SpaceX launches Starlink sats in record 10th liftoff, landing of reused rocket
space.com
space.com
She then pointed out that I know the ID of every active SpaceX booster, including prototypes, and watch nearly every launch live.
Oh no. I'm a rocket spotter.
I know there’s concern about these LEO sats, but we still enjoyed counting the train as it streamed almost directly overhead from West to East.
I hear this and it's like someone admiring the engineering of a cloverleaf exchange running over a buried river.
Very much yes!
Stars and galaxies are. They are as they always[0] were, and always will be. Blobs of fusing hydrogen very far away. As beautiful as they may be if we could see them better, from where we are, they're just points of light.
(Also, wait a few seconds, the satellites will pass, and you're back to watching the stars behind.)
A constellation of satellites in the sky is also just a bunch of points of light. But it's more than that. It means something. Humans have put it there. Those satellites serve a purpose, and their appearance on the night sky reminds us of the great discoveries and feats of engineering that were necessary to put them there. They're a testament to the ingenuity and potential of mankind, and the promise that one day, our descendants will travel among them.
That's what I see when I see a satellite passing overhead.
> it's like someone admiring the engineering of a cloverleaf exchange running over a buried river
Sure, it's exactly that. A cloverleaf exchange is interesting. It's not something that just happens, and its shape is not random. A river is boring. Also full of insects that try to feast on your blood.
I'm totally serious, by the way. Ever since a kid, I've found nature boring. This actually changed for me in my adulthood - my interest in biology sparked when I realized that life is just molecular nanotechnology that wasn't designed by humans, but could still be eventually understood and controlled.
--
[0] - On human-relevant timescales.
The universe of knowledge one could obtain from studying the organisms and ecological connections in a healthy wetland ecosystem or the physics of stars and galaxies and supernovas and black holes and brown dwarfs is vaster by orders of magnitude than what could be won by marveling at highways and satellite trains.
>[0] - On human-relevant timescales.
This was once orthodoxy, but it was overturned ~450 years ago, at least from a Eurocentric perspective.
- If you look at millions of objects, then something that only happens to each one, once in X million years, will be happening to one of them right now. Like a nova.
- If you look at millions of objects, then you will see the one-in-a-million rare one which is doing something on a human timescale. Like a pulsar.(My favorite thing to spot were always Iridium flares. I miss those.)
Here is the Wikipedia page for the star that died over 30 years ago: https://en.wikipedia.org/wiki/Sanduleak_-69_202
You can see meteors all the time. A bit of trivia I read somewhere is that your spot on the earth is facing more "into the wind" the later it gets after midnight, so that's when it's best to look for them.
Usually meteors are just streaks of light, but once I went partway up a mountain for a forecasted meteor shower and I saw one just like people render it for an illustration (except much smaller because of the distance) - you could see it was a white hot fireball, shading to red, shading to blue, with a long bluish tail.
At that moment, yes, absolutely. As I said, I understand the concerns and as with everything else, too much of it is going to be bad but during this moment I talked about it was absolutely wonderful.
Starship doesn't have an unambiguous cost because it's dependent so heavily on factors like market size, whether the Mars thing happens, and reliability. A marginal cost of a few million dollars is an explicit goal, but a more short-term rough goal is about Falcon 9 prices, or $50m/launch. That's both a very reasonable number, and also still more than 10x better than the competition.
Plus $2.9B for the moon contract doesn't hurt either. It will go back into developing more starship features.
So it must be mostly the same boosters all the way, even if engines, valves, electronics, etc have been replaced multiple times.
Back in the days when boosters were recovered, I remember hearing somewhere that SpaceX was confident that they would be able to fly them 10x, and hoped for 100x
SpaceX is taking advantage of technologies that weren't available until recently. Of course, now that they are available, we should see SpaceX's competition adopting them.
We've made non-reusable rockets for quite some time pre-F9.
What one should object to in this scenario is the idea that the conventional aerospace companies, and NASA, would have done anything like this, when their internal incentive structures pushed them away from it.
Yes, D9 was designed around boosters. This means D9 is a different kind of design than F9. I'm contending that a more F9-like design, like Saturn 1B, could have evolved into something like the F9 over time. D-II could not have.
By the way, I don't personally buy this argument, but it's not completely meaningless either.
SpaceX benefits enormously from fast computers, advances in metallurgy, CAD, etc.
