Carl Sagan

The stand that was supporting the next prototype (SN9) collapsed yesterday, causing the Starship to fall into the wall of the chamber (the High Bay) where it was awaiting roll out onto the test pad. At the moment the cranes are there trying to sort things out, but it won't be ready for pressure/engine fires/flight tests quite so quickly. And we don't yet know if it's salvageable.

It's a shame as it was complete and ready to go, but even if it cannot be saved, there are another six (at least) under construction that will be ready soon.

Scored and assisted in an 11-minute cameo against Boro in the week.

https://www.lancs.live/sport/football/football-news/pne-emil-riis-middlesbrough-goal-19433609

4 hours ago, TigerTedd said:

Am I right in thinking of you could build a ship in space and launch it from a space station / moon base, it wouldn’t need to be able to withstand any atmospheric pressure?

but then how do space ships shield against little meteors and things? They must be hitting it like bullets all the time, but I imagine it has to be as light as possible, so doesn’t want to be covered in armour plating. 

The future is definitely "on-orbit manufacturing and assembly". What you need is the infrastructure to be able to use the raw materials available to us in space (so you're not carrying everything up from Earth's gravity well) and an automated industrial/manufacturing process. If Starship works it's big enough to be able to create this infrastructure, so in a way it might be the last big chemical rocket we need. 

Lightweight shielding is currently required because everything needs to be as light as possible when you're carrying it up from Earth, so the Whipple Bumper is the current mainstay, using layers of aluminium foil that are surprisingly effective at slowing down projectiles such as micrometeorites. There's a list of shielding techniques at https://hvit.jsc.nasa.gov/shield-development/

If you're building in space you don't necessarily have the same mass constraints if the final structure is to be stationary. But if you're moving it somewhere then the mass is still an important factor. So space stations would likely have more solid shielding whereas spaceships will be more lightweight to be able to whizz around.

In the future I hope for giant spaceships built in space that criss-cross the solar system but never land anywhere, and then we have smaller vehicles to ascend from and descend to planetary bodies. Earth is the most massive body we'll probably want to land and take off from. Starship is designed to take off on its own from Mars (single stage to orbit) for the trip home, but requires the giant Super Heavy booster to be able to reach orbit from Earth. Also Starship's Raptor engines are a brand new type that use methane and oxygen for fuel, on the premise that you can manufacture both fairly easily on Mars or anywhere in the solar system for that matter. 

SN8 is dead; long live SN9!

The crown passes to Serial Number 9 (the 9th prototype) which rolls out onto the test pad this coming Monday. First off will probably be pressure tests to ensure the fuel tanks are up to the job. The ship can fly if the tanks withstand 7 bar (7x atmospheric pressure) but the goal is to get them over 10 bar as that's what's required for future Human certification. 

15 minutes ago, TigerTedd said:

So is it concerning that this one blew up, or was it all part of the plan? Or do we take the 1 in 90 chance when we fly on it?

Not at all concerning. Pre-flight assessment was that it would almost certainly blow up somewhere as long the way, so to make it all the way to the landing pad and just arrive a little too fast is seen as a great success. These rockets will fly many hundreds, probably thousands of times, before they start transporting Humans. 

4 hours ago, Stive Pesley said:

I posted a question early on in this thread about the effects of (the lack of gravity) on people planning to live on Mars

An interesting article here explains a little more

https://medium.com/predict/space-exploration-needs-artificial-gravity-623cbd42121

Astronauts on the ISS have serious side effects from microgravity after 6 months - and that's just the one way travel time to Mars. If Mars travellers then try to live in microgravity on Mars for a further prolonged period, it  will wreck their bodies

Sorry to miss this. It's a great and important point. As you rightly state out microgravity (what most people think of as Zero-G) wrecks the Human body fairly quickly. One of the issues with Starship is the duration of the Mars flight, which will probably be around 5 months. Not great for then getting to work on Mars. 

There's a key unknown question which is, "what level of gravity is safe enough for Humans to live - and do things such as give birth - long term?" We do not know the answer and should be working to find out. I know some former NASA engineers who have a fantastic design for a rotating space station, which would be large enough to simulate Mars gravity (about one-third Earth). We need to start building structures like this. 

