SpaceX has gotten reduced cost engineering since its inception, due to telling their employees that the entire purpose of SpaceX is to put humans on Mars. Everything was about making money while developing the technology to do, and then using that money to achieve that goal. Going public in this way fundamentally creates a conflict there. Given that Musk has already used SpaceX to bail out his Twitter acquisition, it feels like both investors and hopeful engineers are going to lose.
* There are many useful ways to handle it properly, and your choice depends on your program's constraints. The very small amount of friction (once you're used to it) encourages you to consider what ways to handle it are viable, such as allocating all memory at startup.
* If your strategy is to crash immediately, there is very little additional friction but you get the benefit of it being obvious in your code that this is the case.
* There are environments where memory allocation fails immediately, including if you turn off over-commit on Linux. If your hardware is dedicated to running a high reliability system, configuring it in this way is reasonable.
* Memory is not the only resource. Indeed, removing the special call out is what changed here. That different resources are handled with the same mechanism (errors, instead of eg returning null from malloc) is good.
Autors of Zig did a choice for me. I can't use RAII in it. In C++ it's better - when I don't care, I just use standard library containers, when I do care, I can bypass them.
To add to this excellent explanation:
Rockets have a fundamental problem. They need to go absurdly fast. If you have a rocket that can reach speed X, to go faster than X you need to reach X but also have fuel left over. However to get that fuel to speed X, you need even more fuel. This is the tyranny of the rocket equation.
Roughly put, the rocket equation is: change in speed = (engine efficiency) * log(mass of the rocket with fuel / mass of the rocket without fuel). So there's limited parameters to play with:
- The speed you need to reach is fixed.
- You can change the weight of the payload. Payload (eg, satellite) designers try to make things as light as possible, rocket designers try to give as much capacity as possible, and everyone prays they can meet in the middle.
- You want as little propellant as possible for cost and practicality, but mostly the other parameters fix how much you need. If the other parameters aren't good enough, you can easily get results like needing a rocket the size of Central Park. [1]
- You can make the engine more efficient. This means running it hotter with higher pressure, pushing the limits of material science. [2]
- You can make the non-payload static parts of the rocket lighter. This means removing structural integrity. It also means making the lightest parts to complete hard tasks like being a valve for cryogenically cooled, literally the smallest element, hydrogen.
Both the engine and non-payload static mass are essentially asking the question "How far can I push this without it breaking". Get your answer to that question even slightly wrong on any of the thousands parts in a rocket, and suddenly all of the fuel that you're using to go in one direction fast decide that you should instead go in every direction fast.
[2] Or not using chemical propulsion. However things like ion engines don't have enough thrust to get through the atmosphere and into orbit, and things like nuclear propulsion spew fallout everywhere.
Nuclear rockets aren't suitable to get orbit, they are too heavy. Also, nuclear rockets can separate the reactor and the propellant, called close cycle. I think the solid core reactors that are feasible send propellant through reactor but all of the fuel is encased.
Analysis video by Scott Manley notes that other comparable tests did not have visible fire at all, so it seems it started lower on the rocket and that the upper fire ball was either a secondary explosion or something coming up the transporter stand: https://www.youtube.com/watch?v=aaR6yEE-Myo
- Launch roughly on time, after a scrub yesterday. (Sounds like the scrub was due to ground equipment, most notably the water system.)
- Initial ascent was good, but then one engine on the booster went out.
- Relight of the booster's engines after stage separation for the boost back burn failed. Engines did light again for a landing burn, but seems to have hit the water harder than expected and was very off target.
- Starship lost one engine shortly after stage sep. Turned into an unintentional test of engine out capability. It made it to space.
- Some weird motion and lots of off-gassing after engine cut-off, with uncertainty about if it actually got a good orbital(ish) insertion. Seems to have been benign, with the motion being a weird slow flip to the orientation for payload deployment.
- Test deployment of dummy payloads was successful, including a couple with cameras to look back at Starship.
- An in space engine relight test was skipped, presumably due to the issues during launch.
- Re-entry to over the Indian Ocean seemed to go really well. Nothing obviously burning or falling off. The amazing views of the plasma during re-entry, something never seen live before starship, are now routine.
