totm nov 2023 SpaceX Discussion Thread

[Silavite]

13 minutes ago, Jacke said:

Another thing that's just wrong is Starlink.  A system that will not be better than surface fibre links supplemented by current satellite service.  But will slowly and thoroughly destroy ground-based visual astronomy.  Just another case of tech-giant collateral damage that gets at most crocodile tears.

Fiber internet has high fixed costs which preclude its installation in rural areas. I actually did an ethical analysis of mega constellations (full text is here) for my engineering ethics course. From a purely act utilitarian view:

Quote

The costs and benefits associated with broadband mega-constellations have already been listed above, but to summarize: the primary benefit of building broadband mega-constellations would be increased access to broadband in rural and underserved areas. The costs are the obstruction of ground based optical (and possibly radio) astronomy and increases in orbital debris. It is the author’s opinion that, for a mega-constellation in a relatively low orbit (like Starlink), the benefits outweigh the costs. There are currently sixty million people living in the rural United States alone[11]. Even if a mega-constellation opened the door to low latency broadband to only 1% of rural individuals, that would still be six hundred thousand people in the United States alone. Low altitude (less than 650 km) means that any orbital debris from defective satellites will be dealt with in a few years by the atmosphere, meaning that the net risk posed by orbital debris is relatively low. Although astronomy is a fascinating and enriching field, there are only about ten thousand professional astronomers in the entire world[12]. Of those, a sizable fraction work in unaffected subfields (space based astronomy, X-ray astronomy, gamma ray astronomy, infrared astronomy). While mega-constellations are a large inconvenience to astronomers, they are neither a life-ending nor (hopefully in most cases) career-ending factor. When the number of people standing to benefit from mega-constellations is approximately a hundred times greater than those standing to be debilitated, it seems clear to the author that the benefit of broadband mega-constellations outweighs the cost. Thus, from an act utilitarian standpoint, the moral question of, “Should we build broadband mega-constellations [in low orbits],” is answered by a resounding, “Yes.”

From a Kantian view:

Quote

The analysis and answer to the moral question is a bit different in the Kantian view. It is not enough for Kant that a mega-constellation causes more good than harm. For Kant, the action of creating a mega-constellation must not hurt the autonomy of other agents. In this case, it is quite clear that the autonomy of astronomers working in ground-based optical astronomy will be curtailed. The early stages of SpaceX’s Starlink mega-constellation are already having negative impacts on ground-based optical astronomy, and it is quite clear that more satellites will make the issue worse. Organizations cannot morally build mega-constellations unless they find a way to address the issues that mega-constellations pose to ground based astronomy. There is a Kantian objection on the grounds of orbital debris as well. The act of generating debris does not directly harm anyone’s autonomy. That said, collisions between debris and spacecraft do harm agents’ autonomy (the most severe case being the death of an astronaut due to orbital debris). Thus, the act of building mega-constellations would not be de facto immoral, but the organization building them would have a perfect duty to ensure that no orbital debris is created. Thus, from a Kantian point of view, one must conclude that building a mega-constellation would be an immoral act unless the two points above were dealt with.

 

[zolotiyeruki]

28 minutes ago, Jacke said:

I find Starship fascinating.  As a cargo vessel, because with all launch vehicles still having a minimum failure rate of 1-2%, having no launch escape system and crewing it would means condemning some future crews to die.  I also think using it to go to the Moon is marginal and to Mars is even less so, being it is designed and optimized to get to LEO.

 

Sure, if you were designing a rocket specifically to go to the moon, you could make it significantly more efficient than Starship.  But fuel is relatively cheap, and even though the cargo part of the spacecraft would need engineering, you'd be starting with a propulsion and landing section (engines, tanks, control systems, etc) that is already proven.

[Terwin]

38 minutes ago, Jacke said:

Another thing that's just wrong is Starlink.  A system that will not be better than surface fibre links supplemented by current satellite service.  But will slowly and thoroughly destroy ground-based visual astronomy.  Just another case of tech-giant collateral damage that gets at most crocodile tears.

