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(Spaceflight Now)   Let's see if we can defeat Scrubtober: Starlink launch rescheduled for 11:31 AM ET. This time they'll try to land the booster AND catch the fairings   (spaceflightnow.com) divider line
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303 clicks; posted to Discussion » and STEM » on 24 Oct 2020 at 11:00 AM (5 weeks ago)   |   Favorite    |   share:  Share on Twitter share via Email Share on Facebook



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2020-10-24 1:58:25 AM  
Godspeed, SpaceX.  Good luck with this mission and with the upcoming Starship test flight.
 
2020-10-24 11:05:49 AM  
Really enjoying how routine these have become. Pretty excited for the Falcon Heavy launch next spring where they will need both drone-ships for the boosters.
 
2020-10-24 11:12:35 AM  
Ms Tree and Ms Chief are still in port getting damage repaired from the last catches, so no catch attempt.

Navigator /  Searcher have been deployed to recover the fairings, but won't get there until some time after the fairings hit the water.

I'm actually surprised they didn't delay until the recovery ships were in position.
 
2020-10-24 11:17:24 AM  
What the hell!  It's about 5 - 15 minutes till launch, and no SpaceX.com/webcast.  Has it been scrubbed again?
 
2020-10-24 11:18:52 AM  
OK, the link in the FARK thread is getting to a webcast, but 'SpaceX.com/webcast is not.  WTF?
 
2020-10-24 11:23:13 AM  

Nicholas D. Wolfwood: OK, the link in the FARK thread is getting to a webcast, but 'SpaceX.com/webcast is not.  WTF?


No idea why the SpaceX webcast link isn't working.  I'm watching EveryDayAstronaut's feed, and he has the SpaceX webcast up.
 
2020-10-24 11:24:50 AM  
Number 100? Impressively routine.
 
2020-10-24 11:27:24 AM  
I wonder when StarLink internet be available in the lower 48 states?
It wouldn't be something I'd have at home. But I'd certainly get a 'to go' package for a week when doing some camping, cabin or RV.
 
2020-10-24 11:27:29 AM  

edmo: Number 100? Impressively routine.


Yep.  A couple of 'oopses', but they were fairly early in the vehicle's history.  Every success in the books just improves the record.

There's no substitute for experience.

Glad they're already able to put Starlink to work.
 
2020-10-24 11:28:24 AM  

optikeye: I wonder when StarLink internet be available in the lower 48 states?
It wouldn't be something I'd have at home. But I'd certainly get a 'to go' package for a week when doing some camping, cabin or RV.


They're about to install it for a school district in Texas, so...
 
2020-10-24 11:31:44 AM  
Good luck, we're all counting on you
 
2020-10-24 11:31:45 AM  
YEEE-HAW!  AWAY WE GO-GO-GO!!!

FINALLY!
 
2020-10-24 11:32:49 AM  
Tore a hole in that cloud...
 
2020-10-24 11:34:41 AM  
And stage sep.
 
2020-10-24 11:35:27 AM  
And the eggshell has cracked open.
 
2020-10-24 11:39:14 AM  

clear_prop: Ms Tree and Ms Chief are still in port getting damage repaired from the last catches, so no catch attempt.

Navigator /  Searcher have been deployed to recover the fairings, but won't get there until some time after the fairings hit the water.

I'm actually surprised they didn't delay until the recovery ships were in position.


Ms Chief is underway according to the Space-X feed
 
2020-10-24 11:40:03 AM  
Man, ol' JRTI is looking a bit worn.
 
2020-10-24 11:40:14 AM  
Once again, they stick the landing!
 
2020-10-24 11:40:52 AM  
The Leaning Tower of Falcon.  (Crooked Camera.)
 
2020-10-24 11:41:29 AM  
So, this is *only* the third flight for this booster.  Isn't Junior cute!
 
2020-10-24 11:41:38 AM  
And a good parking orbit.  Suck it, Scrubtober.
 
2020-10-24 11:41:48 AM  
T+plus 5 minutes. The second stage is now flying at an altitude of around 94 miles, or 152 kilometers. The Merlin engine is producing more than 200,000 pounds of thrust.

Do they still need that much thrust after leaving Earth's atmosphere? Seems like a waste of fuel.

