New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: As a reader of NewMars forum, we have opportunities for you to assist with technical discussions in several initiatives underway. NewMars needs volunteers with appropriate education, skills, talent, motivation and generosity of spirit as a highly valued member. Write to newmarsmember * gmail.com to tell us about your ability's to help contribute to NewMars and become a registered member.

#1026 2021-03-29 19:00:57

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Starship is Go...

From what I read the FAA has at least 15,000 employees. The idea they couldn't find one to turn up on time for a Space X launch is just risible. Messages are being sent.

This is going to get far worse once Biden is out of the way and President Harris is in charge. Unelected as President, she will be desperate for the support of the increasingly influential Far Left Democrats. The Space X mission could be halted overnight if she were to sign up to some Planetary Protection nonsense.

On the plus side, I am sure Musk will have an emergency back-up plan involving relocating out of the USA. Where to though? Brazil perhaps.

tahanson43206 wrote:

In the general theme of US government support for private enterprise, which I think is a "good idea", I like the idea of allocating sufficient human resources to the SpaceX operation so there are no delays.  On the other hand, it seems to me we (forum members) have no idea what the responsibilities of the FAA may be, what the staffing level may be, or what the competing demands for specialist time may be.

What those of us who are US Citizens ** can ** do is to contact our local representatives to investigate to see if additional funding is needed, or if there might be other reasons why the supply of specialist services does not seem to be meeting the demand.

(th)


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

Offline

#1027 2021-03-29 19:22:38

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,959

Re: Starship is Go...

Offline

#1028 2021-03-29 20:13:55

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,467
Website

Re: Starship is Go...

Musk apparently pissed off the FAA with what happened on the SN-8 flight,  and they modified his license to require the on-site inspector.  He really needs to pay better attention to meeting his license requirements,  or they will ground him!  That picture has not changed since FAA was formed in 1958,  and it was pretty much the same under their predecessor regulatory agency,  the CAA. 

Musk has not pissed off the entire US government,  because there is no one US government to piss off.  There are an entire plethora of government offices and agencies,  of which NASA and the FAA are only two,  and quite distinct from each other.  Because Musk has contracts with NASA and with DOD,  he knows not to piss them off. 

He has no contract with FAA,  and there is no such thing,  because FAA is a regulatory agency,  quite distinct from the other two.  Musk needs to learn how to deal correctly with them,  that much is clear.

As for Louis's claims about Biden and Harris,  I put that down to him listening to the European form of QANON,  which is becoming fairly well known over here as the bunch of BS that it always was.  It is possible to piss off the White House.  Nixon was the example most think of,  but that effect goes back through Theodore Roosevelt to Andrew Jackson,  at least.  It is best not to piss off powerful government figures.  That much we have known since before we became a country.

As for NASA,  there isn't one NASA either.  Not any more than there isn't one USAF,  one USN,  etc. There have always been contingents here and there within what became NASA,  that oppose humans setting foot on other celestial bodies.  That dates back to before the very first satellite launch in 1957.  There are other contingents very gung-ho on humans going to other worlds,  and other contingents that want nothing but robots to go.  No one of those has the upper hand.

The real problem with NASA is that it is no longer the more-or-less independent agency tasked with spaceflight.  It has not been that since about 1965.  It is now micromanaged by congress,  specifically to support activities within the districts of powerful congressmen or senators.  Or hadn't anyone really noticed how there is now almost no overlap between what we need to go off-earth,  and what we are doing to go off-earth?  Almost no overlap at all. 

It was NOT that way during 1958-1965,  when the Apollo project pretty much gelled. Anybody else see the difference in what got accomplished early-on vs later?

GW

PS:  my laptop is deceased.  I will likely be rather scarce on these forums for a while.

Last edited by GW Johnson (2021-03-29 20:17:46)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#1029 2021-03-30 05:46:26

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Starship is Go...

Well we'll see.

