71–80 of 82 posts
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In Canada? No cost at all.
Actually, that's an interesting question: How much more efficient transportation-wise is ending prices in .95 and transporting nickels?
fascinating!
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Don't know if this comes from SpaceX or SES. But Musk is definitely good at coming up with 'interesting' new terms. See RUD - Rapid Unscheduled Disassembly (aka Crash).
RUD has been a rocket engineering term for decades, same as e.g. lithobraking (slowing your spacecraft down by smashing it into the ground)
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I feel like there is a [Citation Needed] for that Wikipedia quote. All existing landers used an aeroshell and parachute sequence, but that doesn't mean it's impossible to land with just Rockets. The aeroshell/parachute method is used because it allows landers to come straight in from a Hoffman transfer orbit, bleed off all that extra speed and land with the least amount of fuel required. But it's way to risky for a m…
In either case they use heat shields so the post heat shield second stage will be at the same velocity. Mars has ~0.6% of earths atmosphere, and ~40% the gravity so a heat shields going to hit terminal velocity at ~66 times earths terminal velocity. This only get's worse as you scale up due to mass vs surface area issues. Parachute can bleed off 80+% of that speed for little additional weight unlike wings which would…
> Parachute can bleed off 80+% of that speed for little additional weight unlike wings which would need to survive supersonic retry heating making parachutes a no brainier.
Sure, Parachutes make a lot of sense for a one way trip.
But Parachutes are a consumable, one which would be really hard to manufacture on Mars (compared to rocket fuel, which just requires water, carbon dioxide and electricity). Also the size of the parachute gets ridiculously large for larger spacecraft.
If you are planning to make a rocket which shuttles people or cargo (or fuel) between Mars' surface and low Mars orbit, then it makes a whole lot more sense to just manufacture the extra fuel on Mars rather than trying to manufacture parachutes on Mars or shipping extra parachutes to Mars.
As for wings, you don't really want to use them for the subsonic phase. I'm not really sure how viable the idea is, but you want to use them to prolong your trip through the upper atmosphere, where the atmosphere is thinner. This allows you to stretch out all that supersonic atmospheric heating over a much longer time period, at a much slower rate than what your heat shield can dissipate.
Retractable or reconfigurable wings might be needed so you can maximize lift in the upper atmosphere then minimise drag through the supersonic to subsonic transition.
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In either case they use heat shields so the post heat shield second stage will be at the same velocity. Mars has ~0.6% of earths atmosphere, and ~40% the gravity so a heat shields going to hit terminal velocity at ~66 times earths terminal velocity. This only get's worse as you scale up due to mass vs surface area issues. Parachute can bleed off 80+% of that speed for little additional weight unlike wings which would…
Starting from a circular Mars orbit rather than Hoffman transfer would put their initial entry speed closer to 7000mph. > Parachute can bleed off 80+% of that speed for little additional weight unlike wings which would need to survive supersonic retry heating making parachutes a no brainier. Sure, Parachutes make a lot of sense for a one way trip. But Parachutes are a consumable, one which would be really hard to man…
I wonder if they'll really save money right away doing this. I imagine they'll spend a lot on inspections and getting things 100% right. Either way, it's an amazing achievement.
I think I've read that the cost of an empty Falcon 9 first stage is somewhere $10 million. They would have to spend a lot on inspections in order to not save a lot of money. IMHO, a lot of the skepticism I've previously read about SpaceX's reusability program is just inherited from the Space Shuttle program. I.e. ""if the US government can't do it, how can a small-ish private company do it"?
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The experience of the Shuttle program demonstrated that taking off like a rocket and landing like a plane has a lot of problems that make it not as great as you might think. The wings, heat shield, etc are all pretty heavy - notice that the shuttle required two whole extra rockets and a disposable fuel tank to make it to orbit - and the heat shield required for landing like a plane turned out to be a huge problem (se…
Note that the Space Shuttle only needs a heat shield because it's returning from orbital velocity. The Falcon 9 first stage is suborbital.
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Better than "Certified Pre-Owned Rocket" :-) I agree with the folks who have tweeted they should start adding launch "check marks" to the paint but that assumes that they will launch it w/recovery and then do it again.
The title of this article should have been "Used Rocket".
I wonder if they'll really save money right away doing this. I imagine they'll spend a lot on inspections and getting things 100% right. Either way, it's an amazing achievement.
There is a bigger question which was asked in the Economist this week ( http://www.economist.com/technology-quarterly/2016-25-08/spa... ), which is can SpaceX create a big enough market where they can realize the savings of reusability? Right now satellites cost more than the price of the rocket, so if you shave off $10 million on a launch that's pretty much a drop in the bucket compared to the overall price. This is…
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I also wonder this! CRS-8 was launched on the 8th of April this year, so given that the launch of SES-10 is slated for Q4 2016, that means there's like, 6/7/8 months for the turnaround. But I'm hopeful that we'll see an assembly line of rockets landing, being inspected, and being launched, sometime in the future :)
The delay between landing and relaunch has less to do with refurb on this particular booster, than with the series of tests that they're doing on other returned boosters to convince both the customers and their insurance companies that they generally come back in re-flyable condition, which have been happening on and off for months. Among other things, a different booster has been put through at least three full-leng…
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The experience of the Shuttle program demonstrated that taking off like a rocket and landing like a plane has a lot of problems that make it not as great as you might think. The wings, heat shield, etc are all pretty heavy - notice that the shuttle required two whole extra rockets and a disposable fuel tank to make it to orbit - and the heat shield required for landing like a plane turned out to be a huge problem (se…
Note that the Space Shuttle only needs a heat shield because it's returning from orbital velocity. The Falcon 9 first stage is suborbital.