SpaceX FH : Falcon Heavy Demo : Feb 6, 2018 : Discussion Thread 2

[MATTBLAK]

More seriously, does anybody remember Interstellar, and Murph teacher that felt that Apollo had been a 100 billion dollar d--k showing contest with the Soviets to ruin them - and a typical 20th century waste of money and resource ?
Today I'm thinking about that scene, and the morale of it. If Murph teacher ever exists, she is probably barely born, but will probably heard about today's launch. Then you can imagine her feelings about it, if she already thought Apollo was a colossal waste of money, then THIS happened...

(flash forward to the Interstellar (bleak)  timeline, let's say, 2060)

"rockets are a waste of money ! And you know it, M. Cooper, remember when a billionaire I can't remember the name got into an insane vanity project and spent 150 million dollars in rockets to send his own car to Mars just to impress people" poor girl.

More generally: when I was a teen, I got my great fireworks madness that lasted two years. With my elder sister, we blew everything standing: notably my mother's flowers, and also an unfortunate cockroach we placed in a matchbox with fireworks, and blew the hell of it.
At some point I come with an ever grandiose project: I was going to strap a load of fireworks on the back of a playmobil or a barbie, get the unfortunate doll a parachute, and send the thing 100 ft high. That was a boy dream of grandeur.
Well, please forgive me, but what Musk did today is nothing but an upscale variant of that boyish dream. "I strapped my car to a rocket, and send it to Mars. Just because I'm Musk, and just because, boy, it is so funny."

We are really living through strange times, I told yah.

P.S: I respectfully promise to move my last two posts to a party thread if one exists somewhere.

cheers !

I once made two attempts to launch a '5x stick' set of firework rockets. I think I was about 17, in the year 1983. They were big rockets; about as thick as toilet paper rolls, but a bit longer! I rubber-banded them tightly together, putting three of the sticks in sand-ballasted glass milk bottles. I had four butane lighters: I held two and my buddy held the other two. We practiced lighting them as simultaneously as possible. Our first attempt lit unevenly and the thing heeled over and went over the bank fence to crash in the grass field behind, exploding with a bang that still makes me wince when I think about it.

The next attempt was flawless. I lit the center fuse then my buddy Paul and I lit the other pairs and stepped back. The bloody thing took off with an ear-splitting roar and an acceleration so fast you could barely see it leave! But it's fire was bright orange/white and it went up, up and still up. At what I estimate was around 500 or 600 feet, it burst with a retina-punishing explosion that seemed to rattle our chests. The neighbours were swearing black and blue, but Paul and I were jumping up and down; screaming till we were hoarse.

Today; that young man was still inside me - yelling and fist-pumping the air.

[ugordan]

A couple of observations.
The center core was either started right at the lower throttle level or throttled down within a couple of seconds after liftoff judging by the remote camera shots. Unlike Delta IV Heavy which throttles down some 30 sec after, but makes sense given the high T/W ratio on F9 and what it would do to max Q otherwise.

The more interesting observation is that there appears to be a two-part engine shutdown for the side cores. 3 seconds before BECO there is a visual change in the plume noticeable from ground cameras on both boosters. Kind of like engines 6 and 7 shut down before the others. Curiously, if you listen to the countdown audio loop part of the webcast, I can make out a call that sounds like "M7 shutdown" before BECO. I'm not sure why engine no. 7 would be so special, it's actually farther from the vehicle axis than engine 6.

It's best noticeable in this video at 2:24:

It's also noticeable if you watch the booster cam on the webcast, 3 seconds before BECO and the mounting points relaxing as thrust cuts out, there's a slightly smaller event indicating there really was a two-step shutdown.

[dnavas]

I think this other one I found is even closer still - feel free to compare the two:



This one is the closest I've seen yet.
(They'd better put up good security at the Cape, or someone's going to try to get a little too close eventually)

That one is closer, but it kind of misses the landing :>  A tripod and a decent fluid mount would go a long way.  Are they up in the rigging to get these shots?

Regardless, what's with the obvious color difference between the two landings?

[Herb Schaltegger]

Regardless, what's with the obvious color difference between the two landings?

Different paint/coatings on the pad surface of LZ-2 versus LZ-1.

[robert_d]

Here's my footage of the launch through booster landing, uncut, with my telescope.
(snip)

Congratulations and thank you. Reality in all its glory.

[phred]

I was wondering how much time Spaceman will need to complete an orbit?

Lookup a few pages back, I think it was more than 18 months, less than 24.

The figure on the Twitter post says perihelion=.98AU and aphelion=2.61.  That makes A=1.80, which means an orbital period of 2.4yr=29 months.