Neither project was government funded or ordered. There's no particular reason to think it could have even been built in 1967, and even in 1996 it may not have been possible to land a rocket after reentry. Coming in backwards at supersonic speed is incredibly challenging. Flipping around would have been even more so. Transitioning from supersonic to subsonic would have been a total guess. The DC-X certainly could not have done any of those things.
The OP may also not understand the incredible gulf in difficulty between landing a suborbital rocket and a real first stage. A suborbital rocket doesn't weigh that much more going up than it does going down. The F9 first stage weighs less than 5% of what it has to lift on the way up. Getting a rocket to output 25% thrust is easy; use four engines and turn off 3. You can't just turn off 19 engines; the F9 first stage is huge and needs huge power swings to remain stable.
SpaceX built custom sparse voxel GPU solvers to design around combustion instabilities and supersonic flows around the rocket. Even in the 90s they would have had to make huge concessions for the sake of running 20+ engines at once. There's absolutely zero chance they could have done it in the 60s or 70s.
> may not have been possible
> incredibly challenging
> a total guess
Which, yeah, rocket science is hard! But the above is not difficult because it's impossible to solve for, it's difficult because we never tried! Nobody, government or otherwise, thought that rapidly iterating on rocket technology would be a good idea. This above all was the ticket to SpaceX's success - when you can throw rockets away for science, you can learn a lot in a short amount of time.
Did some things need to be invented before SpaceX could use them? Obviously, although I have doubts that the computations being performed by these "GPU solvers" really require a modern custom-built GPU and couldn't have been done on FPGAs or arrays of microcontrollers from the 80s. If we understand the math being crunched, it's just a matter of throwing more computing power at the problem.
> Obviously, although I have doubts that the computations being performed by these "GPU solvers" really require a modern custom-built GPU and couldn't have been done on FPGAs or arrays of microcontrollers from the 80s.
Here's a talk by the guys: https://www.youtube.com/watch?v=vYA0f6R5KAI
The Cray 2 could do <2 gigaflops. So a single simulation with 10,000 points per side at 1 microsecond timesteps for .1 seconds with ~50 flops per cell-step would have taken 79 years to run, assuming the Cray had 50 cycle fetch/store times. Engineers need to run lots of simulations to come up with a working design. And that's just simulating something around the scale of a single nozzle- you'll need to be doing sims for a 40 meter tall stage as it flips around.
Also, the cray had a 256 Mword memory. So you could only store a single timestep of a grid of 400x400x400 cells anyway. The supercomputers of the 80s were really just not very useful for things like this.
An engineer in any one of them who presented a way to make the rocket cheaper to his boss would have been fired for not understanding how the company makes money.
The oversight is supposed to be done by congress, but they are extremely happy to provide good paying jobs in their districts, for decades.
No one even really hides it anymore. Any official, when asked about something like SLS and costs, would answer with "But NASA is going to the moon! Don't you want America to go to the moon?!" and with "tens of thousands of high paying jobs in all 50 states". There is no attempt to say the rising year over year price of orbital launch (before SpaceX), the exorbitant price of SLS + Orion, the use of solid boosters for crewed launches, etc, make any sense except to support the existing contractors to the detriment of the tax payer and space exploration.
See a NASA insider explaining: https://www.youtube.com/watch?v=g3gzwMJWa5w&t=463s
(Or see anything by Dr. Robert Zubrin, or see the story of how the shuttle derived design that lost to RAC-2 (a Saturn V like design) was chosen to be "SLS": https://www.youtube.com/watch?v=ZNZx208bw0g&t=1970s)
I don't disagree that they often make money via cost-plus contracts, that SLS is mainly a jobs program, or any of that. What I disagree with is your apparent inherent assumption that it's malicious. Nobody's "milking" anything - Hanlon's razor, remember. Never assume malice when stupidity (I'd prefer "incompetence") is an adequate explanation. The project managers at ULA, at Boeing, at Lockheed, at Northrop, aren't monsters trying to squeeze more money from the taxpayer. They, quite simply, believe that this is the way you have to build a rocket and you can't possibly do it any cheaper. They do pride themselves on being able to deliver things ahead of schedule and under budget, except they can't because everybody expects projects to be behind schedule and over budget, since that's the way it's always gone. Traditional expectations have a stranglehold on the oldspace industry. I've also worked for a newspace company - there was none of that attitude.
Don't assume the astronautics primes are evil. They're just... old.
