NASA's Take on Starship Progress, Farthest Thing You Can See, Galactic Lagrange Points | Q&A 241

What is the farthest object you can see with the unaided eye? Do galaxies have Lagrange points like stars or planets? What does NASA think about Starship's last flight attempt? Which future space telescopes are the most exciting? How will Starship fly without a crew escape system? Answering all these questions and more in this week's Q&A show.
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00:00 Start
01:01 [Andoria] How will Starship fly humans without a crew escape system?
07:03 [Vulcan] Do galaxies have Lagrange points?
10:43 [Risa] What do I hope JWST discovers next?
12:41 [Aeturen] What's the farthest unaided-eye object?
13:53 [Vendikar] Is life common in the Universe?
15:17 [Remus] How accurate was The Martian?
20:13 [Janus] Are Von Neumann probes doable with current level of technology?
23:11 [Cait] What's the shape of the known Universe?
25:07 [Betazed] Can aliens see dinosaurs?
25:17 [Cheleb] Will the next Starship reach orbit?
26:52 [Nimbus] What will be the next big space telescopes?
30:25 [Belos] What does NASA think about Starship's IFT-2?
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[@tusse67]

The orbiter did NOT survive the desintegration of the stack! It was torn apart the moment it turned sideways in the supersonic airstream... The inner crew cabin on the other hand survived relatively intact until it hit the water. And the shuttle did not explode, it just kind of broke apart with local combustion where hydrogen and oxygen mixed. And yes, there is a significant difference: the lack of a shockwave.

[@iamjasonfoster]

Thanks needed to scroll the comments to make sure someone said this

[@emacinnes]

There is only a small window of time in which crew ejection would even be possible, actually help, within the first ~2 minutes of launch. After that, it's all-in anyway. We don't have passenger ejection on planes for similar reasons. The goal then is to get to plane-level reliability with superheavy. Any RUD on starship thereafter would be too high and too fast to eject safely anyway.

[@AnonymousFreakYT]

One minor quibble: 1:50 - Challenger’s SRBs didn’t explode. They had burn-through that caused the main external tank to explode. In the footage (that is still seared into my memory) there are two contrails that go off slightly curvy away from the main explosion. Those contrails are the SRBs, continuing to fire away for multiple seconds uncontrolled after the main tank exploded, before range safety issued the destruct command for the SRBs. (Approximately 30 seconds after the destruction of Challenger.)

[@R.Instro]

Yep, also noticeable is that the trails veer apart from each other, then come back together again as the guidance systems on the SRBs compensate for the lack of a launch vehicle holding them together.

[@mertc8050]

​@@R.Instroo yeah lmao srbs dont gimble and guidance system???? You mean the aerodynamics making it go straight lmaoooo

[@R.Instro]

@@mertc8050 Glad I could amuse you. =) Still, you may want to recheck your assumptions: en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Booster might be a reasonable place to start.

[@Hevach]

The shuttle SRBs are way more capable than they were ever used for. They have gimbaled thrust and internal guidance. They're fully functional as a first stage in a linear stack (Ares 1-X, Liberty), common core heavy configuration (Boeing SRB-X), and there were a number of rockets they could technically work with that the connection hardware was never built for.

[@Liberty2358]

The saddest the fact I heard was that according Morton Thiokol tests, an SRB joint without any O-ring would have work better sealing in the hot exhaust gas than one with a leaky O-ring. Another word Challenger may have survive that launch if there were no O-ring at all. The reason is that the aluminum structure would have melted and seal off the hot exhaust gases from burning into the giant external fuel tank.

[@SteveBakerIsHere]

I think the concept for StarShip is that it's like an airliner. We don't have escape capsules for 747's. We have built-in reliability - and we have inspections - and we have redundancy. So I guess this change in thinking might be the reason we don't have an escape system.

[@oberonpanopticon]

Ah, the “if they crash it’s gonna be catastrophic so just don’t crash” approach. Though, I believe plane crashes are far more survivable than rocket crashes.

