IS Forum
Forum Index Register Members List Events Search Today's Posts Mark Forums Read Help

Go Back   International Skeptics Forum » General Topics » Science, Mathematics, Medicine, and Technology
 


Welcome to the International Skeptics Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.
Tags musk , space , spacex

Reply
Old 18th November 2023, 10:54 AM   #1081
Doubt
Philosopher
 
Doubt's Avatar
 
Join Date: Apr 2002
Posts: 8,022
Better than the first one. Looks like a lot of work to investigate how both stages meet their ends.

If I had to guess, I think they'll need two more flights to compete that profile they were aiming for.
__________________
45 es un titere
Doubt is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 18th November 2023, 11:43 AM   #1082
a_unique_person
Director of Hatcheries and Conditioning
 
a_unique_person's Avatar
 
Join Date: Jul 2002
Location: Waiting for the pod bay door to open.
Posts: 46,005
Yep. Nothing stupid happened. It will be interesting to see the launch page in detail.
__________________
Continually pushing the boundaries of mediocrity.
Everything is possible, but not everything is probable.
“Perception is real, but the truth is not.” - Imelda Marcos
a_unique_person is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 18th November 2023, 01:35 PM   #1083
smartcooky
Penultimate Amazing
 
smartcooky's Avatar
 
Join Date: Oct 2012
Location: Nelson, New Zealand
Posts: 24,829
Primary objectives

1. Rocket left pad.

2. All 33 Raptor engines remained lit until MECO.

3. Staging Completed.

4. Lauchpad survives launch intact.


Secondary objectives

5. Soft land booster on the water in the Gulf of Mexico.

6. Starship to reach space.

7. Reenter the atmosphere.

8. Fly to soft landing on water about 300 km north of Hawaii.


An unexpected bonus is that the AFTS has now been tested at least once, possibly twice, and it worked OK.

Comments
I'm still not convinced about this hot-staging idea, and I am wondering if this is what damaged the booster, causing it to tumble and ending up with the RUD. I know its not a new idea - Soyuz uses this very successfully, but they are not trying to reuse the first stage (so damage to it does not matter) and when you look at a Soyuz configuration, the second stage is relatively a lot further away from the first stage than it is on Starship. Also, those six Raptor engines on Starship deliver far more thrust (~520,000 lb each) than the single RD-110 or RD-124 (~67,000lb). Its no wonder Starship hot-staging has been described as "stage separation by blunt force trauma"!

We don't yet know what caused the AFTS to fire on the second stage. Everything was nominal as regards the six Raptor engines and the flight trajectory right up until the point contact was lost. It was out of the atmosphere by this point, and well past MaxQ so aerodynamic stress was well below tested maximums.

Conjecture - i.e. pure guesswork on my part
- failure of a pressure vessel (fuel or helium tank) causing the whole vehicle to explode.
- failure of one or more Raptor engines cause the vehicle to suddenly veer off course.
- a Raptor engine exploding.
__________________
Those who claim that something can't be done need to stop getting in the way of those who are actually doing it!
- Anonymous


Its TRE45ON season... convict the F45CIST!!
smartcooky is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 18th November 2023, 01:41 PM   #1084
Trebuchet
Penultimate Amazing
 
Trebuchet's Avatar
 
Join Date: Nov 2003
Location: Port Townsend, Washington
Posts: 38,281
Excellent (as usual) video by Scott Manley.
YouTube Video This video is not hosted by the ISF. The ISF can not be held responsible for the suitability or legality of this material. By clicking the link below you agree to view content from an external website.
I AGREE
__________________
Cum catapultae proscribeantur tum soli proscripti catapultas habeant.
Trebuchet is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 18th November 2023, 02:15 PM   #1085
jeremyp
Illuminator
 
Join Date: Aug 2003
Location: ZZ9 Plural Z Alpha
Posts: 3,824
Originally Posted by theprestige View Post
Why do you believe proven reusable first stages, and significantly lowered launch costs, are scams?
Because nobody outside SpaceX knows if the Falcon 9 really is significantly cheaper than other launch systems. They say it is, but Musk lies about a lot of stuff.
jeremyp is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 18th November 2023, 02:47 PM   #1086
smartcooky
Penultimate Amazing
 
smartcooky's Avatar
 
Join Date: Oct 2012
Location: Nelson, New Zealand
Posts: 24,829
Originally Posted by jeremyp View Post
Because nobody outside SpaceX knows if the Falcon 9 really is significantly cheaper than other launch systems. They say it is, but Musk lies about a lot of stuff.
As I have posted before..
Falcon 9 -70% reusable, 25 metric tons to LEO, US$65 million per launch

Falcon Heavy - 90% reusable, 50 metric tonnes to LEO, US$95 million per launch

Artemis - non-reusable 95 tonnes to LEO, $4.1 billion per launch

...and in case you also missed/ignored this the first time...

