I didn't notice before, but their landing zone is quite far south. I think 70 degrees from the equator makes a record.
I wonder if that's why the weird transit. The "normal" method is only good if you can land close to the same orbital plane you're launching in, and it's really bad for anything close to polar like that. Maybe they're doing something similar to what Juno did to capture directly into a polar orbit.
+1
Options
AbsoluteZeroThe new film by Quentin KoopantinoRegistered Userregular
The 50th anniversary of Apollo 11 has me kinda bummed out we haven't done more since then. Where's our damn moon base?
The 50th anniversary of Apollo 11 has me kinda bummed out we haven't done more since then. Where's our damn moon base?
In the late 70s Wisconsin Senator William Proxmire, fiscal conservative and he of the Golden Fleece award, saw a 60 minutes piece on space colonization and had a massive tirade over it and lead a crusade to slash NASA’s budget because he thought it was sci-fi nonsense.
The 50th anniversary of Apollo 11 has me kinda bummed out we haven't done more since then. Where's our damn moon base?
Lost to politics mostly. The way things are currently, the only way for NASA to get any funding at all for an Apollo scale major spaceflight project is to run it in a pretty terrible way.
The 50th anniversary of Apollo 11 has me kinda bummed out we haven't done more since then. Where's our damn moon base?
Lost to politics mostly. The way things are currently, the only way for NASA to get any funding at all for an Apollo scale major spaceflight project is to run it in a pretty terrible way.
Yeah, if you want to feel bad read just about anything on the development of the SLS.
Shut up, Mr. Burton! You were not brought upon this world to get it!
The 50th anniversary of Apollo 11 has me kinda bummed out we haven't done more since then. Where's our damn moon base?
Lost to politics mostly. The way things are currently, the only way for NASA to get any funding at all for an Apollo scale major spaceflight project is to run it in a pretty terrible way.
Yeah, if you want to feel bad read just about anything on the development of the SLS.
By using existing technology we'll save time and keep costs down :rotate:
Starhopper test ended in fire. The engines fired but the rocket didn't move and fire erupted from the top. looks a lot more intentional and less impressive than the fire ast week, but the reason for an abort hasn't been released.
+2
Options
HonkHonk is this poster.Registered User, __BANNED USERSregular
They’re seriously intending to fly that thing made of sheet metal and two by fours? I don’t get what the purpose of it is supposed to be.
Starhopper isn't much more than a frame to test the engine system on, a lot like their older hopper that tested the booster recovery system. The actual Starship isn't going to have a wooden frame... but it apparently IS going to have a stainless steel skin for little reason except OOH SHINY SHINY.
+1
Options
BrodyThe WatchThe First ShoreRegistered Userregular
Starhopper isn't much more than a frame to test the engine system on, a lot like their older hopper that tested the booster recovery system. The actual Starship isn't going to have a wooden frame... but it apparently IS going to have a stainless steel skin for little reason except OOH SHINY SHINY.
I think they had a couple of reasons. IIRC, if you keep the steel cold enough, it has equivalent or greater performance than what they use for the Falcon 9, and there was talk of having a system where you would pump liquid through small holes in the skin during decent to take the brunt of the re-entry heat.
"I will write your name in the ruin of them. I will paint you across history in the color of their blood."
Starhopper isn't much more than a frame to test the engine system on, a lot like their older hopper that tested the booster recovery system. The actual Starship isn't going to have a wooden frame... but it apparently IS going to have a stainless steel skin for little reason except OOH SHINY SHINY.
I think they had a couple of reasons. IIRC, if you keep the steel cold enough, it has equivalent or greater performance than what they use for the Falcon 9, and there was talk of having a system where you would pump liquid through small holes in the skin during decent to take the brunt of the re-entry heat.
Yeah, at the temperature that the tanks have to be cooled to, stainless is actually competitive to carbon fiber and costs a fraction as much to use.
I can't find the source at the moment but I'll look for it when I get home.
Starhopper test ended in fire. The engines fired but the rocket didn't move and fire erupted from the top. looks a lot more intentional and less impressive than the fire ast week, but the reason for an abort hasn't been released.
Apparently chamber pressure showed higher than expected on startup, probably due to propellants being colder than expected, so it auto-aborted.
0
Options
Zilla36021st Century. |She/Her|Trans* Woman In Aviators Firing A Bazooka. ⚛️Registered Userregular
Starhopper isn't much more than a frame to test the engine system on, a lot like their older hopper that tested the booster recovery system. The actual Starship isn't going to have a wooden frame... but it apparently IS going to have a stainless steel skin for little reason except OOH SHINY SHINY.
