8:00 just a minor correction. You say that this heat is caused by the friction of reentry, but friction isn't the mechanism for generating heat in this case, it is compression. The air right in front of the boosters can't get out of the way fast enough as the booster plows through, so it gets compressed. Ideal gas law says that if a gas in a fixed volume increases pressure, it also increases temperature. So anything moving supersonic is going to have a pressure front which causes heating. It isn't the air rubbing up against it that causes the heat, but the air getting trapped; unable to escape at its maximum speed limit, and getting highly pressurized.
I think this is mostly the case during the orbital reentry but at the speeds the booster was going friction is also a significsnt contributor, no? Not being a smartass, genuine question.
@@TheNheg66 No.. the compression generates the heat. At re entry speeds and altitudes the heat is so great that the molecules change phases into a plasma which would burn up almost anything.. What we saw was less than plasma but still very very hot. There are ways to mitigate the issue. 1) ignite one engine to push the compression wave away from the engines( some designs I have seen have a small engine just for re-entry phase, but that was for the high altitude plasma orbital re-entry) . 2) have a spike out in front to create a shockwave compression wave in front of the spike .. that's why many supersonic jets have a spike nose . sometimes a flat nose design functions to do that as well. 3) just "tank" it. ie. make the material strong enough to take the heating. 4) Slow down more, maybe more grid fins or different designs or materials. or fly more side ways to make the decent slower/longer. ie make the chines more aerodynamic a bit more like wings.. Should be fun to see which way they go.
Yes, there are, several were commenting in a thread about this over on a hobby forum named Starship Modeler _(which was named a couple decades before SpaceX's Starship entered the realm of existence)_
The head of the ESA (european Space Agency) was probably talking bad about it! Whoever it was in 2014, laughed at SpaceX & Elon when he announced they would attempt to land a Falcon 9! It took several tries but SpaceX has landed 350+ Falcon 9's! The people mocking SpaceX are small-minded CAN'T DO people! Not who I want working on the US space program! Go SpaceX!
There are always people eager to find and jump on the slightest imperfection and call it a horrible failure based on that, and if they can't find one they'll just make something up!
Technical or procedural issues arising during a test flight is rather mundane, catching a flying rocket booster is about as far as far from mundane as you can get! (at least it is at this point in history)
Booster Five did a beautiful job she looked fantastic with all engines burning beautifully, and they relit when commanded, Five needs to be in the rocket garden!
Having the vented methane (which would be only a tiny fraction of the total fuel supply anyway) burn as it exits the vehicle is actually better for the environment than releasing it unburned, that's why they used to have flare stacks on the methane system in the ground support equipment (before they got the recondenser system). I bet they were basically trying to eliminate as many potential risk factors as possible, since this was the first time they'd get a booster back intact, assuming it worked, and they really wanted it to work!! 😅 Perhaps they will eventually determine the venting to be unnecessary, or make other improvements that mitigate the amount of fuel that has to be vented.
The venting will be necessary. The landing burn is done with seperate tanks that are pressurized with helium. The autogenous pressurization of the engines has to be vented because it can't go back into the main tanks. The main tanks are already pressurized and you don't want to overinflate the rocket
Thanks for a very good summary and analysis. I saw it all live on Sunday and it is without a doubt spectacular. I want to give you an extra plus for your summary. I think you give us a suitably in-depth insight and analysis. Understand that it requires both time and knowledge. Very much looking forward to new videos.
Great vid. Thanks for this. Re the methane… the amount vented will essentially be sweet nothing in the giant scheme of things. Please correct me if I’m wrong. 👍👍👍
Decent, but the voice has some pitchyness. As someone who has the opposite problem(flat voice) I understand why someone would NOT want to listen. Presentation matters, and here her voice is NOT melodic. Nothing she can do with anymore than I can fix my ~FLAT voice which put the cabosh on a career I was going for.
I just remembered “ you’re go to continue power decent , you’re go to continue power decent, you’re go to continue power decent” that’s what happen over 50 yrs ago when Apollo 11 was descending to the moon! Wow ! Space X you rock!
A truly momentous accomplishment for SpaceX, seeing it is something I'll never forget! Elon said they might try to catch Starship on the next flight, assuming OLM 2 is ready by then. Some commentators have said the fire was from the methane umbilical connection FWIW.