Originally Posted by smartcooky View Post
Booster No - B1058
Version - F9 v1.2 Block 5
Flights - 17

No.Launch DateMission DesignationPayloadDBF*
012020 05 30F9 Mission 86NASA Crew Dragon DM-2New
022020 07 20 F9 Mission 90 ANASIS II51
032020 10 06 F9 Mission 95 Starlink-12 (v1.0)78
042020 12 05 F9 Mission 102NASA CRS-21 & Bishop67
052021 01 24 F9 Mission 107 Transporter-143
062021 03 11 F9 Mission 111 Starlink-20 (v1.0) 46
072021 04 08 F9 Mission 114Starlink-23 (v1.0)25
082021 05 15 F9 Mission 119 Starlink-26 (v1.0)41
092021 11 13 F9 Mission 129 Starlink-4.1 (v1.5)181
102022 01 13 F9 Mission 137 Transporter-361
112022 02 21 F9 Mission 142 Starlink-4.8 (v1.5)39
122022 05 06 F9 Mission 153 Starlink-4.17 (v1.5)75
132022 07 07 F9 Mission 163 Starlink-4.21 (v1.5)62
142022 09 11 F9 Mission 176 Starlink-4.2 (v1.5)65
152022 12 17 F9 Mission 193 Starlink-4.37 (v1.5)97
162023 07 10 F9 Mission 239 Starlink-6.5 (v1.5) 205
172023 09 20 F9 Mission 258 Starlink-6.17 (v1.5)73
*DBF days between flights

On r/spacex (the SpaceX Reddit) some of the SpaceX engineers, both current and ex, have talked about comparative costs.

A Falcon 9 launch with a used booster and used fairings costs them US$15 million (of which US$10 million is a new 2nd stage and around US$250K for the fuel). This means the booster costs them US$5M per launch in various costs involved in the turnaround

1. Booster turnaround costs for each flight.
2. Fairing turnaround costs for each flight.
3. Full refurbishment approximately every 10 flights (inspection dependent and may include replacement of one or more Merlin engines).
4. Ship operating costs for recovery of boosters landed at sea on OCISLY, JRTI or ASOG
5. Ship operating costs for recovery of fairings.

All that averages out to around US$5M per booster/launch, and allows the SpaceX to fly the same booster, on average every 2½ months.
According to Aviation Week, it takes around 18 months to build a new Falcon 9 booster from scratch, at a cost of around US$30M.

Its a no-brainer. Re-use is far more economical than single use.
Now anyone with a brain between their ears (well, at least one that is not overwhelmed with irrational hatred for Musk) and doesn't get a gigantic hard-on every time SpaceX fails at something, can work out for themselves that it must be cheaper. There is a reason why SpaceX charges less than US$3,000/kg to LEO when most others are charging in excess of US$6,000/kg

PS: Artemis would cost US$23,000/kg to LEO
__________________
Those who claim that something can't be done need to stop getting in the way of those who are actually doing it!
- Anonymous


Its TRE45ON season... convict the F45CIST!!
smartcooky is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 18th November 2023, 03:08 PM   #1087
theprestige
Penultimate Amazing
 
Join Date: Aug 2007
Location: The Antimemetics Division
Posts: 67,171
Originally Posted by jeremyp View Post
Because nobody outside SpaceX knows if the Falcon 9 really is significantly cheaper than other launch systems. They say it is, but Musk lies about a lot of stuff.
That's not an explanation for why Gulliver Foyle believes that significantly lower launch costs is a scam. It would be an explanation for why Gulliver Foyle has no idea whether or not it's a scam, but GF's claim is that SpaceX is scamming us in some way.

And of course it's not an explanation for why GF believes reusable first stages are a scam.

Here's an article from Ars Technica, comparing the per-astronaut costs to NASA, for ISS missions from Boeing and from SpaceX. NASA is paying significantly less per astronaut, when they go with SpaceX. Reading the article, it almost seems like Boeing is the scam.

---

I should, perhaps, say "launch prices", rather than "launch costs". SpaceX is offering lower launch prices. GF believes, sight unseen, that this must be a scam of some kind. And also believes, apparently, that reusable first stages aren't real.
__________________
There is no Antimemetics Division.
theprestige is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 18th November 2023, 04:01 PM   #1088
angrysoba
Philosophile
 
angrysoba's Avatar
 
Join Date: Dec 2009
Location: Osaka, Japan
Posts: 35,278
I expect everyone here has already watched it. But here is the launch...

YouTube Video This video is not hosted by the ISF. The ISF can not be held responsible for the suitability or legality of this material. By clicking the link below you agree to view content from an external website.
I AGREE


Before I start reading the commentary on this, my own hot take is that it looks like a success!

Not only that, but it retroactively makes the first launch more of a success, in my book, than before. I think that there were legitimate criticisms of the first, and if this one had gone the same way the criticisms would have seemed even more valid (for example, the launch pad was needlessly compromised). But being able to get all the rockets firing, the booster separation, flipping in the air, etc... all looked like definite accomplishments towards the end goal. It's hard to see how you can bet against SpaceX getting Starship to work now.

Well done to all the SpaceX engineers, and yes, to you too Elon Musk. You may be a douchebag, but I can't knock your achievements here!
__________________
Слава Україні! **** Putin!
angrysoba is online now   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 18th November 2023, 08:01 PM   #1089
Roboramma
Penultimate Amazing
 
Join Date: Feb 2005
Location: Shanghai
Posts: 15,513
Originally Posted by theprestige View Post
I should, perhaps, say "launch prices", rather than "launch costs". SpaceX is offering lower launch prices. GF believes, sight unseen, that this must be a scam of some kind. And also believes, apparently, that reusable first stages aren't real.
Just to add to this (and smartcookie's excellent post), there is also the further fact that SpaceX is responsible for a large fraction of the total number of launches worldwide (and also a large fraction of total mass to orbit worldwide, those numbers are different, but similar).