Also, YAY!
 
2020-10-24 11:45:07 AM  

abhorrent1: T+plus 5 minutes. The second stage is now flying at an altitude of around 94 miles, or 152 kilometers. The Merlin engine is producing more than 200,000 pounds of thrust.

Do they still need that much thrust after leaving Earth's atmosphere? Seems like a waste of fuel.

Also, YAY!


Well, it's better than "Oh Shait, should we call Miami?"
 
2020-10-24 11:49:03 AM  
Nominal parking orbit insertion!
 
2020-10-24 11:49:50 AM  

Peach_Fuz: Nominal parking orbit insertion!


that's what he said.
 
2020-10-24 11:57:34 AM  

abhorrent1: T+plus 5 minutes. The second stage is now flying at an altitude of around 94 miles, or 152 kilometers. The Merlin engine is producing more than 200,000 pounds of thrust.

Do they still need that much thrust after leaving Earth's atmosphere? Seems like a waste of fuel.

Also, YAY!


The only way it wastes fuel is that the stage is carrying a heavier engine than necessary, if you only look at physics.  These things don't get less efficient at full throttle like piston engines do.  Generally the opposite, in fact -- the harder you run them, the better they perform, right up until they blow up.

But the savings in fuel (and tank size) that you'd get from using a smaller upper stage engine have to be weighed against the complexity of using a completely different engine than the nine on the first stage.  Designing, testing, and manufacturing another type of engine would be a matter of tens of millions of dollars up front plus ongoing costs for the second manufacturing line, and it would save maybe a few tens of thousands per flight in fuel and metal (mostly metal).  You'd also lose the reliability benefits of having thousands of engine-flights worth of data about that upper stage engine.  It's harder to put a price tag on that, but it's quite valuable.
 
2020-10-24 11:57:49 AM  

Nicholas D. Wolfwood: So, this is *only* the third flight for this booster.  Isn't Junior cute!


Fastest to get to third flight and the fastest turnaround from landing to another launch according stats compiled by the Everyday Astronaut.
 
2020-10-24 12:06:19 PM  

abhorrent1: T+plus 5 minutes. The second stage is now flying at an altitude of around 94 miles, or 152 kilometers. The Merlin engine is producing more than 200,000 pounds of thrust.

Do they still need that much thrust after leaving Earth's atmosphere? Seems like a waste of fuel.

Also, YAY!


Yeah The Falcon second stage is kind of crap from a performance perspective but that's because SpaceX optimized for cost instead.

The build only one type of engine and have only one type of fuel.  They basically brute force there way to orbit but do it cheaper than the competition.
 
2020-10-24 12:06:32 PM  

abhorrent1: T+plus 5 minutes. The second stage is now flying at an altitude of around 94 miles, or 152 kilometers. The Merlin engine is producing more than 200,000 pounds of thrust.

Do they still need that much thrust after leaving Earth's atmosphere? Seems like a waste of fuel.

Also, YAY!


Yes, yes, they really do.

Orbital Mechanics is all about the vectors (relative direction of travel and relative velocity), and very precise timing (not only having the right vector, but having it at the exact necessary point in time).

The second stage and payload are falling back to Earth under the influence of Earth's gravity.  No technology we have can prevent that.

What we *can* do is use the rocket engines to a) get the payload high enough that atmosphere won't slow it down due to drag, and b) add enough *SIDEWAYS* velocity so that, as the payload falls back toward Earth, the sideways component makes it MISS.

In effect, the payload falls *around* the Earth.  To put it in Douglas Adams' terms, the secret of an orbit is to throw yourself at the Earth, and miss.

Now, Earth is pretty big.  To miss a target like that when you're falling, you need one hell of a lot of sideways vector - roughly 5 miles per second.  And that's what that second stage engine is doing, boosting all that time after they're mostly above the atmosphere.

There's a lot more to it, but that's mostly refinement, ruffles and flourishes.  This kinda covers the essential basics.

Look up an old nonfiction book by Arthur C. Clarke if you want the math - 'Interplanetary Flight'.
 
2020-10-24 12:14:41 PM  
Here's the updated list of successful SpaceX Missions.  I've realigned the dates and order for upcoming flights.  Even if no more missions are added (and we fully expect more Starlink missions to be added as the year goes on), they are on pace to set a new record this year (28 launches), eclipsing the pace of 2018.