[@MediaWML]

You are correct; that is the route it appears they are going down. My worry with that is that an airliner can still land if all its engines fail. They will work it out of course; they always do.

[@saumyacow4435]

After hundreds of flawless unmanned flights we might have a reasonable statistical basis to claim Starship is safe for human flight. How long will that take?

[@SteveBakerIsHere]

@@saumyacow4435 Elon MUsk has said that he wants to see 100 flawless unmanned missions before a human flies aboard StarShip. That's exactly what he did with Falcon-9 by the way...so it's not inconsistent. How long that will take is hard to say...but in principle, they can launch, land, refuel and launch again in just a few hours. SuperHeavy is designed to re-fly one an HOUR. So 100 missions could happen in a month maybe. But that depends on the usual external annoyances. The FAA only granted SpaceX 5 launches per year at Boca Chica...so 20 year! That's why they're building two launchpads at the Cape. Realistically - things like the ability to refill their bulk propellant storage tanks from truckloads of methane and oxygen shipped by road might be a serious problem. I think it takes around 100 truckloads of propellant to fill a StarShip+SuperHeavy - and I can't see any US freeway coping with 2,400 heavy trucks per day without serious repercussions.

[@SteveBakerIsHere]

@@MediaWML Not always - I mean Flight 1549 was famously able to land on/in the Hudson River - but they were very lucky to have the opportunity. Check out en.wikipedia.org/wiki/Category:Airliner_accidents_and_incidents_caused_by_engine_failure - it's a long list.

[@prusak26]

Gemini capsule had actual ejection seats. Good those were never used, as the astronauts would have been burned to a crisp by the explosion, or by the engine exhaust, if the seat was triggered accidentally. If I remember correctly, Scott Manley and Tim Dodd both made great videos about launch escaspe systems.

[@bbartky]

And ejection seats just like the ones used in Gemini were installed during the first four missions of the Space Shuttle. They were removed afterwards since the ejection seats limited the crew to just two astronauts.

[@_photonx6017]

¨ @prusak26 2 days ago (edited) Yes, they did, and this was the answer I too expected to hear. Damn, and I was hoping to hear whether Frasier would pronounce Gemini correctly....

[@PeterHaida]

As a child, 'Robinson Crusoe On Mars' (1964) used to captivate me; I wonder if it was the inspiration for 'The Martian.

[@johnburr9463]

Book suggestion - "Job: A Comedy of Justice" by Robert A. Heinlein in 1984. Won Best Fantasy Novel in 1985. But it plays with the multiverse before the concept was popular.

[@vivienclogger]

I just about remember that. I also remember a book (I think it was called "Have Spacesuit, Will Travel) where they have faster than light travel, but the computers are programmed using machine code, using huge reference books. 😂

[@Chris.Davies]

Despite the Columbia victims still being alive for the 7 minutes it took for the front portion of the orbiter to smash into the ocean, the crew were unconscious within just a few seconds of the disastrous explosion, as the rapidly rotating cabin portion overcame their blood pressure. So, even though their emergency oxygen supply was being used by everyone, no one was awake to experience the end.

[@frasercain]

That's a relief. What a nightmare.

[@bbeen40]

Don't you mean Challenger...... Also, they were wearing high altitude pressure suits. Several oxygen switches were flipped, by several astronauts. Several were alive all the way down.

[@user-jd2gi7dy5d]

@@bbeen40 Challenger exploded on ascent. These people died pretty quickly in an explosion. Columbia had a problem with the heat shield and broke into pieces on descent. I don´t know much about that incident, but I can imagine that some of the pieces survived for a while before killing eveyone on board of these pieces. Just trying to make sense of wat I just heard...

[@Liberty2358]

@@bbeen40 An F-111 type escape capsule may have work in a low mach velocity but ejecting in supersonic or hypersonic speed you would need a ejectable space capsule inside the Shuttle. And if our altitude is too low then we don't the benefit of aerobraking.