They aren't just offering lower prices /kg than everyone else, they are also doing so at scale: lower $/kg and more kg to orbit. It's hard to see how they could do both those things and still be scamming somehow. If they were offering artificially low prices (below cost) in order to create a false reputation, for instance, they wouldn't be able to maintain those losses given the scale.
__________________
"... when people thought the Earth was flat, they were wrong. When people thought the Earth was spherical they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together."
Isaac Asimov
Roboramma is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 12:07 AM   #1090
smartcooky
Penultimate Amazing
 
smartcooky's Avatar
 
Join Date: Oct 2012
Location: Nelson, New Zealand
Posts: 24,829
Originally Posted by Trebuchet View Post
Excellent (as usual) video by Scott Manley.
YouTube Video This video is not hosted by the ISF. The ISF can not be held responsible for the suitability or legality of this material. By clicking the link below you agree to view content from an external website.
I AGREE
Indeed it is an excellent video and his analysis is also excellent. Scott hones in on two aspects, both of which relate to the possibility/probability that both failures were the result of triggering of the AFTS.

1. The Booster (commentary 3:23 to 6:14)


Scott uses some very good slo-mo to analyse the what happened leading up to the RUD: In summary, he suggests that it could be a fuel flow issue, either...

a. "Fuel slosh" when a sudden loss of acceleration causes the fuel to move forwards in the tanks, resulting in air/gas getting into the pipes feeding the engines, which can destroy an engine, or

b. "Fluid hammer" when a sudden stop of the engines can cause an over-pressure in the fuel lines leading to damage to fuel valves and pipes. You may be familiar with this if you have ever lived in a house that had very high cold water pressure - suddenly turning off the tap can result in a loud banging sound.

In any case, he points out that all the trouble appears to be happening at flamey end of the booster, but the RUD clearly begins about half-way up the body - this would indicate either a tank rupture or manual triggering of flight termination system.

2. Starship (commentary 6:19 to 8:31 )

Again, Scott uses slow-mo to analyze the puffs of gas from the rocket, and determines from the telemetry that the Lox levels drop far too quickly, so there is likely to have been an oxygen leak. If so, then running out of one of the components of the fuel (in this case, oxygen) too quickly would be enough to trigger the FTS automatically as the guidance would fall out of nominal limits.

Altogether, an excellent summary by Scott.
__________________
Those who claim that something can't be done need to stop getting in the way of those who are actually doing it!
- Anonymous


Its TRE45ON season... convict the F45CIST!!
smartcooky is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 03:36 AM   #1091
jeremyp
Illuminator
 
Join Date: Aug 2003
Location: ZZ9 Plural Z Alpha
Posts: 3,824
Originally Posted by smartcooky View Post
As I have posted before..
Falcon 9 -70% reusable, 25 metric tons to LEO, US$65 million per launch

Falcon Heavy - 90% reusable, 50 metric tonnes to LEO, US$95 million per launch

Artemis - non-reusable 95 tonnes to LEO, $4.1 billion per launch
You're comparing Artemis to Falcon 9? Come on. The use-case is different and you know it. Shall ewe add Starship to that list?

Starship - non reusable so far, 0 tonnes to LEO so far. $? billions per launch = $infinite per tonne to orbit.

Anyway, the critical thing is not the list price of a Falcon 9 launch, but how much it actually costs. We do not know that. Only people inside SpaceX know that.
jeremyp is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 03:42 AM   #1092
jeremyp
Illuminator
 
Join Date: Aug 2003
Location: ZZ9 Plural Z Alpha
Posts: 3,824
Originally Posted by theprestige View Post
That's not an explanation for why Gulliver Foyle believes that significantly lower launch costs is a scam. It would be an explanation for why Gulliver Foyle has no idea whether or not it's a scam
"X has no idea if Falcon 9 launch costs are a scam"

"X believes Falcon 9 launch costs are a scam".

The above two statements are not mutually exclusive.

Add in

"Y, CEO of SpaceX is a proven habitual liar"

and the second statement follows fairly naturally from the first, even if it is not somewhere you could get by strict reasoning.
jeremyp is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 03:49 AM   #1093
a_unique_person
Director of Hatcheries and Conditioning
 
a_unique_person's Avatar
 
Join Date: Jul 2002
Location: Waiting for the pod bay door to open.
Posts: 46,005
Does Peurto Rico like the idea of being in the path of a failed rocker launch? I thought all launches had to be out to sea more or less.
__________________
Continually pushing the boundaries of mediocrity.
Everything is possible, but not everything is probable.
“Perception is real, but the truth is not.” - Imelda Marcos
a_unique_person is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 03:56 AM   #1094
3point14
Pi
 
3point14's Avatar
 
Join Date: Nov 2005
Posts: 21,734
Originally Posted by jeremyp View Post
You're comparing Artemis to Falcon 9? Come on. The use-case is different and you know it. Shall ewe add Starship to that list?

Starship - non reusable so far, 0 tonnes to LEO so far. $? billions per launch = $infinite per tonne to orbit.

Anyway, the critical thing is not the list price of a Falcon 9 launch, but how much it actually costs. We do not know that. Only people inside SpaceX know that.
You surely can't believe that this is an actual argument???
__________________
Up the River!