Also, I've suggested to them (and they liked the idea!) that they link two counter-rotating stations and then stick a Starship in the middle to power it, and then you have a genuine interplanetary spaceship with artificial gravity, and Bob's your uncle! Here's a video of their concept. 

31 minutes ago, EtoileSportiveDeDerby said:

A couple of questions

Whats the idea behind the horizontal approach ?

why so close to the ground, it barely has time to correct itself back to a vertical position ?

The horizontal approach is to maximize the surface area in contact with the atmosphere. When returning from space this will help increase the air resistance to slow the rocket down and spread the heating over the widest area.

From space, especially if on an interplanetary trajectory, you are travelling *really* fast yet have to bring that speed down to zero. And you will have as little fuel as possible (because of the weight penalty). So getting close to the ground just optimizes this part of the process.

SpaceX has successfully landed more than 60 of its Falcon9 rockets from space missions, and these only relight one engine when close to the landing site, so they know that final burn can be done pretty close to the ground. 

At first this looks like a render, but it's amazing real footage! 

View of the "landing" from the beach: 

First flight was amazing. It all lasted just a little under 7 minutes.

The first 4:45 is a vertical ascent, first on all 3 engines, then down to 2, and then a single 1. The engines cut off and the ship coasts upward a little longer and turns horizontal, preparing to "belly flop" back to Earth, falling with style, until it approaches the ground when it relights its engines and turns vertical again, ending with a controlled upright landing. Quite how any Humans onboard (and ultimately it's meant to hold 100 of us) cope with the changing orientation is yet to be seen.

Well worth watching the full video. Including the dramatic finale!

We're good to go at this point. The SpaceX feed is just about to go live. Launch timetabled for just after 9pm

We're trying again tonight, but in case of more problems the no-fly zone above the launch site has been extended to also cover Thursday and Friday. But the tank farm (which provides the cryogenic fuel) is now active (venting fuel) and the NASA high-altitude spotter plane has filed a flightpath from Florida to Texas to observe the hoped-for launch, so hopefully tonight is the night. Not as many streams right now, but it's live here:

Aborted! The Raptor engines automatically shut down  with 1 second to go (reason unknown). Presume we go again tomorrow. 

Ten minutes to launch!

Roughly. There isn't a set time. Could even be sooner. The official feed (4:30 CST is 22:30 GMT):

Finally we're underway. The test flight will be in the next hour unless there's a problem. The flaps have been extended and fuelling has begun. Also, the NASA high-altitude tracking plane has taken off from Florida and is heading to Texas to monitor the flight, hoping the Starship doesn't explode before it reaches high altitude. It may well!

The SpaceX feed still isn't live, but there's commentary on NASA Spaceflight. I'll see if I can get it to embed this time:

Today's the day of the first proper test flight (all being well). We don't know when, but anytime from now (though they've not started fuelling up yet) over the next severak hours. There are several live feeds.

I'm using NASA Spaceflight because it has commentary so I will hear when something starts to happen:

https://youtu.be/OLpN8Cco3mU

Better quality but mostly quiet is the LabPadre feed:

https://youtu.be/STGWOEKhrtI

Then there's an official SpaceX feed that's not yet live but well over 100k people are already waiting for it!

https://youtu.be/nf83yzzme2I

Apparently SpaceX beginss in five minutes. The "tank farm" (which they fuel te rocket from) is already buzzing with activity.

Traditional rocket development happens in secret, far away from prying eyes. A problem with building your prototypes outdoors in a field in Texas in front of a global audience of space fans, paying for 24/7 streams, is that schedules keep changing. Indoors in secret, we'd never know. 

If you'd set a reminder to watch the 15km first test flight tonight, I'm afraid it's not now happening. It's been changed to tomorrow (hopefully) or Wednesday as a backup, with the altitude reduced to 12.5km (41,000 feet). I don't know why the altitude is lower. It may be SpaceX thinks they can test everything they need flying to a lower altitude or, for a very first flight of an experimental spaceship built in a field, the Federal Aviation Authority might have insisted for safety reasons. 