Year  # flown  Milestones
2006 - 1 - Falcon 1
2007 - 1
2008 - 2
2009 - 1
2010 - 2 - First Falcon 9, June 4, 2010
2011 - 0
2012 - 2 - First private spaceship (Dragon) to visit ISS
2013 - 3 - Falcon 9 v1.1
2014 - 6
2015 - 6 - Falcon 9 'Full Thrust' and first booster landing
2016 - 8
2017 - 18 - First Launch and Recovery of a reused booster / Dragon
2018 - 21 - First Falcon Heavy, First F9 Block 5, First booster with 3 flights
2019 - 13 - Successful Crew Dragon Demo 1; 1st Paying Falcon Heavy; Starlink; 1 F9 flies 4 times

2020:
1    01/06/2020    Falcon 9 - Starlink 2
2    01/19/2020    Falcon 9 - Successful Crew Dragon In-Flight Abort Test
3    01/29/2020    Falcon 9 - Starlink 3
4    02/17/2020    Falcon 9 - Starlink 4
5    03/06/2020    Falcon 9 - CRS 20
6    03/18/2020    Falcon 9 - Starlink 5 - first 'fifth flight' for a booster
7    04/22/2020    Falcon 9 - Starlink 6
8    05/30/2020    Falcon 9 - Crew Dragon Demo 2 launch, docking at ISS next day
9    06/03/2020    Falcon 9 - Starlink 7
10  06/13/2020    Falcon 9 - Starlink 8 / SkySats 16-18
11  06/30/2020    Falcon 9 - GPS 3 SV03
12  07/20/2020    Falcon 9 - Anasis 2
--   08/01/2020    ----------- - Crew Dragon Demo-2 undocking, splashdown next day
--   08/04/2020    Starship SN5 150 meter hop test
13  08/07/2020    Falcon 9 - Starlink 9 / BlackSky Global 5 & 6
14  08/18/2020    Falcon 9 - Starlink 10 / SkySats 19 - 21
15  08/30/2020    Falcon 9 - Saocom 1B
16  09/03/2020    Falcon 9 - Starlink 11
17  10/06/2020    Falcon 9 - Starlink 12
18  10/18/2020    Falcon 9 - Starlink 13
19  10/24/2020    Falcon 9 - Starlink 14

Upcoming Flights:
10/??/2020    Falcon 9 - NROL-108
??/??/2020    Falcon 9 - GPS 3 SV04
11/??/2020    Falcon 9 - SXM 7
11/10/2020    Falcon 9 - Sentinel 6A
11/??/2020    Falcon 9 - Starlink 15
11/??/2020    Falcon 9 - CREW 1
11/30/2020    Falcon 9 - Turksat 5A
12/??/2020    Falcon 9 - CRS 21
12/16/2020    Falcon 9 - Transporter 1

01/??/2021    Falcon 9 - Worldview Legion 1 & 2
03/??/2021    Falcon 9 - CRS 22
03/30/2021    Falcon 9 - CREW 2
??/??/2021    Falcon Heavy - USSF 44

(from http://www.spacex.com/missions and https://spaceflightnow.com/launch-sche​dule/)
 
2020-10-24 12:19:30 PM  

optikeye: abhorrent1: T+plus 5 minutes. The second stage is now flying at an altitude of around 94 miles, or 152 kilometers. The Merlin engine is producing more than 200,000 pounds of thrust.

Do they still need that much thrust after leaving Earth's atmosphere? Seems like a waste of fuel.

Also, YAY!

Well, it's better than "Oh Shait, should we call Miami?"



They don't fire the rocket engine willy nilly. If they are firing that rocket, they need it to get the desired orbit. It is not good enough to merely get into orbit.
 
2020-10-24 12:24:31 PM  

abhorrent1: T+plus 5 minutes. The second stage is now flying at an altitude of around 94 miles, or 152 kilometers. The Merlin engine is producing more than 200,000 pounds of thrust.

Do they still need that much thrust after leaving Earth's atmosphere? Seems like a waste of fuel.

Also, YAY!


Yes.  Most of the velocity in a rocket launch goes to making the payload go sideways really fast, not to piercing the atmosphere.

