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Starship Flight 7

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Re: Starship Flight 7

#681

First Shuttle orbited astronauts and successfully recovered all intended components. Every Saturn 5 was successful, the 3rd flight sent a crew to lunar orbit, and the 6th put a crew on the moon. To date a Starship has yet to be recovered after flight - and those launched are effectively boilerplate as they have carried no cargo (other than a banana) and have none of the systems in place to support a crew. Some people…

> Every Saturn 5 was successful

Do you not count the Saturn 1B rocket capsule that caught on fire on the pad and burnt the Apollo 1 astronauts alive?

What about Apollo 13?

> but just because you are wandering in the desert does not mean there is a promised land

The "promise land" in this analogy is visible past the desert. What's not known is what route to get there.

In your tortured analogy, the people who "are really fetishizing iterative failure" are not doing that; they're fetishizing the fact that the person walking through this desert is trying, and if they hit a barrier, they iterate and try again until they reach the promise land. Along the way they are accomplishing what was once thought to be impossible.

Re: Starship Flight 7

#682
post #611

Earlier quoted context omitted.

The space shuttle lol? Are you not considering the fact that the huge external tank and the two SRBs were destroyed every time? Not to mention the insane costs of refurbishing each space shuttle, not the mention the insanely bad safety of the shuttle and the 14 astronauts who died in it! Space shuttle, while cool, was really, really bad design, bad safety, and totally uneconomical. It was definitely cooler than Soyuz…

The SRBs could land in the ocean with parachutes and be recovered and refurbished. Shuttle wasn't economical as I mentioned, and definitely the space shuttle wasn't safe. What you claimed was: "They have the first rocket ever made which can take payloads to orbit and then be reused." That was known as the space shuttle. The ~$40 million tank was expendable so you are right it wasn't full reuse either. Starship jettis…

Space Shuttle isn't a "rocket" like Falcon 9 is though, it couldnt go to space by itself. So saying its the first reusable rocket is really stretching credibility.

Falson 9 is a one piece rocket, as is Superheavy.

The Space Shuttle got to space with the help of other rockets, tank etc.

Re: Starship Flight 7

#683

Earlier quoted context omitted.

In the official BIPM brochure, hours are technically classified as "Non-SI units accepted for use with SI." This puts them in the same category as liters, hectares, tonnes, decibels, etc. https://en.wikipedia.org/wiki/Non-SI_units_mentioned_in_the_...

I can read Wikipedia too. All the calculations are done in m, s, g, etc. if you want to dumb it down to the public you might as well go in miles per hour, leagues per day, etc., spaceflight is not the place where it is appropriate.

> if you want to dumb it down to the public you might as well go in miles per hour,

The blue origin launch this week used mph and feet of elevation, and I can definitively say that using modified SI is way way better than US customary

Re: Starship Flight 7

#684
post #611

Earlier quoted context omitted.

The SRBs could land in the ocean with parachutes and be recovered and refurbished. Shuttle wasn't economical as I mentioned, and definitely the space shuttle wasn't safe. What you claimed was: "They have the first rocket ever made which can take payloads to orbit and then be reused." That was known as the space shuttle. The ~$40 million tank was expendable so you are right it wasn't full reuse either. Starship jettis…

Space Shuttle isn't a "rocket" like Falcon 9 is though, it couldnt go to space by itself. So saying its the first reusable rocket is really stretching credibility. Falson 9 is a one piece rocket, as is Superheavy. The Space Shuttle got to space with the help of other rockets, tank etc.

And all those other parts were recovered after most flights and re-used after refurbishment on future flights. Since there's no other name than "Space Shuttle" for the whole rocket, it will do. Note that Starhsip is also ambiguous, as it refers both to the entire two stage rocket, but also just stage 2.

Re: Starship Flight 7

#686

Earlier quoted context omitted.

>Some people are really fetishizing iterative failure - but just because you are wandering in the desert does not mean there is a promised land. i guess you didn't follow the falcon 9 failures right? here's two minutes of failures https://www.youtube.com/watch?v=bvim4rsNHkQ and guess what? they finally got it right and now falcon 9 is not only extremely reliable but quite cheap for everyone. NASA (with the shuttle an…

SpaceX’s track record is too fetishized by the Musk fanboys. Falcon 9 has some weird Demi god status even though the launch vehicle is no different than the competitor like Soyuz.