However, it turns out that SpaceX will likely do another static fire test tonight. That normally only fires the engines (this SN8 prototype has 3 Raptor engines) for a second or so, but at this early stage of the journey to Mars, it's still quite exciting. 

For those looking forward to watching the first test flight tomorrow, it's now gone back to "no earlier than Monday". 

The launchpad the prototype is on can't take much more punishment from the pre-flight tests of the super-powerful Raptor engines, so I'd be surprised if they're delaying to perform more engine tests (static fires). 

NASA's relationship with SpaceX has occasionally been tense because NASA has sometimes claimed SpaceX is concentrating too much on the Starship program at the expense of the Dragon contracts for the International Space Station. 

This Saturday sees the first launch of the new SpaceX Cargo Dragon to the ISS, taking up an important new airlock among other things. My sense is that it would look terrible if something went wrong (and it's a new vehicle) at the same time SpaceX is slapping itself on the back for the first launch of its Mars rocket, so I think this may be a political decision. 

2 hours ago, maxjam said:

@Carl Sagan

Not looked at this yet other than the trailer, looks like it might be worth a watch though ?

https://www.netflix.com/gb/title/80221410

Alien Worlds

Applying the laws of life on Earth to the rest of the galaxy, this series blends science fact and fiction to imagine alien life on other planets.

Thanks! Sounds a little like something I made earlier:

The NOTAM (notice to airmen) has been approved by the authorities, creating an air exclusion zone above the Boca Chica launch (and landing) site. This means the 15km altitude test flight can go ahead, any time from Friday (all being well) through to Sunday (in case there are delays). 

If the Starship flies properly and reaches the target height, it then descends (belly flops) over the Gulf of Mexico until the last moment. Only if everything is working well, will it make a late move away from the water to attempt a controlled vertical landing. 

31 minutes ago, 86 Schmokes & a Pancake said:

I think some are making stuff up Mr Sagan! Inception a superior film in every sense in my view. Have you seen Tenet and if so what did you make of it? Initially it did make me think of you as I thought it'd be your kind of movie. By the end I'd changed my mind though! ?

Here's what I wrote in August. 

On 28/08/2020 at 18:38, Carl Sagan said:

Went to TENET last night as a lover of Nolan's Inception, Interstellar, Memento and The Prestige.

I didn't know what the film was going to be about, but it turned out to link to areas of my scientific expertise on which Nolan decided to build the plot. I found it so disappointing. It might be that on the third or fourth watch it falls into place, but a film has got to give you a decent payoff on first viewing.

I'll give it 3/10 for some pretty scenes and the mention in the script of Richard Feynman.

Such high hopes, all shattered. But time is a great healer and having heard the Inception theory (aka made-up nonsense), I might give TENET another go soon. 

8 hours ago, WhiteHorseRam said:

Clever glossy film ... but a bit too clever maybe.

Was it it's own prequel?

Robert Pattinson's speculative job application for 007 too.

6/10 due to Ken being the dogs danglys.

Some say TENET is the sequel to Inception. But I think that's unfair to Inception. You're waiting for a train... 

The 15km test flight (the reason I finally got round to starting this thread) has actually been put back to "no earlier than Wednesday", and potentially a little further into December. That's with the 8th prototype, called SN8 (SN = serial number). But what's brilliant is the backlog of prototypes, each better than the last, which is building up on site. For example, here's the completed SN9 in the hangar (called the High Bay):

Sometimes the improvements are incremental, sometimes they're a step change. The latest prototype being worked on is SN15, and Elon says this will be a major improvement on the previous versions. 

12 hours ago, ramit said:

Hanson's Great Filter is built on a rather shaky foundation.  It supposes that our instruments of observation are fully capable of detecting signs of intelligent life, that our ability to correctly read their measurements is sound and so forth.  It does not consider the possibility that we can only see what we are allowed to see at this time, that advanced civilizations would take the protective steps of cloaking their whereabouts to less advanced races, such as ourselves.

The Big Bang Theory has had many doubters, such as Einstein himself. From Wiki:  "It violates the first law of thermodynamics, which says you can't create or destroy matter or energy. Critics claim that the big bang theory suggests the universe began out of nothing. ... The first is that the big bang doesn't address the creation of the universe, but rather the evolution of it."

