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Starship / Super Heavy

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Re: Starship / Super Heavy

#151

Post by andrewflnr »

blackrock wrote: post #141

What are the odds of Starship working? It seems really complex. And that last phase where the ship flips vertical from the bellyflop, looks insane for human passengers inside. How many G’s is that maneuver pulling? SN8 appears 90% successful, but I’m wondering if that remaining 10% is the killer. As they say: You spend 10% of your time, solving 90% of your problem. And then you spend 90% of your time, solving the las…

Gs come from acceleration, either straight line or centripetal. I don't think there is enough control authority in starship's fins to create much centripetal acceleration the way a fighter jet's wings can. If the rocket is capable of it, it would do the same whether it was belly-flopping or dropping straight down the whole way. Any passengers will certainly get an inner-ear workout, but I can't imagine how the flip, more or less around the rocket's own axis, could contribute significantly to G-loading.

Re: Starship / Super Heavy

#152

Post by juanbyrge »

blackrock wrote: post #141

What are the odds of Starship working? It seems really complex. And that last phase where the ship flips vertical from the bellyflop, looks insane for human passengers inside. How many G’s is that maneuver pulling? SN8 appears 90% successful, but I’m wondering if that remaining 10% is the killer. As they say: You spend 10% of your time, solving 90% of your problem. And then you spend 90% of your time, solving the las…

I don’t mean to trivialize what SpaceX is accomplishing, but maybe we are overestimating the degree of difficulty of building rockets in the 21st century, given the advances in technology over the past few decades? With the immense improvement in compute power, materials, accelerometers, welding techniques, etc.. since the 60s, maybe SpaceX was the first to recognize that building rockets is not as hard as it used to be?

Re: Starship / Super Heavy

#154

Post by simonh »

randallsquared wrote: post #132
hourislate wrote: post #116

Earlier quoted context omitted.

I've walked along the length of the rocket at NASA in Houston. It's massive and to think it took all that power to get that tiny capsule to the moon with a few men. Pretty amazing... The Starship is designed to carry 100 people. SpaceX will be able to send more people to the moon in one mission than all the moon landings ever sent. Wow...

I believe it requires a refuel in orbit to get to the moon. So, two missions, but still super impressive.

More than that actually, it takes I think 3 tankers to fully top up a Starship in orbit, and the Lunar model needs to go into an elliptical orbit towards the moon and have at least one more top up again before having enough fuel for the rest of the mission.

Re: Starship / Super Heavy

#155

Post by simonh »

fnord77 wrote: post #77
mabbo wrote: post #9

> The fully integrated Starship/Super Heavy launch vehicle will be approximately 400 feet tall and 30 feet in diameter. For reference, the Saturn V rocket from the Apollo program was 363 feet tall. It was 33 ft wide at the first stage, while Starship is 30 ft wide all the way to the top. It's just massive. And it's fully reusable. What a game changer.

considering this is over 50 years after Saturn V, I don't feel this is such a huge feat.

Ask the engineers who built the N1 how hard it is.

Re: Starship / Super Heavy

#156

Post by numpad0 »

TeMPOraL wrote: post #146
numpad0 wrote: post #126

Earlier quoted context omitted.

In theory you’re right, in reality Space Shuttle.

IIRC never fired in actual missions; did not help avoid any of the two fatal accidents.

All of standalone LES activation ever in the history of human spaceflight had been successful in saving all occupants' lives.

Space Shuttle failed twice on the other hand, each time killing all aboard, and in neither cases of it its integral abort systems/abort modes did help at all.

So in theory the lack of capsule-only LES do not necessarily mean safer rocket, in the history and in the statistics it does.

Re: Starship / Super Heavy

#157

Post by Swenrekcah »

electriclove wrote: post #87
noveltyaccount wrote: post #81

Earlier quoted context omitted.

Yeah in some ways the Saturn program is the more amazing. Technology finally caught up to the amazing accomplishment of the Saturn rocket program, if that makes sense.

The Apollo program was indeed amazing. Government bureaucracy and mediocrity is responsible for 50 years of regression. What SpaceX is doing with Starship is also amazing on so many levels (Raptor engine, reusable, goal of Mars, etc).

Government bureaucracy also made the Apollo program.

What got in the way was politics.

What revived space tech was competition.

Politics and bureaucracy can plague private enterprise and competition can be had between or at the behest of government institutions.

It's not as simple as government bad, private good. In fact that simplification can be quite dangerous if it leads to the erosion of government as policy.

Re: Starship / Super Heavy

#158

Post by _lbaq »

mabbo wrote: post #9

> The fully integrated Starship/Super Heavy launch vehicle will be approximately 400 feet tall and 30 feet in diameter. For reference, the Saturn V rocket from the Apollo program was 363 feet tall. It was 33 ft wide at the first stage, while Starship is 30 ft wide all the way to the top. It's just massive. And it's fully reusable. What a game changer.

400 feet = 121.9 meters, 30 feet = 9.1 meters

Re: Starship / Super Heavy

#159

Post by patrickk »

babesh wrote: post #115
SECProto wrote: post #103

Earlier quoted context omitted.

Yup. Salinity would be 36 ppt, so for every 1000 tonnes of water they need, they'd produce 2 truck loads of salt (so say maybe 20 truckloads of brine). It's a lot easier to truck out and dispose of 20 loads of brine, than to source and truck in 250 loads of fresh water

Maybe they can use that salt for the Tesla lithium extraction?

Extracting lithium from water is indeed a promising area to keep an eye on: https://www.bbc.com/news/uk-england-cornwall-54188071

Re: Starship / Super Heavy

#160

Post by simonh »

sudosysgen wrote: post #136
adwn wrote: post #128

Earlier quoted context omitted.

> The Saturn V can carry those 3 people way further, though. Saturn V: 3 people to the Moon; Starship: 100 people to Mars (unproven, of course). Mars is a little further than the Moon. Granted, that's with in-orbit refueling.

The Saturn V would be three people to the moon and back. Starship is 100 people more or less around GTO. Multiple starships are needed to go to Mars. It's a pretty ridiculous comparison.

Isn’t excluding comparisons that include refuelling, when contrasting a refuel-able and a non refuel-able vehicle, somewhat ridiculous? Starship is refuel-able , that’s one of its capabilities. Nobody on these vehicles going to Mars will care about you sitting there complaining that is doesn’t count.
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