Poll

What is Elon talking about regarding a new second stage (Nov 2018)?

 A true "mini-BFS"
14 (13%)
A modified 2nd stage
87 (80.6%)
Something else, I will clarify in a comment
7 (6.5%)

Total Members Voted: 108

Voting closed: 12/08/2018 07:06 pm


Author Topic: POLL: "Mini-BFS" or Modified 2nd Stage  (Read 6796 times)

Offline Rocket Science

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #20 on: 11/08/2018 10:05 pm »
Voted B as part of the full reusability desire for Falcon 9...
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Offline Zed_Noir

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #21 on: 11/08/2018 10:45 pm »
Pick C. Think SX will do option B first then option A if there is no hiccups.

They will have to test out the forward canards eventually. Better on a mini-BFS then a full size article.

Offline QuantumG

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #22 on: 11/08/2018 11:26 pm »
I just hope they don't go for B and end up doing A. Feature creep is a project killer.
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Offline tater

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #23 on: 11/08/2018 11:29 pm »
They could do B, and still probably get some sort of folded canard (grid fins?) just under the fairing as well.

Offline hkultala

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #24 on: 11/09/2018 06:03 am »
C.

Both separate fairing AND the hands.

Offline HVM

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #25 on: 11/09/2018 06:57 am »
Clearly they are going to re-engineer the payload adapter and the fearing ring so they can be secured and ejected through TPS; open multiple holes to the TPS and put whole reentry test in jeopardy. In a mission with very little payload margin. And find a customer for this configuration.
« Last Edit: 11/09/2018 07:05 am by HVM »

Offline su27k

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #26 on: 11/09/2018 12:47 pm »
C. It's a modified 2nd stage that looks like A from the outside.

Offline whitelancer64

Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #27 on: 11/09/2018 03:44 pm »
Clearly they are going to re-engineer the payload adapter and the fearing ring so they can be secured and ejected through TPS; open multiple holes to the TPS and put whole reentry test in jeopardy. In a mission with very little payload margin. And find a customer for this configuration.

"Holes in TPS" has never really been a problem. The Shuttle had a similar "issue" with the ET attach points. And its landing gear.
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Offline jongoff

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #28 on: 11/10/2018 09:52 pm »
I voted for the second option. I think this is a modified upper stage with TPS and aerosurfaces to test some of the BFR reentry/control concepts. I wish it were a mini-BFS that had a clear path to making F9US fully-reusable, but I highly doubt it's that, especially given how short the timeframe is between now and then. I remember how crazy it was designing and building Xoie at Masten in a short time period. Trying to build a hypersonic glider system and TPS in 8 months suggests it's the first of a series of post-payload separation experiments to start learning how BFS reentry might work. Which is still awesome, even without acting like a fully reusable Falcon 9 is just around the corner.

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Offline skybum

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #29 on: 11/11/2018 12:01 am »
A, even if it's just a test article rather than a regular-service vehicle. If they're using this thing to test the re-entry interface and hypersonic controls, it'll need to follow the BFS mold lines and mass distribution pretty closely.

Offline deruch

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #30 on: 11/15/2018 06:54 am »
B.

This is the vehicle with the shortest development cycle that answers the question, "We've already got the 2nd stage up there re-entering.  What can we do with it to start learning what we really need to know for a fully operational BFS as soon as possible?"
Shouldn't reality posts be in "Advanced concepts"?  --Nomadd

Offline AndersofOz

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #31 on: 11/16/2018 01:19 am »
I have voted for B if they plan on flying with customers which was the pattern with the first stage landings.

I wonder if they might not need a better ACS in conjunction with a better way to vent residual propellant (i.e. without causing the stage to spin) in addition to the obvious TPS and fins to ensure the correct AoA on reentry.

Offline moreno7798

Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #32 on: 11/18/2018 05:23 pm »
I'd say it's going to be "A". Mini-BFS test article only - no payloads, no propulsive landings - just for testing of heat shield, and atmosphere winged entry, and drag dynamics. This will be the proof of concept for Full BFS tests at Boca Chica. This will also be the backup plan in case there are major delays in Full BFS test developments. In that case, all you have to do is add the propulsive landing capability to mini BFS.
« Last Edit: 11/18/2018 05:28 pm by moreno7798 »
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Offline smoliarm

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #33 on: 11/18/2018 05:48 pm »
B.

As I understand Elon's tweets, the purpose is to study re-entry profile (in search for a survivable one) and control system for it. Therefore no need for "A"-type, just regular s2 plus thermal protection and control surfaces with actuators.

I also would guess that such experiment will take place on the next launch deploying Starlink

Offline Paul451

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Re: POLL: "Mini-BFS" or Modified 2nd Stage
« Reply #34 on: 03/17/2019 10:34 am »
While Starship has gone off on its own stainless steel adventures; with the hints about a "commercial" Orion launch, we may see life breathed back into the old "Modify 2nd Stage" option.

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