I've even been able to spot a daylight launch from San Diego.

Is it still interesting enough that you catch people watching them?

A couple weeks ago I walked out of a shop to find a half dozen people on the sidewalk looking east, but that felt like an anomaly. Was just at WDW yesterday and couldn't even convince anybody to look up!

Happy cake day!!

This was the launch for SAOCOM-1A back in 2018. The launch time was determined by the specific needs of the payload’s target orbit. They didn’t adjust the time for launch viewing purposes.

Edit: typo

Honestly, seeing as how many of these are essentially their own launch windows to pick and choose (well the Starlink stuff anyways) I wouldn't put it past them. :)

Did this happen with any Space Shuttle launches, or is this phenomenon limited to our current rocket “style”?

Thank you for the detail, that was really fucking cool.

after separation and fired its engines again in order to travel back to land near the launch site.

Holy crap, so the booster/first stage rocket itself is smart enough to fly back and land?! I knew the main rocket could set down but not the individual stages. Truly amazing.

Like a truck driving a trailer, then once delivered you just tell the trailer to find it's own way home and it drives itself.

My man. Lol shit was out there and then some ya?

Not really

In this instance, I think it's the perfect air/fuel ratio for most efficient/effective burn. We used it when building cars. For my turbo build 14.3:1 air to fuel ratio was ideal at idle and more rich (~13:1) under boost

I’m envious this is the first you’ve heard of it.

Stoichiometry is basically just the ratios of reactants and products in a given chemical reaction, so the total number of each element on each side of the equation equals one another with whole-number quantities of each molecule.

Remember balancing equations in your early science classes? Where theyd give you a simple chemical reaction, like cell respiration, and ask you how many molecules of product will be created from the reactant. Thats stoichiometry at a very simple level.

Like: " if six molecules of oxygen (O2) and one molecule of glucose (C6H12O6) are consumed in respiration, how many molecules of carbon dioxide (CO2) and water (H20) will be created?" Then you count up the number of atoms and make the simplest possible combination using them. In this case six molecules of oxygen and one of glucose yield six carbon dioxide and six water molecules.

Stoichiometry is kinda like the algebra of chemistry.

You're balancing the equation so that all the variables are "equal" on both sides of the equation. So that, basically, X=X or CO2=CO2... except with more variables (X's or CO2's) included into the equation.

I hated it until I understood it more, and then it kinda felt like doing a puzzle. And now I don't remember how to do it at all, but I still love the word... "stoichiometry" does sound sci-fi as hell

I had a heated argument with my grandfather where it was brought up a few weeks back. If engines are your thing, it will come up more often than expected.

Baader–Meinhof phenomenon

It was those math like equations the chemistry teacher made you do way back in high school that describe the chemical changes going on in a reaction.

The word stochiometry itself is a neologism derived from Greek words for "element" and "measure". For chemical reactions, the actual discrete molecules matter, so everything is done in ratios of moles. A mole is a unit that denotes a specific number of particles (6.022 * 10 ^22). Stoichiometry is basically stuff like "you take 2 moles of this and react it with 4 moles of that to get 1 mole of product". You can almost think of a stochiometric relation like the recipe for a reaction, or the law governing it.

Baader Meinhof effect

its just the math of chemical reactions usually ratios of different compounds

Better than car and jet exhaust

Someone asks an honest question hoping to learn. Reddit downvotes.

Edit: I realize I missed an opportunity to actually answer this. The “exhaust” is just water and carbon dioxide. Even if it was a little bit on the toxic side it pales in comparison to the car exhaust we breath in on a daily basis. Exposure + time is also relevant too.

Did you even read u/OptimusSublime s comment? The end products are water and CO2, so there shouldn't be any noticeable effects on the people below.

Bro you think a rocket is fueled by the same shit as your car lol?

It's pretty easy, it's called a hydrogen engine (spaceX plans on using a methalox instead of hydrolox engine most of the time however) and they already exist. They're just unpopular because hydrogen is highly explosive in pressurized containers (more so than fuel in regular containers), and there is no pro-hydrogen lobby unlike petrochem lobbies.

I'm pretty sure all carbon-based fuel (aka petroleum, wood, any other biological fuel) when completely burned should turn into water and CO2? I'm guessing there are unburnt debris/gasses in exhaust that make it toxic?

Car fuel consists of a fairly wide range of different hydrocarbon molecules of varying lengths and structures. RP-1, probably the most popular rocket fuel, is similar to kerosene but purer, with a tighter range of molecule lengths and near elimination of cyclic and branching compounds. Most of what cars exhaust is CO2 and water also. There are other additives and impurities in gasoline and diesel which can impact exhaust composition, as well as incomplete combustion making CO and catalytic production of NOX, but that is relatively small in comparison to the major combustion products. RP-1/LOX rockets also produce side compounds, but fewer.

Yes, oops. Complete typo. Thanks.