It's been so weird to see people say willfully ignorant shit just because they don't like Elon Musk.

Re: Starship Flight 7

#687
post #426

Earlier quoted context omitted.

While the video post does mention "Right in front of us", and it may have appeared that way to the pilots, it wasn't. Gauging relative distance and altitude between aircraft in flight can be notoriously deceptive even to experts, especially in the case of intensely bright, massive, unfamiliar objects at very high speed and great distance. The RUD was in orbit over 146 kilometers up and >13,000 mph. I'm sure using the…

Stupid comment. Several flights had to be diverted because of the break-up, and anyone in flight at that time would be rightly concerned about barely-visible high-speed shrapnel showering a much larger area than where the visible debris are - especially when you are responsible for keeping your hundreds of passengers safe in a very unexpected situation with no rehearsed procedure to follow.

Ok, this:

> Stupid comment

got me. There's literally an HN rule about this: [0]

> When disagreeing, please reply to the argument instead of calling names. "That is idiotic; 1 + 1 is 2, not 3" can be shortened to "1 + 1 is 2, not 3."

I feel like the world would be a better place if people would tone down the ad-hominem in their day-to-day discourse just a little bit.

[0] https://news.ycombinator.com/newsguidelines.html

Re: Starship Flight 7

#688
post #469
post #454

Earlier quoted context omitted.

Test code by running it. Test a rocket by launching it.

In production? I don't disagree that tests 'in production' are sometimes necessary (canary tests), but most of the quirks are often fixed by then. Honestly I thought they would be live testing fuel exchange in orbit by now. Seems pretty far from it sadly.

Some domains have so many different parties doing different things, you just have to test in production. Rockets are probably one of them.

Re: Starship Flight 7

#689
post #621

Earlier quoted context omitted.

At the incredible speeds Starship was moving (>13,000 mph) by the time it was over the Caribbean, debris from a Starship is expected to burn up by the time it reaches the surface. But you said "depending on the size", so let's imagine it's a different spacecraft carrying something that won't entirely burn up, like the Mir space station from several years back. In that scenario, debris from 100km will survive to pass…

> At the incredible speeds Starship was moving (>13,000 mph) by the time it was over the Caribbean, debris from a Starship is expected to burn up by the time it reaches the surface. Don't the heat tiles at least make it through? And possibly large hunks of metal like the thrust frame and engines.

As I said, I'm only familiar with the high level concepts of vehicle launch safety and not qualified to assess detailed scenarios. I'm just a guy interested enough to read some technical articles and skim a few linked papers several years ago when there was a lot of heat about launch safety from Boca and not much light. When there's a lot of heated rhetoric in the mass media, I find it's better to check directly in scientific and engineering sources.

I dove deep enough to a get sense that these questions have been extremely well-studied and not just by 2020s FAA and SpaceX but going back to the Shuttle and Apollo eras. The body of peer-reviewed engineering studies seemed exhaustive - and not just NASA-centric, the Europeans and Soviets did their own studies too.

Your question is reasonable and occurred to me as well. Components engineered to withstand the enormous heat and pressure of orbital re-entry should be more likely to survive a RUD scenario and subsequent re-entry burn for longer. From what I recall reading, this fits into a safety profile required to ensure very, very low risk because even if a tiny percentage of mass occasionally survives to reach the surface, the actual risk that surviving mass presents is a combination of its quantity, mass, piece size, velocity and, most importantly, where any final surviving bits reach the surface.

I recall seeing a diagram dividing the Boca orbital launch trajectory into windows, like: right around the launch pad, out over the gulf of Mexico, the Caribbean, Atlantic, Africa, Indian ocean, and so on. The entire path until it's out over empty Atlantic ocean has minimal land, people and stuff under it. The gulf of Mexico is by far the highest risk because the rocket is still relatively low and slow. A RUD there could potentially be a lot of stuff coming down. There's not a lot out there in the gulf, just a few ships and planes but the FAA closes a huge area because, while the statistical risk is very low in an absolute sense, it's still too high to take chances.