I think they had a couple of reasons. IIRC, if you keep the steel cold enough, it has equivalent or greater performance than what they use for the Falcon 9, and there was talk of having a system where you would pump liquid through small holes in the skin during decent to take the brunt of the re-entry heat.
Yeah, at the temperature that the tanks have to be cooled to, stainless is actually competitive to carbon fiber and costs a fraction as much to use.
I can't find the source at the moment but I'll look for it when I get home.
I'm sure there's other ones, but there's this Popular Mechanics article. It's probably from early 2019, since it references a January 2019 tweet.
Most steels, as you get to cryogenic temperatures, they become very brittle. You’ve seen the trick with liquid nitrogen on typical carbon steel: You spray liquid nitrogen, you can hit it with a hammer, it shatters like glass. That’s true of most steels, but not of stainless steel that has a high chrome-nickel content. That actually increases in strength, and ductility is still very high. So you have, like, 12 to 18 percent ductility at, say, minus 330 degrees Fahrenheit. Very ductile, very tough. No fracture issues.
...
See, here’s the other benefit of steel: It has a high melting point. Much higher than aluminum, and although carbon fiber doesn’t melt, the resin gets destroyed at a certain temperature. So typically aluminum or carbon fiber, for a steady-state operating temperature, you’re really limited to about 300 degrees Fahrenheit. It’s not that high. You can take little brief excursions above that, maybe 350. Four hundred, you’re really pushing it. It weakens. And there are some carbon fibers that can take 400 degrees Fahrenheit, but then you have strength knockdowns.
But steel, you can do 1500, 1600 degrees Fahrenheit.
...
On the windward side, what I want to do is have the first-ever regenerative heat shield. A double-walled stainless shell—like a stainless-steel sandwich, essentially, with two layers. You just need, essentially, two layers that are joined with stringers. You flow either fuel or water in between the sandwich layer, and then you have micro-perforations on the outside—very tiny perforations—and you essentially bleed water, or you could bleed fuel, through the micro-perforations on the outside. You wouldn’t see them unless you got up close. But you use transpiration cooling to cool the windward side of the rocket.
...
The carbon fiber is $135 a kilogram, 35 percent scrap, so you’re starting to approach almost $200 a kilogram. The steel is $3 a kilogram.
President Rex on
+6
Options
Ninja Snarl PMy helmet is my burden.Ninja Snarl: Gone, but not forgotten.Registered Userregular
Holy shit, I had no idea the price difference was that huge. Also had no idea you could make steel that compatible with cryogenic temperatures, though I'm no materials scientists. Pretty amazing how versatile iron is when you know juuuuust the right amounts and types of impurities to add.
As for the regenerative heat shield idea, that's pretty interesting. You still have to carry the mass of the coolant, but you preserve the heat shield vessel itself. Is that really a possibility, though? I thought reentry heat was high enough that you're generating outright plasma and the particle energy is high enough to ablate whatever it hits, no matter how cold? Maybe with a low-angle lower-temp reentry?
Ablation is not necessary. Shuttle managed fine without ablative protection. You just need to be able to dump/handle the heat you aren't losing through the ablated material.
0
Options
Ninja Snarl PMy helmet is my burden.Ninja Snarl: Gone, but not forgotten.Registered Userregular
The particles indeed do ablate whatever they contact. But because theyre contacting water the steel behind the water doesn’t ablate.
At least that is the idea.
My first thought was that the system they were describing would indeed form a steam barrier between the hull and atmosphere, but I don't think that's the case. It seems to me like the system being described is purely for dumping heat and the outgassing material is just to carry that heat away. I could be wrong, though, and steam can put out quite a lot of force at high enough heat. Enough force to form a vapor barrier between a hull and atmosphere during reentry? No idea.
Ablation is not necessary. Shuttle managed fine without ablative protection. You just need to be able to dump/handle the heat you aren't losing through the ablated material.
Yeah, I was thinking about the shuttle heat tiles and couldn't remember if they're in any way ablative or not. I just remember that they're insanely heat resistant, but even a disposable ablative shield would want high heat resistance. In the interest of cost savings, I guess they could just use a steel variant with a higher melting point for the heat shield and then apply this system to it, as opposed to something like the shuttle's pricey heat tiles.
I'd wonder if there would be any weight saving as well, or if it just ends up being a wash. The coolant ends up being the mass you lose, but you'd need the steel hull and pumps and none of that is low-mass.