[@absalomdraconis]

​@@Liberty2358 : If a capsule ejects low then either you've already had a _second_ massive and fatal safety failure (aka it ejected too late and has upper-atmospheric velocities in the lower atmosphere), or it's atmospheric velocity is already low enough for the capsule's design assumptions to be approximately met despite the low-altitude abort. It's worth remembering that you _can_ design a eject system to be safely used from ground level with zero starting velocity.

[@onebylandtwoifbysearunifby5475]

25:00 Shape of Universe- Topology is a complicated subject with much confusion. The 3 most likely shapes of the Universe (in order): 1) Sphere (DeSitter space, closed geometry. Finite, closes back on itself). 2) Flat (likely infinite with no overall (+ or -) curvature). Locally curved only, if that. 3. Parabolic / Hyperbolic (AdS [anti-DeSitter] Open geometry, where everything curves away from itself. On small scales and large, this seems to be mathematically correct description, as well as for Black Hole geometry. AdS/cft correspondence (see current work in theoretical physics of Susskind, Juan Maldecena, et,al.) Torus is another possibility, and is a form of Closed geometry related to a Sphere. Some unique properties, like preferred frames of reference that turn General Relativity around a bit (there are no preferred frames of reference in vanilla Relativity). A 3D sphere (or 3-sphere) remains the most likely geometry of the Universe. (3D spheres can only occur in 4D or higher dimensions, and CANNOT exist in 3D space, or 3 spatial dimensions not including time as an additional degree of freedom. Another point of common confusion, as people mistakenly believe spheres in our 3D space are 3D objects, which they are decidedly _not._ Topology is tough, especially when you go beyond 3 dimensions. Good video as usual. 👍

[@DavidGuillen-ji6kw]

I truly enjoy your programs. Your efforts are greatly appreciated!

[@MCsCreations]

Janus! Thanks for the Q&A, Fraser! 😊 Stay safe there with your family! 🖖😊 And happy holidays!

[@JohnSostrom]

Thanks for doing a video. Unfortunately, my chemo therapy is on Mondays. This puts a serious set of breaks on anything the rest of the day. So thanks again for the video. Wish I could join the live show.

[@Tayken9127]

I think it's kind of silly to expect SpaceX to have the HLS ready on time given it's practically 2024 now and they haven't even managed to get Starship into orbit.

[@jtjames79]

Fish and wildlife hasn't checked orbit for environmental impact yet.

[@JessiBear]

The Government is directly responsible for the speed of Starship progress. SpaceX progress is limited by the speed at which the Government allows them to launch test articles.

[@frasercain]

Sure, but it would be surprising to see SpaceX be responsible for delays in Artemis. SpaceX moves fast.

[@eugenecbell]

@@jtjames79lol, but yes what is up with those guys?

[@jtjames79]

@@eugenecbell The big guy didn't get his 10%.

[@JohnnyWednesday]

You're the emperor of space science communicators - I'm very happy to see your subs moving towards the numbers you deserve! Universe Today is a piece of art called "damn hard work"!

[@jongross3329]

Thank you for all your hard work Fraser.

[@PlanetXMysteries-pj9nm]

Thanks for another great video, look forward to many more!

[@RockinRobbins13]

The Andromeda Galaxy is not the furthest object you can see with the naked eye. I have clearly seen M33, The Triangulum Galaxy naked eye. I believe there are other galaxies worth a try, but the problem with others isn't their brightness. M51 is plenty bright enough to see naked eye but is too small to be resolved with the naked eye. It would be fun to find a pristine dark place and try out some alternatives to M31 and M33. I think M101 is the only other possible one because it's big. But it might be worthwhile to try NGC 253. Note: HA! You covered my point! I think the Ursa Major galaxies would suffer the same fate as M51 and the Virgo Cluster: plenty of brightness but they're too small for the eye to resolve.

[@lorrinbarth1969]

Jon Kelling if you are referring to the Space Shuttle, yes it originally had ejection seats, but only two seats, the size of the crew that originally flew it to space.

