181–190 of 444 posts
"Congrats @SpaceX on landing Falcon's suborbital booster stage. Welcome to the club!" Oy... someone needs to tell Bezos it's a whole different scale than what he did. https://twitter.com/JeffBezos/status/679116636310360067
EDIT: Here's a video that compares/contrasts: https://www.youtube.com/watch?v=b8c7RUjNFDo
Earlier quoted context omitted.
A follow-up question to that would be - how much $$ do you save per launch by reusing the first stage?
Depends on the procedure they ultimately decided to use for the prep. Originally the the shuttle main engines had to be taken apart, with every part inspected before the next launch. If they have to do something like that there's not much point. But if they can get it to point where it's a matter of gassing it up for the next flight, that's a huge savings. Fuel is a few hundred grand for a rocket that costs sixty mil…
SpaceX seems to build things a lot more low-key. They don't use fancy propellants, their engines aren't particularly efficient, and overall they seem to go more for robustness and simplicity.
(Simplicity doesn't really apply for a crazy-ass landing scheme. But aside from that....)
Obviously it remains to be seen, but I think it's likely to be a lot more gas-and-go than the Shuttle.
Earlier quoted context omitted.
"Welcome to the club"? Wow, that was classless. What Blue Origin did was impressive, but it was utterly trivial compared to what just happened with this flight.
Really, 'classless'? The achievement is landing a space-capable booster vertically, after an actual mission above 100km, which can then be reused. And, Blue Origin managed that first, no two ways about it. I think it's probably pretty classless to imply that what Blue Origin managed to do was 'trivial'. Just because SpaceX is the current hacker's favourite, doesn't mean you have to downplay everyone else. I think Mus…
Who said that was the achievement? What is important about that achievement?
The important achievement is dramatically reducing the cost of sending things into space (such that they will stay there). SpaceX's rockets achieve this, Blue Origin's don't even attempt to be in that league. Using your Everest analogy, Blue Origin was the first to climb some lesser peak nobody cared that much about (still, nice job), then SpaceX climbed Everest, and Bezos said "welcome to the tall mountain club."
So now how do they secure the booster they landed? Do they have some kind of truck mounted gantry they move into position? There didn't seem to be anything like that near the landing pad. They may want to let the engines cool and any excess propellant boil off before they move in, but they have to have something to hold it, tilt it down to horizontal, and carry it off.
Earlier quoted context omitted.
Lots. There's really not a lot of costs that can add up for reuse of these stages. It'll require a bit of cleaning up, a few new bits and pieces replaced and added, and a lot of inspection work. But most of the cost of the stage is in manufacturing the engines and tanks, so it should add up to enormous savings, even if it's relatively costly to reuse each stage compared to the theoretical limits. Edit: the flip-side…
And with the amount of redundancy built in they might even go with 'acceptable loss' in terms of engines that cut out early in flight. Which makes you wonder how many engines they could lose and still complete a mission.
Reusability makes it more interesting. There's a lot of extra fuel on board now which could be used to make up for lost engines if you're willing to throw away the first stage.
"Congrats @SpaceX on landing Falcon's suborbital booster stage. Welcome to the club!" Oy... someone needs to tell Bezos it's a whole different scale than what he did. https://twitter.com/JeffBezos/status/679116636310360067
Can someone explain exactly what Bezos/Blue Origin did, and how it is different than what SpaceX did? EDIT: Here's a video that compares/contrasts: https://www.youtube.com/watch?v=b8c7RUjNFDo
- SpaceX rocket goes really fast horizontally; it has to flip around and boost back, and then correct from horizontal to vertical orientation.
- Falcon 9 is an actual space launch system; it has different (i.e. much stricter) engineering constraints than a suborbital rocket. In particular, this affects the engine design.
- Most importantly, the first stage of Falcon 9 does what's known as "suicide burn" - it waits until the last possible second to fire back the engine, so that it reaches exactly zero velocity relative to the ground as it touches down. It does so, because it can't hover - even the single one one of the nine Merlin engines, throttled down to minimum, still generates more thrust than the now almost empty booster weights. On the other hand, Blue Origin's rocket can slow down to a hover, and then take its time to stabilize and land.
Earlier quoted context omitted.
I guess it's like Hilary and Tenzing being the first to climb Everest, and then someone else (can't remember who it was) coming along and doing it without supplementary oxygen. Just because that was harder doesn't detract from the fact that Hilary and Tenzing were first and anyone else is just joining the ever-growing club of Everest summiters. Now, if you want to invent an extra category of 'first VTOL landing for a…
Ok, in that case, SpaceX was 'first' to land a VTOL rocket with Grasshopper... unless you want to invent an extra category of "first VTOL landing for a ground launched rocket that crossed an arbitrary altitude threshold before returning at terminal velocity".
Landing the F9 stage is not even the first "reusable part of an orbital launch system", the Space Shuttle was that. It just wasn't very effective in terms of lowering the cost, which is where F9's true claim of being a game changer is going to be. Let's hope that pans out.
Earlier quoted context omitted.
http://www.space.com/21386-spacex-reusable-rockets-cost.html ~75%.
The money quote: > Musk said that a rocket's first stage accounts for three-quarters of its total price tag, so a vehicle with a reusable first stage can be produced at far less cost — assuming the hardware is fully and rapidly reusable. ~75% savings seems like a "best case scenario" number.
Not sure if the "USA" chant after the first stage landed was warranted.
There's no foreign employees in SpaceX due to ITAR restrictions.
I can't seem to locate the exact time, but this is most likely the interview where Elon Musk mentioned it: https://www.youtube.com/watch?v=xIDoTKMqwT4