For later windows, they don't close the corridor underneath to plane and ship traffic because the rocket's much greater speed and altitude later in the flight allows more precisely modeling where the debris field will come down. There was another diagram showing a statistical model of a debris field impact zone as an elongated oval with color-coded concentric rings dividing the debris mass into classes. The outermost ring is the debris that breaks up into smaller, lighter pieces. It's the widest and longest but it's the stuff that's much lower risk because it's smaller and slower.

The smallest concentric ring in the middle is where the small amount of heavier pieces most likely to survive will come down, if any do survive. As you'd expect, that innermost ring is shifted toward the far end of the oval and is a much smaller area. The headline I took away was that there's a very small amount of higher mass debris that both A) is less likely to break up into tiny, lower mass pieces, and B) is less likely to completely burn up. This is the higher-risk mass and, due to its mass, it tends to stay on trajectory, go fastest, farthest and not spread out much. In short, the statistical model showed a very high probability of any higher risk stuff which survives coming down in a surprisingly tiny area. The overall safety model is based on a combination of factors working together so it meets the safety requirements in each window of the flight for each class of mass. The carefully chosen launch location, spacecraft design, component materials, flight path and a bunch of other factors all work together to put the small amount of higher risk stuff down somewhere that fits the safety profile of very, very low risk to people and property. Disclaimer: I've probably got some details wrong and left some things out but this is the sense I got from what I learned. I came away feeling that the safety work done on space launches is comprehensive, diligent and based on a long history of robust, peer-reviewed science backed up by detailed engineering tests as well as real-world data from decades of launches, RUDs and de-orbits.

A fun side story: a few months ago I was at the Hacker's Conference and Scott Manley ("Everyday Astronaut" on YouTube) was attending as he often does. He brought along some interesting space artifacts just to set out on a table for casual show and tell. I was able to pick up and examine a Starship heat tile that was fished out of the gulf of Mexico. It was surprisingly light weight. Sort of like a thick wall piece from a styrofoam picnic cooler. It had a very thin hard shell on one side. This shell was clearly very brittle as it had already been broken up and I was holding an index card-sized shattered piece that weighed maybe a couple ounces. This was clearly not something that was going to maintain structural integrity post-RUD. Once it wasn't packed tightly together into a smooth aerodynamic surface, it's gonna shred into tiny pieces. And that seemed by design - which apparently worked as intended because even without a RUD, at the low and slow speeds over the gulf and near the launch pad it did shatter into small, light pieces - assisted only by the rocket tipping over into the water followed by the relatively mild explosion of the remaining propellant (mild compared to an unimaginably violent orbital RUD, that is). Holding it I remembered the debris field oval diagram and thought, "this is smaller, slower, safer stuff in the outer zones."

Re: Starship Flight 7

#690

Earlier quoted context omitted.

- "And for expandable rockets, virtually all rockets designed and launched in the last few decades have successfully accomplished their first ever flight," That doesn't resonate as true to me. The first Ariane 5 flight blew up [0]. That Europe's current heavy-lift workhorse with 112 successful launches (including JWST), but the first one blew up. The first PSLV blew up [1]. That's India's current workhorse with 58 su…

You're right that I exaggerated, sorry about that. Still, many of these are more successful than Starship: The first GSLV was still able to deploy a satellite, just in a lower orbit than intended. The first Delta IV had the same problem, satellite deployed, but in a lower orbit than planned. The first Long March 5 is classed as a full success on Wikipedia, I couldn't find info there about a failure (the second one di…

> Still, many of these are more successful than Starship:

Your definition of success doesn't leave room for anomalies. Your mindset seems to be "if you try and it's doesn't turn out perfectly, it's a failure" -- which results in spending tons of time and money iterating behind closed doors (or even worse, trying to model/calculate the whole thing without many test runs), and only unveiling the result when it's "perfect". This approach costs more time and money, and more embarrassment if/when the product fails in public. It also doesn't build a culture of learning a lot from anomalies.

Meanwhile, SpaceX doesn't care about iterating, testing, and failing in public. So they skip all the costly effort of trying too hard not to fail, setting expectations that they get it right the first time, and not learning as much from anomalies.

Anomalies, properly understood, are opportunities to learn and improve -- and never something to be ashamed of. The only true "failures" are to give up because it's too hard, to stop learning from the data that anomalies provide, or to never try in the first place because you're too afraid of anomalies.

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