Gotta wear shades
> "Sunday's launch is scheduled for 1042 PT..."
In the daytime? But what if it prangs again? Explosions are so much cooler at night...
Elon Musk has confirmed that the Falcon 9 rocket his firm landed last month has successfully completed a test firing with almost no problems. Conducted hold-down firing of returned Falcon rocket. Data looks good overall, but engine 9 showed thrust fluctuations. — Elon Musk (@elonmusk) January 16, 2016 Musk said that the …
@Duncan wee feisty MacDonald
We've explored this sort of question (the effect of extra fuel and landing gear) in some detail in previous SpaceX news items.
Summary, less than you'd expect. It's mostly fuel (and oxidizer) at launch, and it's mostly empty when they bring it back - so it's vastly less mass (although it looks the same*).
[ * If it was transparent, there would be fewer such questions. :-) ]
> How much bigger would the launch window be if the first stage did not have to carry the landing gear or reserve fuel for for the landing ?
The initial stage of the trip carries all of the vehicle through a substantial proportion of atmosphere at velocities that have little to no aerodynamic penalty. It would make sense to put as much fuel into that portion of the burn. This was not the consideration given to things in the days of slave labour. The Germanic point of view was to just throw money at the whole concept equally as in the first place it was all stolen and in its haste to steal yet more the Third Reich didn't give a shit until around 1944.
The Kennedy government hadn't the third idea about what makes a rocket and went along with whatever they were told at whatever the cost.
Instead of making mild steel first stages they were using dangerous second hand Titan missiles. From there, the no idea of not using titanium/aluminimum alloys in the pre-cyclocross bicycle days, continued until the cost of a launch kept rocket use to a minimum which lead to woodpeckers setting up homes in the first reusables.
Any government agency setting itself up to run a money pig like NASA is giving a committee a license to print its own currency. The only claw back from that is the political overseers already ensconced in their own cash cows. Whilst paying lip-service to free enterprise, things were never going to change until the accidents put an end to it all.
The cost of fuel versus the cost of the landing gear is a no brainer. It does not matter how much fuel it takes to launch if the savings are the whole vehicle against a few tons of paraffin and lubricant. Compare the price of an artic at 5 to 12 MPG to that of an airliner at 6000 pounds per hour -call it 750 gallons or more of agricultural fuel -which is very cheap; for every hour of intercontinental traffic. Divide that among 200 to 300 people.
4 gallons per person/per hour plus spare for emergencies?
Now take the maths across to driving a family car to the edge of the atmosphere. If it had five people in it, how much would it cost to take them the 60 miles to the edge of space, if you put your foot down all the way?
> (Without the penalty weight, there would be more delta-v available to correct for a mistimed launch.)
I don't know anything about rocket performance but I don't think Delta Vee means what you imply. Obviously the less something weighs the quicker it can accelerate but the idea of getting a rocket to a certain stage is so that it is performing a correct balancing act for a certain part of the flight.
Maybe I have it wrong but when you reach a certain aspect you can ditch the party of the first part and get on with the act. It just happens that to put a thing in orbit you make sure the orbiting object is a certain weight and certain speed and certain distance from the heavier object. They usually mean that, "by the time you have got rid of the earlier stages."
The booster stages are not filled to overcapacity. They are just fireworks on a one way trip -and once thrown off, as long as they don't hit anyone, they are just lost to radar and recollection. All the controls, guidance and ditching gear is housed on the command part of the ship.
The first stage on a reusable is every bit as expensive as the rest of the bus as it has to have guidance systems and fail-safes as well as wheels and fuel.
The first stage of a reusable is just as expensive (actually substantially more expensive) as the rest of the bus because it has (in the case of the F9) nine stonking great engines in it that cost a small fortune each. Adding the capability to land a tail sitter is a relatively small marginal cost once you know how to do it. Learning how to do it is the expensive part.
Titan III and IV satellite launch vehicles were not "second hand", they were all new built. I worked on that program for 12 years. And the use of mild steel would have made the tanks and air frame four times heavier, resulting in a much larger impossible to transport booster.
I'm pretty sure SpaceX have done their homework on this, but perhaps someone can enlighten me on exactly why they need to recover their first stage by means of a controlled landing rather than something simpler like say some kind of flexible webbing to catch it as it falls a short distance or some kind of docking clamp system with room for error, thus reducing the odds of hard collisions.