I don't need any Q Tips...the White House are already referring to the government as the "Biden-Harris administration" and Harris' photo even has a more central position that Biden's!

https://www.whitehouse.gov/administration/

You don't have to be Sherlock Holmes to work out what's going on!

Anyway, I hope I am wrong about the Starship project being blocked...it would be a very serious step for any President to take but we may see more bureaucratic interference that slows everything down.

GW Johnson wrote:

Musk apparently pissed off the FAA with what happened on the SN-8 flight,  and they modified his license to require the on-site inspector.  He really needs to pay better attention to meeting his license requirements,  or they will ground him!  That picture has not changed since FAA was formed in 1958,  and it was pretty much the same under their predecessor regulatory agency,  the CAA. 

Musk has not pissed off the entire US government,  because there is no one US government to piss off.  There are an entire plethora of government offices and agencies,  of which NASA and the FAA are only two,  and quite distinct from each other.  Because Musk has contracts with NASA and with DOD,  he knows not to piss them off. 

He has no contract with FAA,  and there is no such thing,  because FAA is a regulatory agency,  quite distinct from the other two.  Musk needs to learn how to deal correctly with them,  that much is clear.

As for Louis's claims about Biden and Harris,  I put that down to him listening to the European form of QANON,  which is becoming fairly well known over here as the bunch of BS that it always was.  It is possible to piss off the White House.  Nixon was the example most think of,  but that effect goes back through Theodore Roosevelt to Andrew Jackson,  at least.  It is best not to piss off powerful government figures.  That much we have known since before we became a country.

As for NASA,  there isn't one NASA either.  Not any more than there isn't one USAF,  one USN,  etc. There have always been contingents here and there within what became NASA,  that oppose humans setting foot on other celestial bodies.  That dates back to before the very first satellite launch in 1957.  There are other contingents very gung-ho on humans going to other worlds,  and other contingents that want nothing but robots to go.  No one of those has the upper hand.

The real problem with NASA is that it is no longer the more-or-less independent agency tasked with spaceflight.  It has not been that since about 1965.  It is now micromanaged by congress,  specifically to support activities within the districts of powerful congressmen or senators.  Or hadn't anyone really noticed how there is now almost no overlap between what we need to go off-earth,  and what we are doing to go off-earth?  Almost no overlap at all. 

It was NOT that way during 1958-1965,  when the Apollo project pretty much gelled. Anybody else see the difference in what got accomplished early-on vs later?

GW

PS:  my laptop is deceased.  I will likely be rather scarce on these forums for a while.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

Offline

#1030 2021-03-30 07:45:40

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Starship is Go...

Whoops - another failed landing...SN11 crash and burn...

https://www.youtube.com/watch?v=pBde7FWWGLw

Seems odd to have gone for a launch in fog, when you are gathering data, which must include visual data surely...


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

Offline

#1031 2021-03-30 08:23:53

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,389

Re: Starship is Go...

"Space is HARD!"

Still no statement from SpaceX, re: RUD or flight termination?

Offline

#1032 2021-03-30 09:17:49

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,389

Re: Starship is Go...

From the SpaceX webcast:

“It looks like we’ve had another exciting test,” SpaceX’s John Insprucker said on the webcast, several minutes after the loss of video. “We’re going to have to find out from the team what happened.”

He did not confirm that the vehicle had been lost, but independent video of the landing showed debris falling around the test site at the time of landing. SpaceX Chief Executive Elon Musk later acknowledged the vehicle was destroyed, tweeting that “At least the crater is in the right place!”

Offline

#1033 2021-03-30 10:44:03

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,306

Re: Starship is Go...

I was happy to see this report in a Space.com article on the latest test:

According to sources familiar with the incident, the inspector was in Texas ahead of the planned launch, but went home to Florida as the agency thought the test would be pushed back. Typically the FAA waits until a static fire test has been completed before sending an inspector to Texas, but is now looking into having an inspector in Texas to handle Starship. The agency also is requiring SpaceX to give adequate notice so an inspector can be on site.

It seems to me having someone (qualified) on site is a reasonable accommodation by the FAA, considering the potential significance to US GDP if SpaceX succeeds.