> "We had released a series of papers showing how a depot/refueling architecture would enable a human exploration program using existing (at the time) commercial rockets," Sowers tweeted on Wednesday. "Boeing became furious and tried to get me fired. Kudos to my CEO for protecting me. But we were banned from even saying the 'd' word out loud. Sad part is that ULA did a lot of pathfinding work in that area and could have owned the refueling/depot market, enriching Boeing (and Lockheed) in the process. But it was shut down because it threatened SLS."
https://arstechnica.com/science/2019/08/rocket-scientist-say...
Even if the majority of employees are just there to work on the future of rocketry, if the incentives all reward the companies for being as overbudget and underperforming as possible, they are going to respond by being overbudget and underperforming.
ULA is the real problem. The government allowed all the launch providers to merge into one with no domestic competition. Think space Comcast. Other countries allowed the same. Nobody innovated for decades. Russia and US ULA are flying rockets from 50 years ago with minimal updates.
Old Babushka proverb, if complicated explosion related plumbing is working as intended, best not to completely rework it for sake of changelog.
Minimal updates to the shape, maybe?
But I bet the electronics and manufacturing have seen steady improvements over that time.
SLS does feel quite like a pork barrel, but I understand the funding of it along with the other commercial companies as "more options, less risk", if something grounds the Dragon capsules, having a "home" alternative instead of buying seats on a foreign rocket makes sense.
Aye, but everyone stuck with that proverb for too long. Then Musk appeared and he doesn't seem to care that his test rockets explode. He revels in it.
To me it's the classic startup vs giant corporation. The bigger you are, the harder it is to change course. And exploding rockets look bad to management. The same reason so many companies are still on IBM mainframes running FORTRAN.
SLS is an insurance policy against SpaceX. But it's being managed by the same old wasteful monopolies as always, plus plenty of government mandated pork.
I wanted [object Object] but it was taken haha
I'd guess it's pretty unlikely to occur, even when the virus detection actually deletes infected files.
Then again, I guess a filesystem filter driver can return whatever it pleases. Not sure if Windows anti-virus support works through filter drivers anymore, though.
Yes we need a second, competing system but Boeing may have lost the last of its engineering expertise.
In 1969 America landed the first man on the moon, using the Saturn V rocket, capable of launching 140 tons to LEO.
In 2021 NASA has yet to build a single rocket better than the Saturn V, with the in-construction SLS being not realistically much cheaper, and no more powerful.
We have had zero advances in launch technology from old space in fifty years. There was an attempt in 1981, but that attempt was bad and then they just gave up.
The original plan for recovering the F9 first stage was to use parachutes and this was tried with the first couple of launches, but the boosters broke up on re-entry. That’s when the idea of a re-entry burn came up, and from that the concept of a propulsive landing.
But propulsive landing is only possible with the F9 because it has a central engine and the engines are small enough to throttle down low enough to do a suicide burn. You have to have an engine at or very close to the centre of the vehicle for it to work. But this 9 engine cluster with a central engine was not originally designed with propulsive landing in mind. It was an accident.
If SpaceX had better funding early on, they probably would have developed a larger main engine for the booster, which wouldn’t have been able to throttle low enough to stick a landing and may not have had a cluster arrangement with a central engine anyway. This is also why the other rocket companies mostly can’t adapt their rockets for reusability easily.
Are you sure about that? The Merlin engine Falcon 9 uses has the highest thrust-to-weight ratio of any rocket engine currently being used, more than double that of the much more powerful RD-180 used on the Atlas V. You'll lose some advantage because structural support and plumbing for more engines is heavier, but I'd expect they'll still come out ahead. The Raptor has been downsized from the original plans, and Musk has said that was to improve thrust-to-weight ratio.
Why? I can't think of any reason why more powerful engines would fundamentally be more weight-efficient.
As I understand it, the main driver of scale is that the combustion chamber has an optimal size. Too small and you get incomplete mixing, too large and you get instabilities.
That wrong. They tried this on the Falcon 9, not the Falcon 9.
Re-usability was their goal early on and and it was just a question of how to get there. Its not an accident. You could of course claim the exact architecture they have is an accident. But then again had they developed this larger engine they might have moved to a larger vehicle with 5 of those before going to a fully reusable Starship style vehicle.
The important point is consistently worked towards a known goal.
NASA tried to build a reusable spacecraft with the Shuttle. Valuable lessons were learned.