Anyone that wraps themselves in the Union Flag and also lives in tax exile is a [redacted]
3point14 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 08:58 AM   #1095
Doubt
Philosopher
 
Doubt's Avatar
 
Join Date: Apr 2002
Posts: 8,022
Originally Posted by smartcooky View Post
As I have posted before..
Falcon 9 -70% reusable, 25 metric tons to LEO, US$65 million per launch

Falcon Heavy - 90% reusable, 50 metric tonnes to LEO, US$95 million per launch

Artemis - non-reusable 95 tonnes to LEO, $4.1 billion per launch

...and in case you also missed/ignored this the first time...



Now anyone with a brain between their ears (well, at least one that is not overwhelmed with irrational hatred for Musk) and doesn't get a gigantic hard-on every time SpaceX fails at something, can work out for themselves that it must be cheaper. There is a reason why SpaceX charges less than US$3,000/kg to LEO when most others are charging in excess of US$6,000/kg

PS: Artemis would cost US$23,000/kg to LEO
One correction on the Falcon Heavy. They are not trying to recover the core booster anymore. Much less than 90% reusable now. And those center cores are different structure than the regular Falcon 9 booster.
__________________
45 es un titere
Doubt is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 12:08 PM   #1096
smartcooky
Penultimate Amazing
 
smartcooky's Avatar
 
Join Date: Oct 2012
Location: Nelson, New Zealand
Posts: 24,829
Originally Posted by Doubt View Post
One correction on the Falcon Heavy. They are not trying to recover the core booster anymore. Much less than 90% reusable now. And those center cores are different structure than the regular Falcon 9 booster.
For most missions, true. But not for all.

The feasibility of recovering the centre core is dependent upon energy levels, which is determined from the payload mass and the energy of the target orbit.

1. The higher the payload mass, the more fuel is needed to lift the payload to orbit, so there is less fuel left for re-entry and landing.

2. The higher the energy of the target orbit the longer the booster engines have to burn, the higher the velocity the centre core will get to, and the greater the energy level, so more forces are imposed during re-entry.

This is a double ended issue - higher fuel loads give you extra energy to lift bigger loads, but these are the very things that make re-entry and landing harder.

What most people don't understand about Falcon 9 and Falcon Heavy is that it is very flexible, with several different flight profiles.

1. F9 return to launch point
The payload mass is low enough and the target orbit is low energy enough that sufficient fuel can be left on board to perform a "boostback burn" to bring the booster back for a landing at LZ-1 or LZ-2 (or LZ-4 if the lauch is from VAFB in California. If the payload and orbital requirements just exceed this, then...

2. F9 drone ship landing
When there is insufficient fuel for a return to launch point, the booster is landed on an autonomous spaceport drone ship (ASDS). If the payload and orbital requirements just exceed this, then...

3. F9 fully expended
As the name suggests, there is no attempt to recover the booster and it is allowed to fall into the sea. If the payload and orbital requirements just exceed this, then...

4. FH fully recoverable*1
The two side boosters return to launch point, and the centre core is landed on an ASDS. If the payload and orbital requirements just exceed this, then...

5. FH partially recoverable *2
The two side boosters return to launch point, and the centre core is expended because its velocity and energy levels are too high to allow recovery. . If the payload and orbital requirements just exceed this, then...

6. FH ASDS side booster recovery
The two side boosters land at sea on two ASDS' and the centre core is expended If the payload and orbital requirements just exceed this, then...

7. FH fully expended [/b]*3
All three cores are expended as their velocity and energy levels are too high for recovery.

For most FH missions the velocity of center core is at least twice that of a F9 booster. The centre core is also heavier. Increase in energy is calculated from mass and the square of the velocity so a centre core has at least four times the energy to shed of a normal F9 booster.


*1 FH fully recoverable: Only one mission so far has successfully used this profile - Arabsat 6. The centre core landed, but fell overboard during rough weather while returning to Florida.

*2 FH partially recoverable: Four missions so far have used this profile - USSF44, USSF67, Echostar 24 and Psyche. The core lacked any fins and landing gear, as it was deliberately expended, underwent the most energetic reentry, and impacted at 1,300 km (810 mi) downrange

*3 Only one mission so far has used this profile. Rideshare ViaSat-3 Americas / Aurora 4A / G-Space 1. All three cores had no grid fins or landing legs and were expended.
__________________
Those who claim that something can't be done need to stop getting in the way of those who are actually doing it!
- Anonymous


Its TRE45ON season... convict the F45CIST!!
smartcooky is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 12:11 PM   #1097
smartcooky
Penultimate Amazing
 
smartcooky's Avatar
 
Join Date: Oct 2012
Location: Nelson, New Zealand
Posts: 24,829
Originally Posted by 3point14 View Post
You surely can't believe that this is an actual argument???
Yes, he does, and his name isn't Shirley (AFAIK)

When you're desperate to show your hater colours, and want so badly to cut that tall poppy down, ANY argument will suffice, even one that is deeply flawed and complete BS!
__________________
Those who claim that something can't be done need to stop getting in the way of those who are actually doing it!
- Anonymous


Its TRE45ON season... convict the F45CIST!!
smartcooky is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 12:22 PM   #1098
smartcooky
Penultimate Amazing
 
smartcooky's Avatar
 
Join Date: Oct 2012
Location: Nelson, New Zealand
Posts: 24,829
Originally Posted by jeremyp View Post
"X has no idea if Falcon 9 launch costs are a scam"

"X believes Falcon 9 launch costs are a scam".