- Starship did a maneuver to simulate how they'll have to go out over the gulf and back to the landing site.
- Nailed the target, evidenced by views from drones and buoys. Soft landing before falling over and giving us a big (expected) boom.
As far as overall progress from previous test flights goes, they're at least treading water while making many large changes. I think they were hoping to try for a tower catch and actually going orbital for next flight, but I highly doubt that now. The boostback burn failing was the largest failure, with the engine failure on Starship being a close second. Good performance despite engine out seems to be an unintentional success.
Good summary. The booster appeared to hit the water at 1400 km/h (a bit under 900 mph) so not really survivable :-). Engine out on ship seems to left them with just enough fuel to land but not enough to do the hover thing (simulates being caught by chopsticks). They notched it down to two engines (vs planned 3) on the landing it seems?
Basically if they can figure out the engine issues, it looks like they should be able to do a full end to end flight. That's reasonable progress. Given the IPO this was a pretty important flight and I don't think they hurt it (like blowing up on the launch pad would have). So their one step closer it seems.
Hmm, I've seen data that landing the booster on 2 engines was the plan, but hadn't seem similar things about Starship. The difference is the chamber pressure you need in the individual engines. Lower chamber pressure has, in the past, been easier to modulate for precise control. Do you know if they've done any white papers or patents on V3's flow aeronautics?
Rocket engines can’t throttle down very much. Raptor can go down to 40% of its rated thrust, which for V3 would be 100 tons. The ship’s mass is maybe 150 tons with remaining propellant at the start of the landing burn, and probably around 100 tons at the end of the burn. Even at the lowest throttle, three engines would give it a thrust to weight ratio of 2, making hovering impossible and a suicide burn tricky. Two engines gives them redundancy, roll control, and a lower thrust to weight ratio to help with landing precision.
I’m surprised they went down to one engine at the end, because that means they lose most of their roll control. The only way to roll with one engine is to use the cold gas thrusters, which aren’t nearly as powerful.
They have a new RCS system on V3 which appeared to be hot gas thrusters. The landing was 3 engines lit to 2 to 1, using the lesson learned in very early flights to have an extra engine in case one fails unexpectedly.
I doubt it since many of the booster engines didn't seem to relight, the location of touchdown wasn't near any pre-positioned cameras (if there were any).
Not that I have been able to find, the 1400 km/h number comes from the telemetry on the video just before it contacted the water. Presumably one could estimate the return point if you had access to the telemetry and perhaps a platform in the Gulf might have eyes on it. Depends on how far east it got.
It looks like the ships software did a phenomenal job compensating by adding that much longer Second stage burn time. It was also very cool to see the sea levels vector to compensate for the thrust asymmetry. All and all that ship is look really realllllly good. Seems like they just need to add some mass to Raptor to reduce the tendency to tear itself apart..
1 out of 33 failing hardly seems like a tendency - probably some minor issue. Relight was likely an issue with new downcomer that was supposed to improve boost back engine feeds for its flip maneuver - that seems to need work.
Scott Manley pointed out that it seemed to flip in the wrong direction, with one of the grid fins passing through the plume and inducing a roll. Will be interesting to hear more about that.
The videos are great!, but the rest of it is never going to work lol, just never. Even without a rethink about how to get heavy payloads to another planet this is still good entertainment.
The hardest problem in the entire design had yet to be solved. Having a robust human rated tile system that can be rapidly turned around is a huge engineering challenge that kind of breaks the whole point of the design if it doesn't work. I wouldn't be surprised if they eventually give up and go back to a cheaper throw away second stage, or throw out the tile design completely and try for some evaporative cooling approach, again.
Bear in mind that a lot of what's happening to the tiles now is deliberate experiments to see how much weight they can shave off and how many failed tiles they can survive. Given that the vehicle is routinely surviving reentry at this point, it doesn't seem "hard" to make the tiles more robust by paying for it with added weight. The question is whether they'll have enough weight budget to pay for it? But at this point...probably? Not my area ofc.