[@BG101UK]

I'd think the one big error in "The Martian" is where he uses a bit of flimsy plastic sheet and some tape to hold enough internal atmospheric pressure to actually breathe it!

[@adamhardy6765]

Your videos are always so informative and professional. I'm just curious, what video editing software do you use for your videos?

[@DrDiff952]

Starship. The shuttle didn't have ejection seats for all crew either

[@Freak80MC]

I could see Starship going either way with becoming a crew vehicle. Either they re-invent a Dragon equivalent or just re-use Dragon itself on top of Starship, or they really do just test the system like a hundred times through successful re-entries and landings and then say it's safe enough for crew. Most rockets are usually crew rated over after a few tens of successful, reliable flights. Starship could manage a hundred flights if it's fully reusable. And test ouf the issues before putting crew on-board. I do think the end-goal is a spaceship that works like an airplane, so reliable that it doesn't need an abort option for passengers.

[@tactileslut]

The part that bothered me most about The Martian was his air. The structure looked nowhere near pressure tight so he's at the ambient pressure of about 1%. Even at near 100% oxygen in that barely any pressure and presuming he got there very slowly, could be stay conscious?

[@KF-bj3ce]

Thanks for confirming the fact about the Storms on Mars and the lower air pressure. This has been a question for me whenever you listen to commentary on Mars videos and the terrible nature of storms, it never added up for me.

[@DVSx86]

thank you once again for references!

[@g.p.vershner5126]

Question: Given the possibility that the observable universe may only be a tiny fraction of the entire universe:- is it plausible that we happen to exist in a vast blob of matter containing the whole observable universe, and that other blobs of matter and antimatter exist, and so there is no baryonic asymmetry?

[@ericsmith6394]

I suspect that hypothesis is not testable. Someone can probably put numerical odds to it, but it seems to rely on something we can't observe. Can we rule it out? Probably not, so first we'll be looking into every other hypothesis we can test.

[@absalomdraconis]

​@@ericsmith6394 : The Cosmic Neutrino Background _might_ give us a route to testing it, but it's very much a _might_ and not a _will._

[@GreenJimll]

Tricky choice for best item as they're all good, but I think Nimbus just gets my vote (closely followed by the two Starship questions).

[@jmacd8817]

The orbiter was NOT in one piece after the explosion. Aviation Week and Space Technology did a deep dive years ago. There are valves on the oxygen system that were tuened, indicating that someone was alive , post explosion, but thats it. The crew cabin was allegedly pretty visible during its descent. If the entire orbiter was in one piece, it would have been clearly visible.

[@MediaWML]

Correct. The crew compartment of the Orbiter appears to have been intact, but that is a small part of the overall Orbiter.

[@johnwuethrich4196]

His point remains. The people were probably alive. NASA's report indicates that. I've read it myself.

[@aaaaa5272]

@frasercain, I think that it would be relevant to compare with planes as well. No one would request escape system in a Boing 474. We passengers accept the risk when flying. Yes, the likelihood for a disaster is different, but the concept is the same.

[@DexLuther]

21:08 A tablet/smart phone is also a good example of the Star Trek data pads. They had data pads that seemed to be single-use. You wrote a report and then handed it off for someone else to read, or you could load a book onto it and read a book, but it seemed like you had to clear data from it to be able to use it for anything else. Today we have data pads that are multi-use and multi-functional. You can write multiple reports on a tablet/smartphone, and read a ton of books. Smartphones even double as a communicator sometimes! Star Trek still has us beat on Holodecks though. Not sure I'd want to use a public one though no matter how self-cleaning they are.

[@yewtoob2007]

"Vendikar". 'A Taste of Armageddon' is a great episode. Thanks for another great video, Fraser!

[@nigelericogden3200]

Thanks for the recommendation Fraser. Here’s one for you, again not sci fi, but most enjoyable nonetheless … “Piranesi”, Susanna Clarke.