I saw a comment by another forum member that with 15,000 employees, FAA should be able to provide a full time person in Texas.

I am confident that ** every ** one of those 15,000 is good at whatever they are doing, but supervising a rocket development activity is not something an aircraft engine blade inspector is going to be able to do.  There may be ONLY one such employee in FAA.

There are probably only 5 in the world, or maybe 6.

(th)

Offline

#1034 2021-03-30 11:24:21

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,449

Re: Starship is Go...

louis wrote:

From what I read the FAA has at least 15,000 employees. The idea they couldn't find one to turn up on time for a Space X launch is just risible. Messages are being sent.

This is going to get far worse once Biden is out of the way and President Harris is in charge. Unelected as President, she will be desperate for the support of the increasingly influential Far Left Democrats. The Space X mission could be halted overnight if she were to sign up to some Planetary Protection nonsense.

On the plus side, I am sure Musk will have an emergency back-up plan involving relocating out of the USA. Where to though? Brazil perhaps.

The Far Left under Harris are likely to hasten America's decline.  They have already fiddled the electoral process to the point where it will be impossible for them to be 'democratically' removed from power.  The recent 2 trillion dollar stimulus bill is a foretaste of things to come.  Money created out of nothing by a central bank and then spent on politico projects.  By the time Harris and Co have finished, the US Dollar will have gone the way of the Weimar deutschmark.  The status of the dollar as reserve currency is unlikely to survive another decade.

As for SpaceX relocating launch operations, I would imagine ITAR regulations will be used to thwart that.  But I hope to be proven wrong.


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

Offline

#1035 2021-03-30 13:30:12

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,440

Re: Starship is Go...

Everyone,

This sub-forum is about human missions to other worlds.

This thread is about a rocket that could take us to those other worlds.

We're unlikely to go anywhere if we keep arguing over our personal political beliefs.  The ISS doesn't have a Democrat Commander or a Republican Commander.  ISS runs on public funding for science, not political ideology.  ISS has a space flight qualified and highly experienced astronaut or cosmonaut / scientist with the backing of multiple space flight agencies employing thousands of dedicated professionals that, collectively, make ISS possible.

America will continue forward, no matter who is currently President.  We always have and always will.  There are frequently minor speed bumps along the way, and that's the "going fast tax", such as it were, but rest assured that the US military is still the US military, NASA is still NASA, SpaceX is still SpaceX, and all cheap internet banter to the contrary is still just that.

The FAA exists to regulate air and space flight, to assure public confidence that all reasonable precautions have been taken to prevent needless accidents resulting in loss of life and property.  If SpaceX hasn't taken their commitment to prevent such accidents from occurring with the seriousness that it warrants, then that's their fault, not the US government.  If you explode enough rockets the size of grain silos, then sooner or later someone is going to get seriously injured or killed.  The FAA is concerned about what's happening at Boca Chica and they're well within their authority to demand improved flight-readiness measures to assure that nobody gets killed by a rocket crash / explosion.  Ultimately, such regulations are intended to benefit both SpaceX and the general public.  The FAA is not a punitive organization and never has been.

The message from the FAA to SpaceX is simple and clear:

We want to see successful rocket flights and rocket landings that operate within their designated design parameters.  SpaceX is the one designating the flight parameters and filing their flight plans.  Crashing rockets wasn't mentioned anywhere in their flight plans, so they need to figure out what's causing these crashes and then they need to correct it.

None of that has anything at all to do with who is currently President and is wholly unrelated to politics.

I'm a fan of the work that SpaceX does, but if I was a FAA regulator my position would be that we're not flying one more rocket until someone can demonstrate to me that material changes have taken place to reduce the risk of another crash and subsequent explosion.  Flying grain silos filled with explosives is not a computer game.  We've had the same ultimate result (crash and/or explosion) nearly a dozen times in a row here.  Maybe they are learning something new with every flight test, but SpaceX already has orbital class rocket boosters that land successfully far more often than not.  In short, this isn't their first rodeo.  Somehow, their R&D team is failing to do something that their launch team does successfully at least once per month, if not more often, and there is indeed something wrong with that.

