SpaceX Getting Ready To Mass Produce Falcon 9 Rockets

[Ludus]

I don't think this is the intent. SpaceX can't overfly Florida with launches from Texas. They won't be launching from Texas for several years anyway. Moving the boosters on the barge would be MUCH more expensive than landing them at the nearest port and trucking them. They are sized to move by highway. They don't want to refurb them in Hawthorne. Rapid Reusability means just that. Gas and Go. They bring them back to the launch point, refuel and relaunch.

The reason for the barge landings (ASDS) is just physics. They can't launch payloads that need more propellant AND fly back. In those cases the booster just drops down on a ballistic path and lands at sea down range. The ASDS allows recovery of boosters that need more propellant ...it's that simple.

 

[SageBrush]

The reason for the barge landings (ASDS) is just physics. They can't launch payloads that need more propellant AND fly back. In those cases the booster just drops down on a ballistic path and lands at sea down range. The ASDS allows recovery of boosters that need more propellant ...it's that simple.

I think you are saying what I guessed after I wondered how SpaceX was able to land on a dime: the rocket (ideally) goes straight up, and then straight down, but in the meantime the earth has rotated.

 

[thimel]

I think you are saying what I guessed after I wondered how SpaceX was able to land on a dime: the rocket (ideally) goes straight up, and then straight down, but in the meantime the earth has turned.

No, the rocket does not ideally go straight up and then down. It helps to put a satellite in orbit. That requires a horizontal velocity of about 17,000 mph. The first stage provides some of that horizontal velocity.

 

[ggr]

I think you are saying what I guessed after I wondered how SpaceX was able to land on a dime: the rocket (ideally) goes straight up, and then straight down, but in the meantime the earth has rotated.

Quite the opposite. If it went up and down and the earth rotated under it, it would come down WEST of the launch site. As @thimel noted, most of launching to any kind of orbit involves adding a lot of horizontal velocity, with the first stage contributing about 1500km/h of that. They launch somewhat eastward to use the earth's rotation to add to that velocity rather than subtracting from it.

 

[SageBrush]

Quite the opposite. If it went up and down and the earth rotated under it, it would come down WEST

Oops ... you are right. Thanks to the two of you for the clarification.

And now I know that rocket engines rotate and perform 'gravity turns'

 

[Gerasimental]

Quite the opposite. If it went up and down and the earth rotated under it, it would come down WEST of the launch site. As @thimel noted, most of launching to any kind of orbit involves adding a lot of horizontal velocity, with the first stage contributing about 1500km/h of that. They launch somewhat eastward to use the earth's rotation to add to that velocity rather than subtracting from it.

Do all satellites orbit counter-clockwise (looking down on earth from the north pole), i.e. travel west to east?

 

[RDoc]

Do all satellites orbit counter-clockwise (looking down on earth from the north pole), i.e. travel west to east?

I believe so, although there might be a few exceptions. The issue is that at Florida's latitude, the Earth's rotation gives you about 900 miles per hour of free velocity towards the needed orbital velocity. If you launched the other way, East to West, you'd have to cancel the rotational velocity out as well as add full orbital velocity, so it would be about 1800 mph additional velocity.

The thing about orbiting is that the entire issue is horizontal velocity. The main reason we don't orbit satellites at low altitude, say 10 miles is because of air drag, although there would be problems with keeping such an orbit stable.

 

[Gerasimental]

I believe so, although there might be a few exceptions. The issue is that at Florida's latitude, the Earth's rotation gives you about 900 miles per hour of free velocity towards the needed orbital velocity. If you launched the other way, East to West, you'd have to cancel the rotational velocity out as well as add full orbital velocity, so it would be about 1800 mph additional velocity.

The thing about orbiting is that the entire issue is horizontal velocity. The main reason we don't orbit satellites at low altitude, say 10 miles is because of air drag, although there would be problems with keeping such an orbit stable.

Thanks for the answer. I understand the physics of it (and have had to explain to plenty of people why Blue Origin's landing was promising but not quite a breakthrough), but I thought that there would be applications where the additional required thrust would be worth it. For example in situations where you want a high relative ground speed, to have the shortest possible orbital period, it would be beneficial to go the other way.
Was just curious, for no real reason.

 

[Cosmacelf]

I haven't heard about any satellites that go east to west, but there are satellites that do polar orbits, eg. Mapping satellites that want to cover the entire earth.

Btw, the reason why all rockets take off over water is safety. Should something go wrong, you won't have a giant bomb falling out of the sky into some populated area (assuming the rocket fails early and still has a lot of fuel). Which is why they need drone ships, since some missions just do not have enough fuel margin to boost all the way back to land. Orbital rockets almost immediately start adding horizontal velocity as well as going up. By the time the first stage separates, it is up to several hundreds of kilometers horizontally away from the launch point and going really fast in that direction too. It takes a lot of fuel to cancel out that velocity and then to add new westward velocity.