I live just outside the city limits of Austin, TX(aka 'silicon hills'/'Silicon Valley II'), and the Starlink beta has a lower monthly cost and higher bandwith that any other broad-band provider to which I have access at my current address.(which is less than a mile from the GM innovation and Amazon distribution centers on the old Dell Campus, so hardly out in the sticks).

If I was not in the process of buying a new house (which may or may not be in a different Starlink 'cell' which may or may not require a new dish), I would already be on the waiting list for service in 'mid 2021' just for the service improvement and cost reduction.

If I can't get better service in a tech-hub living less than a mile from a Dell/GM technology/Amazon campus, I imagine that the number listed above for potential subscribers to be a very pessimistic estimate.

[Jacke]

[snip]

Who says everyone on Earth will be able to afford Starlink?  These aren't altruists running these corporations.  Like with launch services, they'll charge what the market will bear.

This is someone taking advantage of owning a launch company reducing the cost of moving into a new variant of a market.  Who doesn't care what damage he does.  You're enabling him in his destruction.

And there's already a better, cheaper, and more robust way to bring the Internet to the world already well deployed.  Cell-phone systems with towers and companies linked by fibre.

 

8 hours ago, Silavite said:

Fiber internet has high fixed costs which preclude its installation in rural areas. I actually did an ethical analysis of mega constellations (full text is here) for my engineering ethics course. From a purely act utilitarian view:

From a Kantian view:

 

Some interesting thoughts; I'll have to read them in depth later.

However, even from a utilitarian view, you can't rate the value of visual astronomers, professional and amateur, just by their numbers and their own needs and welfare but also by their utilitarian contribution to World science and societies.  With many of the recent improvements with optics, ground-based astronomy is near equivalent with orbital astronomy and is much cheaper and has far more instruments.

Be careful when numbers of people come up, because it could become the utilitarian equivalent of the Trolley Dilemma.

 

7 hours ago, Terwin said:

I live just outside the city limits of Austin, TX(aka 'silicon hills'/'Silicon Valley II'), and the Starlink beta has a lower monthly cost and higher bandwith that any other broad-band provider to which I have access at my current address.(which is less than a mile from the GM innovation and Amazon distribution centers on the old Dell Campus, so hardly out in the sticks).

The U.S. Internet market because of its history and regulation makes its service more expensive and lower quality compared to most of the World.  (I live in Canada and it's not much better.)  It's part of what gives Starlink an edge there.  But if the fundamental problems aren't solved, things will not get significantly better and likely get worse.  Similar to how expensive cable bills are being replaced by expensive streaming bills of roughly the same total cost.

 

Edited February 24, 2021 by Vanamonde

[Flavio hc16]

1 minute ago, Jacke said:

Who are you to rate the value of visual astronomy?  Which has given more enlightenment, science, and enjoyment over the years to many many people.

Are you seriously comparing the enlightenment, improvement in life and science and enjoyment ( we are on a forum about a videogame) in everyday life that the internet has given compared to astronomy?

1 minute ago, Jacke said:

Who says everyone on Earth will be able to afford Starlink?  These aren't altruists running these corporations.  Like with launch services, they'll charge what the market will bear.

And it would still be massive, almost 50% of the earth population doesn't have internet connection. If you don't get how much important the internet is, try to sta completely offline for 1 month, you just can't .

1 minute ago, Jacke said:

This is someone taking advantage of owning a launch company reducing the cost of moving into a new variant of a market.  Who doesn't care what damage he does.  You're enabling him in his destruction.

if he wouldn't care about damage he wouldn't have put his satellite in a low orbit, with blancket on the to get them a bit darker and it would have left all his 2nd stages in orbit, from what i recall, stats do that, not private companies

1 minute ago, Jacke said:

And there's already a better, cheaper, and more robust way to bring the Internet to the world already well deployed.  Cell-phone systems with towers and companies linked by fibre.

if that would be the case, it would have been already done, but it is un-economical, this is why starlink will disrupt them. And in case of natural disaster?