[Galactic Penguin SST]

Does anyone have a list/table of first stage MECO altitude/velocity data and comparison with recovery outcome for all v1.2/Heavy missions? I have seen such a table updated yesterday (in French IIRC) that indicates that the central core for this launch was the stage with the highest velocity at MECO that have been attempted to be recovered so far - at around 2.65 km/s, comparable with those expended stages for heavy GTO F9 missions. Unfortunately I can't seem to find it back, so if you know where I can find this please post here!

[OxCartMark]

SPECIAL STATEMENT REGARDING STAR MAN:

Fate has ordained that the mannequin who went to space to explore in peace will stay in space to rest in peace.

This brave man knows that there is no hope for his recovery. But he also knows that there is hope for mankind in his sacrifice.

This man is laying down his life in mankind's most noble goal: the search for truth and understanding.

He will be mourned by his family and friends; he will be mourned by the nation; he will be mourned by the people of the world; he will be mourned by a Mother Earth that dared send its anthropomorph son into the unknown.

In his exploration, he stirred the people of the world to feel as one; in his sacrifice, he binds more tightly the brotherhood of man.

In ancient days, men looked at the stars and saw their heroes in the constellations. In modern times, we do much the same, but our heroes are epic mannequins of urethane and polyester.

Others will follow, and surely find their way home. Man's search will not be denied. But this mannequin was the first, and he will remain the foremost in our hearts.

For every human being who looks up at the heavens in the nights to come will know that there is some corner of another world that is forever mankind.

Source: http://www.lettersofnote.com/2010/11/in-event-of-moon-disaster.html

[LouScheffer]

A couple of observations.
[...]

The more interesting observation is that there appears to be a two-part engine shutdown for the side cores. 3 seconds before BECO there is a visual change in the plume noticeable from ground cameras on both boosters. Kind of like engines 6 and 7 shut down before the others. Curiously, if you listen to the countdown audio loop part of the webcast, I can make out a call that sounds like "M7 shutdown" before BECO. I'm not sure why engine no. 7 would be so special, it's actually farther from the vehicle axis than engine 6.

It's also noticeable if you watch the booster cam on the webcast, 3 seconds before BECO and the mounting points relaxing as thrust cuts out, there's a slightly smaller event indicating there really was a two-step shutdown.

Shutting down the furthest engine makes some sense.  The unbalanced thrust will then cause the side booster to try to rotate with the top away from the center core.  This is just what you want for separation.

[mattrog]

Sorry if its been posted already - closest video that i have seen of the landing - with astonishing sound !!

I think this other one I found is even closer still - feel free to compare the two:

This one is the closest I've seen yet.
(They'd better put up good security at the Cape, or someone's going to try to get a little too close eventually)

I think that may be from the same spot - just zoomed in - some other videos from the 1st one are from a similar angle with the tower obstruction - either way cool addition

EDIT - also i cant see anything on the 1st video that is closer that would give the angle and the obstructions of the tower...

[abaddon]

From the Update thread:

Just a question, not intended to ruffle any feathers.

Was it ever considered to create a third thread per event, titled "Mission Congratulations?" It's just a bit difficult to find actual updates in a thread swamped  by congratulatory posts. One per person can still result in a few thousand if every member decides to add his obligatory kind word.

We are supposed to withhold our congratulations until after the final event of the launch, with any followup events being posted to a new thread (typically iss dockings, GEO insertion progress, activation etc..)

However the nature of this launch with both its *explosive* emotional impact, coupled with the expected 6-hour delay to TMI burn, completely overwhelmed the sensible, sedate approach.

What we should have is a true updates page, posted to ONLY by a very select cadre, and not including such 'trivia' as a sighting of a venting during oxy load. Let the true updates stay in this dedicated thread.
Keep the riffraff (like me) out of the updates thread.
And make a second thread for Launch Day (location,name, date) wherein the trivia and user semi-sensible content is allowed, including the congratulatory comments.. 24 hours after the launch, lock this thread! The launch is done and gone, anything further goes to the normal discussion threads.

Just my 2c.


p.s. This post should also not be under updates for this event.. Mods feel free to relocate and/or nuke it as needed. Thx.

First off, there's a Discussion thread - this one - that can be used instead of an Update thread.  There is also a Party thread for the more frivolous posts.

Due to the level of excitement, it's natural that folks that don't post as frequently here, or people caught up in the moment, forget themselves and post material in the Update thread that would be better posted in the Discussion or Party threads.  I will admit to some twinges of annoyance myself.  However, for 99% of NFS live flight threads, they are quite orderly.  The tradition of the congratulatory post extends well back before I was a member and is rarely an issue.

How about we all take a deep breath, celebrate this amazing launch, and dial back on the nine-alarm-fire overreactions that the structure NFS follows for its live threads has to change because of this one (or even a small handful of) launches?

