Comment by txcwpalpha | Hacker News Reader

Comment by txcwpalpha | Hacker News Reader

Parent Full thread

That's such a reduction that it completely misses the crucial point that the Falcon 9 is overall not smoother than the shuttle.

The first stage was smoother, because as you said "liquid smoother than solid rockets", but the second stage was noticeably rougher than the shuttle (specifically the stage separation/transition, which the shuttle did not suffer from due to the SSMEs continously firing even during SRB separation).

The article is quoting comments from a press event, but I remember on the livestream one of Bob/Doug specifically commented on how rough the ride was as one of the first things they said after SECO/docking (can't remember exactly which). I'm thinking it must have been pretty dang rough if it was the first thing on their mind.

It's unsourced, but I've seen other comments on the internet remark that certain satellite payloads actually can't use the Falcon 9 due to its vibration profile being too rough compared to others rockets.

Correct about the comment in the livestream, see here:

https://youtu.be/zNklfC6jgBs?t=14653

It was Bob. Rough transcript:

"We were surprised a little bit at how smooth things were off the pad. The space shuttle is a pretty rough ride heading into orbit with the SRBs, and our expectation was as we continued with the flight into second stage that things would basically get a lot smoother than the space shuttle did, but Dragon was huffing and puffing all the way into orbit and we were definitely driving and riding a dragon all the way up, and so it was not quite the same ride, the smooth ride, as the space shuttle was, up to MECO. A little bit less Gs, but a little bit more alive is probably the best way I would describe it."

Edit: Just noticed that that description is in the original article, too, fwiw

Thanks for finding the timestamp/quote! That is what I was talking about, I specifically remembered the "riding a dragon" part. I do see it included in the article now too.

> but Dragon was huffing and puffing all the way into orbit and we were definitely driving and riding a dragon all the way up...

How can this be interpreted as a negative thing, if anything if I were a school boy watching that it that would make me want to get involved and want to experience it myself! An astronaut talking about taking a Capsule (dragon) all the way to Space, and describing it that way... what could be cooler than that?

Also worth noting that no one in involved in Space is expected to do a comfy job, much less being an Astronaut as it requires decades of rigorous physical and mental conditioning, training and exercise and psychological evaluation to just be a candidate in order to prepare you to live in an environment where even going to the bathroom, sneezing, or coughing could all kill you and potentially everyone in your crew in Space.

Yi So-yeon did an interview at MIT earlier this year with Mar's Society [1] describing this exact situation, and even when having almost died upon re-entry due to a faulty heat-shield malfunction that messed up the trajectory of the landing that almost killer her and her whole crew she was the first to sign up for another mission!

That's what an Astronaut is, they're cut from the same clothe as protype Fighter Jet pilots, where death was the most likely outcome; they're not 'normal' People and this doesn't phase them when confronted to do it again for a bigger purpose. Its why they're such exceptional Human beings and why they should be treated as such.

1: https://www.youtube.com/watch?v=jvXAy6YKWOU

because as a parent poster says - a rougher vibration profile rules out certain payloads.

Its not about astronauts playing lift off buckaroo, its about developing viable travel and transport systems.

> because as a parent poster says - a rougher vibration profile rules out certain payloads.

I guess that is true, Yi made the same argument about sending construction based equipment and the dilemma of having to make it more robust than necessary tolerances and specs thus increasing the weight of the payloads.

But SpaceX hasn't had a satellite failure to date, with the exception of the secret spy satellite that was 'lost,' or the facebook one that exploded on the launchpad (THANKS, ELON!).

I wonder what payloads specifically that would include?

SpaceX is all about getting the cost down. You are going to make a lot more travel and payloads viable by focusing on dropping the price to orbit by 10x or 100x or 1000x (about $20/kg is the goal for the in development superheavy rocket) than on optimizing for smoothness. For now it is smooth enough.

Reply on news.ycombinator.com