I don't think they have anything close to approval for that. They have to fly over land from the west and not break up. They have been in talks with Australia to potentially do some testing on their coast land to prove. Alternatively once block 2 of Starship has done a couple successful full orbit insertions and de orbit burns, with a reentry that has no burn through, then they can deal with just the public issue of sonic booms and the safety of a failed catch is not a concern in a controlled area
Also those babies were glowing red hot on the way down , smoking baby! That might be an issue if something melts or burns up , man she was falling at what over 3,000 km things got real HOT!
After booster 12 was caught and lowered to the OLM, the quick disconnect automatically connected. When they are going for quick turnaround, it will be refilled instead of vented. While they are in analysis phase they will start capturing and re-chilling leftover prop. In addition, they had excess landing prop this time for safety margin. When they have the landing requirements dialed in, they will run the booster longer after launch before returning to tower, which will decrease the excess booster prop and the dV starship needs to reach orbit.
Thank you for discussing the fire that was coming out the sides. No one has been talking about it, and it seemed important to me, especially since it continued several minutes *after* the catch, and that didn't seem normal to me.
If they do end up doing high quantity of launches, it should be trivial by then to build a bleed-off methane capture system around tower base, to reduce a large percentage of release. Long-term they are looking into CO2 capture from atmosphere to offset emissions entirely.
The reason why the booster is not fitted with landing legs is because it is a big rocket and it’s going to get even bigger in future. The size is critical for the success of the mission to colonise Mars. A colony there meant to preserve humanity and human consciousness must be self sustaining which means it must be big. The way it’s going to be done is lots of huge rockets sending lots of materials to build the colony as quickly as possible. Hence why Starship and its booster is so big and will be made as big as possible.
Saying that the arms 'catch' the booster is like saying an aircraft carrier 'catches' it's returning aircraft. They both move and they both provide a landing surface. Just because the chopsticks have more fine control in presenting it's contact surfaces for the landing doesn't mean it 'catches' the booster.
Love, love, love your videos! What I found to be the most incredible thing about this test flight was how Super Heavy was able to literally thread a needle to get caught by the chop sticks. How was SpaceX able to be so precisely maneuver the 20-story booster? I find it hard to believe the unexplained flames shooting out were that accurate! I'm surprised that this incredible feat isn't even mentioned. Keep up the excellent work! Looking forward to your next upload.
Great work very clearly put together and easy to understand ! I hope one day you’ll get to cover a live launch at starbase or even just a walk around Keep up the great work
The catch of the booster will uncover a huge amount of flight data, but having the booster back for physical inspection will greatly increase the pace to update the design to correct any problems!
Great breakdown. I think another important point is if your landing infrastructure is ground based its easier to repair and improve on than if its on the rocket.
Thank you for the summary and explanation. Especially thank you for mentioning the methane venting and its environmental implications at the end. That last bit was among my biggest takeaways from this particular test flight (aside from the insanity that is catching that booster, obviously): How did they safe the booster afterwards? In fact, how do they safe the F9 booster after landing? They can't just vent and de-press all their tanks, or can they? - Okay, LOX I can understand, no biggie. - RP-1 should also be able to just depress and happily sit in its tank until being drained later. - But methane really is an issue, no? I bet they vented it for this flight, unless they were able to attach the QD fuel line again. In a distant future, the plan likely is to never safe and depress the tanks at all until next launch, but even then gaseous methane has to leave the tank somehow via the propellant load system.
Some of your initial questions are relevant, but some of them are silly and have been answered several times for other rockets, e.g. why not use a parachute.
One minor correction, you said in previous flights SpaceX dropped the booster into the ocean which is not quite right since the first few were blown up using the FTS and the last had a simulated landing on top of the ocean rather than dropped.
Once Starship goes fully online Falcon 9 and all other launchers that are not fully reusable become virtually obsolete and irrelevant. As cool as it would be to see Falcon upgraded, I doubt SpaceX will even bother since Starship is so vastly more capable.
TY TY Thank you you are the first to address the fire on the side , there was one comment about venting fuel but still a couple of panels were missing.
Not everyone can watch every video. Nasaspaceflight noticed right away and started theory crafting minutes after the catch. It’s great that we can have so many audiences interested in space flight!