[@sproctor1958]

As I recall, the first Cosmonaut ejected and parachuted down for landing. Seems that Gemini also had a form of ejection seat... have to look that up.

[@MrMegaMetroid]

For the Question Show: What does it mean for a Black hole to spin exactly? I've just realized now that whatever i assumed was spinning must lie under the event horizon and can therefore not be measured, so is it the event Horizon itself thats spinning, or something else entirely? Thank you so much for the content you provide and the quality standards you hold yourself and your team to. Your channel is a treasure trove of science communication and a wonderful place to learn about the universe!

[@eamonia]

"The dream is, that you've got this greenhouse and you've got your Martian plants out there, ya know, or your 'poo potatoes' or whatever..."

[@samson1200]

I love how knowledgeable you are about space everything and not afraid you do not have all the answers. Can you explain how a Black hole (that rips suns and planets and dust apart ) that can be so greedy about sucking in all matter and at the same time eject matter! How the heck can it do that? what turns a black hole on and off?

[@midi1529]

A pole. I wasn't expecting that! Thks Fraser

[@augustwest9727]

Challenger Explosion: I was in 4th Grade, we watched it in the auditorium, when it exploded, the teachers just turned the screen off and ushered us back to class, they didnt talk about it or anything, just acted like everything was fine... Which is ironic, sense their was a teacher on board.

[@RGAstrofotografia]

Answering [Vulcan] Yes, the center of the Milky Way and Sgr A* have lagrangian points and the L4 and L5 must each contain another SMBH much smaller than Sgr A* and if we find them, we could triangulate the positions to find the center of the galaxy!

[@absalomdraconis]

The L4 and L5 within the galactic core _aren't_ required to have super-massive black holes in them, and there's so much other mass in the core that their orbits would be dominated by local conditions instead of galactic conditions, rendering them useless as a way to find the galactic center of mass. Frankly, if we really care then it's more practical to define Sgr* as the center and start estimating offsets from it than to hope that we can find objects that might not exist, and likely won't help with the job even if they do.

[@harry.tallbelt6707]

I still can't get over the fact that The Martian chose to show Martian sunsets red instead of blue as they should be. I don't know if they genuinely did not catch that or did they think that the audience would think that it looks too strange and it would break their immersion. Still a great movie of course! But this is a pet peeve that would forever be with me :)

[@frasercain]

Hah, I'm not sure they knew that when they did the movie. It would look blue over on the horizon where the Sun is going down and then shift to yellow-red as you get away from the horizon.

[@Liberty2358]

@@frasercain NASA made the same mistake with their first lander on Mars, the picture that was sent back was a composite of RGB input and the technician just tune it until it looks right thus the blue sky appears on Mars. Carl Sagan mention this story in his book The Pale Blue Dot.

[@Bitchslapper316]

They probably didn't know when they made the movie. Just like Spielberg didn't know a Velociraptor was the size of a turkey when he made jurassic park.

[@ashleyobrien4937]

and probably just as tasty !@@Bitchslapper316

[@Liberty2358]

@@Bitchslapper316 It is just human prejudice as we are used to blue sky. NASA made the same mistake on their first Viking picture of Mars, they tuned the RGB inputs until the sky looks right (blue).

[@notmyname327]

Nimbus! I enjoyed all of this week's questions but this one made me hopeful for the future of science in space.

[@vicvicious5328]

Hey Fraser, I understand that our solar system is not stationary, can we track the movement of our solar system?, Is it elliptical too?

[@Hexeris]

22:23 OMG I am literally playing Stellaris watching this, great callout to an even greater 4x grand RTS game.

[@tcayzer]

I like the "Volcan" story!! Super interesting 😊

[@_PatrickO]

Everyone needs to watch the show "For all Mankind". It is like the tv show version of the martian combined with every dramatized movie about apollo. This show is about the space race pivoting into putting a base on the moon and each season skips 9 years ahead. It is unbelievably awesome. The show is centered on nasa, astronauts, and engineers. It is "alternative history"(but actually good). It basically is about what happens with nasa and the nation if the space race did not end with landing on the moon.