Human rating is irrelevant to what they want to do, it is only a NASA rating - if NASA wants to ride they will have to come up with a rationale but private astronauts can fly on it.
I really hope to see the evaporative cooling make a comeback but it seems unnecessary when it’s returning to earth right now.
It would also be interesting to see them do shallower dips into the atmosphere then pull back out and repeat. Like a skipping stone. Lots of expansion contraction, but might work better without tiles.
They’ve already shown they can replace all the tiles in a couple of days with removal and new install. No reason they couldn’t do even faster turn around with just re-install if that was needed.
And human rating is a NASA requirement they won’t have to worry about for a few years.
Even if it landed perfectly how is it going to be rapidly reusable with all those tiles breaking and needing repair? Then if that problem was magically engineered-away through some sort of materials science breakthrough, it still makes more sense to me to keep your big ships in a space staging area and your smaller ones as atmospheric gophers.
All what tiles breaking and needing repair? There was remarkably little visible damage this time around compared with previous flights.
There's no materials science breakthrough needed -- the shuttle used ceramic tiles successfully its entire service life. What's needed is engineering work, and that's what SpaceX has been doing.
You know a whole the size of a quarter can wreck the entire spacecraft and make it effectively throw away? Also, you'd want to use this many times. Making a system robust while not requiring months of refurbishment is really really hard.
coming back in one piece, and being good enough to use for 5 more missions are two very different things. For example, all existing reentry vehicles come back "fine" but they need to be completely remade to go up again.
uncritically believing this design will succeed, despite having all the signs of Elon interfering and massively shifting requirements, isn't "hard" either
Deliberately testing its survivability with that failure mode over different parts of the vehicle has been one of the major foci throughout the entire test campaign, and it has proven remarkably resilient. That generalisation pretty much does not hold for starship.
Weren't the tiles one of the worst obstacles to quick turnaround times for the shuttle? It was something like 18 months before one could be launched again, and that's if they were in a hurry.
SpaceX has been specifically engineering both the tiles themselves (e.g. manufacturing) and the way that are used on the ship to be much more rapidly repairable than the Shuttle.
Could you tell me more? I suppose a heavy two-stage rocket is not optimized from the point of view of the rocket equation, but I know nothing about this field.
In short, the more stages the better to discard mass once it isnt necessary, and the larger to the better to improve the ratio of (ship+payload) to fuel.
This is only true to an extent. Yes, a larger rocket means a better mass:payload ratio, but a larger rocket also means more mass in absolute terms, and more mass means more fuel, and more fuel means more mass, and more mass means more fuel, and more fuel means more mass, and so on. This is "the tyranny of the rocket equation", and it places an upper bound on the size of rockets that need to carry their own fuel for a given gravity well. And because the larger absolute mass of a larger rocket means more fuel, which means more cost, it relies on actually being able to find enough paying customers to fill out that payload capacity every single time. This is why, for example, despite the existence of jumbo jets (which have a better mass:payload ration than smaller planes), most passenger flights are not on jumbo jets, because there's just not enough demand on most routes.
No it doesn’t matter if the payload is full or not. If they succeed in full reuse, flying on a mostly empty Starship will be ten times cheaper than flying on an F9 and that means everything will switch eventually.
If a jumbo jet was ten times more efficient than a smaller plane, they would go everywhere. If a giant pickup truck got a 100MPG, why would you take a 30MPG economy sedan anywhere?
> This is why, for example, despite the existence of jumbo jets (which have a better mass:payload ration than smaller planes), most passenger flights are not on jumbo jets, because there's just not enough demand on most routes.
Airlines used to use a hub and spoke model where it would make sense to have larger planes between hubs and smaller ones to get to and from the hubs, but consumers strongly preferred direct routing, so it didn't work out. For orbital payloads, most payloads probably do not mind too much if it takes a month or more to boost/deboost themselves to their intended orbits.
You fundamentally misunderstand the implications of the rocket equation. It does not put and upper limit on rocket size for a given gravity. Smaller rockets would not be successful where larger fail.