When you compress air all the heat that was already present in the air is now concentrated in a smaller space causing the temperature to rise. Imagine all the heat in the room you are in, now compress all that air into a small box. The same amount of heat that was once distributed into the whole room is now concentrated inside your small box. It isn't friction that increases the temperature, it is compression that concentrates the heat increasing the temperature.
@@wally7856And that same principal is used in heat pumps, concentrate the energy on the condensing side and get rid of the heat, then with a restricting device you create a low pressure side where the refrigerant will more readily evaporate once it takes on heat from the evaporator coil. Rinse and repeat
The amount of GG that is created by starship is minuscule. Landing at the pad for immediate reuse means less transportation to get it back. If it had to propulsively land elsewhere and the get trucked back to the pad, that's more GG. But ultimately look at the pollution created by the entire rocket industry, and it'll barely register as a blip. Also, the water deluge "issue" is a non-issue. It's not industrial water, never in contact with industrial process. It's potable water. No different (or maybe cleaner) than a rain shower.
To cover arguments made against it. The potable water does collect some metals from the plate, but they've done water testing and have passed by enough to get an industrial waste water permit and the EPA issue is purely paperwork and no change has to be made. They had the wrong permit from the wrong organization, but the requirements are the same.
I wonder why Space X didnt rent a landing zone in Australia to test the small landing feet they use for starship 5. Crashing at sea during night is not very instructive
They wanted a nighttime re-entry, makes it much easier to see the plasma flow and any burn through. They added additional cameras to monitor each flap. Being Australian, our government is 10x worse than the FAA.
Just guessing here, but I think either SpaceX or the Gov't (maybe both) aren't keen on letting the technology be exposed. Which is likely also the reason we saw the ship explode once it was in the water.
They intentionally timed the it to have the launch happen at sunrise and reentry at night. It gave them daylight for the booster catch, and also allowed them to better see the thermal glowing. The primary focus for this Starship was heat tile improvements. With the suite of onboard sensors they don’t need light to know if the telemetry was nominal. It landed in the ocean right next to a stationary buoy with a camera so that part worked perfectly. The heat tiles were a vast improvement and the redesigned flaps on Block 2 boosters will likely fully solve the heat tile issues.
Don't know if it was intended, but its better that vented methane burns if it doesn't damage anything. Methane is a much more potent greenhouse gas than CO2.
Yep. Any hydrocarbon creates soot. You can see it on the inside of the engine bells. It's not as sticky as kerosene but it still makes soot, fine soot.
Concerning the exhaust gases (CH4 and CO2), it's really hard to make a spacecraft that can go to Mars, refuel in situ and return using something less toxic. It's not like we'll be launching rockets using wind or solar anytime soon. Also, considering the amount of exhaust gases, In 2018, the global CO output of rockets was only 0.0000059% of all CO emissions, so even if we increased the launch cadence 100,000 fold, it still would only make up 1% of industrial emissions. Even the most hardcore climate activists can find better places to spend their energy.
I think this topic deserves a deeper dive. I'm not a hardcore climate activist, or anti-SpaceX/anti-Elon. First, the Raptor engine is the first methalox-based engine that can be in any way be considered production level. It clearly is designed that way for some good reasons, works well, and is and will be copied. Blue Origin is developing the BE-4 engine, and China is developing something as well. So an analysis based on the absurdity of a 100,000 fold increase is invalid because we are starting from essentially zero. Second, the Everyday Astronaut mentioned something that alarmed me in a Q/A during his live-stream of this event. He was asked; "During a mission-scrub, how much of the fuel can be re-used,?" He said that 50% of the fuel can be returned to tank-farm before it boils-off and is vented into the atmosphere. I don't know what the break-down is in the boil-off of methane versus oxygen. I'd love to hear some data about that. Thinking in terms of the full life-cycle of a rocket launch, you also need to consider the atmospheric losses associated with the engine tests, as well as the losses involved in the production and transportation of the methane. I don't know if this totals to a significant amount; but I sure would be reassured to learn we have good ways to monitor, measure and regulated this. Finally, and this is the area I'm least familiar with - do we really have any idea how much commercially-generated Natural Gas (methane) is released into the atmosphere? People always mention cows when this topic comes up, but the cynic in me thinks that this may be just a well-placed red herring inserted into the public dialog to dismiss and distract. In the last decade America has made a significant transition from coal-fired to natural gas power plants. And while that sounds like a win to a layperson like me; I heard a Wall Street analyst mention that natural gas plants are still much "dirtier" than nuclear and renewables because there is so much methane that gets released into the atmosphere throughout the supply chain. How is inadvertent commercial methane gas released into the atmosphere monitored? Can it be accurately measured? Is it effectively regulated? I have no idea. Circling back to rockets, I think what SpaceX is doing is both amazing and great. There are a huge number of trade-offs in any endeavor like this. I'm not interested in an analysis of alternatives, because I understand the reasons behind SpaceX development of a methalox-based engine for this mission. So, if we assume methalox becomes a dominant rocket-fuel this century, what are the near and long term implications on our atmosphere? And in the short-term, what can be done to minimize how much methane gets released?
