Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

SpaceX Starship Users' Guide [pdf]

spacex.com

Post reply on HN
Print view View original

241–246 of 246 posts

Re: SpaceX Starship Users' Guide [pdf]

#241

Post by temporalparts »

garmaine wrote: post #223
temporalparts wrote: post #78

Earlier quoted context omitted.

In the context of space launches, ridesharing means that multiple satellites share a single launch as opposed to the traditional 1 satellite 1 rocket approach. All Starlink satellites have been launched via ridesharing missions, with ~60 satellites per launch (and sometimes with satellites from other companies!).

> All Starlink satellites have been launched via ridesharing missions, with ~60 satellites per launch (and sometimes with satellites from other companies!). Actually aside from the first couple of Starlink test units, it has been the other way around. SpaceX launches dedicated Starlink missions on a regular cadence using previously flown boosters, and offsets the cost somewhat by offering rideshare opportunities. The…

The definition of rideshare is that they ride with multiple other satellites. 60 satellites means that each are ridesharing with 59 other ones.

The ridesharing program is what SpaceX offers to outsiders, but the concept of rideshared rocket is whenever a rocket ferries multiple satellites to save cost.

Re: SpaceX Starship Users' Guide [pdf]

#242

Post by WizardAustralis »

njarboe wrote: post #178
WizardAustralis wrote: post #141

Earlier quoted context omitted.

It isnt so much a case of schadenfreude but more a case of seeing what issues still need to be addressed. Personally I would love nothing more that to see the doubters get shown up by the likes of SpaceX actually going out there and making it all actually happen. It is when legitimate issues are being brought up but arent being actively addressed by the likes of SpaceX that is when one has to wonder about how the upp…

"I fear that, what if a company like SpaceX over promises and under delivers and causes more damage to the field long term than if they had not done anything at all?" Not sure how you think SpaceX could cause more damage than doing nothing. They are the only group for the last two decades, besides Blue Origin, that is trying to advance the technology of heavy lift rockets past what we had with the Saturn V. Just imag…

It can cause more damage than good by making people doubt the entire mission as a whole. Funding will dry up pretty quick if folks think it is just another dead end.

And $30 per Kg would be nice, the last figure for SpaceX is $2,720 per kg. That is a very big difference.

I have nothing against revolutionary technology. The thing is, when it comes to the reusable rockets and near earth orbital stuff - I have never had much doubts that SpaceX would achieve this outside of earth based political issues. I worry that they are pushing an image of what they want rather than what they will achieve.

Look at Blue Origin, I actually don't have a problem with them as they seem to be taking the more cautious approach. It could be a Turtle and the Hare situation going on here.

Re: SpaceX Starship Users' Guide [pdf]

#243

Post by WizardAustralis »

dgritsko wrote: post #181
renewiltord wrote: post #119

Earlier quoted context omitted.

No one cares about this shit anymore. Everyone and their uncle had a Youtube channel telling us why Crew Dragon would fail because they used electron for their interface or Tesla would fail because they don't understand what Real Car Companies™ do or Tesla is just a bunch of techies who think they can solve other problems because they can write software or Space X is doomed because their rocket exploded once. Well, i…

"It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, who comes short again and again, because there is no effort without error and shortcoming; but who does actually strive to do the d…

It is all very well to quote Roosevelt and yes he is correct. But there is a difference between putting in the hard work and trying achieve something great, SpaceX have done that and will continue to do great things, and the difference between claiming a million people on Mars.

The thing is there are many folks out there that were the nay-sayers and were completely wrong but also many that were completely correct. They are typically not remembered. It is one thing to make bold claims, it is another to out right deny the realities of the universe because they get in the way of a vision.

Re: SpaceX Starship Users' Guide [pdf]

#244

Post by WizardAustralis »

skykooler wrote: post #167
WizardAustralis wrote: post #135

Earlier quoted context omitted.

The issues of space radiation is far from discredited. It is one.of the major issues that still doesn't have an elegant solution. One.idea that SpaceX is proposing is to try and get the trip to Mars to 6 months. It will still be a serious issue but it would at least be better than the typical trip proposal. One of the reasons I posted that channel was because they seem to have really done their research far beyond th…

It does have a pretty elegant solution: water. Water is an excellent shield against radiation, and any long duration mission will have a large amount of water on board for the humans. With proper positioning of the tanks, said water can do double duty as a radiation shield.

Water does work, it is also astoundingly heavy. That is the major issue. Elegant but impractical.

It simply blows out any useful payload volume and costings because of the amount of water required. Last estimate I have seen is they would need 1,500 tons of water to make Starship radiation resistant (80% decrease in exposure). Even at $300 per Kg, about 1/8th the cost of current launches, that is still approaching a half billion dollars per ship with a significant lost of internal space.

Technical viability and economic viability are two very different things as well. This is going to be the thing that I feel will eventually limit our travel outside of the earth system.

I suspect we will see rampant use of Starship in orbit, the occasional run to the moon and maybe once or twice to Mars but beyond that. It will be just another technological lead that ends up in civilizations recycling bin.

Re: SpaceX Starship Users' Guide [pdf]

#245

Post by skykooler »

WizardAustralis wrote: post #244
skykooler wrote: post #167

Earlier quoted context omitted.

It does have a pretty elegant solution: water. Water is an excellent shield against radiation, and any long duration mission will have a large amount of water on board for the humans. With proper positioning of the tanks, said water can do double duty as a radiation shield.

Water does work, it is also astoundingly heavy. That is the major issue. Elegant but impractical. It simply blows out any useful payload volume and costings because of the amount of water required. Last estimate I have seen is they would need 1,500 tons of water to make Starship radiation resistant (80% decrease in exposure). Even at $300 per Kg, about 1/8th the cost of current launches, that is still approaching a h…

One possibility is the use of a cycler - in other words, putting only a couple Starships with massive amounts of water onboard in an orbit that loops back and forth between the Earth and Mars. Passengers would board it for the transit, then transfer back into an unshielded starship that flies in formation for the journey. This way, the shielding mass only needs to be launched once, and can be reused for an arbitrary number of flights.

Re: SpaceX Starship Users' Guide [pdf]

#246

Post by WizardAustralis »

skykooler wrote: post #245
WizardAustralis wrote: post #244

Earlier quoted context omitted.

Water does work, it is also astoundingly heavy. That is the major issue. Elegant but impractical. It simply blows out any useful payload volume and costings because of the amount of water required. Last estimate I have seen is they would need 1,500 tons of water to make Starship radiation resistant (80% decrease in exposure). Even at $300 per Kg, about 1/8th the cost of current launches, that is still approaching a h…

One possibility is the use of a cycler - in other words, putting only a couple Starships with massive amounts of water onboard in an orbit that loops back and forth between the Earth and Mars. Passengers would board it for the transit, then transfer back into an unshielded starship that flies in formation for the journey. This way, the shielding mass only needs to be launched once, and can be reused for an arbitrary…

That is a pretty smart idea actually.
Post reply on HN