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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!
Here is a great post from Elon with background on tonight's launch: http://www.spacex.com/news/201...
Look, I just made you read my signature.
No one knows, this booster will probably be dissected to see just where the wear/tear occurs. After that, SpaceX will probably have to mod/update future boosters to ensure it can fly multiple times. It may be that the cost to mod/upgrade/refurbish will be more expensive than just rebuilding, but we'll have to see.
Yeah, but the New Shepherd was launched essentially straight up and came straight back down, all in the middle of the desert. Falcon 9, going orbital and coming back near population, had significantly higher range safety considerations.
No one knows, this booster will probably be dissected to see just where the wear/tear occurs. After that, SpaceX will probably have to mod/update future boosters to ensure it can fly multiple times. It may be that the cost to mod/upgrade/refurbish will be more expensive than just rebuilding, but we'll have to see.
Actually I think SpaceX got a pretty good idea, they've tested burn/reignite cycles staticly and found the engines can be reused 40 times, since that's likely to be the most expensive component that'll probably be their target. And if the reliability stays high there's a good chance that 1 in 40 launches will require a full burn, no reuse booster so there's no waste. They've said the first stage is roughly 70% of the cost and just refueling the rocket costs about 0.3% of a full launch, so the cost savings potential is huge.
Live today, because you never know what tomorrow brings
Insurance is 10%, paid by the payload owner. Fuel is 0.3%. 70% is the 1st stage.
This is huge.
Just to be clear, the Falcon 9 first stage went nowhere close to going orbital - altitude accounts for only about 5% of the energy difference between orbit and the Earth's surface, the rest is kinetic energy, or speed. And Stage 1 only got up to what, 5800km/h? That's only 1.6km/s. Meanwhile Low Earth Orbit velocity is 7.8km/s. Stage 1 barely reached 20% of the necessary speed, which translates to barely 4% of the necessary kinetic energy. It's job is mostly just to get above the efficiency-robbing atmosphere and give Stage 2 as much of a boost as its fuel budget allows. Most of its energy is wasted fighting aerodynamic drag and providing a support force against gravity. It's Stage 2 that can really pour on the speed, and it did, reaching 7.22m/s at an altitude of 630km (orbital speed falls with increasing altitude)
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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.
I think this is much more relevant actually: https://youtu.be/O5bTbVbe4e4?t...