Live data from Hacker News

SpaceX launch webcast: Orbcomm-2 Mission [video]

spacex.com

111–120 of 444 posts

Re: SpaceX launch webcast: Orbcomm-2 Mission [video]

#111
post #9

They really poured on the PR, lots of people going "Hi, I'm lead mechanical engineer for this or that" and then delivering a perfect speech that would have taken a lot of prectice to deliver to a camera as smoothly like that. It's nice to see a lot of the lessons from media training. :D

Earlier today Tim Urban mentioned in his post that there were a few dry runs, even including high-fives.

Re: SpaceX launch webcast: Orbcomm-2 Mission [video]

#112
post #102

Earlier quoted context omitted.

He knows, but the public doesn't and he can say what he wants to twist the perception in his favor and give the impression that the feats were equally challenging. Not to remove any merit to Blue Origin's achievement, but it's nowhere near what SpaceX just pulled off.

The public that cares about this achievement (or Blue Origin's) likely understands the difference.

As does the public that might decide to host a bunch of stuff with AWS (or not). Really bad move on Bezos' part, not everything is economics.

Re: SpaceX launch webcast: Orbcomm-2 Mission [video]

#113

Earlier quoted context omitted.

Maybe there was a secondary thruster somewhere to provide some separation. I went back and recorded the release speed (km/hr), altitude (km) for each drop: 25960 626 25954 627 25950 628 25944 630 25937 632 25935 632 A circular orbit at that height is about 29000 km around; 25 km/hour of difference between release 1 and 6 would give them a separation of 6 degrees longitude/day, or ~50 days until the faster satellites…

The satellites themselves usually have small thrusters but I'm not sure what kind of orbital change the can effect, usually they are there for detailed maneuvering and to boost the satellite to a slightly higher orbit as it decays. When it runs out of fuel it dies so you'd try to use as little of that as possible during launch.

>A hydrazine propulsion system is installed on the spacecraft for orbit adjustment maneuvers and orbit maintenance providing a delta-v budget of more than 100 meters per second for each satellite.

>Because OG2 satellites are launched in groups of several spacecraft, they require propulsion systems to place the satellite into different nodal planes to begin operations.

There's the answer, courtesy Orbcomm.

Re: SpaceX launch webcast: Orbcomm-2 Mission [video]

#114

I live on the south end of Merritt Island, FL (~25 miles from the launch complex) and the sudden noise reminded me I wanted to watch this! For a second, based on the sound, I thought it may have catastrophically failed until I caught the live stream and people cheering. Are there any replay videos?

It's absolutely insane how loud the rockets are. Spend about 15 minutes of your time and just search YouTube for test firings - you won't regret it.

Re: SpaceX launch webcast: Orbcomm-2 Mission [video]

#115
post #107

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…

I think you underestimate the degree of difficulty between these two achievements. They are both very impressive but what SpaceX just did is many times more difficult than what Blue Origin did.

Re: SpaceX launch webcast: Orbcomm-2 Mission [video]

#116
post #67

"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

Dear Mr Bezos: people will care about your rocket when you offer free shipping to space for Prime customers

I think his remark was an ugly bit of ego, but I care about any endeavor to develop space travel technology.

Re: SpaceX launch webcast: Orbcomm-2 Mission [video]

#117
post #107

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…

New Shepard is able to make several compromises that make landing _much_ easier. New Shepard doesn't have to get anywhere close to orbital velocity, so it can use a far less powerful engine. That means it can throttle down far enough to hover. That is a _huge_ advantage over Falcon 9, which must time the landing burn perfectly to hit 0 velocity at the exact moment it touches the ground.

They're in the same club like a general aviation pilot landing his Piper Cub on a giant runway and a navy pilot landing his F-14 on a carrier are "in the same club". While it's technically true, pointing it out would be pretty tacky...

Re: SpaceX launch webcast: Orbcomm-2 Mission [video]

#118

Earlier quoted context omitted.

The satellites themselves usually have small thrusters but I'm not sure what kind of orbital change the can effect, usually they are there for detailed maneuvering and to boost the satellite to a slightly higher orbit as it decays. When it runs out of fuel it dies so you'd try to use as little of that as possible during launch.

>A hydrazine propulsion system is installed on the spacecraft for orbit adjustment maneuvers and orbit maintenance providing a delta-v budget of more than 100 meters per second for each satellite. >Because OG2 satellites are launched in groups of several spacecraft, they require propulsion systems to place the satellite into different nodal planes to begin operations. There's the answer, courtesy Orbcomm.

Neat :) So they do their own placement. Nasty stuff, hydrazine. F16's use it as emergency fuel.

Re: SpaceX launch webcast: Orbcomm-2 Mission [video]

#119
post #50

I must have missed it, but can anyone explain why Orbcomm wants 11 satellites in the same orbit? The stage 2 engine isn't firing in between letting the satellites go.

Leo, they are so low they don't cover a whole lot of territory. The oribits may be at slightly different altitudes simply because of the inertia of the second stage, I really should have monitored that altitude indicator during the releases, were they identical?

Pretty sure both altitude and speed were constant during the satellite deployment phase.

Re: SpaceX launch webcast: Orbcomm-2 Mission [video]

#120

Earlier quoted context omitted.

Leo, they are so low they don't cover a whole lot of territory. The oribits may be at slightly different altitudes simply because of the inertia of the second stage, I really should have monitored that altitude indicator during the releases, were they identical?

Maybe there was a secondary thruster somewhere to provide some separation. I went back and recorded the release speed (km/hr), altitude (km) for each drop: 25960 626 25954 627 25950 628 25944 630 25937 632 25935 632 A circular orbit at that height is about 29000 km around; 25 km/hour of difference between release 1 and 6 would give them a separation of 6 degrees longitude/day, or ~50 days until the faster satellites…

You'll notice that the speed decreases as the altitude increases. That's not maneuvering, that's just an elliptical orbit. There is no actual speed or altitude difference between the various releases, that's just the whole group coasting slightly uphill. Separation will be done by maneuvering the satellites afterwards.
Post reply on HN