Due to strucrually efficiency, larger ones suceede where smaller fail due to higher m0/mf ratio
The design is wrong in a fundamental level. The rocket equation says it all. By adding so much extra weight for “reusability” (which they don’t release numbers on in terms of cost and means nothing when the rockets end up in the Indian Ocean) they nerf the performance.
Hence tens of launches to make the moon and zero payload to orbit in a dozen flights.
This forum is full of fanboys but their arguments don’t hold up to reality. Saturn 5 had men on the mock. This much time and this many rockets in. Starship has launched a dozen times for $15B - over a billion per launch - and it hasn’t made orbit.
Say what you want about SLS, it works.
Musk is a conman and Starship is a failure. Like the F-35 supposed libertarians and conservatives will happily throw money at it until it achieves its targets, after multiple redesigns, and then claim success as if the neigh-sayers weren’t right all along.
SpaceX probably spends a lot of money on marketing/public relations creating great media. I'm guessing NASA's on a shoestring budget for that kind of thing.
SLS was far from a shoestring budget and both NASA and Boeing/Northrop/etc have equally strong incentive to provide solid coverage for the public to keep the jobs program going.
SpaceX has much better infrastructure for video with their satellites and are just generally more competent at production
If we look at the venting from the propellant tank (around T+16:15) it looks thick white closer to the vent, becoming more transparent and blue as it expands. That's just sunlight scattering on the particles and density fluctuations in the flow.
A good cold gas thruster produces a lower density, more expanded flow, which looks blue for the same the reason the sky looks blue.
One can compare this to the exhaust from various Falcon-9 engines and thrusters when it is illuminated by the sun on the backdrop of the night sky:
https://youtu.be/JRzZl_nq6fk?t=193
From what I've read there was "unintentional mixing of fuel and oxidizer" which caused a fire in the engine section, so the engines automatically shut down. I don't thing we have official word yet, though.
Shuttle's tiles not being durable as hoped is what killed it's turnaround time.
The problem was never solved and turned what was supposed to be a few days into weeks or months. Every mission the shuttle had to go back into the assembly building and have all tiles inspected and potentially replaced.
I thought Starship has many unique tiles, they ended up needing to vary thickness to match heat patterns to save weight and have some complicated geometry near the fins.
Shuttle had more unique perimeter shapes, but starship still has a lot of variation due to tickness. I don't know if that is easier to vary in production or still needs custom molds for the variation.
The tiles are not supposed to ablate - they're supposed to be ~fully reusable. That said I think it's plausible that the much higher iteration speed and lack of a need for human-rating (at least during reentry, for now) will allow for more success than the space shuttle saw with its similar approach.
Its turn around time is ridiculous, it has to be maintained with specialized equipment/hangers, along with external contractor assistance.
Compared to the Gripen, as an example, which can land on a freeway and be up in the air again in a few minutes.
One was designed to be used in war, in desperate scenarios, with no ability to coddle it. The other, the F-35? Is designed around milking the taxpayer as much as possible, and employing people in as many politician's states as possible.
The shuttle was like that, I think. Which is really sad.
The F-35 is designed to be able to break into and defeat modern air defense networks.
The gripen is a much less capable non expeditonary platform designed to maximize asymmetric losses if sweden is invaded. As a small country sweden has to follow a porcupine strategy to deter invasion.
Presently the actual comparable to the F-35 is attritable drones, which is why every mid-size and major power is developing them.
The Russians have been trying to use attritable drones for years to break down the Ukrainian IADS and have not yet succeeded. Meanwhile the Israeli F35 fleet with no direct American support was able to crack open Iran’s air defenses at the start of the Twelve Day War with relative ease.
Israel used long range air launched ballistic missiles (ROCKS) and cruise missiles, mostly from F15s, to degrade Iran's ancient radar network and S300s (which allegedly weren't moved around much). That was before the invasion, so Iran didn't have much long range radar coverage when the war started.
Loyal wingman aircraft would have to be stealthy though to do it.
The whole point of the F-35 is that it is a stealthy platform with a very advanced set of targeting and weapons capabilities: but the issue is a similar capability drone would basically have a similar price tag since the expense of the pilot is minor in that case.
Like plausibly the best autonomous F-35 platform would just be an F-35.