How about hovering over the ocean, then a quick flip to splash down with the engines facing up? You'd need fins to dampen the entry so that the bottom always stays dry, and far enough above the water to avoid waves. Only the top would get wet, and that could easily be sealed.
'Nearly impossible' you say? So is what they're doing.
The remaining fuel sloshing around in the tanks might be a problem with this manoeuver worthy of a dolphin. And how do you get the gravity center far below buoyancy center so that the engines STAY in the aire?
The problem with going into seawater is the seawater. Don't get it into the engines.
Retrieving the rocket? You will have to pull the upturned rocket out and basically cut of the maybe-not-empty tank section while the house-sized stage is hanging off a crane. In open seas. Not fun.
> ...where they are designing rockets to go to and come back from.
No they are not. At the moment they are trying to design a relaunch vehicle; that is all. When they have that in their pocket and presuming they won't be bought out at bargain basement prices by Texans, they will hope to interest whatever governments are still interested in space travel. At the moment the only business they can almost guarantee to find is servicing satellites and local space tours with perhaps some freelance espionage.
> flexible webbing to catch it as it falls a short distance
The barge would have to be very large, the webbing very tough and able to withstand fire from above and the 1st stage able to sustain sudden lateral compression (plus major forces in a few points along the webbing lines) as it settles and topples
> docking clamp system with room for error
Again, a very large docking system would be needed, and the likelyhood of wrecking the first stage and the docking system both would be very high. An expensive loss..
Keep it simple! If you have a rocket engine on the object-to-land, use it!
Webbing would not guarantee a stable stop. In order for it to not be destroyed by the rocket exhaust the engine would have to cut out quite some distance above it, in the range of tens of metres or more, which means a long unpowered drop toward a hard surface and a net that will be much more likely to fail than a controlled landing. Rocket goes crack, knackered components, fuel everywhere, big boom.
To make the net robust enough to catch the rocket without tearing apart you'd have to make it of some highly elastic material that still has a very high tensile strength, which means you're then dropping your rocket several tens of metres onto a giant trampoline, which will guarantee that your rocket begins to ascend with the wrong parts pointing toward the sky and descend shortly afterwards in an unpredictable location. So, even if the net holds, you have something taller than a house and full of volatile fuel flinging itself about in random directions and making an uncontrolled landing. Assuming it doesn't explode, the engines will almost certainly be damaged beyond repair by the impact.
Your docking clamp idea suffers the same problems of height and heat and adds a shitton of unnecessary complexity as well, not to mention time and fuel use. The rocket would have to come to a stop to be grabbed by the clamp, which means it would have to hover in place, using more fuel than a controlled landing and obviating the clamp's entire purpose - if you can hover the rocket, you can land the rocket, and that means you don't need the clamp. The reason why it has to hover is simple: if the rocket is still moving, it will impart energy to the clamp, by which I mean it will damage a complex piece of machinery. That adds repair time. It adds risk. There's also the very likely outcome of the clamp damaging the rocket, which more than likely results in - again - a big boom, at which point you've not only lost your engines, but you've also destroyed your docking clamp and have to rebuild it.
This is all assuming you're on a stable surface too. On the barge, you'd either have that big net swinging around like a trebuchet or you'd have the clamp waving about like a gigantic bat just waiting to slap the returning stage out of the sky.
So that's why.
But the clamp can have a larger margin of error AND could potentially be able to clamp the rocket beyond the unstable point, which you cannot guarantee with a passive barge rolling in unexpectedly unstable seas. Also, thrusting into the clamp can be employed as a motive force, like how lever action closes the clamps of a grab arm. Use a decent diameter cone, like how mid-air refueling boom has a margin, plus with such a rig there's a greater margin of vertical velocity error versus trying to land on a rolling deck.
> AND could potentially be able to clamp the rocket beyond the unstable point,
But then parts of the rocket would be subject to big tension and shear/bending loads. So you need to make the rocket body + fuel tanks much stronger than if they purely go up and then powered vertically down. Then they experience almost entirely compression loads on axis
Use a decent diameter cone, like how mid-air refueling boom has a margin
To quote a Vulcan pilot of some repute, in-flight refuelling is like "sticking wet spaghetti up a cat's arse". You shouldn't consider it trivial...
A returning first stage already has to do all the balancing to sit on its own flame, already has to do all the braking, already has to cope with all the heat - it might as well go a little further and actually land. Anything else is simply adding complexity without really gaining anything.