Starhopper isn't much more than a frame to test the engine system on, a lot like their older hopper that tested the booster recovery system. The actual Starship isn't going to have a wooden frame... but it apparently IS going to have a stainless steel skin for little reason except OOH SHINY SHINY.
I think they had a couple of reasons. IIRC, if you keep the steel cold enough, it has equivalent or greater performance than what they use for the Falcon 9, and there was talk of having a system where you would pump liquid through small holes in the skin during decent to take the brunt of the re-entry heat.
Yeah, at the temperature that the tanks have to be cooled to, stainless is actually competitive to carbon fiber and costs a fraction as much to use.
I can't find the source at the moment but I'll look for it when I get home.
I'm sure there's other ones, but there's this Popular Mechanics article. It's probably from early 2019, since it references a January 2019 tweet.
Most steels, as you get to cryogenic temperatures, they become very brittle. You’ve seen the trick with liquid nitrogen on typical carbon steel: You spray liquid nitrogen, you can hit it with a hammer, it shatters like glass. That’s true of most steels, but not of stainless steel that has a high chrome-nickel content. That actually increases in strength, and ductility is still very high. So you have, like, 12 to 18 percent ductility at, say, minus 330 degrees Fahrenheit. Very ductile, very tough. No fracture issues.
...
See, here’s the other benefit of steel: It has a high melting point. Much higher than aluminum, and although carbon fiber doesn’t melt, the resin gets destroyed at a certain temperature. So typically aluminum or carbon fiber, for a steady-state operating temperature, you’re really limited to about 300 degrees Fahrenheit. It’s not that high. You can take little brief excursions above that, maybe 350. Four hundred, you’re really pushing it. It weakens. And there are some carbon fibers that can take 400 degrees Fahrenheit, but then you have strength knockdowns.
But steel, you can do 1500, 1600 degrees Fahrenheit.
...
On the windward side, what I want to do is have the first-ever regenerative heat shield. A double-walled stainless shell—like a stainless-steel sandwich, essentially, with two layers. You just need, essentially, two layers that are joined with stringers. You flow either fuel or water in between the sandwich layer, and then you have micro-perforations on the outside—very tiny perforations—and you essentially bleed water, or you could bleed fuel, through the micro-perforations on the outside. You wouldn’t see them unless you got up close. But you use transpiration cooling to cool the windward side of the rocket.
...
The carbon fiber is $135 a kilogram, 35 percent scrap, so you’re starting to approach almost $200 a kilogram. The steel is $3 a kilogram.
Thank you for finding that, lol. Looks like I completely forgot to follow up.
The particles indeed do ablate whatever they contact. But because theyre contacting water the steel behind the water doesn’t ablate.
At least that is the idea.
My first thought was that the system they were describing would indeed form a steam barrier between the hull and atmosphere, but I don't think that's the case. It seems to me like the system being described is purely for dumping heat and the outgassing material is just to carry that heat away. I could be wrong, though, and steam can put out quite a lot of force at high enough heat. Enough force to form a vapor barrier between a hull and atmosphere during reentry? No idea.
Ablation is not necessary. Shuttle managed fine without ablative protection. You just need to be able to dump/handle the heat you aren't losing through the ablated material.
Yeah, I was thinking about the shuttle heat tiles and couldn't remember if they're in any way ablative or not. I just remember that they're insanely heat resistant, but even a disposable ablative shield would want high heat resistance. In the interest of cost savings, I guess they could just use a steel variant with a higher melting point for the heat shield and then apply this system to it, as opposed to something like the shuttle's pricey heat tiles.
I'd wonder if there would be any weight saving as well, or if it just ends up being a wash. The coolant ends up being the mass you lose, but you'd need the steel hull and pumps and none of that is low-mass.
Depending on how long the BFR will be in space, you are going to need water anyways, might as well use the grey water to pump through the skin.
"I will write your name in the ruin of them. I will paint you across history in the color of their blood."
The particles indeed do ablate whatever they contact. But because theyre contacting water the steel behind the water doesn’t ablate.
At least that is the idea.
My first thought was that the system they were describing would indeed form a steam barrier between the hull and atmosphere, but I don't think that's the case. It seems to me like the system being described is purely for dumping heat and the outgassing material is just to carry that heat away. I could be wrong, though, and steam can put out quite a lot of force at high enough heat. Enough force to form a vapor barrier between a hull and atmosphere during reentry? No idea.
Ablation is not necessary. Shuttle managed fine without ablative protection. You just need to be able to dump/handle the heat you aren't losing through the ablated material.
