SpaceX Falcon Heavy

[NeilChapman]

Another good reason for moving to the BFR design.

Building a big rocket was hard. Building a much bigger rocket should be easier.

So it seems. Perhaps building a big single rocket is easier than strapping three together.

 

[sferrin]

Another good reason for moving to the BFR design.

Building a big rocket was hard. Building a much bigger rocket should be easier.

So it seems. Perhaps building a big single rocket is easier than strapping three together.

Recovery has to be simpler. It'll be interesting if they try to bring all three boosters back on the first Heavy launch. (Would the two strap-on booster fly back to the Cape with the central booster landing at sea?

 

[Michel Van]

Recovery has to be simpler. It'll be interesting if they try to bring all three boosters back on the first Heavy launch. (Would the two strap-on booster fly back to the Cape with the central booster landing at sea?

So far i know the Two Booster are to land at KSC and Core Stage make a landing on drone ships "Of Course I Still Love You"
But it's will be father out as normal, do longer downrange of Core Stage.

 

[fredymac]

Video and pic from Spacex Twitter (video already copied by a Youtuber).

Surprising how Delta 4 Heavy and Falcon Heavy have similar size but >2x difference in performance. It reflects the single RS68 vs 9 Merlin thrust difference (plus upper stage performance of single Merlin vs Centaur). It would seem the Delta is heavier/bigger than it should have been even compared to Atlas V. And of course then there is the price difference as well.

https://www.youtube.com/watch?v=6u0Kfw3UKuY

 

[sferrin]

LH2 has relatively low energy density so the rockets end up bigger. The differences energy density and ISP can make in vehicle size are telling here:

Titan IVB Delta IV Heavy
Vehicle Weight 2,079,060 1,616,000
Thrust at Lift Off 3,400,000 2,130,000
lbs to LEO ~48k ~63k

 

[sferrin]

More over here:

https://www.flickr.com/photos/spacex

Looks like lots of plumbing on the outside. I wonder if they'll eventually try cross-feeding like they'd talked about in the past.

 

[Hobbes]

The arms connecting the cores at the top may contain electrical connections for the control system. They're in the wrong place for propellant crossfeed.

 

[sferrin]

The arms connecting the cores at the top may contain electrical connections for the control system. They're in the wrong place for propellant crossfeed.

It will be interesting to see if those nose caps on the boosters and the horizontal conduits have much of an effect on the flight back.

 

[merriman]

Good point about the conduit -- at the high angle-of-attack these boosters take in the final phase of the landing maneuver, the conduit might act like a strake (think Standard missile). likely the conduit will be oriented on the downstream side of the booster to keep it in the aerodynamic 'shadow'.

Or, am I full of it?

David

 

[sferrin]

Good point about the conduit -- at the high angle-of-attack these boosters take in the final phase of the landing maneuver, the conduit might act like a strake (think Standard missile). likely the conduit will be oriented on the downstream side of the booster to keep it in the aerodynamic 'shadow'.

Or, am I full of it?

David

No idea. I was wondering where the split on the horizontal conduits are. Do they all stay with the core? Does a portion stay with the booster, and if so, how much is the asymmetry going to effect things? I've no doubt they've studied all this, and maybe the computer, thrusters, and control surfaces have enough smarts and authority to compensate. Will definitely be interesting.

 

[Hobbes]

In the animation, the horizontal conduits are folded up and stay with the central core.

 

[Dragon029]

https://www.instagram.com/p/BdjBHqdAIzs/

Hold-down test fire next week. Launch end of the month.

Delays might be due to Zuma. Hopefully 'next week' means something like Monday. 'End of the month' almost certainly rules out the Jan 15th window as well.

 

[flanker]

Looks like lots of plumbing on the outside. I wonder if they'll eventually try cross-feeding like they'd talked about in the past.

No, cross-feed is dead.

 

[fredymac]

Somewhat over the top presentation but this guy does a good job explaining the historical timeline for Falcon Heavy development and includes a lot of interesting technical details on how it evolved.

https://www.youtube.com/watch?v=FOdoNQXQYv8

 

[fredymac]

Short but interesting comparison video.

https://www.youtube.com/watch?v=8GRqZ0sjuso

 

[Byeman]

The boosters have 2 raceways each: a large one on one side, and a much narrower one on the opposite side. As far as I can see, the 2 side boosters are identical, not mirrored.

If they were mirrored, they wouldn't be identical

 

[Byeman]

Another good reason for moving to the BFR design.

Building a big rocket was hard. Building a much bigger rocket should be easier.

So it seems. Perhaps building a big single rocket is easier than strapping three together.

It isn't that hard strapping three together. See Delta IV Heavy, Titan IV and Titan III.

 

[Dragon029]

It is when you're using rockets that weren't originally designed for it and are intended to be reusable.

 

[Byeman]

It is when you're using rockets that weren't originally designed for it and are intended to be reusable.

Wrong on both parts. Reusability has no part in the issue. It doesn't come into play while they are all strapped together.
And FH was alway part of the equation, no different than Delta IV heavy.

the issue is the separation of the strap on boosters without the use of solid motor separation rockets.

 

[sferrin]

the issue is the separation of the strap on boosters without the use of solid motor separation rockets.

They still have the cold gas maneuver system.

 

[Byeman]

the issue is the separation of the strap on boosters without the use of solid motor separation rockets.

They still have the cold gas maneuver system.

That is the issue. Can't get the same type of impulse from it.

 

[TomS]

SpaceX's preference appears to be to avoid expendable components wherever possible. Instead of solid rockets, there are pneumatic pushers in the longerons (struts) connecting the side boosters to the core to expedite the separation. I believe the center engine in the boosters will also restart after separation to help keep the side boosters clear of the core.