Low-level drones are also stealthy. If they're not stealthy enough you can send them in bulk to overwhelm defences.
Ukraine's success with precision targeting of Russian assets would have been unthinkable with a fleet of F-35s and associated missiles because of the cost.
Cheap, smart, disposable drones are orders of magnitude cheaper and at least as effective for many mission profiles.
It's not the expense of the pilot but the fact that the human pilot is subject to human biological constraints. Ie they black out after 9 Gs or so. An autonomous platform you'd want to design to be able to routinely do outside that envelope in a way that a platform designed for a human occupant is not.
Its a nontrivial exercise to design a plane which can regularly do more Gs then that though.
There's no drones currently in development AFAIK with this goal either - the focus is on getting them to do useful mission without a pilot, rather then out dogfight or outmanoeuver missiles.
Basically the point stands: a hypothetical "better then F-35" drone is likely more, not less expensive then an F-35.
>Its turn around time is ridiculous, it has to be maintained with specialized equipment/hangers, along with external contractor assistance.
>Compared to the Gripen, as an example, which can land on a freeway and be up in the air again in a few minutes.
I have no idea where people got the idea that the F-35 requires a major refit after each sortie or that it needs climate controlled hangars, but there's literally no truth to any of it.
The turnaround time for an F-35 after a mission in a wartime scenario isn't going to be much different from any other older fighter jet. Refuel, rearm, get back in the air.
One of the key requirements for the F-35 programs was to minimize extra care needed for the RAM (Radar Absorbent Material). Unlike older stealth aircraft the F-35's ram is "baked in" to the aircraft skin, rather than being a coating. The F-117 and B-2 require climate controlled hangars because their coatings are old and delicate, the F-22 doesn't, but needs regular touch-ups for its coating, the F-35 is just left sitting outside most of the time regardless of where it's operating, a desert, the arctic, a jungle, the deck of a ship, you just leave it out there. The only common maintenance done on the F-35's RAM is replacing a relatively small amount of special RAM tape which is usually used around the edges of the access panels which are opened for other types of maintenance.
I think there's also some exaggerations about the differing highway landing capabilities of various aircraft. [1] is a video showing Eurofighter, F/A-18 and F-35 all landing on a highway in an exercise. Capability with stores and fuel load is another thing but I've read material that doesn't find the contemporary aircraft drastically different in that regard. Now, maintenance hours per flight hour and general operability certainly are interesting topics and there could be large differences.
Landing is the trivial part, though the USAF traditions of "FOD walk" do seem funny to air forces where donations you found out the aircraft spent whole day flying with maintenance toolkit left in intake.
The maintenance is the real difference - US specifically USAF gear is designed for nice air conditioned hangars to do regular maintenance, Gripen, MiG-29, and to way lower effect F-18 (when compared with F-16) - the first two assume forward bases without ability to do major maintenance, and even the latter (and other carrier adapted ones) promote things like quick swap engines because that's no space for hangar queen to have deep engine maintenance just so engine vendor can claim long time between overhauls
The main reason the Mig29s have a reputation for easy maintenance is because they don't replace parts, they just throw away the whole airframe. The structural and engine service life is like 1/10th that of western fighters.
Not really. This "reputation" is based on misunderstanding of differences in doctrine.
The engines did have lower overall hours, yes, but the suggestion they need whole overhaul after very few hours is because it looks so when looking at it from USAF doctrine where "removing engine and sending it to special facility" is only for rare complete overhauls, and local mechanics are supposed to do regular minor work all the time.
MiG-29 instead was done under doctrine that the airbase does not have mechanics capable of doing such overhaul, nor the facilities to do so, and instead you swap the engine and send the used one to maintenance facilities further away from the front, same with other aggregates.
The Gripen is a light multirole aircraft like the F-16. The F-35 is a stealth strike fighter. It requires another level of special care to maintain its stealth performance. If you want mass-produced stealth aircraft, that's what's required. Stealth aircraft up to this point have been in extremely limited numbers at astronomical costs.