The above two statements are not mutually exclusive.
...but they are irrelevant

X claims rocket re-usability is a scam, but provides no evidence to substantiate his claim. That which is claimed, without evidence, can be dismissed, without evidence.

The fact that the evidence might be difficult or impossible to obtain is the claimant's problem and no-one else's. If the claimant cannot find the evidence, he should not have made the claim in the first place. This is how skepticism works!

X's claim is no more than an opinion based on nothing (and a biased one at that) and as well all know opinions are like... sphincters - everybody has one.
__________________
Those who claim that something can't be done need to stop getting in the way of those who are actually doing it!
- Anonymous


Its TRE45ON season... convict the F45CIST!!
smartcooky is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 12:23 PM   #1099
GlennB
Loggerheaded, earth-vexing fustilarian
 
GlennB's Avatar
 
Join Date: Sep 2006
Location: Wales
Posts: 30,954
Originally Posted by smartcooky View Post
Yes, he does, and his name isn't Shirley (AFAIK)

When you're desperate to show your hater colours, and want so badly to cut that tall poppy down, ANY argument will suffice, even one that is deeply flawed and complete BS!
Just an aside, but you seriously over-use that word. It's a cheap and nasty way of dismissing/demeaning those who disagree with you. 'fanboy' is in the same category.
__________________
"There ain't half been some clever bastards" - Ian Dury
GlennB is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 12:27 PM   #1100
smartcooky
Penultimate Amazing
 
smartcooky's Avatar
 
Join Date: Oct 2012
Location: Nelson, New Zealand
Posts: 24,829
Originally Posted by GlennB View Post
Just an aside, but you seriously over-use that word. It's a cheap and nasty way of dismissing/demeaning those who disagree with you. 'fanboy' is in the same category.
Make hater arguments, get hater labels... its that simple.
__________________
Those who claim that something can't be done need to stop getting in the way of those who are actually doing it!
- Anonymous


Its TRE45ON season... convict the F45CIST!!
smartcooky is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 02:08 PM   #1101
Checkmite
Skepticifimisticalationist
 
Checkmite's Avatar
 
Join Date: Jun 2002
Location: Gulf Coast
Posts: 28,499
Originally Posted by wobs View Post
Well an improvement on last time.
Vastly so from the sound of it.
__________________
"¿WHAT KIND OF BIRD?
¿A PARANORMAL BIRD?"
--- Carlos S., 2002
Checkmite is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 06:31 PM   #1102
Roboramma
Penultimate Amazing
 
Join Date: Feb 2005
Location: Shanghai
Posts: 15,513
Originally Posted by jeremyp View Post
Anyway, the critical thing is not the list price of a Falcon 9 launch, but how much it actually costs. We do not know that. Only people inside SpaceX know that.
I'm unclear on what you're claiming here. Are you claiming:

1) they are charging their customers more than the list price.
2) the actual cost is more than the price they charge their customers
3) the cost is less than the price they charge their customers, but we can't know how much less

1 seems extremely unlikely. If the price they actually charge were higher than that advertised, its certainly not true that "only people inside SpaceX know that". All of their customers would know. Seems like that information would have got out by now. And if it were similar to other launch companies, there would be no reason for their current dominance of the industry. SpaceX has cheaper prices for the same service, and those who contract that service have moved to them for that reason.

2 is also extremely unlikely. Given the number of launches they perform, and that fact that this is their main source of income, if they were performing launches at a loss, they'd have gone bankrupt by now. Instead they are pumping money into Starship.

3 is pretty clearly true, but not really relevant to your point. Yeah, we don't know how cheap SpaceX launch costs are, but we know that they're significantly lower than everyone else, because the price the charge their customers is low enough for that conclusion.
__________________
"... when people thought the Earth was flat, they were wrong. When people thought the Earth was spherical they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together."
Isaac Asimov
Roboramma is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 06:55 PM   #1103
theprestige
Penultimate Amazing
 
Join Date: Aug 2007
Location: The Antimemetics Division
Posts: 67,171
Originally Posted by smartcooky View Post
For most missions, true. But not for all.

The feasibility of recovering the centre core is dependent upon energy levels, which is determined from the payload mass and the energy of the target orbit.

1. The higher the payload mass, the more fuel is needed to lift the payload to orbit, so there is less fuel left for re-entry and landing.

2. The higher the energy of the target orbit the longer the booster engines have to burn, the higher the velocity the centre core will get to, and the greater the energy level, so more forces are imposed during re-entry.

This is a double ended issue - higher fuel loads give you extra energy to lift bigger loads, but these are the very things that make re-entry and landing harder.

What most people don't understand about Falcon 9 and Falcon Heavy is that it is very flexible, with several different flight profiles.

1. F9 return to launch point
The payload mass is low enough and the target orbit is low energy enough that sufficient fuel can be left on board to perform a "boostback burn" to bring the booster back for a landing at LZ-1 or LZ-2 (or LZ-4 if the lauch is from VAFB in California. If the payload and orbital requirements just exceed this, then...

2. F9 drone ship landing
When there is insufficient fuel for a return to launch point, the booster is landed on an autonomous spaceport drone ship (ASDS). If the payload and orbital requirements just exceed this, then...