In general, I'm of the opinion that they can do whatever they want with their money, but not if it significantly endangers the lives of their workers or the general public.  These days, even experimental high performance military aircraft are allowed about one or two crashes during the entire test program before the government pulls the funding plug.  The stealth supersonic VTOL (words that don't belong together in the same sentence) F-35 had zero crashes during a very protracted 15 year development program that included daily test flights with new / untested computer control software.  Crashing so many test airframes back in WWII, when we still knew very little about aerodynamics and control systems, may have been deemed acceptable war time losses, but times have changed, we're not fighting a war with VTOL rockets, and technology has improved by leaps and bounds.  There's no excuse that passes muster for failing a simple pressure test, for example.  Welded sheet metal for pressure vessels is some of the most well-understood and thoroughly-tested technology that exists, and they're using existing steel alloys and fabrication techniques that are routinely used for that specific application.  When something that fundamental to rocketry fails more than once, I start to question everything else that's going on with the design as well.

Now, can we get back to discussing rockets and rocket testing, instead of our politics?

Offline

#1036 2021-03-30 15:30:56

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,389

Re: Starship is Go...

kbd512-
Thanks for reminding everyone that we're all Space Nerds here, and regardless of political persuasion, need to "keep our eyes on the ball." Manned spaceflight and betterment of humanity as a result thereof.

Offline

#1037 2021-03-30 16:36:29

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,959

Re: Starship is Go...

I second that as its got a place for it.

Raining down engine bits after it ignites is the clue that shows its being damaged in the shutdown banging against each other.

Offline

#1038 2021-03-30 17:53:12

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Starship is Go...

I am happy to leave the politics to other threads (although nearly all of your post carries with it dubious political assumptions which I won't bother analysing here).  But let us be in no doubt:  politics has always, but always, been closely intertwined with rocketry and space exploration. It could never be otherwise.


kbd512 wrote:

Everyone,

This sub-forum is about human missions to other worlds.

This thread is about a rocket that could take us to those other worlds.

We're unlikely to go anywhere if we keep arguing over our personal political beliefs.  The ISS doesn't have a Democrat Commander or a Republican Commander.  ISS runs on public funding for science, not political ideology.  ISS has a space flight qualified and highly experienced astronaut or cosmonaut / scientist with the backing of multiple space flight agencies employing thousands of dedicated professionals that, collectively, make ISS possible.

America will continue forward, no matter who is currently President.  We always have and always will.  There are frequently minor speed bumps along the way, and that's the "going fast tax", such as it were, but rest assured that the US military is still the US military, NASA is still NASA, SpaceX is still SpaceX, and all cheap internet banter to the contrary is still just that.

The FAA exists to regulate air and space flight, to assure public confidence that all reasonable precautions have been taken to prevent needless accidents resulting in loss of life and property.  If SpaceX hasn't taken their commitment to prevent such accidents from occurring with the seriousness that it warrants, then that's their fault, not the US government.  If you explode enough rockets the size of grain silos, then sooner or later someone is going to get seriously injured or killed.  The FAA is concerned about what's happening at Boca Chica and they're well within their authority to demand improved flight-readiness measures to assure that nobody gets killed by a rocket crash / explosion.  Ultimately, such regulations are intended to benefit both SpaceX and the general public.  The FAA is not a punitive organization and never has been.

The message from the FAA to SpaceX is simple and clear:

We want to see successful rocket flights and rocket landings that operate within their designated design parameters.  SpaceX is the one designating the flight parameters and filing their flight plans.  Crashing rockets wasn't mentioned anywhere in their flight plans, so they need to figure out what's causing these crashes and then they need to correct it.

None of that has anything at all to do with who is currently President and is wholly unrelated to politics.