True, its really the first mass produced stealth plane. Everything before it has been in pretty limited numbers (even the F-22 didn't break 200). We definitely could build a new non-stealth fighter that's cheap to build and maintain but that's like saying we should design a new incandescent lightbulb, the money spent on development just isn't worth it over just building more F-35s.
Gripen will not be able to fly higher than tree lines in zones with active anti-air. Russia can't really use any of it's air power in Ukraine war, for example.
F35 can actually do something in such scenarios, as detecting them in the first place is hard.
Russia can and did start the war with using airpower but stopped due to losses. Currently Russia is using its airpower to lob guided bombs which is effective due to the limited range of ukraines missiles. They have nothing comparable to the R33.
Agreed and specifically in the case of the Gripen the “test condition” was “Needs to be serviceable by a few conscripts working under the direction of one person who knows what they are doing”.
It’s an extremely different design goal, the US doesn’t mind exotic weapons that require exquisite (and expensive) methods of servicing, they have the budget and the assumption that a well equipped air field will be immaculately maintained.
Meanwhile the Mig-29 designers assumed it’d operate from damaged/poorly maintained fields, so on the ground you can shut the primary air intakes and it uses ones on top of the plane to get air, drastically reducing the FOD risk on taxi/takeoff.
I do wonder how well the F-35 would fare in an actual shooting war against near peers when all the peacetime assumptions breakdown.
>It performed as expected and was able to roll back Iran's air defense network in days.
"Rolling back" Iran's air defense seems like very fuzzy phrasing. Certainly, Iran was not able to close its own airspace, nor prevent ongoing airstrikes on many American and Israeli targets. At the same time, my armchair observation is that a great many US and Israeli airstrikes were accomplished using stand-off weapons [1], which would not have been needed if the United States and Israel had achieved 'air supremacy'[2] as has been the case in America's conflicts in recent history.
The observed trend in USAF readiness has been downward for some time [3][4]. Air war is more than single sorties. If you have anything resembling an accurate summary of sorties flown, targets successfully hit, and number of combat-ready aircraft throughout the (currently on hold) war, and so on, please share. Absent such detailed information, all we have are various degrees of speculation.
Iran innovated with the loitering optically guided missile. This was enough to dissuade a longer air campaign. Political support is low so any losses create a political problem.
I mean ... step 1 is probably fixing the part where it lands in the ocean, falls over and explodes. Once they've done that and can get their hands on the tiles I'm guessing they can continue to iterate there until they get a more easily reusable design.
It was also noticeably wayyy faster off the launch mount. These V3 raptors are pretty fierce. It took off so fast it seems destined to be stretched imminently.
“seems to have hit the water harder than expected and was very off target.”
SpaceX’s people were saying it was on target, and it seems to have landed in about the same position relative to the camera buoy as previous flights. I don’t think there’s any evidence to call it off target. The landing and toppling looked the same as previous flights too.
First item is wrong - scrub was due to hydraulic pin on launch QD arm not releasing (apparently when released it caused an arm vibration that triggered a re-lock) and they had to improve arm stabilization when pin releases.
Also Ship reached original intended orbit.
A tower catch was never in the plans for this flight.
Booster is a totaly new rocket.
It did launch with acarity and by any other standard did well, but the failure to relight could be anything, but I am going for the giant fuel feeder tube bieng the failed part, based on nothing more than how tickled they were with it,and tank baffling bieng a dark art.
The slosh of the fuel durring the flip is going to produce an internal tidal wave, lots of stuff gets "tested" there.
Did the landing burn light two engines as expected? It happened fast, but the graphic made it look like only one lit. If that’s true, that would be impressive as only lighting two was meant to be a test. At least according to the live stream hosts.
You do realize that every company so far has been doing that to every booster for every launch, right?
There's 2 options if you don't want to drop stages back on earth. You don't launch, you land the stage.
SpaceX is the company that pioneered propulsive landing of a booster. You can say a lot about them but not that they pollute with dropping stages in the ocean. Even in absolute sense that doesn't happen often and that's ignoring that they put over 90% of all the weight in orbit nowadays
The takeoff looked almost normal but I noticed a slight drift from vertical, likely because one of the engines was dead or dying. Overall the V3 is supposed to be an upgrade but actual progress is more or less stalling compared V2.