3. F9 fully expended
As the name suggests, there is no attempt to recover the booster and it is allowed to fall into the sea. If the payload and orbital requirements just exceed this, then...

4. FH fully recoverable*1
The two side boosters return to launch point, and the centre core is landed on an ASDS. If the payload and orbital requirements just exceed this, then...

5. FH partially recoverable *2
The two side boosters return to launch point, and the centre core is expended because its velocity and energy levels are too high to allow recovery. . If the payload and orbital requirements just exceed this, then...

6. FH ASDS side booster recovery
The two side boosters land at sea on two ASDS' and the centre core is expended If the payload and orbital requirements just exceed this, then...

7. FH fully expended [/b]*3
All three cores are expended as their velocity and energy levels are too high for recovery.

For most FH missions the velocity of center core is at least twice that of a F9 booster. The centre core is also heavier. Increase in energy is calculated from mass and the square of the velocity so a centre core has at least four times the energy to shed of a normal F9 booster.


*1 FH fully recoverable: Only one mission so far has successfully used this profile - Arabsat 6. The centre core landed, but fell overboard during rough weather while returning to Florida.

*2 FH partially recoverable: Four missions so far have used this profile - USSF44, USSF67, Echostar 24 and Psyche. The core lacked any fins and landing gear, as it was deliberately expended, underwent the most energetic reentry, and impacted at 1,300 km (810 mi) downrange

*3 Only one mission so far has used this profile. Rideshare ViaSat-3 Americas / Aurora 4A / G-Space 1. All three cores had no grid fins or landing legs and were expended.
I would be very interested to know which parts of this Gulliver Foyle believes to be scams, and why. Or which other parts of SpaceX's operations and achievements he believes are actually scams.
__________________
There is no Antimemetics Division.

Last edited by theprestige; 19th November 2023 at 06:57 PM.
theprestige is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 07:07 PM   #1104
smartcooky
Penultimate Amazing
 
smartcooky's Avatar
 
Join Date: Oct 2012
Location: Nelson, New Zealand
Posts: 24,829
Originally Posted by Roboramma View Post
I'm unclear on what you're claiming here. Are you claiming:

1) they are charging their customers more than the list price.
2) the actual cost is more than the price they charge their customers
3) the cost is less than the price they charge their customers, but we can't know how much less

1 seems extremely unlikely. If the price they actually charge were higher than that advertised, its certainly not true that "only people inside SpaceX know that". All of their customers would know. Seems like that information would have got out by now. And if it were similar to other launch companies, there would be no reason for their current dominance of the industry. SpaceX has cheaper prices for the same service, and those who contract that service have moved to them for that reason.

2 is also extremely unlikely. Given the number of launches they perform, and that fact that this is their main source of income, if they were performing launches at a loss, they'd have gone bankrupt by now. Instead they are pumping money into Starship.

3 is pretty clearly true, but not really relevant to your point. Yeah, we don't know how cheap SpaceX launch costs are, but we know that they're significantly lower than everyone else, because the price the charge their customers is low enough for that conclusion.
And Starlink!

They have to be making enough money to cover those launches... all 121 of them so far. If they were losing money on Falcon 9 and Falcon Heavy launches, there is no ******* way they could pump money into Starlink and Starship.

Nah, its just all hater rhetoric to deny the success SpaceX are having (because Musk = douchebag....or something). They are not grown up enough to be able to separate the man from the mission.

As someone who has followed Space Programs for most of my life, and particularly the rise of Private Space, I can tell you (and I am sure you already know this) that the impact SpaceX has had on the launch industry cannot be overstated... it has been huge!!
__________________
Those who claim that something can't be done need to stop getting in the way of those who are actually doing it!
- Anonymous


Its TRE45ON season... convict the F45CIST!!
smartcooky is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 09:11 PM   #1105
Doubt
Philosopher
 
Doubt's Avatar
 
Join Date: Apr 2002
Posts: 8,022
Originally Posted by smartcooky View Post
For most missions, true. But not for all.
https://forum.nasaspaceflight.com/in...?topic=59109.0

I have not heard it from an offical source. But the first person to talk about it was Everyday Astronaut during the last Falcon Heavy mission. There does not seem to be much planning for recovery on future missions.

We will just have to wait and see if they actually do it again.
__________________
45 es un titere
Doubt is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 19th November 2023, 10:44 PM   #1106
smartcooky
Penultimate Amazing
 
smartcooky's Avatar
 
Join Date: Oct 2012
Location: Nelson, New Zealand
Posts: 24,829
Originally Posted by Doubt View Post
https://forum.nasaspaceflight.com/in...?topic=59109.0

I have not heard it from an offical source. But the first person to talk about it was Everyday Astronaut during the last Falcon Heavy mission. There does not seem to be much planning for recovery on future missions.

We will just have to wait and see if they actually do it again.
AIUI, the margin between 3. (F9 fully expended) and 5. (FH partially recovered) may be very small and if that is so, then when they weigh up the pros and cons, they may well decide it is not worth the effort. If they have actually made that decision, it will be down to the results of the Engineering Innovation Algorithm they use. I posted about this back in post #922

http://www.internationalskeptics.com...&postcount=922

Its lengthy and contains a long video, so I will summarize.