[tater]

We know what initial Starlink costs. $499 for the dish, and $99/mo. The dish is also wifi, so you could have multiple people use the same wifi. People with the beta already get ~5X my DSL speed ($50/mo), so I could share with my neighbors and get what we all currently get for $20/mo.

As for astronomy, I have concerns, but they appear to be mitigating things reasonably well. Early launches I saw many Starlink passes. I've tried to watch a few in the last months to no avail. Never spot them.

My friend with 4 domes at his house (and a few whole sky cameras for meteor observations) is out in the sticks here in NM, and is already signed up for Starlink, he wants the internet so he can use his multiple telescopes better from Houston, lol.

1 hour ago, Jacke said:

Re-useability does reduce performance to about 70% of an equivalent disposable booster due to having to carry the landing equipment and hold back propellants for deceleration and landing.  Refit is on top of that.

Reuse is the only thing that will ever make space exploration more than just satellites and occasional space probes.

Rapid reuse.

The hit on boosters is nothing like 70%, it's ~40% for return to launch site, and ~18% for sea landings.

Unsure what the hit is on Starship, but it doesn't matter, as the payload is huge. If they manage to make it rapidly reusable, it obviates all other launch vehicles at that point which cost more than the operational cost of a SS launch for whatever their max payload is (likely a smallsat launcher). If it costs X million to turn a SS around and refly, and some smallsat launcher can throw Ykg to LEO for less than that, the smallsat launcher can survive. If the payload is more than Ykg? They lose.

 

Quoting Philip Bono and Kenneth Gatland from their 1969 book:

Quote

As we enter the age of the space rocket much remains to be done before it can take its place alongside more conventional means of transportation. The rocket boosters of today are not recovered for re-use; they are allowed to burn up while penetrating Earth's atmosphere or to splash down wastefully into the sea. No other method of transportation could long survive the extravagance associated with disposal of the carrier vehicle after only one use. Truly efficient space exploration awaits the day when launching can be accomplished by a booster which can be recovered and re-used repeatedly.

 

Edited February 23, 2021 by tater

[tater]

Simple poll.

If you could snap your fingers, and have the spaceflight capability of a show like the Expanse be a thing, would that be something you'd want to see?

If yes, then Starlink, etc, are pretty unconcerning, as the night sky would literally be filled with the reflections of large spacecraft +- X hours from sunset/sunrise, and all night long from more distant craft, and any coming or going from Earth blazing with their fusion blowtorches. Any "science fiction" future for humanity has the pure night sky no longer a thing near any transportation hub (just like within a decent radious of any large city, the sky is covered with aircraft, 24/7).

[mikegarrison]

There is another thread for Starlink. (Trying not to backseat moderate here, but...)

[tater]

1 minute ago, mikegarrison said:

There is another thread for Starlink. (Trying not to backseat moderate here, but...)

1000 Starships setting out for Mars will be pretty shiny

Meanwhile in Boca Chica, static fire possible on SN10 in under 10 min.

[magnemoe]

1 hour ago, Jacke said:

To me Elon Musk will always have one thing on his side: he's not Jeff Bezos, the Modern Day Sweatshop Operator.

Otherwise, I think Musk is full of flaws.  He's said very stupid things that he should have know better not to say.  He lacks the immediate near-instinctive sense good engineers (also good scientists, especially experimental) have of what's possible and the costs and limitations and where things can be improved.  He's more like a lot of tech CEO's, a part-showman who gets far too close to snake-oil salesman.

One example where showmanship won out over engineering: the launchpad crew.  They should not be dressed all in black.   They should be dressed in proper anti-flash gear, which is white, not black.  Someday when there's a incident, that could make the difference between degree of injury or even life and death.  (See images in the spoiler below.)

