SpaceX rolls Inspiration4 Falcon 9 rocket to the pad for historic launch | Hacker News Reader

SpaceX rolls Inspiration4 Falcon 9 rocket to the pad for historic launch

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68 pointsPikkie26 comments

Interesting choice by SpaceX to use their booster B1062.

One would presume that, given the profile of this launch, they will definitely pick the booster that they have the absolute most confidence in. And so they didn't choose a brand-new-from-the-factory booster. They picked B1062, which has flown twice already.

It's not a real champ like 1051 which has flown 10 times and may have picked up some age-related defects. But it's also not likely to have any serious build flaws, since it's survived launch twice already without any problems.

I imagine this is the same reason they pushed NASA so hard to let them use re-flown boosters for their human launches. A decade ago, it would be an insane thought, but using previously-flown hardware reduces the risk.

It’s a very interesting approach but makes some sense. When it comes to failures the two big cohorts are “crib deaths” and “old age”. By picking something that flew twice they are able to pick a machine still early in its life cycle but survived adolescence.

https://en.wikipedia.org/wiki/Bathtub_curve

It's well understood.

Yeah its kind of insane that we ever did it any other way. Its akin to buying a car that no human has ever driven outside of a test lab and taking it on a cross country road trip.

Except that if the car breaks down, people maybe die.

Except it's not trivial at all to land back a booster and rockets are used far closer to the limit of their physical tolerance than cars. It's not too dissimilar to how F1 engines used to last only one race but are now engineered to last much longer.

According to Elon, insurance rates decrease after first launch. So the insurers think the same too.

Is B1062 a proven design or literally the same physical thing?

They are reusing the same physical engine.

They're reusing the whole rocket, not just the engine. In many SpaceX launches, you can see the carbon deposits left on the side of the rocket from its previous flights.

Both are the "Falcon 9 Block 5" version. Earlier in the Falcon 9's history they were constantly iterating on the design, but NASA's certification for human spaceflight required them to make seven flights on the same design.

So it's both a proven design, and they're reusing one that has flown before. But not the most heavily reused one.

https://en.wikipedia.org/wiki/Falcon_9_Block_5

https://en.wikipedia.org/wiki/List_of_Falcon_9_first-stage_b...

Note that even within Falcon 9 Block 5 there are changes to make reusability easier and cheaper. The earlier Block 5 are not as easy to reuse as later Block 5. ("Pain in the ass" as mentioned in Elon in the conversation with Tim Dodd[0])

[0]: https://everydayastronaut.com/starbase-tour-and-interview-wi...

B1062 is the serial number of a particular booster that SpaceX has in its fleet of boosters. So "the same physical thing", as in "we are flying the plane with this particular tail number"

Yes, what you said. Sorry to the above, I should have been clearer.

I'm so deep into the rocketry nerd-world I've fallen victim to this xkcd: https://xkcd.com/2501/

Haha no worries. Is it obvious that a rocket run 10 times is safer than a rocket run 2 times? To my uninformed mind I would think there's an obvious tradeoff in proven functionality vs. accumulated damage from launches.

As far as billionaires go, Isaacman is kind of well qualified:

2012, he co-founded Draken International, a Florida-based company that trains pilots for the United States Armed Forces. The company operates one of the world's largest fleets of privately-owned fighter jets.

In 2004, Isaacman began taking flying lessons. In 2009, he set a world record for circumnavigating the globe.[6][8] He received a bachelor's degree in professional aeronautics from Embry-Riddle Aeronautical University in 2011. He is flight qualified in multiple military jet aircraft.[4] In his 20s, he flew in many airshows, but by his 30s, he had stopped flying much.

My sense of time is warped.

When I read "2004", I thought "that's not that long ago" then I read "his 30s" and all sense of time went out the window.

How could someone become a pilot in 2004, fly in airshows in 20s and stop being a pilot in his 30s and it only be "a few years ago"

You can solo a glider (with a student license) at 14. So one could be born as late as 1990 and become a pilot in 2004.

Someone born as early as 1981 is still in their 30's today. "A few years ago" winds the clock back to 1978ish.

So there's about a 12 year window that fit the constraints.

Is that related to the (old) Swedish jet fighter Draken? It has a lovely design, quite iconic.

https://en.wikipedia.org/wiki/Saab_35_Draken

> Unlike the Shuttle, which was largely designed by politicians and committees and engineered retroactively

It's like saying a service is designed by PMs and engineered retroactively :( . It's a bad choice of words.

Can anything be engineered retroactively? I mean: the thing flew and landed, so there was clearly some successful engineering going on, before launch.

The requirements were heavily influenced by politics, that is for sure.

Biggest problem was that since the astronaut office demanded it should always be manned, design changes were very conservative. No rapid iteration was possible.

The usual way of describing Shuttle in this way (which I assuming they are paraphrasing here) is it was “zip code engineered,” meaning it was intentionally designed with contractors spread across the country so as to maximize its political support base.

> It's like saying a service is designed by PMs and engineered retroactively

Which is a genuine problem on some teams right? The most effective teams I've worked on had engineering a part of the product design process from the beginning. On the worst teams we received a "fully specced" ticket and no engineer had ever seen it.

> Set to fly on a twice-flown Falcon 9 booster and in a once-flown Crew Dragon capsule, SpaceX’s first fully private astronaut launch will also be reaping the fruits of the company’s decade-long pursuit of reusability.

Is this the first time a Crew Dragon has been re-used?

The Crew-2 mission earlier this year reused the Demo-2 Dragon capsule

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