I'm a fan of the work that SpaceX does, but if I was a FAA regulator my position would be that we're not flying one more rocket until someone can demonstrate to me that material changes have taken place to reduce the risk of another crash and subsequent explosion.  Flying grain silos filled with explosives is not a computer game.  We've had the same ultimate result (crash and/or explosion) nearly a dozen times in a row here.  Maybe they are learning something new with every flight test, but SpaceX already has orbital class rocket boosters that land successfully far more often than not.  In short, this isn't their first rodeo.  Somehow, their R&D team is failing to do something that their launch team does successfully at least once per month, if not more often, and there is indeed something wrong with that.

In general, I'm of the opinion that they can do whatever they want with their money, but not if it significantly endangers the lives of their workers or the general public.  These days, even experimental high performance military aircraft are allowed about one or two crashes during the entire test program before the government pulls the funding plug.  The stealth supersonic VTOL (words that don't belong together in the same sentence) F-35 had zero crashes during a very protracted 15 year development program that included daily test flights with new / untested computer control software.  Crashing so many test airframes back in WWII, when we still knew very little about aerodynamics and control systems, may have been deemed acceptable war time losses, but times have changed, we're not fighting a war with VTOL rockets, and technology has improved by leaps and bounds.  There's no excuse that passes muster for failing a simple pressure test, for example.  Welded sheet metal for pressure vessels is some of the most well-understood and thoroughly-tested technology that exists, and they're using existing steel alloys and fabrication techniques that are routinely used for that specific application.  When something that fundamental to rocketry fails more than once, I start to question everything else that's going on with the design as well.

Now, can we get back to discussing rockets and rocket testing, instead of our politics?


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

Offline

#1039 2021-03-30 19:27:13

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,959

Re: Starship is Go...

Offline

#1040 2021-03-30 20:54:41

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,306

Re: Starship is Go...

For SpaceNut re #1039

Thanks for the link to that interesting video!

The concluding comments (from tweets by Elon) sure do hint that we can expect lots more RUD events after the orbital test begin.

(th)

Offline

#1041 2021-03-31 19:15:27

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,959

Re: Starship is Go...

This one shows a fire high on the engines

https://youtu.be/MoEv0dkWlvA

Offline

#1042 2021-03-31 21:01:25

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,467
Website

Re: Starship is Go...

I think they were extremely stupid to fly in the fog without possibility of photography from the ground.  The camera failures in the engine bay are telling you in no uncertain terms that there were more fires going on in that engine bay than just the one seen high up on that one engine.  Which failed to work right,  surprise,  surprise!

Fires do damage to control hardware of all kinds,  especially wiring.  Those fires are fed by something,  in this case,  propellant leaks.  What you saw on the side of that engine powerhead was a methane fire from a methane leak.  Add an oxygen leak into an ongoing methane leak-and-fire and you ALWAYS get an explosion. 

I have two recommendations for Spacex:  (1) Start finding and fixing these propellant leaks.  These cause fires that damage your engine controls,  and loss of control means an engine that cannot do what you want it to.  This has slapped you hard in the face on 4 successive flights now.  (2) NEVER EVER fly a test in conditions where you cannot see the test article from the ground!  That is Flight Test 101 stuff!  Which you just flunked,  in my book!

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#1043 2021-04-01 17:51:34

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,959

Re: Starship is Go...

Here is the rud flyover
https://youtu.be/CPHh3NPgLEw

Offline

#1044 2021-04-01 18:48:22

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,440

Re: Starship is Go...

GW,

I know that the design of the stainless balloon tanks used in the Centaur upper stage gave the engineers fits during development, but that was using Hydrogen and the tank had to remain pressurized.  I thought Starship doesn't require pressurization to maintain its shape.

Do you think that conical thrust structure that the engines are pushing against is cracking the welds or otherwise messing with the attachment of the propellant lines feeding the engines?

I seem to recall you saying something about that particular aspect of the tank design having been tested before, but not holding up well to the thrust loads generated by the engines, but maybe that only applies to Aluminum.