But the clamp can have a larger margin of error AND could potentially be able to clamp the rocket beyond the unstable point
I think you are seriously underestimating the size of a Falcon 9 first stage. See for instance this pic: https://images.duckduckgo.com/iu/?u=http%3A%2F%2Fwww.extremetech.com%2Fwp-content%2Fuploads%2F2013%2F12%2Ffalcon-9-v1.1-new-engine-layout.jpg&f=1 and compare the size of the person with the size of the engines.
The span of the landing legs is probably around 10 meters (see for instance) http://www.spacex.com/news/2013/03/26/landing-leg. Having margin for error here means you would have to design a clamping mechanism that can capture a 20 ton (empty stage weight, probably a bit more in hot landing config) within a 30 meter area reliably and fast enough. And then you are even proposing that it should be strong enough to even adjust and compensate for misalignment. Designing such a thing would actually be LESS trivial than designing a stage to just land and stand on end on its own. KISS really does apply in these cases
A 5-6 axis stabilised grabber that can grab hold of a moving rocket and can move fast enough to deal with a rolling/pitching/heaving/surging/swaying barge and is strong enough to take the weight of the rocket is not a small thing to build and will be expensive the first time your rocket crashes into it cause something went wrong. You still have to have all the guidance and control and fuel to get the rocket to the grabber in the first place, the only thing you don't need is the legs, which would have to get replaced by something equally strong and heavy for the grabber to get hold of since you can't just grab hold of the body of the rocket. I think it's ULA who are looking at dumping the fuel tanks and recovering the engines (the expensive bit) with parachutes. That makes a hell of a lot of sense is you're not game to land a tail-sitter. But eventually the tailsitter will win.
There's a story (that may or may not be true) about the first jet airlines. The runways of the time were pretty short. In the US Boeing decided to say, 'screw the airports, we're going to build what we want to build and the airports can deal with it' and we got the 707. In the UK they went 'extending runways is expensive, so we'll compromise on performance and build something that can take off on short runways' and we got the VC-10. Turns out the airlines were more interested in their own ongoing profits than those of the airports so in the end they chose the more efficient aircraft and the airports had to pay the one-off costs to extend the runways. The parallel with spaceX is that they have decided that the one-off development cost (which is largely funded by government contracts anyway) to perfect the tail-sitter (the most efficient way to recover the first stage) was better than having something that is more expensive long term. ULA (or whoever was going to recover the engines by parachute) are going the VC-10 route and saving on capex at the expense of opex. I don't think there is any question that SpaceX will win out on that one. Boeing sold the 707 nearly 20:1 to the VC-10 and I expect SpaceX won't be too far behind.
Correction: There *never* was a compromise on performance on the VC-10 and there never was a thought about "extending runways is expensive". The VC-10 was designed for jet transport on the Imperial routes, which included hot and high airports with existing shortish strips. The VC-10 was designed for those because that's what BOAC wanted. Except they changed their minds when new board management arrived.
The 707 on the other hand was designed for airports with long runways, and Boeing didn't care much for the advanced high lift devices that the VC-10 employed (until they later realised that they'd be a bonus). They were happy to specify 'y'all better have one damn long runway at a hot-n-high airport' as a prereq for the 707, and considering how many airports were lengthening their runways anyway, that suited the 707 market perfectly.
Funny though how passengers preferred the VC-10 over the 707 for the superior (and quieter) ride... many BOAC/BA flight crews recall the vast difference in customer satisfaction from those days. The load factors on the VC-10s were a lot higher than on the 707 for that reason.
There's no such thing as a free lunch when it comes to engineering. If you want good STO or hot and high performance you're going to have to compromise something else; speed, fuel efficiency, cost, weight, reliability, whatever. Sure the VC-10 did lots of things well but if it could achieve the same cost per seat mile as the 707 there's no way the 707 would have out-sold it the way that it did. The fact that it didn't even come close to the 707's sales figures speaks volumes about its performance in the one area that really matters - running costs.
If there was never any issue with extending runways why on earth would they not have just said "extend the damn runways" and the VC-10 could have been cheaper both to buy and to operate. Every high lift device costs you weight and maintenance costs. If they could get away without them the aircraft would have been cheaper to operate.
Sure the VC-10 did lots of things well but if it could achieve the same cost per seat mile as the 707 there's no way the 707 would have out-sold it the way that it did.
You're entirely missing the historical context.
Vickers built the aircraft because its biggest customer - BOAC - said it wanted an aircraft that could fly to hot & high airfields, and use the airfields that were currently in place. That was a design requirement, and everything else stemmed from that.