Another thing that's just wrong is Starlink.  A system that will not be better than surface fibre links supplemented by current satellite service.  But will slowly and thoroughly destroy ground-based visual astronomy.  Just another case of tech-giant collateral damage that gets at most crocodile tears.

What Elon Musk really did was bring a good supply-chain to launch vehicles, push engine development, and push re-useability.

However, re-useability is not a panacea.  Condoms were original hard-shelled and re-useable before ones more like what are made now were produced.

Re-useability does reduce performance to about 70% of an equivalent disposable booster due to having to carry the landing equipment and hold back propellants for deceleration and landing.  Refit is on top of that.

Thunderf00t's videos, for all they ridicule Elon Musk (alas YouTube video makers need to be part-showman as well to survive and thrive), give legitimate analysis and criticism of SpaceX and Musk's other companies and projects.  Like any engineer, Thunderf00t did a rough calculation of the costs to find the break-even point for re-useability and thought it likely to be approaching 10 flights rather 2 or 3.  Without more reliable data, no one is going to be able to say what it is with greater confidence.

What is true is that SpaceX is charging roughly the same as other launch providers.

I find Starship fascinating.  As a cargo vessel, because with all launch vehicles still having a minimum failure rate of 1-2%, having no launch escape system and crewing it would means condemning some future crews to die.  I also think using it to go to the Moon is marginal and to Mars is even less so, being it is designed and optimized to get to LEO.

You want a real program to get to Mars?  The only one I've read that gives me any confidence is Robert Zurbin's The Case for Mars.  You need to read all the chapters.  Saturn-5-class-sized rockets with ground checkout (for quality, thoroughness, and cost reduction), 2 of them per mission, an uncrewed return vessel with ISRU to make fuel, followed once the return vessel is ready by the crewed stay vessel to get to Mars.  Or change it as NASA suggested.  Either way, there's minimal cost, reliability, and proper abort modes throughout the mission.  Then run them in succession to build up a Mars colony.

Agree he is an showman and he know its important to get people exited. 
However have fun getting fiber on an remote farm  in the first world. Now you have planes, ships and cars. or nor in the first world. and not in an town.  

Agree in performance reduction with reuse, however its throwing away hardware is expensive. Only other use is drop tanks and they are only dropped in war and are magnitudes less expensive than rocket stages. 
Yes disposable is common but it has environmental problems and its used on stuff who is stamped or cast. Not complex stuff like cars or planes, again war is an exception.

No i don't think intercontinental starship transport will be an thing, the launch cost divided on customers wanting to go on launch time rater than buying an first class ticket on any flight is very limited, its worse than the concord problem. 
It might have first response or military use but then it has to land away from any launch pad so you might recover the engine and expensive hardware the hull will be lost and it takes time to set this up. 
You could use it for orbital bombardment however but this is strategic bombing who you plan. 
 

[Flavio hc16]

aannd, we've got a static fire!

[CatastrophicFailure]

1 hour ago, tater said:

If you could snap your fingers, and have the spaceflight capability of a show like the Expanse be a thing, would that be something you'd want to see?

Nitrogen. Freaking. Glaciers. 

And someone pelted with a Plutonian snowball. 
 

1 hour ago, tater said:

yes, then Starlink, etc, are pretty unconcerning, as the night sky would literally be filled with the reflections of large spacecraft +- X hours from sunset/sunrise, and all night long from more distant craft,

This. Whether Starlink happens or not, the night sky will look very different in a hundred years, or a thousand. What happens once we start building orbiting megastructures visible to the naked eye? Progress demands change. Visual astronomy may not seem so crucial some future day when one can buy a cheap ticket and go setup a telescope on the dark side of the moon...

...or Pluto... 

1 hour ago, tater said:

We know what initial Starlink costs. $499 for the dish, and $99/mo. The dish is also wifi, so you could have multiple people use the same wifi. People with the beta already get ~5X my DSL speed ($50/mo), so I could share with my neighbors and get what we all currently get for $20/mo.

