I think we all understand this. Possibly one could release from a space elevator close to GEO and use aerobraking to move a satellite into LEO, since the overall kinetic plus potential energy is higher for GEO than LEO?
But damn, where’s my space elevator? And my flying car (NOT self-driving, thank you, I’ll fly it myself)!
I hear you, but I would still like to see some numbers here. Does anyone have an estimate for cost-to-GEO per Kg for starship, assuming it becomes routine? Don’t get me wrong, I really want to see this succed!
And of course a space elevator is still science fiction.
The numbers for Starship are still speculative. Musk says that one day it could be as low as $10/kg. Take that with a giant grain of salt.
But we can start with the basics. Fueling Starship reportedly costs about a million bucks. Musk says he thinks he can launch and return for a total variable cost of about $2 million. That would be labor, fuel, maintenance. That’s an ‘aspirational’ number that doesn’t include fixed costs, recouping capital investment, etc.
But let’s start with that. $2 million per launch is about $13/kg, assuming the rocket is going to LEO and is full. That’s an insanely low price, and we wouldn’t see anything close to that for decades, assuming rockets become commodified and there are huge numbers of launches.
In the near term, Starship will likely be more like $100 million per launch, which still gets us a payload price of $650/kg. For comparison, a Falcon 9 launch is about $2500 per kg. Very soon though Starship should fly for less than a falcon 9, as it is fully recoverable. Prices of $20-30 million per launch are not unreasonable in the near future, so we could see launch prices near $200/kg fairly soon if everything works as planned.
All of these considerations apply to a space elevator. One day in the far distant future they might operate close to their energy costs, but today it would take many billions to build one, and that investment would have to be recouped. And I don’t think anything as complex as a space elevator could operate without a huge infrastructure behind it driving up costs.
In the case of Starship it’s not all-or-nothing. It could easily start out expensive and then have costs come down as the system becomes more mature.
Sure, that’s the nature of any new transport system that ultimately becomes widespread. I just wish it would mature a bit faster: I want to take that monorail ride up Olympus Mons before they cremate me!
Then hope for Starship and similar fully reusable rockets, because even if a space elevator could be funded and built, it would still be decades away. Starship may be a reality in a week or two. And because it is being built on an assembly line and is reusable, the inventory of Starships will begin to grow and the flight rate will increase.
If Starship works, we are on the cusp of a new era in space where our ability to lift mass into space goes up by orders of magnitude while the cost goes down.
Couldn’t you just invert the polarity of the transducer coils to the +/- ion flow regulator?
You may have learnt from KSP. I learnt from Star Trek!
See also this recent thread on the importance of creative use of polarity 
:
Absolutely. We don’t even have the materials to build a space elevator yet, if ever.
The idea is great and it doesn’t violate any laws of physics, but of course it won’t happen any time soon.
Maybe around the time of commercial fusion power and room temperature superconductors?
And maybe actual strong AI? But I don’t want to derail into chatgpt discussions…
I wasn’t give to understand that the hypothetical materials needed violate the laws of physics, but are rather beyond our current materials engineering. Graphene ribbons have extended the break length to something like 5000 KM, which is still too short (but really cool). Diamond nanothreads are seen as potential candidate (Carbon nanothread - Wikipedia).
Here’s a current space elevator thread with an interesting twist:
Simple back-of-envelope calcs, rough numbers; Earth is 8,000mi diameter, or 4,000mi radius. 24,000mi circumference. LEO at 150 miles takes about 90 minutes or so. A space elevator at that height is only going around every 24 hours. If you jump off there, you roughtly need to go 24/1.5=16 times faster than earth rotation to maintain LEO. That’s a lot of delta-V. (earth rotation - 24,000mi/24h = 1000mph=1466fps)
A tether at LEO altitude - say 200 miles, 300km - is essentially just hanging there. Centrifugal force adds nothing really. The balance does not happen until GEO at about 22,000 miles above the surface. So a material that cannot hold up, guessing, 15,000 or more miles of itself won’t make a proper space elevator. Figure out how much a 15,000 mile skien of your favourite unobtanium weights and can you dangle that from a single strand of it? I don’t think we’re there yet. And we haven’t even talked about supporting the weight of the crawler making its way up that thread, but I bet that detail is irrelevant compared to the weight of 15,000 miles of thread.
What’s the best fishing line or kite thread you can buy nowadays?
So you either speed up your planet’s rotation, reduce gravity, or both, and you can construct a space elevator. At a certain point, the planet will spin too fast and chunks will fly off the equator. Slightly below that speed, you barely need an elevator; but you’re living on an oblate spheroid.
Not exactly the same, but Hal Clement’s Meslikn (Mesklin - Wikipedia) was something like this. An 18-minute day meant a huge difference between 3g at the equator and 700g at the poles.
I like the idea of the spinning tethers in space weighted to absorb momentum of incoming soaceships and transfer it to outgoing spaceships. It’s an old idea, and I have no idea if it’s feasible.
The idea is that it’s large enough that spacecraft needing to shed velocity can match with it at the outside part of the tether and latch on, then wind their way down to the hub, transferring momentum to the tether, speeding it up. Outgoing spacecraft dock at the hub then ratchet up the tether and fling away on a tangent line to their orbit. This slows the tether back down. Nearly 100% efficient energy recovery and reuse.
I haven’t seen this news posted in amongst the interesting diversion into space elevators, but Starship and Super Heavy are fully stacked. Launch window looks like next week.
It’s getting close! There’s an official SpaceX page on the test flight as well:
No booster catch or even vertical ship landing. Looks like they’re not being too ambitious for their first flight.
It’s darn hard to catch flaming debris. I applaud their overall audacity, but I think this suggests they’re not highly confident of end-to-end success.
In the alternative, this is a bit of a boilerplate launch. As in some certain systems aren’t mature enough to include; in their current state they’d just add risk, not reward. So better to install ballast in their place and simply have the thing best-case belly flop into the ocean or worst-case become the aforementioned flaming debris.
Whatever happens, it’s gonna be tres cool.
I think just getting far enough away from the launch tower before a RUD is the main mission, everything else is bonus. Making it to stage sep would be icing on the cake. The champagne will be flowing if 2nd stage makes it into “orbit” with the rest of the mission being an after-credits scene of little consequence.
I think it’s quite feasable. But there don’t seem to be any incoming spaceships at the moment… 
Discounting the risk of RUD - I think the first time, they probably want to be sure things work all the way up before seeing if they also work all the way down to a soft landing. If the thing has problems, planning it to aim for an inhabited area is probably not a good idea - you want to be sure assorted systems work as advertised first. Plus, I wonder what the mission profile looks like, whether the ship once it starts leaning over to go to orbit can make it back. IIRC, Falcons land on the landing ship because except for low-payload missions, they don’t allow for enough fuel to return to start.
I have no clue about the specific Starship mission profile. But yeah, trying to stick the landing on your only very expensive pad the first time sounds like a bridge a bunch too far. Success on the way up is success enough.