 

[Byeman]

SpaceX's preference appears to be to avoid expendable components wherever possible. Instead of solid rockets, there are pneumatic pushers in the longerons (struts) connecting the side boosters to the core to expedite the separation. I believe the center engine in the boosters will also restart after separation to help keep the side boosters clear of the core.

They likely won't shut them down. Restart would take too long.

 

[Michel Van]

SpaceX's preference appears to be to avoid expendable components wherever possible. Instead of solid rockets, there are pneumatic pushers in the longerons (struts) connecting the side boosters to the core to expedite the separation. I believe the center engine in the boosters will also restart after separation to help keep the side boosters clear of the core.

They likely won't shut them down. Restart would take too long.

nope, not Restart or High altitude ignition for core
all three stages take off with Rocket power, but the core stage Merlin engines are on minimum thrust
after Booster jettison they go on full throttle, advantage lower fuel consumption for core stage during Booster operation.

 

[TomS]

SpaceX's preference appears to be to avoid expendable components wherever possible. Instead of solid rockets, there are pneumatic pushers in the longerons (struts) connecting the side boosters to the core to expedite the separation. I believe the center engine in the boosters will also restart after separation to help keep the side boosters clear of the core.

They likely won't shut them down. Restart would take too long.

You're right, I mis-remembered something I'd read. I found this comment in the environmental impact statement confirming that the side booster center engines don't shut down.

"The center engine in each side core continues to burn for a few seconds after separation to control the trajectory of the side booster."

The center engine gimbals, so it's got quite a bit of authority to keep the side booster away for the core after the separation pushers get it started.

 

[Michel Van]

something going on at Pad 39A

https://www.youtube.com/watch?v=UtrFjzDaeMA

 

[TomS]

They did a propellant load test/wet dress rehearsal on Saturday. Apparently they can't do the planned static fire because the range personnel are mostly furloughed.

 

[TomS]

Also here, if you're more digitally minded: https://www.nytimes.com/2018/01/22/science/falcon-heavy-spacex-elon-musk.html

 

[sferrin]

Live coverage: Falcon Heavy test-firing planned Wednesday

https://spaceflightnow.com/2018/01/09/falcon-heavy-demo-flight-preparations/

When's the last time anybody ever test fired 5 million+ pounds of thrust? The only two examples that come to mind are the 5 F-1s tests for Apollo and the AJ260 solid motor.

 

[bring_it_on]

https://www.youtube.com/watch?v=_EAhy4ZHkDE

 

[merriman]

Hey! ... it didn't explode. I call that a win.

What I could hear there was about four-seconds of water sound/heat suppression and seven-seconds of engine(s) run. Wow!

Can't wait to see the close up shots of this test. Just ... Wow!

David

 

[fredymac]

Nothing on Spacex twitter yet. Here is a slightly better view.

https://www.youtube.com/watch?v=NuXHriwQB9g

 

[fredymac]

Pretty short firing. I wonder if there was an abort? Just have to wait for the official statement.

https://www.youtube.com/watch?v=sTqbKDl4yAo


Update: Musk's twitter statement---
"Falcon Heavy hold-down firing this morning was good. Generated quite a thunderhead of steam. Launching in a week or so."

 

[TomS]

The normal static fire for Falcon 9 is 3.5 seconds. This seems like it was at least that long.

 

[Flyaway]

The White House seems interested in the Falcon Heavy launch

That appeared to be confirmed Saturday in a tweet by Nick Ayers, chief of staff for Pence. Referring directly to the upcoming Falcon Heavy launch, Ayers tweeted, "Major (positive) ramifications for US space industry if this goes according to plan." Here, a key Pence confidant seems to be saying that the Falcon Heavy could prove a game changer by offering the United States a new launch capability at low cost to taxpayers.

https://arstechnica.com/science/2018/01/the-white-house-seems-interested-in-the-falcon-heavy-launch/

 

[sferrin]

February 6th.

"Aiming for first flight of Falcon Heavy on Feb 6 from Apollo launchpad 39A at Cape Kennedy. Easy viewing from the public causeway."

 

[sferrin]

"The Federal Aviation Administration has approved a launch license for SpaceX’s Falcon Heavy rocket set for blastoff Tuesday, giving the U.S. government’s regulatory green light for the heavy-lifter to dispatch Elon Musk’s used electric sports car on a one-way trip into deep space.

Dated Feb. 2, the FAA launch license clears a final regulatory hurdle for the Falcon Heavy’s test launch from pad 39A at NASA’s Kennedy Space Center in Florida.

The launch window Tuesday opens at 1:30 p.m. EST (1830 GMT) and extends until 4 p.m. EST (2100 GMT).

The official weather forecast issued Sunday by the U.S. Air Force’s 45th Weather Squadron predicts an 80 percent chance of favorable conditions during Tuesday’s launch window.

“On Tuesday, winds will become easterly at 15 mph, bringing a few low-level clouds in off the water,” forecasters wrote in Sunday’s outlook. “The main weather concerns are liftoff winds and thick clouds. Maximum upper-level winds will be from the west at 90 knots near 40,000 feet.”"

https://twitter.com/SpaceflightNow

"Falcon Heavy remains go for launch at 1:30pm on Tuesday" - Elon Musk (That was yesterday so we'll see.)

 

[Michel Van]

There is interesting Detail about Musk Roadster.
on the Dashboard is small model of Tesla roaster with a figure in space suit.
now that Roadster is on Falcon Heavy with Dummy in space suit on driver seat...

 

[Michel Van]

Just publish by SpaceX
https://www.youtube.com/watch?v=Tk338VXcb24

 

[sferrin]

I can't hear sound at the moment. They better be playing the intro to Heavy Metal when they show that car flying through space! ;D