SpaceX wanted to catch fairings with a ship and a net to keep them out of the ocean, thereby making it easier and cheaper to prepare them for any future launches. The problem was that that were not having much success in catching them with their special boats, Mr Steven (later replaced by Ms Chief) and Ms Tree. So, they applied an algorithm to the problem and long story short, they found that all the operational costs involving having two specialist ships to catch the fairing halves added up to a lot more than simply having two less complicated recovery ships, Doug and Bob (named after the first two NASA astronauts to fly on a Crew Dragon - Doug Hurley and Bob Benkehen) to fish them out of the water. It is intrinsically harder and more expensive to service a "wet" fairing than a "dry" fairing, but when all the additional costs were taken into account, it was better the let them splash. The added bonus was that the two fairing recovery vessels also double as tow ships for the ASDS

Now I'll bet they applied a similar algorithm to the centre core recovery problem.

For a F9 fully expended, they get nothing back except the fairings and they know they're not getting the booster back, so the landing legs (and the hardware systems necessary to deploy them) and the grid fins (and the hardware necessary to operate them) are never fitted.

For a FH partially recovered, they get both side boosters back, but they expend the centre core, and those things are expensive to build. If they are already planning to not recover it, they can again forego the landing gear and the grid fins and their associated hardware. They also forego the ASDS and the cost of all its associated operations.

Add to that, if centre core recovery is a high-risk/low-percentage endeavor, then they are risking a set of landing legs, and a set of grid fins (and those titanium grid fins are ******* expensive). To date, no Falcon Heavy has ever flown with a modified flight proven booster for a centre core. If I had to guess, I'd say they are purpose-building them from scratch now - cheaper than modifying an existing core. This fact alone lends much weight to your suggestion that they no longer try. But like you, I have never seen any announcement to that effect.
__________________
Those who claim that something can't be done need to stop getting in the way of those who are actually doing it!
- Anonymous


Its TRE45ON season... convict the F45CIST!!
smartcooky is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2023, 12:52 AM   #1107
Roboramma
Penultimate Amazing
 
Join Date: Feb 2005
Location: Shanghai
Posts: 15,513
My understanding was just that recovering the center core was a difficult challenge and that while it could be done, focus (ie. money and manpower) was shifted from Falcon Heavy to Starship, and so they sort of gave up on that not necessarily because it couldn't be done or wouldn't be worthwhile, but because resources were seen as better spent on developing the next innovation (starship) than perfecting the last (falcon heavy).

I could be entirely wrong here, though. I'm not entirely sure where I formed this impression.
__________________
"... when people thought the Earth was flat, they were wrong. When people thought the Earth was spherical they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together."
Isaac Asimov
Roboramma is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2023, 02:28 AM   #1108
a_unique_person
Director of Hatcheries and Conditioning
 
a_unique_person's Avatar
 
Join Date: Jul 2002
Location: Waiting for the pod bay door to open.
Posts: 46,005
Originally Posted by smartcooky View Post
Make hater arguments, get hater labels... its that simple.

Usually it's better to just disagree. You won't change their mind and it just gets nasty for everyone else.
__________________
Continually pushing the boundaries of mediocrity.
Everything is possible, but not everything is probable.
“Perception is real, but the truth is not.” - Imelda Marcos
a_unique_person is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2023, 02:32 AM   #1109
Darat
Lackey
Administrator
 
Darat's Avatar
 
Join Date: Aug 2001
Location: South East, UK
Posts: 112,598
I can see in quite the near future (near future is now for me "in my lifetime", so a couple of decades) that dumping stuff like rocket stages into the ocean will not be allowed, SpaceX will be in the forefront of companies that can manage that.
__________________
I wish I knew how to quit you
Darat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2023, 08:26 AM   #1110
The Great Zaganza
Maledictorian
 
The Great Zaganza's Avatar
 
Join Date: Aug 2016
Posts: 21,603
Imagine how much more we could learn from these risky tests if we used manned rockets !
__________________
“Don’t blame me. I voted for Kodos.”
The Great Zaganza is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2023, 09:25 AM   #1111
Ziggurat
Penultimate Amazing
 
Ziggurat's Avatar
 
Join Date: Jun 2003
Posts: 55,297
Originally Posted by jeremyp View Post
Because nobody outside SpaceX knows if the Falcon 9 really is significantly cheaper than other launch systems. They say it is, but Musk lies about a lot of stuff.
Everyone with any sense knows that Falcon 9 is significantly cheaper. It really couldn't be any other way. The launch cadence, the turnaround times, the complexity of the vehicle itself... there's really no plausible scenario where it isn't significantly cheaper.

Sure, we don't know the exact margins SpaceX is working with. But the Falcon 9 rocket itself isn't significantly more complex than alternatives, so manufacturing costs are going to be similar. And as I've already explained, we know re-use is a money saver, because they're able to do it so quickly. The cost of re-use is dominated by labor costs, and given how quickly SpaceX can get a Falcon 9 ready for re-launch, those labor costs are going to be a fraction of the manufacturing costs (which also have a ton of labor in them). There is no plausible scenario under which SpaceX isn't able to launch Falcon 9 for much less than its non-reusable competitors. Seriously, where's all that extra cost even supposed to come from? Are they making their rockets out of gold or something?
__________________
"As long as it is admitted that the law may be diverted from its true purpose -- that it may violate property instead of protecting it -- then everyone will want to participate in making the law, either to protect himself against plunder or to use it for plunder. Political questions will always be prejudicial, dominant, and all-absorbing. There will be fighting at the door of the Legislative Palace, and the struggle within will be no less furious." - Bastiat, The Law
Ziggurat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2023, 06:41 PM   #1112
Checkmite
Skepticifimisticalationist
 