[@Bitchslapper316]

I wish I could. I don't have apple TV and there is no apple TV app for android anymore.

[@hael8680]

It's only on apple TV?

[@saumyacow4435]

At least there we are talking about a base (where people visit) rather than colonies. So it has some credibility.

[@_PatrickO]

@@Bitchslapper316 You may need to sail the high seas then. This show is way too good to be limited to apple tv.

[@user-fr3hy9uh6y]

I thought you were going to bring up the fact that both the Enterprise and Columbia were built with ejection seats. Of course there were only two, so they were only installed during the test flights.

[@TibbersandTvStatc]

I will take your advice and watch the martian, i've actually never really thought about it since it came out, so I never watched it, but since you say its good ill check it out

[@BabyMakR]

19:16 The book says that the "Hab Canvas" was super good at blocking radiation. That was why he couldn't take Pathfinder into the hab to make communicating with Huston easier. It was designed to protect the inside from radiation. So in that respect he would have been able to grow them. The perchlorates were not in the book because it wasn't known when the book was written. However, is not that hard to get rid of them. As you say, you wash the perchlorates out. Then using the same system Watney used to have a hot bath, you distil the water to separate the perchlorates and then reuse the water to wash the soil again until you get enough out.

[@avgjoe5969]

Nice analysis.

[@DSlyde]

Question in the thumbnail is the first question answered. Nice.

[@BookmansBlues]

I think that people probably underestimate the time in which we could populate the solar system with Von-Neuman like robotics, and how that would be leveraged to supercharge the industrialization of space. 50-100 years seems like a conservative estimate.

[@lazarus2691]

Regarding NASA's thoughts on the IFT-2, NASA administrator Bill Nelson tweeted the following shortly after the test: Congrats to the teams who made progress on today’s flight test. Spaceflight is a bold adventure demanding a can-do spirit and daring innovation. Today’s test is an opportunity to learn-then fly again. Together @NASA and @SpaceX will return humanity to the Moon, Mars & beyond.

[@noahway13]

. I have read where a black holes temperature is almost absolute zero. But when things are compressed, like in an air tank, they heat up. So how are black holes so cold?

[@JessiBear]

Commercial Airplanes don't have crew escape capsules. We design airplanes to the safety margins needed. The same should be done with spacecraft.

[@frasercain]

Sure, so they just need to get Starship's safety margins down to the same level as an airplane. But rockets go so much faster, it'll be a tough thing to do.

[@sadham2668]

When a plane’s engines fail, it can glide. If Starships engine’s fails during landing, then it will crash.

[@johnbennett1465]

Another point. Commercial Airplanes go between heavily developed and maintained airports. If you want to fly to the Outback of Australia, your risks go way up, even if you use an appropriate aircraft. Trying to fly something the size of a commercial plane to an undeveloped area is basically a guaranteed disaster. Then consider that the Outback is actually a nice safe place compared to outer space.

[@saumyacow4435]

It took us decades, countless flights and many lives lost before we had an understanding of how to design a safe plane. You're not going to get the same level of confidence even out of a few hundred flights on Starship. Also as others have pointed out, when planes fail they tend to become a glider. When Starship fails, it turns into a crater.

[@jamescobban857]