Can’t find it, of course, but there’s a tweet upthread mentioning Starlink will shortly be upping to like 300mbps. 

34 minutes ago, magnemoe said:

However have fun getting fiber on an remote farm  in the first world.

*raises hand*

And it’s not even that remote. I don’t even have reliable cell service, I’m dependent on the internet or the (lousy) local phone company for communication. And that’s shown no signs of changing in the 14 years I’ve been here, there’s just no market to support that kind of infrastructure upgrade, and if anyone tried the local NIMBYs would go apoplectic. There’s “supposed” to be gig fiber in my area “soon,” but still waiting, and same lousy local phone company to deal with. And will probably drop out in a power outage, and CERTAINLY in an earthquake. Satellites don’t do that. 

[cubinator]

9 minutes ago, CatastrophicFailure said:

This. Whether Starlink happens or not, the night sky will look very different in a hundred years, or a thousand. What happens once we start building orbiting megastructures visible to the naked eye? Progress demands change. Visual astronomy may not seem so crucial some future day when one can buy a cheap ticket and go setup a telescope on the dark side of the moon...

...or Pluto... 

It's also worth noting that once you get to space, you can see the sky to the fullest as long as you have a shade to block the brighter objects. Of course, that's harder if there are thousands of enormous torch ships flying about, but light pollution doesn't spread away from direct line of sight like it does on Earth.

[Jacke]

4 hours ago, mikegarrison said:

There is another thread for Starlink.

5 hours ago, tater said:

As for astronomy, I have concerns, but they appear to be mitigating things reasonably well. Early launches I saw many Starlink passes. I've tried to watch a few in the last months to no avail. Never spot them.

My friend with 4 domes at his house (and a few whole sky cameras for meteor observations) is out in the sticks here in NM, and is already signed up for Starlink, he wants the internet so he can use his multiple telescopes better from Houston, lol.

I brought up Starlink not in and of itself, but as an example of Elon Musk using SpaceX to establish a new project that didn't take into account all of its consequences, especially the negative ones.  And it's good that there has been some changes to reduce Starlink's light pollution, but why wasn't that thought of before the first launch?

Astronomy both professional and amateur will adapt to deal Starlink as best it can.  But those who get the benefits from Starlink won't be footing any significant part of the costs of dealing with its negative effects.  This is all too much like other pollution in the past.  It should have been handled better this time.

 

Quote

The hit on boosters is nothing like 70%, it's ~40% for return to launch site, and ~18% for sea landings.

That was just a misconstrue of the numbers.  I said "reduce performance to about 70% of an equivalent disposable booster" which is about a 30% hit.  Return-to-launch-site has to be cheaper than sea-landings due to less infrastructure operations and distance delays.   It's hard to get better numbers than this within more reliable data.

Is sea-landing really as low as ~18% ?

 

Quote

Reuse is the only thing that will ever make space exploration more than just satellites and occasional space probes.

Rapid reuse.

Quote

Quoting Philip Bono and Kenneth Gatland from their 1969 book:

Quote

As we enter the age of the space rocket much remains to be done before it can take its place alongside more conventional means of transportation. The rocket boosters of today are not recovered for re-use; they are allowed to burn up while penetrating Earth's atmosphere or to splash down wastefully into the sea. No other method of transportation could long survive the extravagance associated with disposal of the carrier vehicle after only one use. Truly efficient space exploration awaits the day when launching can be accomplished by a booster which can be recovered and re-used repeatedly.

 

I agree that developing re-use and rapid re-use is vital.  But it has to be developed properly and where it is worthwhile.

Early on in the Shuttle program, ~1982, I didn't like that what was still an experimental bleeding-edge spacecraft was expected to be a space truck too.  We all know where that went.

Rocketry ain't aviation.  Aviation is tough enough, but it developed and matured relatively rapidly, partly due to the two World Wars as well as the Cold War throwing a lot of resources at finding better ways nawh and taking the hits in resources and *lives* of pushing the bleeding edge.  It's a highly technical and still somewhat bleeding-edge area of human endeavours that all too many people have thought would become routine.

