I know its literally rocket science and a lot of very complex systems need to work together, but shouldnt we be able to iterate on a working formular?
In: Engineering
A good thing to keep in mind about rockets is that they’re mostly balloons filled with two things that want to explode. Their engines mix those two things to create a directed explosion that gets them into space. So, when something goes wrong with them, especially with anything close to or relating to their fuel tanks, an explosion is to be expected.
As to why we don’t do the same thing every time to prevent problems; we usually try to do exactly that. What happens though is that conditions are not the exact same with every launch. The two times we lost shuttles, the tragedies didn’t occur because anything different was done. Challenger exploded due to a leak that was caused by it being too cold outside. Columbia didn’t survive reentry because a piece of foam fell during launch and damaged its heat shielding. Nothing special was done by NASA on either of those, but the tragedies still occurred.
When you succeed, you don’t know how much went wrong that was just barely not enough to explode the whole damned thing. Succeeding tells you nothing about how consistent or lucky your flight was.
An explosion tells you a lot more about what you should get right before putting a man in there. While rockets keep exploding, the last time someone died in a rocket was like 10 years ago. And before that it was another 10 year gap.
Spacecraft are incredibly complex machines with about a zillion different things that can go wrong. A frighteningly high number of those things that can go wrong are both difficult to immediately spot and can result in explosions.
Your question implies we ‘solved’ space flight in 1961. We didn’t. We couldn’t even land a rocket until a few years ago. We still can’t put anything larger than a van on the moon. We’re at the beginning, not the end.
Something other replies fail to mention:
Most rockets explode on purpose. All rockets have a Flight Termination System (FTS). When the computer system detects that something is going extremely wrong with the flight – the FTS is triggered and the rocket goes boom. This is done to avoid the rocket flying off and exploding in a populated area or big debris falling down on one. The flight trajectories are planned so that the rocket can be blown up safely and debris will fall in the ocean.
There are some working formula, like the Soyuz, Ariane V/VI and Delta IV, they are incredibly reliable and relatively expensive.
Rockets have very low production numbers, by just iterating carefully, not much progress will be made. For developing a new rocket there are basically two different design paths that can be taken.
The NASA/ESA approach acknowledges that rockets are expensive and failure is not an option. There is a lot of testing, research and quality checks that go into every single part, making sure that the probability of success is as close to 100% as possible. This makes an already costly rocket even more expensive and in the worst case, too expensive ti built the planned number of rockets per year. In that case all the development and running costs of the facility have to be shared over a smaller number of launches, making them hideously expensive, like SLS.
The other way is SpaceX/Soyuz admitting that failure is possible and making every failure as cheap and informative as possible. The goal is to try out a lot of different stuff for as little cost as possible and see what works best. Building cheaper launch vehicles will attract new customers and with a lot of launches per year, costs can be spread much wider.
A lot of what’s been in the news recently has been played explosions. If there’s even the smallest hint that something is wrong, out of extreme caution they detonate it to save lives potentially.
The fuels are (in most case) quite volatile.
Weight matters. See [Tyranny of the Rocket Equation](https://newspaceeconomy.ca/2023/05/28/the-tyranny-of-the-rocket-equation-an-in-depth-examination/?amp=1) Therefore the structures that contain the fuels and carry the fuels are likely engineered to what humans think the bare minimum to achieve success. Sometimes those calculations are off; Mother Nature can throw some curve balls and it can be challenging to assess some of those conditions to know what to design for.
Sometimes the team changes something, and doesn’t refer back to the requirements nor the dependencies. A change of voltage ultimately caused the “successful failure” of Apollo 13, as the higher voltage wasn’t accounted for in dependent systems.
Aren’t a lot of the rocket explosions due to self destruction because something went wrong and they want to blow up mid air to prevent the rocket from going off course and hitting something?
There are different types of rocket engines. Some are easier to make than others. Some use different types of fuel. Some are reusable. What we figured out ages ago was how to make a rocket engine that use dirty fuel, that wastes some of the fuel, and that can only be used once. And that’s the kind of rocket engine we used for most of the space missions in history.
The Space Shuttle main engines were an attempt at making something reusable, that wasted less fuel. They were pretty good, but they were too expensive to maintain and ultimately not cost effective.
SpaceX started with the old type of engine — they called it the Merlin — and they had very good luck with it. The Falcon series of rockets with Merlin engines do not keep exploding. But they also use dirty fuel, waste some of the fuel, and can only be used a few times.
Currently they’re trying to make something that wastes no fuel, is very reusable, uses a cleaner fuel that can be made on Mars, and is inexpensive enough to make lots of them. That is something that hasn’t been worked out perfectly yet. But they’re getting there.
Also, they’re trying to put 33 of these engines in one rocket so that its very powerful, and they’re trying to do some fancy things with them that a lot of other rockets can’t do well — like throttling, and stoping and starting them mid-flight.
And they’ve also taken the development philosophy that it’s better to test than spend too much time at the drawing board.
Put it all together and there are a lot of unknowns on each launch. And that often means exploding.
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