Once the VC-10 was in production, BOAC changed its mind.
The 707 simply could not perform to the requirement that BOAC had made; if it had stuck to its spec, the 707 wouldn't have got a look-in, because it couldn't do the job.
The advantage of the current model is that once you have the physical mods done its mostly a software problem.
Besides the barges are mostly a secondary solution to allow them to get their hands on resuable 1st stages more regularly that just the lauches they have that are in range of an allowed land based site. They only have 1 at the moment - expect them to have more in the end.
Imagine a sliding scale of possible outcomes, with a Perfect Landing at one end, and a fireball at the other:
[Perfect Landing] - - - - - - - - - - - - - - - - - - - - - - - - - - - - - [BANG!]
Where on this scale would a giant net (or airbag) make sense?
At one end of the scale, a giant net or airbag is redundant, and at the other extreme it wouldn't help at all.
"With a barge you just sail it to the right place each time."
That's what you do with an oil rig too. Well, tow rather than sail. Deep sea oil rigs float. The just sink the floaty bits well down under the waves so the don't move up and down much. Then they use anchors or thrusters to stay on station. If SpaceX are going to go for more sea landings then they may choose to at some point to invest in something bigger and more stable. With the current crude price at such a low point, deep sea oil rigs may well be available cheap, especially any near EOL.
Don't forget those barges are huge; far bigger than they look on the photos. In fact in terms of landing area they are about the same as an oil rig and a lot more mobile.
Also SpaceX nearly achieved a controlled landing on one the last time around; it only failed because they did not have the control algorithms quite right and the launcher and it ended up with slightly too much lateral velocity which meant it toppled over. Had they tried that landing on a dry pad the result would probably have been the same.
They are trying to achieve something that the Shuttle miserably failed at - a truely re-usable launcher. With the shuttle they ended up throwing away the main tank, and after each mission they had to perform a very expensive refurb of the SRBs and of the Shuttle itself. SpaceX are trying to develop the technology that will allow them to avoid most of that and hence drop the cost of a launch significantly!
A very wide barge that size is not going to do much pitching around in normal seas. It's too big relative to the waves. That's why they feel they can land on it. If the booster does its job the barge will be there, nice and steady.
Those who suggest that a barge landing is inherently harder for the booster are incorrect IMO. The last booster hit the mark with scary precision, as well it should. The same will happen on the barge, barring any glitches like happened last time at the barge. And glitches don't just happen at sea.
But what do they say about the weather? Sure, under calm seas the barge should hold steady, but Murphy can strike, and if the barge is caught up in a sudden storm too late to scrub the mission, you got a problem, because even massive tankers get nervous around sudden storms.
Sure, under calm seas the barge should hold steady, but Murphy can strike, and if the barge is caught up in a sudden storm too late to scrub the mission
Why? You just delay the start. It's only a few minutes from start to first-stage landing. If a storm comes in that suddenly, you probably have time girl problems and you will have to sacrifice Arcadia Bay. Even Apollo missions managed to land not-too-far-from-a-carrier-group in good weather.
Now, heavy weather might become a problem as the barge heads for home. Do they strap the first stage down onto the deck?
Object supported by fluid [rocket on fast jet of gasses] landing on object supported by fluid [barge on slow moving water].
I'd assume that any control systems that deal with landing the rocket can additionally deal with and small movement of the barge without much extra effort.
Those who suggest that a barge landing is inherently harder for the booster are incorrect IMO
No - it's definitely harder, because you have some uncertainty over the attitude of the surface you're landing on. But it's not *much* harder - and as we saw the last time they tried it, they've probably got it nailed...
The liquid oxygen is only 20 C below it's boiling point, which seems like caution, not going for efficiency. In any case, LOX as it is known is the standard oxidizer for all liquid fuel rockets launched from the ground. The "fuel" part is either a highly refined hydrocarbon or liquid hydrogen. The first has more thrust, the second is more efficient because you get higher average gas velocity for a given chamber temperature.
In space the preferred fuel is hydrazine with dinitrogen tetroxide. These don't have the cooling needs of liquid oxygen.
"While the firm's upgrade cycle means the rocket will never be used for another commercial launch..."
They have to essentially stop upgrading if they're to endlessly reuse. Or (more realistically) at least align the timing of upgrades with opportunities offered by wear out. A real trade-off that wasn't immediately obvious.
It's an interesting point that needs to be kept in mind when considering such business models.