@@michaeliamsbefore attempting to respond, I’d like to say the numbers put forth in my comment were taken directly from google AI and I’m in no way trying to come off as an expert. With that said, everything is “dirtier” than nuclear as it has no emissions unless a major failure occurs. In 2018 almost all rockets launched (114 total) were kerosene rockets which by most standards are much worse for the atmosphere. We’d literally have to go from 114 rockets per year to millions of rockets per year to get close to basically any other industrial sector in terms of being bad for the environment.
@@michaeliams Great points, both of you. Thanks for the comments. I am a big space enthusiast and also a tiny bit of a climate activist. Both interests do not align very well, let me tell you, and I am struggling with that regularly. If I may add my two cents: Rockets are certainly not a big factor when it comes to GHG emissions, and they'll likely not become one in the near future. (In fact, satellites are great tools to study climate change) But they are not climate neutral in any sense either. They are bad for the environment and there is no way around that. We should do everything we can to make them as sustainable as possible (re-usability is great for this, btw). If we don't then one day we might lose access to the great tool that is spaceflight altogether.
Thank you for walking us through this. It's also good to celebrate the advances in rocketry-science while separating it from the complicated emotions surrounding the company itself.
Black smoke after Raptor shutdown is normal. You can see at their McGregor Raptor engine testing. Raptor use LNG, not a pure methane. And the engine compartment is protected by a metal shield, to protect it from the heat of reentry.
@@danwhiffen9235 Not really. Here's a quote from their PEA: "The natural gas pretreatment system and liquefier are no longer needed due to advances in the design and capabilities of SpaceX’s Raptor engines"
@@807800The difference between LNG and LCH4 is barely worth mentioning though. They're very nearly the same because at the liquid temp of natural gas, pretty much everything is past the solid temp and separated. No smells, no water, no CO2, really nothing but methane. Definitely so impurities that would cause black smoke. Methane alone can burn black when extremely rich, or something on the vehicle itself. Any carbon based fuel creates soot. The soot of methane is much finer than kerosene, but it's still there. It's less sticky and won't gum things up, but you can see a black soot coating on the inside of raptor engine bells that have fired enough.
@@Jaker788 Well, that's why comment regarding it being LNG and not pure methane was in a separate line. As for Raptor, it's using the propellant for the throat film cooling, so, there would always be more propellant than oxidizer, making it fuel-rich exhaust. That's probably most of where the black smoke comes from.
@@807800 fair enough. I never knew they were using LNG. Everything I’ve ever seen speaks of pure methane. So sure, a little more soot or uncombusted hydrocarbons. Nothing of interest imo.
SLS is not super heavy, don't confuse the two rockets. SLS is not going to refuse, only Starship can refuel. This is why Orion space capsule is so tiny.
Still a worry that this system both booster and ship use too much fuel for any useful orbital operations. The ship is already out of fuel during these suborbital test flights. Fuel economy is a great concern.
I personally am much more concerned about global thermonuclear war than global warming. We can quite easily survive warming. We cannot survive nuclear extinction. Elon putting our species on Mars mitigates both scenarios, so well worth any possible negative impacts from this relatively miniscule greenhouse gas emission.
Soooooo.. should SpaceX now try to catch falcon nines the same way. Sounds like they could save 8% of the total rocket weight. I guess creating a hoverable falcon 9 might be in order?
The black smoke is probably methane (fuel) -rich vent gas burning. Not a big deal. Parachutes are huge added complexity and not precise enough for a precision landing. Legs are too much added mass (and complexity) that reduce mass fraction. The chopsticks are better.