Checkmite's Avatar
 
Join Date: Jun 2002
Location: Gulf Coast
Posts: 28,499
Originally Posted by angrysoba View Post
flipping in the air, etc...
Eh?
__________________
"¿WHAT KIND OF BIRD?
¿A PARANORMAL BIRD?"
--- Carlos S., 2002
Checkmite is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2023, 06:50 PM   #1113
angrysoba
Philosophile
 
angrysoba's Avatar
 
Join Date: Dec 2009
Location: Osaka, Japan
Posts: 35,278
Originally Posted by Checkmite View Post
Eh?
The booster rotated as part of the planned return to Earth. It looked impressive to me even if it ultimately exploded.

Later I watched the Scot Manley video posted by Trebuchet where he speculated about the explosion. I believe he also used the terms “flipping” to describe the booster’s movement.
__________________
Слава Україні! **** Putin!
angrysoba is online now   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 22nd November 2023, 12:40 AM   #1114
Checkmite
Skepticifimisticalationist
 
Checkmite's Avatar
 
Join Date: Jun 2002
Location: Gulf Coast
Posts: 28,499
I see - it looked to me to be the same general kind of tumbling movement that all boosters make when they separate during rocket launches; but if it was an actual deliberate maneuver or something that's nice I suppose.
__________________
"¿WHAT KIND OF BIRD?
¿A PARANORMAL BIRD?"
--- Carlos S., 2002
Checkmite is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 22nd November 2023, 11:05 AM   #1115
Mr Clingford
Master Poster
 
Mr Clingford's Avatar
 
Join Date: Nov 2003
Posts: 2,091
Er, it is a deliberate manoeuvre as part of the booster stage landing itself to be used again. A work in progress.
__________________
God is my copilot.

But we crashed into a mountain and I had to eat him.
Mr Clingford is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 22nd November 2023, 12:18 PM   #1116
gabeygoat
Graduate Poster
 
gabeygoat's Avatar
 
Join Date: Dec 2008
Location: Hard Corvallis Oregon
Posts: 1,746
Originally Posted by a_unique_person View Post
Does Peurto Rico like the idea of being in the path of a failed rocker launch? I thought all launches had to be out to sea more or less.
Trump doesn't believe Puerto Rico is worth more than throwing rolls of paper towels at. Why should Musk care more?
__________________
"May I interest you in some coconut milk?" ~Akhenaten Wallabe Esq
gabeygoat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 22nd November 2023, 12:50 PM   #1117
theprestige
Penultimate Amazing
 
Join Date: Aug 2007
Location: The Antimemetics Division
Posts: 67,171
Originally Posted by gabeygoat View Post
Trump doesn't believe Puerto Rico is worth more than throwing rolls of paper towels at. Why should Musk care more?
Because the FAA regulates that sort of thing, obviously. Contrary to what you seem to imagine, Donald Trump is not actually the measure of all things. It's totally okay to leave him out of a conversation about commercial spaceflight. In fact, it's even okay to leave Elon Musk out of a conversation about approved launch trajectories, since it's not really his decision.
__________________
There is no Antimemetics Division.
theprestige is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 22nd November 2023, 01:34 PM   #1118
gabeygoat
Graduate Poster
 
gabeygoat's Avatar
 
Join Date: Dec 2008
Location: Hard Corvallis Oregon
Posts: 1,746
Originally Posted by theprestige View Post
Because the FAA regulates that sort of thing, obviously. Contrary to what you seem to imagine, Donald Trump is not actually the measure of all things. It's totally okay to leave him out of a conversation about commercial spaceflight. In fact, it's even okay to leave Elon Musk out of a conversation about approved launch trajectories, since it's not really his decision.
aw, man, it was just a (failed) joke.
__________________
"May I interest you in some coconut milk?" ~Akhenaten Wallabe Esq
gabeygoat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 22nd November 2023, 01:37 PM   #1119
theprestige
Penultimate Amazing
 
Join Date: Aug 2007
Location: The Antimemetics Division
Posts: 67,171
Just A Prank Bro has entered the chat.
__________________
There is no Antimemetics Division.
theprestige is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 22nd November 2023, 01:51 PM   #1120
gabeygoat
Graduate Poster
 
gabeygoat's Avatar
 
Join Date: Dec 2008
Location: Hard Corvallis Oregon
Posts: 1,746
totally bro'in'

seriously,Puerto Rico was mentioned and that incident popped into my head. That, and a Puerto Rican friend I miss from my old Job. Musk's name comes up, because, well, SpaceX
__________________
"May I interest you in some coconut milk?" ~Akhenaten Wallabe Esq

Last edited by gabeygoat; 22nd November 2023 at 01:54 PM.
gabeygoat is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Reply

International Skeptics Forum » General Topics » Science, Mathematics, Medicine, and Technology

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 02:51 AM.
Powered by vBulletin. Copyright ©2000 - 2023, Jelsoft Enterprises Ltd.

This forum began as part of the James Randi Education Foundation (JREF). However, the forum now exists as
an independent entity with no affiliation with or endorsement by the JREF, including the section in reference to "JREF" topics.

Disclaimer: Messages posted in the Forum are solely the opinion of their authors.