And rocketry is tougher that the hardest parts of aviation.  Because the engines and vehicles are pushed to perform right at the bleeding edge.  It's why new rocket lines usually have about 10% failure rates when put into service and the best get it down to 1-2%.

Starship is important because it will advance the development of re-use and rapid re-use.  Always remember it is still an experimental bleeding-edge spacecraft.  I like the way it's being developed and tested.  But because I can't see it having a launch escape system that would not hurt its performance in a big way, I think it should be used as cargo only.  Other craft should be used to get people to orbit and beyond.

 

4 hours ago, tater said:

If you could snap your fingers, and have the spaceflight capability of a show like the Expanse be a thing, would that be something you'd want to see?

There's many a slip twixt cup and lip.  "The Expanse" is conjecture, though a good one, like other good science fiction.  We don't know what the future will truly be like and this is a case where the details are important.

But for space, let's consider just two places: inside the Van Allen belts and outside of them.  Inside is where the light-pollution concerns are greatest, because going outside has the reciprocal square of the distance on its side.  Just outside there's geostationary orbit, where light pollution is still a concern. but not as much.  How many satellites can fit there?  And it's all on the celestial equator.  And except for craft in transit (small in number and moving on likely reported courses), the rest is much farther away.

In the solar system, even with a lot of colonies, how many ships would operate?  I'd say even approaching the number of maritime ships operating now would take a long time.  And at distances many many times farther ("Space is big.  Really, really, big.  ...."), millions of times farther than LEO, and that reciprocal square of the distance makes them even angularly dimmer and much smaller.  And virtually all of the traffic would be on the ecliptic and moving in regular paths.

Both of those are a lot easier for astronomy to adapt to than hundred of thousands of LEO commnet satellites that will be relatively a lot brighter and larger angularly.

 

4 hours ago, magnemoe said:

Agree he is an showman and he know its important to get people exited. 

Yes, it is important.  But it has similar risks to any demagogue.  I wish Elon Musk also showed more care in his words and his engineering.

 

3 hours ago, CatastrophicFailure said:

I don’t even have reliable cell service, I’m dependent on the internet or the (lousy) local phone company for communication. And that’s shown no signs of changing in the 14 years I’ve been here, there’s just no market to support that kind of infrastructure upgrade, and if anyone tried the local NIMBYs would go apoplectic. There’s “supposed” to be gig fiber in my area “soon,” but still waiting, and same lousy local phone company to deal with. And will probably drop out in a power outage, and CERTAINLY in an earthquake. Satellites don’t do that. 

Quote

However have fun getting fiber on an remote farm  in the first world. Now you have planes, ships and cars. or nor in the first world. and not in an town.

These are serious problems.  That Starlink may provide a workaround for somewhat.  But it won't solve all of them.  The root causes need to be addressed.  And a disaster-robust infrastructure doesn't have to have Starlink.

 

Quote

Agree in performance reduction with reuse, however its throwing away hardware is expensive. Only other use is drop tanks and they are only dropped in war and are magnitudes less expensive than rocket stages.
Yes disposable is common but it has environmental problems and its used on stuff who is stamped or cast. Not complex stuff like cars or planes, again war is an exception.

Excluding warfare (where operational performance trumps almost everything), we have a whole society that is far too oriented around disposal.  Even some of the current recycling industry isn't truly effective.  There needs to be a re-think and regulation on how things are packaged to improve this.
https://en.wikipedia.org/wiki/Cradle-to-cradle_design

But rocketry is and will remain for a long time a minor part of society.  And it is bleeding edge and uses disposal to largely operate at all.  This should and will change and that development is ongoing now is very good.

But there's other places in society that would be better to push harder on redesigning to reduce disposal.