This flight used Raptor 2s. The current assumption is that Raptor 3s will be used for the Block 2 boosters along with Starship V2, but there are already plans for the generation of boosters/ships beyond that.
If water and CO2 are bad for the environment then we should all stop breathing. The earth recycles it all. IMO we'll move past the petroleum age before it is any huge threat. Still, I support good stewardship, but let's not get all crazy apocalyptic about it.
The issue is introducing carbon back into the atmosphere that has been locked away deep below the earth’s crust for millions of years as oil & natural gas. Also the rate at which the carbon is being released since the beginning of the Industrial Revolution. The change is happening faster than earth’s current recycling system can handle and it will take centuries for the system to adapt. In the meantime tge excess carbon is destabilizing climate patterns. As far as getting apocalyptic about it I agree to some extent. We are not going to cause mass extinction due to climatic effects. What will happen is some currently populated places will become much more difficult to live there. Which will dramatically increase migration and immigration. Given the current world events how do you think the world will handle at massive spike in immigration?
@@ReinReads Great points. I would just like to add that climate change is indeed already starting to cause mass extinction events. The IPBES estimates that climate change alone might threaten up to 5% of Earth's species, ranking it the 3rd largest threat to biodiversity, after land and sea use change (1st) and exploitation (i.e. overfishing) (2nd).
You raised the issue of environmental concerns with the methane venting, but what you failed to do was compare that environmental impact to any alternatives, for example to send the same mass to orbit on a few Soyuz rockets that get expended would that be more environmentally friendly? Many countries phased out leaded fuels in cars because of the health impacts of lead poisoning, but the solution in the 1980's was unleaded fuel which is a known carcinogen, given the choice between cancer and lead poisoning I'd probably choose lead poisoning, my point being apply context to your environmental concerns, because if something is blocked by environmental concerns because it's not environmentally perfect but is less bad than the thing it would replace and is in current use, then we all loose. I'm not saying Starship is better, I'm asking how does it compare? I don't know the answer, but since you raised the environmental concerns, you should have also answered this question.
Geeez people… the fire is just another small thing Elon has to tweak once he sees it needs addressing.. How many of you have ever invented anything and have to keep refining it after each testing… good grief… just hush …..
Hi , Skrishna ...mention was made about all the carbon based fuel was being used which is not good for the environment......agreed......in contrast do you have any idea what the carbon savings would be on not have to produce a super heavy booster every launch.......based on my limited knowledge, steel production is a huge carbon producer.... if you consider it from mining...transport ...processing ...finished delivery ....final product... etc etc...........its my guess that methane burning is not the real culprit compared to total Production Carbon numbers......i would be interest to know the final figures....production verses operation carbon,,,,
If you are going to use rockets, you are going to have pollution. This is like fretting over the fact that some town in Connecticut heats all its homes during the winter . . . .
18 mins spent and the only new thing that i havent heard before was that black smoke is black possibly because of internal non-methane fire this video shouldve been a short
Been waiting for your video. I trust your analysis more than anyone else. I’ve checked. I love your explanations. You’ve got information I don’t, and don’t know how to evaluate.
Typical climate change view--I am sure you are smart enough to realize the following fact if you could just think a little. Let’s look at the total amount of “global warming” gases added to the atmosphere in the production and use of a booster. From the gases produced in the mining and production of the finished parts of a booster to the launch to the venting. You have to realize this is only a one time event if the booster is reused. If the booster is dumped into the ocean after each flight you must make a new booster. Common sense says that if the booster is used multiple times there are not only big financial savings but also much less “global warming gases produced.
@@danwhiffen9235 Probably a combination of HLS, Commercial Crew/Resupply, Starlink and other customers. Starship is mostly an investment in Starlink. Landing on the moon is an investment in nothing.
No it wasn't, they said they were attempting to keep it intact and adjusted the landing angle to do so. The issue is the after it tips over and slams in the water, the downcomer tube breaks and the propellant tanks connect and combust. This is the same thing that happened to the booster on the last test
Global warming is real. Man made global warming is dubious. Human contribution to climate change is somewhere between 0% and 100%. The climate alarmists think it’s 100%. My guess is closer to 5%. But trust “The Science” (tm). Look at how well it worked with Covid…
Worrying about the current CO2 output of rockets compared to the rest of the world's contributions would be like worrying about focusing on a single leaf in a forest fire. There are much worse offenders that we should be focusing on