It is supposed to tilt away from the launch tower immediately, you can see this on previous flights. This keeps the engine plume away from the chopsticks and top of the launch tower.
I have a hard time saying that its stalled. For one we don't really have the hard data to quantify the V3s vs V2s actual performance. On their first flight we lost one on the booster and one on the ship. I don't know that the boostback burn problems are related to the engine themselves given that they had multiple failures and a premature cutoff. That feels like thats a problem upstream of the Raptor.
>> As far as overall progress from previous test flights goes, they're at least treading water while making many large changes.
What a kind take on what is again the continuous trend of: Every flight fails for a different reason. And they still cant make the most basic use case: https://www.instagram.com/p/DWzTFAEAhSe/
Lots of engine failures. Doesn't exactly bode well for a company looking to go public immediately. One of the engine failures was not on the booster but Starship as you noted, and that is a bit unexpected. I don't think they have spoken about it being equal in capability with one engine out, right? Those engines don't move around to compensate IIRC.
Not sure how you come to that conclusion. The capabilities can overcome loss of engines. The fact it was successful with loss of engines shows it is working as designed.
No, it just means the mission happened to be salvageable because of its parameters. The booster is designed to have engines out and can compensate because it has so many engines and many of them are on gimbals. On starship, the vacuum engines aren’t on a gimbal. I’m not sure how it could compensate for one of three engines being out.
Some are on a gimbal and they specifically talked how others gimbaled out a bit to compensate. This is specifically something they designed in and not an accidental lucky save. In this flight they didn’t intend to test “one engine out” feature but it worked out that way.
See my other comment. The vacuum engines are NOT on a gimbal. None of them. The sea level engines on starship and several of the engines on the booster are on a gimbal. But not the vacuum engines for space.
EDIT: I cannot reply further in this thread, but my understanding is that the non vacuum engines are not intended to stay lit throughout the orbital flight in a typical mission. If they are, they can gimbal and compensate.
> The vacuum engines are NOT on a gimbal. None of them
I said some raptor engines are on a gimbal, not vacuum engines.
To be precise, the three central engines can gimbal up to 15 degrees. That can control the thrust vectoring when an engine fails, and that’s what happens in the last flight.
Since the flight already happened and we know it didn’t spin out of control (unless you imply their diagnostic and telemetry was completely off and the engine was actually on) something must have compensated for the failure. It wasn’t magic, it was in fact the central 3 engines that did that.
You may be confused because those are called sea level engines, but that doesn’t mean they can’t work in vacuum.
I think previous comment means "on a gimbal" as in "angled at a non completely prograde direction" (presumably angled such that each engine points through center of mass so that none of the engines impart a torque)
The person you’re replying to is trying to play rhetorical word games.
The upper stage has six engines. The outer three engines are “vacuum engines” (optimized for operation in space). The inner three engines are “non vacuum engines” (optimized for operation in the atmosphere, at sea level).
The outer three vacuum engines are not gimbaled, but the inner three sea level engines are. Thus, it is completely accurate to say that they gimbaled some of the engines to compensate for the engine failure.
That’s for the booster (the big lower part) not for starship (the upper part that continues to space). They were surprised to have a vacuum engine out. In space there’s no atmosphere so you can’t use fins or wings to change direction. And if the engines can’t move around, you only have thrust and gravity and the tiny attitude adjusters to direct your ship.
You're simply wrong. The non-vacuum-optimized engines on the upper stage are still functioning in a vacuum, and their ability to gimbal to offset the loss of one of the vacuum-optimized engines was planned for.
Watch the stream again starting with the ship burn. They explicitly said they have engine out capability on ship. The sea level engines on the ship are running and gimballing.
The Witness is, in my opinion, simply one of the best games ever made. There are many layers to the game, and moments of insight that the game leads you to, but also trusts for you to make the final connections.
However, I do understand why some consider it a slog. There are many puzzles in the game that people will dislike, indeed many puzzles that I disliked. It seems Jon prioritized finding all of the interesting things that they could say about the puzzles in the game over making sure that all of the puzzles were actually enjoyable to a majority of people. My advice is if you don't like an area, just go somewhere else. You don't need to complete every area to roll credits.