Yeah, I was thinking about the shuttle heat tiles and couldn't remember if they're in any way ablative or not. I just remember that they're insanely heat resistant, but even a disposable ablative shield would want high heat resistance. In the interest of cost savings, I guess they could just use a steel variant with a higher melting point for the heat shield and then apply this system to it, as opposed to something like the shuttle's pricey heat tiles.
I'd wonder if there would be any weight saving as well, or if it just ends up being a wash. The coolant ends up being the mass you lose, but you'd need the steel hull and pumps and none of that is low-mass.
Depending on how long the BFR will be in space, you are going to need water anyways, might as well use the grey water to pump through the skin.
I'm looking forward to the first pee-cooled starship.
Posts
as it went through the clouds all i could hear was
I wonder if that's why the weird transit. The "normal" method is only good if you can land close to the same orbital plane you're launching in, and it's really bad for anything close to polar like that. Maybe they're doing something similar to what Juno did to capture directly into a polar orbit.
In Saudi Arabia based on where NASA's budget went.
In the late 70s Wisconsin Senator William Proxmire, fiscal conservative and he of the Golden Fleece award, saw a 60 minutes piece on space colonization and had a massive tirade over it and lead a crusade to slash NASA’s budget because he thought it was sci-fi nonsense.
Lost to politics mostly. The way things are currently, the only way for NASA to get any funding at all for an Apollo scale major spaceflight project is to run it in a pretty terrible way.
Yeah, if you want to feel bad read just about anything on the development of the SLS.
By using existing technology we'll save time and keep costs down :rotate:
At this point I'll believe the thing's actually going to fly sometime around its fourth successful launch...
Starhopper test ended in fire. The engines fired but the rocket didn't move and fire erupted from the top. looks a lot more intentional and less impressive than the fire ast week, but the reason for an abort hasn't been released.
Or shifted into reverse.
I think they had a couple of reasons. IIRC, if you keep the steel cold enough, it has equivalent or greater performance than what they use for the Falcon 9, and there was talk of having a system where you would pump liquid through small holes in the skin during decent to take the brunt of the re-entry heat.
The Monster Baru Cormorant - Seth Dickinson
Steam: Korvalain
Yeah, at the temperature that the tanks have to be cooled to, stainless is actually competitive to carbon fiber and costs a fraction as much to use.
I can't find the source at the moment but I'll look for it when I get home.
PSN: ShogunGunshow
Origin: ShogunGunshow
Apparently chamber pressure showed higher than expected on startup, probably due to propellants being colder than expected, so it auto-aborted.
It's amazing Pegasus costs about the same as a Falcon 9 launch for 1/50 the payload. And it's cool that Russia is launching a science mission.
Holy crap! I am into this.
THE 1950'S WARNED US.
I'm sure there's other ones, but there's this Popular Mechanics article. It's probably from early 2019, since it references a January 2019 tweet.
As for the regenerative heat shield idea, that's pretty interesting. You still have to carry the mass of the coolant, but you preserve the heat shield vessel itself. Is that really a possibility, though? I thought reentry heat was high enough that you're generating outright plasma and the particle energy is high enough to ablate whatever it hits, no matter how cold? Maybe with a low-angle lower-temp reentry?
At least that is the idea.
My first thought was that the system they were describing would indeed form a steam barrier between the hull and atmosphere, but I don't think that's the case. It seems to me like the system being described is purely for dumping heat and the outgassing material is just to carry that heat away. I could be wrong, though, and steam can put out quite a lot of force at high enough heat. Enough force to form a vapor barrier between a hull and atmosphere during reentry? No idea.
Yeah, I was thinking about the shuttle heat tiles and couldn't remember if they're in any way ablative or not. I just remember that they're insanely heat resistant, but even a disposable ablative shield would want high heat resistance. In the interest of cost savings, I guess they could just use a steel variant with a higher melting point for the heat shield and then apply this system to it, as opposed to something like the shuttle's pricey heat tiles.
I'd wonder if there would be any weight saving as well, or if it just ends up being a wash. The coolant ends up being the mass you lose, but you'd need the steel hull and pumps and none of that is low-mass.
Thank you for finding that, lol. Looks like I completely forgot to follow up.
PSN: ShogunGunshow
Origin: ShogunGunshow
Depending on how long the BFR will be in space, you are going to need water anyways, might as well use the grey water to pump through the skin.
The Monster Baru Cormorant - Seth Dickinson
Steam: Korvalain
I'm looking forward to the first pee-cooled starship.
I have previously referred to Virgin's SpaceShipTwo, which burns HTPB-infused rubber and nitrous oxide, as "the world's first suborbital tire fire."