To paraphrase Douglas Adams, the trick to being in orbit is to throw yourself at the ground really fast, and miss.
 
2020-10-24 12:26:55 PM  

pehvbot: Yeah The Falcon second stage is kind of crap from a performance perspective but that's because SpaceX optimized for cost instead.


Actually, the second stage uses a variant of the engine which is optimized for vacuum conditions. The first stage engines are designed to operate with air pressure around them.
 
2020-10-24 12:33:12 PM  

Professor Science: abhorrent1: T+plus 5 minutes. The second stage is now flying at an altitude of around 94 miles, or 152 kilometers. The Merlin engine is producing more than 200,000 pounds of thrust.

Do they still need that much thrust after leaving Earth's atmosphere? Seems like a waste of fuel.

Also, YAY!

The only way it wastes fuel is that the stage is carrying a heavier engine than necessary, if you only look at physics.  These things don't get less efficient at full throttle like piston engines do.  Generally the opposite, in fact -- the harder you run them, the better they perform, right up until they blow up.

But the savings in fuel (and tank size) that you'd get from using a smaller upper stage engine have to be weighed against the complexity of using a completely different engine than the nine on the first stage.  Designing, testing, and manufacturing another type of engine would be a matter of tens of millions of dollars up front plus ongoing costs for the second manufacturing line, and it would save maybe a few tens of thousands per flight in fuel and metal (mostly metal).  You'd also lose the reliability benefits of having thousands of engine-flights worth of data about that upper stage engine.  It's harder to put a price tag on that, but it's quite valuable.


Thank you for that.  That's a good analysis, well said.

I can see that we interpreted abhorrent1's question in different ways.  I approached it from, "Well, orbital mechanics is orbital mechanics.  If you have a vehicle of mass X and you want it to be in orbit Y, then the equations dictate that you need such-and-such Delta-V."  The actual flight profile - how you get to your desired orbit - is, as you say, dependent on the vehicle configuration, engine design and optimization, etc.  But the energy needed, the Delta-V, will be the same for the same vehicle and orbit, affected only by whether a change in the vehicle design and optimization affects the mass.

Anyway, another great launch, and a welcome bright spot in the year.
 
2020-10-24 12:35:51 PM  

Nicholas D. Wolfwood: Look up an old nonfiction book by Arthur C. Clarke if you want the math - 'Interplanetary Flight'.


Disney has a "Space 220" resturant in the works at EPCOT. It's on hold now, but they've started some constrution.
It's themed to be a space station.
Fark user imageView Full Size

They've devloped some impressive 'multilayer' hdtv screens to give the illusion of depth...instead of just looking at a screen.
However.  The thing that I really like. Is how your enter the restaurant.
A Clark "Space Elevator" That's tethered in Epcot.
Fark user imageView Full Size
 
2020-10-24 12:37:15 PM  
Payload Deploy!

Put this one in the books, Done and Done.
 
2020-10-24 12:43:08 PM  

optikeye: They've devloped some impressive 'multilayer' hdtv screens to give the illusion of depth...instead of just looking at a screen.
However.  The thing that I really like. Is how your enter the restaurant.
A Clark "Space Elevator" That's tethered in Epcot.


Those see through TV screens that were launched a few weeks ago seem to lend themselves to that. Have several screens a foot apart so you're looking through them and have several layers of background.

As for the elevator, the ride up the CN Tower in Toronto is pretty cool. You're looking out the side and seeing the earth just fall away...
 
2020-10-24 12:44:30 PM  

abhorrent1: T+plus 5 minutes. The second stage is now flying at an altitude of around 94 miles, or 152 kilometers. The Merlin engine is producing more than 200,000 pounds of thrust.

Do they still need that much thrust after leaving Earth's atmosphere? Seems like a waste of fuel.

Also, YAY!


Just to add to what's already been said: At stage separation, the second stage is doing about 7900 km/h. It needs to get up to almost 27,000 km/h to stay in orbit. So yes, they still need a lot of thrust.
 
2020-10-24 12:48:29 PM  

optikeye: I wonder when StarLink internet be available in the lower 48 states?
It wouldn't be something I'd have at home. But I'd certainly get a 'to go' package for a week when doing some camping, cabin or RV.


