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Comment by throw5959 | Hacker News Reader

Sure, I'm not saying Musk is the only person who has interesting things to say about it. You're absolutely correct about these other people and I listen to them too.

But you're not giving Musk enough credit. All engineers and other professionals told him that landing rockets is bullshit, and what is interesting here is that he went and made it happen anyways.

I'm not talking just about the engineering, everything is interesting here - the project management, the hiring, the investments, the business side... Musk has a lot of input and influence in all of these, he was the one who decided and paid for it.

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> All engineers and other professionals told him that landing rockets is bullshit

You literally responded to a guy citing Lars Blackmore, who is the engineer that designed their landing algorithm--which was developed at NASA's JPL lab (before SpaceX existed).

Musk bet on landing rockets _because_ engineers told him that it was possible.

Oh no, Musk convinced the engineers it's possible. One of the interesting things about him.

The landing was completely developed at SpaceX without NASA tech, assistance or money. By Lars. After figuring out parachutes were infeasible.

In fact it was one of the reasons red dragon was cancelled.

The group studying hypersonic retro propulsion of boosters at NASA was let go because that's what SpaceX did to land

The Air Force was studying RTLS as part of the ARES (Affordable REsponsive Spacelift) program in 2005 (Which was the result of 1992/1994-era discussions on "spacecast 2020"):

https://arc.aiaa.org/doi/abs/10.2514/6.2005-6682

Lars and Beschet wrote their groundbreaking paper on lossless convexification of the powered descent problem at JPL before Lars went to SpaceX:

http://www.larsblackmore.com/CarsonAcikmeseBlackmoreACC11.pd...

Blue Origin landed first, where was that from?

And I don't see any rocket actually coming back with an orbital payload? Where's the demonstrator? Like that quiet supersonic thing Lockheed is demonstrating.

Even Lars didn't deliver at the first attempt. So it's not like it was something available off the shelf. Like some cryptography library you include in your code.

NASA was also considering reusable two stage to orbit for the shuttle back in the 1960s. By 1998 NASA was proposing Liquid Flyback Boosters:

https://ntrs.nasa.gov/api/citations/19980237254/downloads/19...

Those were still winged boosters, but were not helicopter-caught and did RTLS.

Musk didn't invent the concept.

You can write papers all you want.

I know only one company landing orbital boosters.

> All engineers and other professionals told him that landing rockets is bullshit

Every company has some kind of mythology where someone says "you'll never make it in this town!". The reality is that uncrewed propulsive landing was technologically feasible since the soviets landed a rover on the moon. NASA propulsively landed a rover on Mars back in 2011.

Like I said, listening to billionaires is probably interesting if your goal is "acquire boatloads of money". But we already know how to do that. 1. Appear confident 2. Lie 3. Have no morals or ethics 4. Prioritize the pursuit of power above all else

Sorry but no, this is absolutely not what happened. I am watching it closely ever since SpaceX was founded in 2002. There is an incredible gap between the tech demo you're speaking about, and actually landing a heavy orbital rocket, and then doing it 100 times in a row without a hiccup.

Mars is completely off topic, as they didn't land the booster there. We had Space Shuttle before and it didn't say much about landing rocket boosters.

I think it is? Like, this sounds like a pretty silly claim:

> All engineers and other professionals told him that landing rockets is bullshit

Where did you hear that?

Well I heard it myself from practically anybody up until 2015. I even attended quite a lot of conference talks on this topic... I'm sure it's not hard to find it online, famously a NASA director (I think?) did so.

You're saying every engineer and every person with any other type of profession you've ever spoken with, said that it was impossible to land a rocket? I feel like plenty of professionals don't even have an opinion on the matter.

Even if that's true, there's still every engineer and every other professional in the world you haven't spoken with. To take an example, I'm an engineer, I didn't say it. That disproves the claim.

Please, this is a conversation, not math exam.

If we wanted to be more accurate, we could say that less than 0.00001% of all engineers and professionals told elmu that it was impossible to land a rocket.

That seems less impressive than saying 100%, doesn't it? But hey, this is hacker news, not a math exam, and 100% is pretty much < 0.00001%, lol.

Yeah lol, who cares about this?

You can check the NASA Spaceflight forums. There was a gloating thread were bets were settled and people called out.

Also the head of ULA said they'd need to do 10 rides of a booster before it makes financial sense to reuse. SpaceX claims it's one

Arianespace director literally laughed in public over that idea.

https://www.youtube.com/watch?v=W676Kk9LSYw

Okay, that is one down. You've got to get through literally all the rest of the engineers and professionals. At some point, you'll hit the engineers at NASA that were working on this problem before SpaceX existed.

> Sorry but no, this is absolutely not what happened

What didn't happen? I didn't provide you a narrative, I gave 2 examples of uncrewed propulsive landing which literally happened.

> There is an incredible gap between the tech demo you're speaking about, and actually landing a heavy orbital rocket, and then doing it 100 times in a row without a hiccup.

I agree. Now please point to me which part of the self-landing booster Elon built.

I told you what didn't happen - the situation wasn't as clear as you say. Everybody in the space industry was absolutely sure he is totally crazy and it's impossible to do with an entire first/second stage rocket booster.

He built the company that built the booster, which to me is at least as interesting as building the booster itself.

It's not just about money - Bezos has much more money available than SpaceX had in 2002-2015, and yet his rockets still don't land.

Actually, Blue Origin beat SpaceX to land a booster. The difference is that BO landed New Shepard, which can barely bump a manned capsule over the Karman line, whereas SpaceX is landing an orbital-class booster, which is a much more difficult proposition.

I do agree though that SpaceX has used their money much more efficiently and moved a lot faster in general than BO.

> There is an incredible gap between the tech demo you're speaking about,

Didn't Apollo 11 land on the moon using a rocket, then take off from the moon again, back in the 1960s?

Not exactly a tech demo. And the Apollo missions had the additional challenges of being crewed, and targeting an atmosphere and gravity they couldn't reproduce on earth for test purposes.

The SpaceX stuff is neat though, compared to the defence industry clowns they're competing with.

Apollo 11 had a three stage rocket and every stage was discarded. SpaceX is obviously not the first company to land something - but landing a rocket booster that just performed an orbital lift is the interesting and extremely hard thing to do. The payload can be entirely designed to land - but the booster has many other constraints (payload weight and its desired velocity and trajectory being some of them).

To do what Apollo 11 did without discarding the boosters you also need orbital refueling and probably rapid turnaround (or a huge inventory of boosters), which SpaceX plans to develop next. Awesome stuff.

I'm talking about the Apollo Lunar Module.

You know, this bit https://en.wikipedia.org/wiki/Apollo_Lunar_Module that descended to the moon, landed, some guys walked out and grabbed some moon rocks, then they took off again and made it back to earth.

That's a rocket-propelled space vehicle gently landing tail first, and ready for immediately reuse.

Given that it clearly had been done, I doubt anyone who knew what they were talking about was telling Musk it couldn't be done.

I don't know how to put this if you don't see the difference yourself by now, but that's not an orbital rocket that could lift anything from Earth nor land back there. One huge problem is hypersonic aerodynamics, something you absolutely don't care about on the Moon. The payload weight can be much greater due to tiny gravity. Google "tyranny of the rocket equation".

It's not reused. Only the top half goes up. The bottom half with the legs and descending engine is still in the Moon.

Apollo 11 was crewed, though.

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