It also may be a matter of expectations. Puzzle games tend to be on the shorter side, but The Witness is lengthy. So jumping in expecting to finish in an afternoon is a way to set yourself up for frustration.
How do you compare it to the Portal games or the Talos principle? I find those superior in puzzle mechanics, sense of achievement and playing dynamics. They can be challenging but you never feel aimlessly going around without a purpose like the Witness. There is good review of the game on youtube by the title "The Witness - A Great Game That You Shouldn't Play", it covers a lot and resonates well with my experience, the panels could've been a standalone mobile/tablet game. Everything else in the game is beautiful but frustrating.
The Witness would have been better if it was half as long definitely, but the problem was not that it was long, it was that it didn't have enough interesting content to fill the time. The puzzles are not mechanically interesting enough to enjoy repeating to the level the game forces you to and the variations are explored so slowly it's just tedious.
I think Blow achieved what he wanted, which I guess makes it a good game in a sense but also it wasn't an experience I enjoyed or can easily recommend to others.
I agree, though I think the real winner here is the customers. The New Glenn 9x4 has a higher targeted payload capacity that an expended Falcon Heavy. Mission design takes years, and payload mass is the most important constraining factor. So it'd now be fairly reasonable approach to start building now for 9x4's constraints, and then fly on it or Starship depending on readiness and price. If customers start doing this now, that also means a quicker pickup on using the increased launch capability.
On a funnier note, the 9 in Falcon 9 is the number of engines. So blue origin is somewhat picking up on their naming scheme. Or, by BO's scheme, it'd be the Falcon 9x1, or the Starship 33x6.
No law in relation to pennies has changed. The executive branch has simply took the law stating the mint should create as many pennies as necessary, and decided that the necessary amount is 0.
The practicalities of their illegality then comes down to enforcement. Given the current executive branch's behavior related to enforcement of laws, that can mean anything from "melt them all down", to "don't do it", to "if our friends start doing it, it'll be legal, if our enemies start doing it, we'll enforce".
I've managed to visualize a Klein bottle in 4d. I easily visualize 3d objects. However I can't really do color - I startled myself recently when I briefly saw red. On that aphantasia test with an apple, I can hold it's 3d shape, but no surface texture or color.
People seem to have surprisingly different internal experiences. I don't know how common 4d visualization is, and I suspect even those capable require exposure to the concepts and practice. However I do think it possible.
The blind French mathematician Bernard Morin is well-known for creating the first visualization of a sphere eversion, a method for turning a sphere inside out without creasing it. His work was based on Stephen Smale's 1958 proof of sphere eversion's existence and on ideas shared by Arnold Shapiro. Morin's method involved constructing a sequence of models, including his "Morin surface," to demonstrate the process.
Your hippocampus has several special clusters of neurons whose members activate and deactivate based on your body's understanding of your position and momentum in a 3D world.
The arrangement of these neurons physically corresponds to reality, and so things are pretty hardwired.
Repurposing these neurons might be possible with advanced training and nootropics, but I'm not sure. You might have better luck engaging other parts of your brain, for example using metaphor or abstraction such as mathematics.
For me, being able to visualize 4D would imply that I can picture four mutually perpendicular axes, something which I find completely impossible for me to do. And I thought it is impossible for any human brain. It would be fascinating if I am wrong.
1. It still took nearly 7 years to after JFK's speech in the 60s.
2. The institutional knowledge of working directly on the Apollo program has largely been lost in the US, and certainly isn't present in China.
Those are the unimportant pieces. The real reason is:
3. The US was actively at war with Russia. While it was a cold war (except for the proxy wars), the Apollo program had a wartime budget (spent nearly half a trillion in today's dollars), and a wartime risk tolerance (Neil Armstrong thought they had a 10% chance of not making it back).
2. Uh huh. The knowledge for 1960s tech is limited, agreed, but the tech is so much more superior now, and China as a nation has a high understanding. What does China not have that would be of any relevance?
3. Cool, China is in an economic Cold War with the USA.
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