And OneWeb are due to resume launches in December, with sixteen launches each of 34 satellites planned for their LEO internet service.
But looks like Space X are ahead of them so they've got some catching up to do.
 
2020-10-24 12:51:35 PM  

Nicholas D. Wolfwood: I can see that we interpreted abhorrent1's question in different ways. I approached it from, "Well, orbital mechanics is orbital mechanics. If you have a vehicle of mass X and you want it to be in orbit Y, then the equations dictate that you need such-and-such Delta-V." The actual flight profile - how you get to your desired orbit - is, as you say, dependent on the vehicle configuration, engine design and optimization, etc. But the energy needed, the Delta-V, will be the same for the same vehicle and orbit, affected only by whether a change in the vehicle design and optimization affects the mass.


Yep, and I'm not sure which, if either, of us gave the answer they were looking for.  I figured the most likely basis for questions like that is everyday experience down here on the ground, where everybody knows that mashing the gas pedal is bad for efficiency.  Or maybe from looking at other rockets, like the Atlas and Delta upper stages that use tiny little RL10s making around 1/10th of the thrust of a vacuum Merlin.  The actual answer might lie somewhere in the complexities of lofted trajectories and hydrogen vs. kerosene and expander vs. gas generator cycles, but that gets to be a bit much for a Fark comment.
 
2020-10-24 1:40:21 PM  

Professor Science: Nicholas D. Wolfwood: I can see that we interpreted abhorrent1's question in different ways. I approached it from, "Well, orbital mechanics is orbital mechanics. If you have a vehicle of mass X and you want it to be in orbit Y, then the equations dictate that you need such-and-such Delta-V." The actual flight profile - how you get to your desired orbit - is, as you say, dependent on the vehicle configuration, engine design and optimization, etc. But the energy needed, the Delta-V, will be the same for the same vehicle and orbit, affected only by whether a change in the vehicle design and optimization affects the mass.

Yep, and I'm not sure which, if either, of us gave the answer they were looking for.  I figured the most likely basis for questions like that is everyday experience down here on the ground, where everybody knows that mashing the gas pedal is bad for efficiency.  Or maybe from looking at other rockets, like the Atlas and Delta upper stages that use tiny little RL10s making around 1/10th of the thrust of a vacuum Merlin.  The actual answer might lie somewhere in the complexities of lofted trajectories and hydrogen vs. kerosene and expander vs. gas generator cycles, but that gets to be a bit much for a Fark comment.


All the responses answered my question. Obviously this stuff is way more complicated than, go straight up as fast as possible to get out of the atmosphere.

This stuff is all waaaay over my head. My knowledge of physics couldn't fill a pin-hole. So my question was coming from a much simpler thought which was.. if they didn't need that much thrust and could throttle back, could carry less fuel and have more weight available for payload or save some fuel or whatever.

So don't give my question too much credit. In these threads, I'm basically Penny from Big Bang.
Appreciate the answers though. I learned something and even though I don't completely understand it, I can use it to impress my friends. :D
 
2020-10-24 2:20:07 PM  

FrancoFile: abhorrent1: T+plus 5 minutes. The second stage is now flying at an altitude of around 94 miles, or 152 kilometers. The Merlin engine is producing more than 200,000 pounds of thrust.

Do they still need that much thrust after leaving Earth's atmosphere? Seems like a waste of fuel.

Also, YAY!

Yes.  Most of the velocity in a rocket launch goes to making the payload go sideways really fast, not to piercing the atmosphere.

To paraphrase Douglas Adams, the trick to being in orbit is to throw yourself at the ground really fast, and miss.


KSP is great just for getting a feel for the mechanics involved
 
2020-10-24 3:52:34 PM  

WelldeadLink: pehvbot: Yeah The Falcon second stage is kind of crap from a performance perspective but that's because SpaceX optimized for cost instead.

Actually, the second stage uses a variant of the engine which is optimized for vacuum conditions. The first stage engines are designed to operate with air pressure around them.


Although the main difference is the just size of the exit nozzle.

The Starship will have three atmospheric engines and three vacuum engines.
 
2020-10-24 10:12:52 PM  
100 Successful Flights
Youtube Q_s_7iTydYU
 
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