 

[Gerasimental]

Wait is this a thing in KSP? Is this why I never got any good at it? Don't think I ever took into account my planet's rotation when launching into orbit.

(sorry for being totally OT. thanks for the explanations above!)

 

[ggr]

... all rockets take off over water ...

That is, if you don't count Russian or Chinese launches. Baikonur and Jiuquan are both seriously inland.

"I don't care where they come down."

 

[Grendal]

NASA just announced that the next CRS mission will happen on July 16th.

That means that SpaceX has 4!! orbital launches in July. We'll see how well SpaceX manages to pull that off. Right now they only have one launch in June. Maybe they'll bump one of those July missions up. We've had 4 successful missions this year and Gwynne said the goal for this year is 18. They might count the booster reuse flight as one and they will definitely count the Falcon Heavy test flight in November.

Launch Schedule – Spaceflight Now

 

[glhs272]

4 launches in July is a bit ambitious even for SpaceX at the moment (they like those impossible goals). I guess it helps that at least one of those launches is at Vandenberg. Although from what I hear the range may be down at Vandenberg all the way into August potentially... They typically don't update the place holder launch dates until the prior launch is completed. Assuming Thaicom8 goes smoothly this week, followed by Eutelsat in Mid June. I see 2 launches in July. CRS-9 mid July and Amos 6 around the end of July. If SLC-4E goes back on line in early July, I see the Formostat launch as a possible bonus. Still an impressive stride SpaceX is building up to.

 

[Stiction]

I don't think this is the intent. SpaceX can't overfly Florida with launches from Texas. They won't be launching from Texas for several years anyway. Moving the boosters on the barge would be MUCH more expensive than landing them at the nearest port and trucking them. They are sized to move by highway. They don't want to refurb them in Hawthorne. Rapid Reusability means just that. Gas and Go. They bring them back to the launch point, refuel and relaunch.

The reason for the barge landings (ASDS) is just physics. They can't launch payloads that need more propellant AND fly back. In those cases the booster just drops down on a ballistic path and lands at sea down range. The ASDS allows recovery of boosters that need more propellant ...it's that simple.

Thanks for sorting people out with this post!

If you watch any of the droneship landing attempts they explain this all quite well. Basically the only
stuff that can land back at the cape is stuff going only to LEO. Any GEO sats launches get booking too fast and they don't have enough fuel for a 'flyback' boost...only enough to slow down for the re-entry and then light up for the landing....all very much downrange from stage separation.

 

[rsquared99]

Is it possible to have the 1st stage continue to boost enough so one orbit could be made and then land at the start of the second orbit? Or, does that take even more fuel than trying to return right after the launch?

 

[thimel]

Is it possible to have the 1st stage continue to boost enough so one orbit could be made and then land at the start of the second orbit? Or, does that take even more fuel than trying to return right after the launch?

It would take a lot more fuel. Look at how long the second stage burns to get into orbit after the first stage stops.

 

[Stiction]

It would take a lot more fuel. Look at how long the second stage burns to get into orbit after the first stage stops.

Well said....I will add that a "hot" reentry stages at 4,000 mph-ish and lands on the barge with almost zero fuel (one of the failures ran out just seconds before touchdown). It's spent all it's fuel lifting the rest of the rocket!

No way to get to the 17,000 mph required for an orbit. Energy ~ v^2 by the way.
Forgive the non-metric units 8-/

A falcon 9 heavy (3 cores) lifting a huge mass ( but not the most) to LEO could fly back all three stages to the cape. There was news recently about them looking to build two more landing pads so this could happen.

I'm bummed the first Heavy launch isn't going to be a Vandenberg as originally promised. (I can drive there in a few hours)

 

[Grendal]

Lots of launches coming up soon:

JSAT16 on August 14th
Amos 6 on September 4th-11th
Iridium Next 1-10 on September 19th/20th out of Vandenberg

Six more besides that for this year, FH demo flight, and the Re-Use flight for SES? as well.

They've had seven successful flights this year. If they succeed at all of these then they will have completed the 18 flights this year that Shotwell said they would.

 

[Grendal]

Officially seen is the new F9 booster transporter:

This is a refurbished Space Shuttle Orbiter Transport System that was obviously bought and refurbished by SpaceX. It has 76 wheels.

A link to earlier picture of the system:
GSA auction: Orbiter Transporter System (OTS) - collectSPACE: Messages

 

[GoTslaGo]

Officially seen is the new F9 booster transporter:

View attachment 188632

This is a refurbished Space Shuttle Orbiter Transport System that was obviously bought and refurbished by SpaceX. It has 76 wheels.

A link to earlier picture of the system:
GSA auction: Orbiter Transporter System (OTS) - collectSPACE: Messages

37k based on your link! Pretty sweet deal.