Didn't NASA also have problems with propellant leaks from flexible feed lines during the J-2 and RS-25 test programs?

Offline

#1045 2021-04-01 19:12:21

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,467
Website

Re: Starship is Go...

Hi Kbd512:

I don't think Starship has to stay pressurized not to collapse,  but I don't know how close those margins are.  I do know they have to have some significant pressures in those tanks to maintain sufficient positive pressure at the turbopump inlets.  It's called "net positive suction head",  and it is required to prevent cavitation or vapor lock in the pump inlet feed lines. 

All these same issues were faced with Centaur.  I don't know much about collapse of Centaur if unpressurized,  but the old original Atlas had that problem.  It was also stainless construction,  and very thin.  It only took a modest pressure to prevent collapse,  something like a single handful of psi if memory serves,  but without it,  the booster tankage failed,  catastrophically. 

I think the more-or-less conical "thrust puck" in Starship is a definite risk for weld cracking or outright puncture.  I'm guessing it is quite thin.  Not an optimal shape for a pressure vessel dome.  Neither is an ellipse,  which surprises a lot of people.  A segment of a sphere is the right shape,  connected to a thick ring that is actually quite localized at the joint,  to which is also connected the cylindrical section. 

Most boilers and pressure vessels are made that way. Because it works.  And not much is ever mounted to those end membranes.  Because that doesn't work very well.  You often see piping joints there,  but these are carefully stress-relieved pipe lines,  something you simply cannot do with engine thrusts.

I don't know if flexible plumbing lines are a leak risk or not.  Generally speaking,  in cars and airplanes,  they are not.  But,  hydrogen and to some extent methane,  challenge just about everything we have,  as far as leak risks are concerned. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#1046 2021-04-04 10:39:56

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: Starship is Go...


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

Offline

#1047 2021-04-04 11:17:25

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,467
Website

Re: Starship is Go...

Interesting.  I see workmanship is improving.  They are still developing their construction process,  but it looks more developed now.  I like seeing that they have been building the jigs and tools they need for this work. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#1048 2021-04-05 19:32:15

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,959

Re: Starship is Go...

Elon Musk reveals what made SpaceX's Starship SN11 prototype explode

"A (relatively) small CH4 leak led to fire on engine 2 and fried part of avionics, causing hard start attempting landing burn in CH4 turbopump," he wrote.

SpaceX will jump ahead to SN15, which reportedly incorporates a slew of upgrades Musk is excited enough about he opted to essentially throw out SN12, SN13 and SN14.

Offline

#1049 2021-04-05 21:19:31

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,389

Re: Starship is Go...

Gas leaks of high pressure cryogens are difficult to contain, but maybe some attention to using some armored wiring, in spite of the added weight, might seem prudent to protect the avionics? I know that weight is a major consideration, but survivability would rank higher in my estimation of handling problems.

Offline

#1050 2021-04-06 01:14:13

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,813
Website

Re: Starship is Go...

Rather than armoured wiring, I would expect simpler measures. First, fix the damn leak. A rocket can't survive a leak like that. Yes, Shuttle had measures to deal with hydrogen leaks. Silane sprayed under the main engine nozzles was not an igniter as I thought for many years, it was to burn off hydrogen. Because hydrogen is invisible, and hydrogen fires burn hot, can cause a lot of damage. So burn it off where rocket exhaust is supposed to go, where the vehicle can handle it. But still, a fire in the engine compartment of SpaceX Starship is a bad idea.

Alternate idea: instead of armoured cables, use wiring with Teflon insulation. Yes, Teflon insulated wiring is more expensive, but it's the same weight as polyethylene or polypropylene or nylon insulation, but Teflon is non-flammable and can withstand a lot of heat without melting. There's a reason it's used for Navy combat vessels. 10 minute endurance temperature for PTFE (common Teflon) is 325°C. Furthermore it can withstand cryogenic cold. If wiring is immersed in densified liquid methane for extended time, you would have to check which grade of PTFE.

Offline

Board footer

Powered by FluxBB