaced by a much longer parachute ride, but it's also the smallest of the burns, using only a single engine for a brief time to slow down from terminal velocity to a stop.
I could see the last leg of 2 and most of 3 being done by parachute, but at that point you've already done all the "heavy lifting" via rocket, and I have serious doubts that you could make the chute, cables, and deployment mechanism at a lower mass than the fuel needed to do the remaining job. Plus there's all the complexity and new opportunities for catastrophic failure you're introducing. And the loss of precision landing you mentioned.
I don't doubt that it could be done, just that it would be cost (or mass) effective to do so.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
I agree it comes with benefits, but it makes the system far less comprehensible to the initiate, and hence it's no surprise that the number of hobbyists has dropped dramatically.
It also doesn't help that there were a couple decades of blatantly user-hostile shenaginas by the manufacturers - making it difficult and expensive for non-dealer mechanics to get their hands on necessary parts and diagnostic equipment.
And of course we can't forget that modern cars are often not designed with user service as a priority - the pressure of emissions reduction and urban crowding has increased the amount of necessary hardware, while also decreasing the amount of desirable volume in the engine compartment, to the point that you often have to go to drastic lengths to access the engine and other core components. (I recently replaced the alternator in a 2000 Volvo, hardly a small car. The recommended technique involved first removing the radiator and fluid reservoirs to give yourself room to work...)
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Stay stupid (clearly your preference) or google "US rocket explodes".
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
ESA mostly does rational, beneficial missions. Astronauts do not factor in most of those. The US does many "patriotic" missions (i.e. publicity stunts for the stupid), these need people on board.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Keep kidding yourself. Your question was refused because it has no relevance. Just like the other nonsense you seem to honestly believe.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
(I recently replaced the alternator in a 2000 Volvo, hardly a small car. The recommended technique involved first removing the radiator and fluid reservoirs to give yourself room to work...)
Too bad it doesn't have a bolted core support like my 1997 A8. I just did a head job, and have to finish up the timing belt part now, but it started raining and I don't have an inside to work in. The nose of the car is in the carport, so the engine compartment doesn't get rained in, but it still gets too crappy out there. I just remove the bumper (2 bolts) and the bumper shock mounts (6 bolts) and then I can disconnect the core support from the fenders (2 bolts) and move it out of the way. I'm going through a lot of pain, but at least it's a vehicle which was designed to be maintained.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The Japanese try to turn them into sat launchers with little success so far. I guess it is because solid fuel cannot be nicely controlled like the V2-style engines. And that means imperfect satellite orbit.
Incorrect.
The Japanese M-V solid fuel rocket system had 6 of 7 launches succeed. The follow on Epsilon solid fuel launcher has 1 out of 1 launch successes.
The Indian ASLV launch vehicle, also all solid fuel, had the first 3 launches fail, which is not unheard of for a new vehicle. The 4th launch succeeded.
So after seeing the video, I thought, why not?
While not an astonishing success like SpaceX's (I am after all only one man with a dual core laptop or six, they have hundreds if not thousands of brains and supercomputers pouring out their wazoos), I did manage a water landing AND put a payload into orbit. Photo op here.
Political debates have me rolling my eyes so much I think I got optical whiplash. I should sue. - Foamy The Squirrel
Heh. This isn't the first time Audi/VW has created something with the intention of never needing service for the life of the vehicle only to discover that they undershot the mark tenfold. There's a performance engine whose cam geartrain is located at the back of the engine sandwiched up against the transmission and adjacent to the firewall. It's a complex assembly of something like five timing chains with tensioners that cannot be accessed with the engine in the car. It's also an interference engine, so when the tensioners fail the valves contact the pistons and the engine is ruined. It costs about $10,000 to have the tensioners replaced (like $3000 in parts alone) and they still aren't any better than the factory units.
Automakers need to stop treating some systems as if they're black boxes (the engineering term, not the flight data recorder term) because the systems concealed within inevitably require service.
Do not look into laser with remaining eye.
I think you are thinking of the R8 engine. Which is Italian.
Granting VW has done some brain dead things on their water cooled cars. The first step in replacing the brake master cylinder on a new 'beetle' is 'remove the front bumper...'