In one sense, it reminds of the promise of 'interchangeable' SIM cards, then the reality that they kept shrinking with every new phone generation or becoming 'LTE compatible'. Nine phones in our family history and not once ever able to slip an old SIM card into a new phone. Not once! Eventually bought a SIM cutter tool, with a selection of adapters. But I expect it's hopeless, something else will change.
Tangentially from the above discussion about soft landings, the aeronautics are fixed, so the challenge is handling the massive stresses caused by gravity - twice - which are greater on landing than on take-off - is that correct? Which more than doubles the wear (to put it mildly) on the equipment. Why fight gravity twice, and use so much energy, when parachutes have been used for decades to drop the personnel module "gently" on to Earth's surface. Or even several parachutes for separate parts. No doubt the engineers will explain that a parachute is too unpredictable as are weather patterns etc but why not have both options ready?
What Musk and his team are doing is brilliant and essential, and I would not want to have 2 different modes of propulsion for, say, a quick trip to the shops - hey how about a large elastic band on the back of my car to tug me back home in an eco-friendly fashion - but I think there has to be an ingenious way to avoid the huge expenditure of power than we have grown accustomed to with rocketry.
Hydrogen balloon stored in the nose? Or hot air - one thing a rocket has is plenty of heat. After all, what is the hurry to bring the thing down again?
Any smokers ready with the fag packet ready to make notes on the back of?
It's difficult to steer parachutes precisely with a big rocket hanging off the end.
With the Apollo modules they were aiming for an ocean. It's a lot harder to open a parachute 100km up and steer to a barge or landing pad.
The only use for a parachute would be to lose some velocity at higher altitude and then release it to steer back to the pad, but the mass of fuel to lift the extra mass of the parachute is likely to be higher than the margin of fuel needed to slow it by the same amount
There is also the problem of re-entry at Mach 10, a heat resistant "ballute" would be needed for that. And a drogue chute to slow down in the transonic range. So now you have three different parachute systems that would probably weigh just as much as the rocket fuel used for re-entry and landing.
.....the firm's upgrade cycle means the rocket will never be used for another commercial launch.....
And there's the "commercial" bit. If you make things durable, reusable and reliable, how do you sell more? Planned obsolescence.
You can tell these things are built by someone in the car business......
You are taking the piss yes?
They're selling a service (a launch) not a product (a rocket).
Therefore it is very much in their interest to keep costs low and to make things durable. These things will have planned obsolescence indeed, but in the order of tens of launches. You can plan for and around that.
SSMEs were lifed at something like 50 launches (I forget the number of minutes of use).
The Nazi used that kind of unstable highly dangerous rocket fuel because they were desperate.
We had this stupid shit in the last thread. Fuck off, troll, die under a bridge.
For reference: Wehrmacht used Alcohol (from potatoes) + LOX. Here we are using Kero + LOX. None of these is "unstable".
ME-163, the rocket plane. It used hydrazine. Quite a few went "boom" on launch.
More of them exploded on landing - the pilot had to run them out of fuel before gliding down, and then land on a skid (the wheels it used for launch were not fixed - they fell away at lift-off). Attempt to land with even a teaspoon of fuel, and the whole lot went up...
Winkle Brown was sent out at the end of the war to fly a captured one. He describes the ME163A as "a very easy and pleasant aircraft to fly as a glider". Under power, the ME163B "felt like being in charge of a runaway train".
The man was a nutcase. I'm hoping to get tickets to a talk he's giving in April :-)
You appear to be confusing rocketry with airships. The Zeppelins of old used hydrogen instead of helium, because the US had a monopoly on the latter. Hence the Hindenburg disaster.
Rocketry was very much in its infancy at the time of WW2, but given that all rockets are essentially gigantic fireworks, "unstable" goes with the territory, and always has done. As long as we stick to rocketry, there will always be an unexpected bang every so often. The goal is to keep those bangs as far apart as is humanly possible, but there's a limit to how safe these things can get.
Besides, all new transport technologies go through a long period of incremental refinements and improvements before people see them as truly safe. It took many decades for the routine adoption of fixed block signalling on the railways, and there are a hell of a lot more of those than there are rockets.
The DeHavilland Comet's inadvertent discovery of the problem of metal fatigue is another example of how innovations in a technology can throw up brand new problems that require solutions. Reusable rockets are unlikely to be an exception. This is why the likes of SpaceX should be encouraged: if nobody tries anything new, we'll never learn anything new.