 

Quote

No i don't think intercontinental starship transport will be an thing, the launch cost divided on customers wanting to go on launch time rater than buying an first class ticket on any flight is very limited, its worse than the concord problem. 
It might have first response or military use but then it has to land away from any launch pad so you might recover the engine and expensive hardware the hull will be lost and it takes time to set this up. 
You could use it for orbital bombardment however but this is strategic bombing who you plan.

Beside the costs involve, the big often unstated problem with Earth point-to-point rocketry is the real time involved, the handling at the end points, customs, logistics, and maintenance.  Sure, a 30-minute flight, bookended by 6 hours or more both ends for the vessel, cargo, and crew.  And then there's that 1-2% complete loss of craft that has to be improved upon.

Edited February 24, 2021 by Jacke

[CatastrophicFailure]

31 minutes ago, Jacke said:

brought up Starlink not in and of itself, but as an example of Elon Musk using SpaceX to establish a new project that didn't take into account all of its consequences, especially the negative ones.  And it's good that there has been some changes to reduce Starlink's light pollution, but why wasn't that thought of before the first launch?

I think that’s a bit unfair. Elon doesn’t run SpaceX in a vacuum (har har), not even Shotwell does. Before they ever started bending metal for StarLink, he had to convince a lot of other people (including actual Rocket Scientists™️) that it was worthwhile. From my understanding, they did take impacts on astronomy into account, what with low orbit choice and what not, but perhaps didn’t realize the magnitude of the effect, which has since been largely corrected (good luck seeing a StarLink anywhere now, except maybe under ideal conditions). As they say, hindsight is 2020, and with engineering as with anything, sometimes you have to actually make a thing to fully realize the problems. 
 

38 minutes ago, Jacke said:

These are serious problems.  That Starlink may provide a workaround for somewhat.  But it won't solve all of them.  The root causes need to be addressed.  And a disaster-robust infrastructure doesn't have to have Starlink.

I would argue that it does have to include StarLink, or something very like it. The system’s value was already demonstrated during last summer’s wildfires. A massive earthquake could cause region-wide disruption of land-based communication, leaving satellites the only option. Information is becoming as crucial as food and clean water during such disasters. 

[tater]

4 minutes ago, Jacke said:

That was just a misconstrue of the numbers.  I said "reduce performance to about 70% of an equivalent disposable booster" which is about a 30% hit.  Return-to-launch-site has to be cheaper than sea-landings due to less infrastructure operations and distance delays.   It's hard to get better numbers than this within more reliable data.

Is sea-landing really as low as ~18% ?

My bad, I misread that.

Yeah, the reduction for sea is supposedly ~18% per SpaceX, but they may not ever really realize that as it's hard to put the 22.8t or whatever the max expendable mass to LEO is under the fairing anyway.

The performance hit is pretty much meaningless as long as actual payloads are not at max LEO mass anyway. Loads of margin.

7 minutes ago, Jacke said:

I agree that developing re-use and rapid re-use is vital.  But it has to be developed properly and where it is worthwhile.

Early on in the Shuttle program, ~1982, I didn't like that what was still an experimental bleeding-edge spacecraft was expected to be a space truck too.  We all know where that went.

Rocketry ain't aviation.  Aviation is tough enough, but it developed and matured relatively rapidly, partly due to the two World Wars as well as the Cold War throwing a lot of resources at finding better ways nawh and taking the hits in resources and *lives* of pushing the bleeding edge.  It's a highly technical and still somewhat bleeding-edge area of human endeavours that all too many people have thought would become routine.

And rocketry is tougher that the hardest parts of aviation.  Because the engines and vehicles are pushed to perform right at the bleeding edge.  It's why new rocket lines usually have about 10% failure rates when put into service and the best get it down to 1-2%.

Starship is important because it will advance the development of re-use and rapid re-use.  Always remember it is still an experimental bleeding-edge spacecraft.  I like the way it's being developed and tested.  But because I can't see it having a launch escape system that would not hurt its performance in a big way, I think it should be used as cargo only.  Other craft should be can get people to orbit and beyond.