We can discuss, formulate theories and even arrive at a conclusion of how life can spring from chemical interaction in a certain sort of timing and environment, but we still won't be much nearer to solving the greatest mystery of all, consciousness, which i believe is the key to understanding, life, ourselves and this universe we inhabit.

Hanson is a good Bayesian. He adjusts his reasoning based on his observations, so the Great Filter supposes nothing over the longer term, but is right to use current knowledge to draw conclusions. Over the past 60 years or so we have made quite remarkable progress in astrobiology. We now know every star comes with planets, that it's a straightforward process to colonize the Galaxy in a million years or so, and that Earth is a relatively young planet in the Milky Way so others would have had headstarts on us of billions of years. But now with instruments like the WISE telescope we can also look beyond and see there are apparently no alien dyson spheres in the nearest million other galaxies we observe. The further and better we see, there remains nothing there. The next constraints will be the likes of the James Webb Space Telescope and the much better analysis of atmospheres around exoplanets. Maybe things will change, because you're right that we still can't observe anything like as much as we'd like, but we can see a lot. It's my belief it's telling us something fundamental about the Universe and the nature of reality.

Consciousness is an interesting one. In my day job I'm a publisher (for instance Robin Hanson's editor, and Milan Cirkovic's for his work on the Fermi Paradox), and I'm working with a brilliant author on a fascinating book at the moment that is a very interesting exploration of consciousness, but of your three areas it's mainly about understanding ourselves. But probably not out for a couple of years if I can persuade the powers that be to let me sign it up!

33 minutes ago, ramit said:

I am surprised that you consider it likely that we are the only intelligence in this unbelievably vast universe.

https://www.informationisbeautiful.net/visualizations/the-drake-equation/

It's a brilliant observation. You can have no idea how pleased I am you made it. 

This is a topic I think about daily (I'm writing a novel about it, a bit of a homage to my namesake's "Contact") and is exercising many of the world's great minds. It's perhaps the biggest challenge to modern science, trying to combine the ideas of the cosmological principle (that the universe looks largely the same when viewed from anywhere, that the laws of physics apply equally everywhere and there's nothing privileged about our place in the Universe) with our observations that there isn't a shred of evidence for complex life anywhere else in the universe. How long can these ideas remain compatible? 

We tend to think of the Drake Equation as part of old-fashioned SETI when people expected aliens to be listening with radio telescopes for whispers of intelligence elsewhere. Nowadays a lot of things are framed through the lens of Robin Hanson's Great Filter. 

Every nook and cranny here on Earth is teeming with life. Everything out there in the vastness of the Universe can be explained by dead processes. It's a conundrum.

On 26/11/2020 at 14:36, SchtivePesley said:

An interesting take from Werner Herzog this colonising Mars - that  "We should not be like the locusts, coming, grazing empty our planet, okay, and now where do we go next?"

23 hours ago, ramit said:

And we take for granted that Mars and other planets and moons in our solar system are ours for the taking

Few humans have done more for the planet than Musk. For decades we were facing Carmageddon with the motor industry not giving a stuff. Elon single-handedly has transitioned the world towards electric cars and sustainable transport, with a heavy focus on solar power too. Reluctantly the traditional car companies are being dragged kicking and screaming in Tesla's wake, but they're all a decade behind now so effectively are already dead. 

You can look after your own planet and want to improve it at the same time as wanting to colonize others. Call me crazy, but I'm speciesist. I want Humanity to survive. We might be the only complex intelligence in the Universe, and if we go that could be the end of intelligence everywhere. Of course the other planets of the solar system should be ours to do with as we see fit, to help protect intelligence in the Universe and let it flourish. 

Meanwhile, Starship is to begin twice monthly test flights from next week, having established a 90 square mile safety zone around Boca Chica, mainly in the ocean, where spaceships will be blown up if they get out of control. 

https://www.krgv.com/news/spacex-planned-9-mile-launch-self-destruct-zone-over-gulf

It was a very short static fire, but everything went well. According to Elon, we remain on course for next week's historic test flight. 

He gives it a one in three chance of succeeding fully, but whatever happens we'll learn something.