Re the Hindenburg - I do wonder whether H2 is not the ideal solution - with an inert gas enclosure and detectors. The Hindenburg was leaking gas at a rate the would have dropped it into the sea quite quickly so He would not have made it much safer.
H2 would be so much cheaper - and far more buoyant, and more importantly you can make h2 impermeable and inflammable membranes but not impermeable for He.
I should add I discussed this with someone who flew as an engineer on the R103 and he was pretty much convinced that by the time H2 would become a problem its really a question of how hard you hit the ground irrelevant of what gas you were using.
Now the greedy 1% force contract workers to work with the stuff with no pension, no health benefits and little to no safety regulations.
SpaceX has great retirement and health benefits. It also regularly hires environmental, health, and safety personnel - the positions were open when I last sniffed around their jobs website.
Safety regulations are supplied at great length from the US's OSHA, EPA, and state and local regulatory agencies, which federal contractors like SpaceX cannot legally escape. It can try to dodge them and wave lawyers at problems, but the costs of having a workplace injury investigation by a regulator turn up nonconformances is far higher than running a proper safety program. In the case of a federal contractor like SpaceX, it can mean losing federal (i.e., NASA) contracts after several injuries and no sign of safety improvements. And in the US, the only lawyers who advertise more frequently than workplace injury lawyers are medical malpractice lawyers.
Having its main plant in California means SpaceX gets a double helping of workplace safety and environmental regulations, along with higher wages to match California's elevated cost of living. They must've gotten some great tax breaks to pick California over Washington or Florida.
> Falcon Heavy the most powerful operational rocket in the world can launch over 53 metric tons. Composed of three Falcon 9 nine-engine cores generating 4.5 million pounds of thrust, equal to nearly eighteen 747 aircraft.
It is probably underpowered by a factor of two. It needs to have a manned crew with at least two people and a set of wings. A major redesign of aircraft wings need to be taken from the concept of extending them, after launch, to the shape of the underside that allows them to fit snugly at launch.
I get the impression the firm is making the mistake that the RAF made when it moved to mono winged planes. It decided to concentrate on the mini,um weight possible. It then ended up concentrating on optimising a massively underpowered engine for the next ten years.
With long distance 20:20 vision, North American Aviation came along in 1940 and designed and produced in less than 12 months what it took SuperMarine 12 years to never accomplish. A Spitfire that could escort bombers to Germany and back.
"With long distance 20:20 vision, North American Aviation came along in 1940 and designed and produced in less than 12 months what it took SuperMarine 12 years to never accomplish."
I think that's because Supermarine were trying to accomplish something different. The Spitfire was designed as a fighter, the Mustang was intended to replace the P40 which was primarily used for ground attack. In trials the Mustang I was quicker at 15,000ft, but the Spitfire V was quicker at 20,000ft, furthermore the Mustang took 11 minutes to climb to 20,000ft, while the Spitfire V took 7 minutes, which is a very big deal for a fighter.
Nonetheless NAA did pull off an engineering marvel in 120 days, and the Mustang was a superb aeroplane with or without a Merlin in it. :)
The spitfire was never designed as a bomber escort. Its purpose from the very start was as an interceptor, a role that it fulfilled admirably (though the Hurricane outperformed it in the interception of German bombers and their escorting heavy fighters). RAF doctrine for the early part of world war 2 did not call for mass-escorted daytime bomber fleets, but lone, unescorted, raiders. Because of this, bomber escort wasn't considered necessary until well into the war, and by the time any serious thought was being given to purpose-built heavy fighters the role was already being rendered largely obsolete by technological advances, doctrinal changes and the fact that Germany had been driven back within her own borders - meaning that escorts didn't have to fly as far in the first place.
Musk is laughing all the way to the bank as another SpaceX blows itself up after landing. It's a good thing that U.S. tax payers are underwriting all of Musk's businesses as they can't make a profit on their own and are all currently losing money. So let's just use a few hundred million of U.S. tax payer money to help Elon with his dubious business endeavors?
Musk is laughing all the way to the bank as another SpaceX blows itself up after landing.
Which is just like every other rocket in service: Long March, Soyuz, Ariane V, Delta IV, Atlas V, Antares - they all throw their first stage away. Musk has the only operating commercial launcher that is attempting to recover the first stage and when recovery fails, well, that's no different than what all the other launchers except for the extra engineering data.
Biting the hand that feeds IT © 1998–2019