I actually think an aviation model—airworthiness—is a good idea going forward.

As reuse becomes a thing, certifying individual componenets is certainly still an issue, but it's not the same with parts that literally only ever get used ONCE (most rockets).

 

[kerbiloid]

Humans should live in hi-tech cities.
Cities should be optically fibered.
Any long-range emitting hardware should be reduced and finally eliminated.
Space-X and 1Web networks are selfish business projects which have no excuses and raise unnecessary radio noise which will unveil our position to aliens, and this is just a sloppy parasite emission.

SpaceX Mars == Mars Two. 
(Mars One has already been).

Did I miss something?

[Vanamonde]

Some comments have been removed. Please do not make the discussions personal, and watch the language. 

[RealKerbal3x]

Back to our regularly scheduled program! SN10 did a static fire, but one of the engines didn't cooperate:

 

[RealKerbal3x]

 

[RyanRising]

On 2/23/2021 at 11:54 PM, RealKerbal3x said:

Back to our regularly scheduled program! SN10 did a static fire, but one of the engines didn't cooperate:

 

Raptors are still finicky, I see. I wonder if we’ll ever get to hear the stories of the development challenges with Raptor, much like the early days of the SSME or the F1? I hope we do, and it’s from the same angle of “we had to throw this many engines in the meat grinder to get something that consistently worked, but once it did, it really worked.” Even then, the SSMEs had to be taken apart between flights.

 

On 2/24/2021 at 12:15 AM, RealKerbal3x said:

 

...I thought the people who were suggesting this were joking. Had no idea it was an actual option. 

Edited February 25, 2021 by RyanRising
Made that second sentence read better.

[Gargamel]

14 hours ago, mikegarrison said:

There is another thread for Starlink. (Trying not to backseat moderate here, but...)

 

Yes there is.   So....  Please take any conversation regarding Starlink specifically to that thread.   Quote and ping anybody you need to from this thread if necessary, but further posts on Starlink will probably be moved there.   I know the two topics are pretty intertwined, and some overlap will be unavoidable, so just do your best when possible.   Thanks!

 

 

[JoeSchmuckatelli]

... 

Okay. 

... I'm not a rocket scientist.  But it seems to me that when you can't yet stick the landing on a parking lot, to say you plan on landing a rocket on the helo pad of an oil rig (and between towers, at that)... 

Ya might be a bit daft. Because I'm not sure how many crashes into the oil rig it takes to destroy said expensive man made island - but I'm guessing it is close to 'one'. 

[RealKerbal3x]

12 minutes ago, JoeSchmuckatelli said:

... 

Okay. 

... I'm not a rocket scientist.  But it seems to me that when you can't yet stick the landing on a parking lot, to say you plan on landing a rocket on the helo pad of an oil rig (and between towers, at that)... 

Ya might be a bit daft. Because I'm not sure how many crashes into the oil rig it takes to destroy said expensive man made island - but I'm guessing it is close to 'one'. 

Two things:

1. It's a testing program. They've literally only tried this landing maneuver twice before. Just because they didn't quite get there on the first two attempts definitely doesn't mean they're not allowed to announce their future plans for the system, especially when they seem confident that they can land successfully on the next attempt, or the one after that. Remember: Falcon 9 was announced while Falcon 1 was still having launch failures.
2. The oil rigs will be heavily modified, so they'll likely have a bigger target than a helipad to aim for. I don't even think a regular helipad could survive the vibrations, heat and sheer mass of a spacecraft landing on it.

[JoeSchmuckatelli]

29 minutes ago, RealKerbal3x said:

It's a testing program.

I get it.  And if you've read my past posts on my amazed appreciation for the fact that they can land a spacecraft on a barge, it might bring my snark into context. I actually appreciate SpaceX's aggressive 'lean forward' development strategy. 

But that said - I'm a bit skeptical about the aim of landing between towers.  That plan takes absolute precision - whereas a flat barge (or reinforced structure atop a platform) allows for some wiggle room.