It's like they realized all the old jokes about English cars. At least there are no Lucas electrics.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
How much effect does the CP have in vacuum?
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Yes. There is economic disincentive to reuseability if you are a manufacturer. Why build one rocket when you can build 20?
There is if you're the only manufacturer. But what if your competitor starts offering a lower price? Well then you might want to find some ways to lower your own costs so that you can offer an even lower price. This is actually one of the wonderful things about capitalism is that it encourages people to find more practical ways of doing things.
And believe it or not, SpaceX does in fact have multiple competitors, though most of them aren't private sector, rather they're foreign governments (i.e. Russia, India.)
I don't recall Congress or the President ever giving NASA the leeway to pursue its own plans unmolested for any length of time---at least not in my lifetime.
Their goals and priorities were reshuffled at least twice within the last decade due to political decisions originating outside the organization.
SpaceX was founded in 2002 IIRC, which gives them 13 years of a single vision. And they had the freedom along the way to adjust the means and the goal as the technology developed. They didn't need congressional approval to scrap or rework projects as they went along.
Bureaucrats may be able to shepherd innovation from time to time, but once politics comes into play you can forget about it. We managed the moon landings only because everyone on the political spectrum wanted to win that race.
---
According to the latest ruleset, this post should be modded as Vorpal Flamebait +5.
I think you are thinking of the R8 engine. Which is Italian.
Could be, but actually the 40V Audi V8 also resembles that remark. It's got at least three timing chains plus magic tensioners that change the timing, and if anything goes wrong with any of it the engine has to come out to be serviced. But I've done both heads and the timing belt on my 32V engine and it's been bolted down the whole time.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The Boostback can be - and will be forfeited for heavier payloads. The rocket will travel in a ballistic trajectory instead of looping back to the launchpad.
The reentry burn - that highly depends on the rocket's speed. Not viable for orbital reentry but quite realistic for this - we're dealing with energy roughly 16 times lower. A drogue chute is often used in a later phase for these purposes - most Russian reentry vehicles used one. Another option is airbrakes - even disposable(ablative) ones.
Then the landing, upon which we mostly agree. Discarding the parachute some 50m above the landing would mitigate the headaches of it dragging the rocket upon landing.
Yes, it's not entirely simple, but it's neither as bad as you present it.
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Well, if we're forfeiting the boostback for a larger load and/or greater speed at separation, then the reentry burn has to slow it from 100% of seperation speed. Which was already 5800kph for this latest "low energy" launch with boostback. From an energetic standpoint we should really look at it as:
A) Slow from suborbital lateral speeds to zero
B) Optionally do a lateral return burn and later braking burn
C) Bring vertical speed to zero as we reach ground level.
So, ignoring B altogether, we still need to decelerate from suborital speeds. You're probably right that a chute could do the job, but it's going to have to be ferociously durable, we're talking about a 27,000kg dry weight compared to ~7,000kg for a Soyuz. Plus successful deployment will likely be one of the most failure-prone parts of the process, with no back-up option.
As for the final landing, you can't just cut the chute loose - after all it will immediately start falling in a chaotic fashion, while the rocket beneath it begins slowing dramatically. It would be a serious challenge to avoid having them get tangled up.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
The atmosphere does great most of the deceleration, including slowing the lateral speed. You only need to slow down enough not to burn up, and that is an engineering issue - especially that it's only 1.6km/s vs Soyuz's 8km/s. Energy proportional to square of velocity, Soyuz kinetic energy despite being so much lighter is still 6 times higher, and concentrated in a much smaller package - lesser radiation/absorption/conduction area. I also believe in that phase a classic parachute would be a mistake; instead it should be a kind of a solid metal airbrake/heatshield discarded once it overheats.
As for cutting the chute, it starts falling in a semi-chaotic fashion (still somewhat weighed down with whatever clamp was holding it to the rocket, but no longer burdened by the many tons of the rocket), at something like 5m/s. Meanwhile the rocket quickly drops to the landing pad and finishes the landing before the chute reaches it (and needs to be extremely unlucky to tangle into it once it falls, I mean, wind direction reversing or something like that...)
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2