Falcon 9R Launch

JoshNH4H · 2013-09-11 19:15:26

So I've heard that SpaceX is planning to launch its 9R rocket this Sunday, at 9 AM PST. It seems that the ground test fire today was scrubbed. I have no information regarding how this will affect the launch.

Updates at: http://spaceflightnow.com/falcon9/006/status.html

GW Johnson · 2013-09-12 08:38:40

From what I've seen and heard, the Merlin 1-D has about the same thrust as the Merlin 1-C's, just a lower hardware weight, for a substantially higher engine T/W ratio. They sure sound about the same when tested on the stand in McGregor.

Haven't seen anything yet on the Spacex site about the redesign changes for v 1.1, but I haven't been there for a while.

I do know Falcon-Heavy is supposed to be based on the Merlin 1-D's. Haven't heard one of those tested yet.

GW

Gregori · 2013-09-30 09:13:25

The launch was a success but the goal of slowing down the rocket at it reentered the atmosphere was a complete disaster. Looks like this stuff is harder than in simulations.

Void · 2013-09-30 09:57:58

At the risk of being redundant:
http://www.space.com/22996-spacex-launc … light.html

If they got test data, then they got something.

The article also seems to claim some engine performance improvement in a Vacuum.

RGClark · 2013-10-01 07:21:53

GW Johnson wrote:

From what I've seen and heard, the Merlin 1-D has about the same thrust as the Merlin 1-C's, just a lower hardware weight, for a substantially higher engine T/W ratio. They sure sound about the same when tested on the stand in McGregor.
Haven't seen anything yet on the Spacex site about the redesign changes for v 1.1, but I haven't been there for a while.
I do know Falcon-Heavy is supposed to be based on the Merlin 1-D's. Haven't heard one of those tested yet.
GW

The thrust for the Merlin 1D has been increased over the 1C, as well as the weight being reduced. The Isp was also slightly increased:

http://www.spacex.com/falcon9

Bob Clark

GW Johnson · 2013-10-02 09:29:16

Spacex's site has dramatically changed recently. I'm still trying to figure out how to navigate it. This stuff is not intuitive to an old guy like me.

But, Bob is right: Merlin 1D has a slightly-higher thrust and specific impulse than Merlin 1C, and a significant weight reduction. Falcon 9 v1.1 is bigger (longer tanks), thrustier, and heavier-at-ignition than what they flew before. The most remarkable thing is the re-arrangement of the first stage engine cluster. This changes the geometry of the tail of the bird considerably, and might even reduce its drag slightly. It looks a tad "cleaner", anyway.

From the published news reports, it appears that Spacex made some progress toward its goal of recovering and reusing Falcon-9 first stages. They got it back into the air without breaking up, and then lost it to an uncontrolled spin. That's a control problem, not something fundamental. And that's definitely progress.

They seemed to have kicked up a storm among observers over pieces of debris off the second stage, after payload deployment, when they vented the tanks. Apparently, a bunch of pieces of foil-backed insulation look like tankage pieces on radar.

GW

louis · 2013-10-02 13:08:49

GW - I agree about the Space X site...I think it's a bit of a trend for sites to determine what you look at, rather than letting you choose. It's a shame. I have so much respect for Musk, but he's obviosuly passed his site over to a bunch of media monkeys.

RGClark · 2013-10-12 15:06:02

GW Johnson wrote:

From what I've seen and heard, the Merlin 1-D has about the same thrust as the Merlin 1-C's, just a lower hardware weight, for a substantially higher engine T/W ratio. They sure sound about the same when tested on the stand in McGregor.
...
GW

Can you see the Grasshopper tests from your farm?

Bob Clark

JoshNH4H · 2013-10-13 17:00:10

If anyone can find the mass numbers and help me out on this one, I believe that I heard that the 1D has the highest T/W ratio of any rocket engine ever fired, overtaking the NK-33 which had a T/W of 133.

GW Johnson · 2013-10-15 06:32:50

If I had known, I could have seen that last Grasshopper test at half a mile peak altitude, 6 miles from my house. I certainly heard it. Bravo, Spacex!

GW

RGClark · 2013-10-17 06:22:29

JoshNH4H wrote:

If anyone can find the mass numbers and help me out on this one, I believe that I heard that the 1D has the highest T/W ratio of any rocket engine ever fired, overtaking the NK-33 which had a T/W of 133.

According to Wikipedia the 1D has a T/W ratio exceeding 150 to 1. From the thrust values given there you can calculate the weight:

http://en.wikipedia.org/wiki/Merlin_(ro … #Merlin_1D

Bob Clark

JoshNH4H · 2013-10-18 12:58:14

Yeah but neither of wikipedia's links actually has anyone saying what the T/W of the engine actually is

RGClark · 2013-10-21 01:51:17

JoshNH4H wrote:

Yeah but neither of wikipedia's links actually has anyone saying what the T/W of the engine actually is

Here's a SpaceX page where the vacuum T/W is given as 150 to 1:

JUNE 25, 2012
SPACEX'S MERLIN 1D ENGINE ACHIEVES FULL MISSION DURATION FIRING.
http://www.spacex.com/press/2012/12/19/ … ion-firing

Bob Clark

JoshNH4H · 2013-10-21 11:31:39

I think that pretty much seals it that SpaceX has built a kerolox engine with the highest vacuum Isp of any US kerolox engine (right? Only the Russians have done better, I think), and the highest T/W of any rocket engine ever built.

With a T/W of 150 and 801 kN of thrust (Vacuum), that means that the engine mass is just 550 kg.

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Announcement

#1 2013-09-11 19:15:26

Falcon 9R Launch

#2 2013-09-12 08:38:40

Re: Falcon 9R Launch

#3 2013-09-30 09:13:25

Re: Falcon 9R Launch

#4 2013-09-30 09:57:58

Re: Falcon 9R Launch

#5 2013-10-01 07:21:53

Re: Falcon 9R Launch

#6 2013-10-02 09:29:16

Re: Falcon 9R Launch

#7 2013-10-02 13:08:49

Re: Falcon 9R Launch

#8 2013-10-12 15:06:02

Re: Falcon 9R Launch

#9 2013-10-13 17:00:10

Re: Falcon 9R Launch

#10 2013-10-15 06:32:50

Re: Falcon 9R Launch

#11 2013-10-17 06:22:29

Re: Falcon 9R Launch

#12 2013-10-18 12:58:14

Re: Falcon 9R Launch

#13 2013-10-21 01:51:17

Re: Falcon 9R Launch

#14 2013-10-21 11:31:39

Re: Falcon 9R Launch

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