And if you're going to make a suggestion, may I politely suggest you do it in the discussion thread (this one) instead of the Update thread?

[Herb Schaltegger]

Further, Chris B. posted about congrats posts at least three times last night: first to allow them during S2 coast, second to suspend them during the presser, and third to allow them again after the presser.

Everyone just lighten up and let the mods do their jobs.

[the_other_Doug]

Not the separation. It was the long coast and 3rd relight was what they were looking for.

The Tesla is permanently connected to the second stage, yes? No separation of it?

Nothing suggests it would separate, which serves no purpose. No chance to see the car slowly floats away, and after all it is not a spacecraft.

I thought they were going to separate it for demonstration of a deep space mission for US military national security program.

They were not very clear about the end of mission. Even Elon in his post launch press conference was talking about ejection into the final orbit. I guess he was referring to the whole thing including the stage 2. I assumed they would try to eject/separate the car to prove all their hardware survived the long coast.

I know the sound during the presser wasn't consistently good, but I am positive Musk discussed injection into the escape trajectory, not ejection.  There is a pretty big difference, in this context.

I don't recall any variant of the verb eject being used during the entire presser.  But I heard variants of the verb inject a few times.

[cebri]

The launch is being mentioned in the cover of almost every important newspaper in the world. Hopefully some space nerds were made yesterday. We need all support we can get. 

[DecoLV]

Can we break from heliocentric calcs for a moment? Elon was the main person who rep'd SpaceX yesterday, but let's not forget the executive who actually runs the company: Gwynne Shotwell. It bothers me that her name was mentioned slim to none yesterday. As much as Elon, and maybe more, she made Falcon Heavy happen yesterday. So thanks and congrats to her.

[spacetraveler]

I was wondering how much time Spaceman will need to complete an orbit?

Lookup a few pages back, I think it was more than 18 months, less than 24.

It's actually a bit more than 2 years, almost 2.5.

[the_other_Doug]

A couple of observations.
The center core was either started right at the lower throttle level or throttled down within a couple of seconds after liftoff judging by the remote camera shots. Unlike Delta IV Heavy which throttles down some 30 sec after, but makes sense given the high T/W ratio on F9 and what it would do to max Q otherwise.

The more interesting observation is that there appears to be a two-part engine shutdown for the side cores. 3 seconds before BECO there is a visual change in the plume noticeable from ground cameras on both boosters. Kind of like engines 6 and 7 shut down before the others. Curiously, if you listen to the countdown audio loop part of the webcast, I can make out a call that sounds like "M7 shutdown" before BECO. I'm not sure why engine no. 7 would be so special, it's actually farther from the vehicle axis than engine 6.

It's best noticeable in this video at 2:24:

It's also noticeable if you watch the booster cam on the webcast, 3 seconds before BECO and the mounting points relaxing as thrust cuts out, there's a slightly smaller event indicating there really was a two-step shutdown.

In re initial throttling -- I noticed the same thing.  I believe all three cores were running at "liftoff thrust" (which, in this case, was 92% of a Block 4's regular rated thrust) up to about tower clear.  Then the center core definitely throttles down, at least based on its exhaust running about 15% or so shorter than those of the outer two cores.

As for the call-out, I hate to say, I heard "main engine shutdown" and not "M7 shutdown".  I assumed they were calling out the beginning of the side core shutdown sequence, which of course did not shut down each engine in the side cores, nor likely all at the same time.  I'd have to believe they shut down the side cores in a staggered fashion, to manage the stress of the force release from the center core, and, as Lou noted later, to steer them clear of the center core.

Note, for example, that the one N-1 launch that came closest to success actually failed because its stage one "inboard cutoff" process, designed to cut off the inner six engines first to reduce MECO stresses through the stack, in and of itself (because all six were cut off simultaneously) caused so much stress to the first stage, both directly to the thrust structure and aerodynamically, through the sudden removal of their exhaust pressures, that fuel lines broke and one turbopump failed.  This resulted in LOV.  I'm sure the SpaceX engineers looked hard and long at the details of that failure when designing FH launch events.

But yeah, good observations.  Thanks!

[Ademptis]

Was there a fire on the TEL just after liftoff, again? This happened a while back on a F9 launch.

[ugordan]

GOX and water vapor illuminated by the exhaust.

[ArbitraryConstant]

I think the question was other way around, could anyone else have launched this payload to this orbit. FH did it in fully reusable mode, could a Delta IV Heavy have done it?

Looks to me like they did a very inefficient launch partly to minimize stresses and partly to demo the long coast phase. Because of that I wouldn't be surprised if Delta IV medium could do it, or Falcon 9 with reusability.