Shuttle had no escape mechanism. Period. The team of "aerospace engineers" on Capitol Hill decided it was unnecessary. Challenger *should* have survived and brought its crew safely back. The problem was that the damage to the thermal protection system was such that the Shuttle could not survive a mach 20 reentry. But after the SRB separation, and *after* the damage had already happened, the crew on the Shuttle, and in the control centre in Houston, had insufficient information about the condition of the TPS to honestly answer "Yes" when they were polled on the "Go for orbit." If they had access to a real-time image of the leading heat shield the Shuttle could have aborted either back to KSC or to Europe. So why wasn't there a camera mounted on the ET and feeding its image to the flight deck of the Shuttle? As I understand it Houston only saw the damage when PHOTOGRAPHIC FILM from a chase plane was developed, by which time Columbia was already in orbit, that Houston learned how much of the heat shield was gone. I wonder how Houston notified the seven astronauts that they should phone their families to say goodbye? Note that the first stage of Falcon has *never* failed and the only time the second stage ever failed the Cargo Dragon successfully separated and safely rendered and could have been recovered except for a trivial programming glitch which meant its parachutes did not deploy. The Cargo Dragon, unlike the Crew Dragon does not have a working launch abort system. All other NASA spacecraft discarded their launch escape systems after first atage MECO in order to reduce the mass that has to be accelerated by the second and third stages. For comparison Starship should only need a launch escape system while the first stage is firing, and for that the engines of the second stage are more than adequate. Crewed Starships will have nine Raptors. Further Elon Musk has publicly indicated that Starship will not carry a Crew until after it has flown autonomously over one hundred times successfully. By comparison NASA risked crew on the VERY FIRST SHUTTLE and intends to risk astronauts on just the SECOND SLS flight! Even the GODLESS COMMIES did not risk cosmonauts on the first flight of their Shuttle clone!

[@ajcross7]

Hi Fraser, question show question: can you explain David Hilbert's specific contributions to General Relativity? Thanks in advance

[@danlewellyn6734]

Tim Dodd did a whole thing about the Starship escape thing.

[@frasercain]

Yep

[@DaZAvocado]

i dint wath but read martian and LOVEEEDD IT, i liked Weirs book Artemis way more tho its just so amazing and im in the process of reading project hail mary

[@RobReggioIns]

Given a choice between getting to see Betelgeus go super nova to finding and seeing planet 9 which you you pick and why?

[@miinyoo]

Only came here for starship / nasa. Didn't bother with the bait. I'll find out later. Love you Fraser. Will watch later.

[@giovannifoulmouth7205]

I haven't seen The Martian but I'm very much looking forward to watch it in a few years.

[@kevinsayes]

Fraser, random question that’s been on my mind and I can’t seem to find an answer (that I understand at least), but in Guth’s inflationary multiverse, what are these pocket universes “in”? I can understand one universe not having to be in anything, but multiple throwing me off for some reason. Or put another way, if we’re disconnected from them due to distance, but hypothetically we could travel FTL, what is separating these universes? I guess to me it seems like there would still be s narrow corridor of sorts connecting them, but maybe I’m viewing our big bang in some preferential way.

[@ThanosSustainable]

On the Starship question, you completely forgot to mention that Starship’s nose survived the FTS explosion at the end of IFT2. That probably means that the nose’s hull is quite tough and that (maybe) they could engineer some kind of “safe crash” procedure.

[@Raz.C]

I was a kid when I first saw the Challenger going bye-bye. I didn't understand what they were saying on the news, but I remember watching the video of the launch and thinking "There's something wrong with that!" as flames started jumping out from areas that they shouldn't have been jumping from. Then the whole thing went BOOM and I was really scared that they might stop all space exploration (I understood the constant threat of nuclear annihilation that we all lived under [even in Australia] during the late Cold War, but in '86, I don't think I really understood that the USSR was a competing entity and that if the USA had ceased all space flights, the USSR would likely have continued and so the loss to humanity would have been minimal). Anyway, even now when someone mentions "space shuttle disaster," my first thoughts are always of the Challenger, rather than the Columbia.

[@pebmets]

Challenger broke apart from aerodynamic forces after the explosion. There is a detailed Challenger report video which shows this frame by frame. The crew compartment broke free but stayed in one piece. It appears the crew survived the SRB failure, but lost their lives when the crew compartment hit the ocean.

[@giovannifoulmouth7205]

Hey I think I thought of a solution to Starship's lack of crew escape system, at least during the ascent stage: send the Starship crew to space on Dragon capsules and launch the empty Starship and then have the crew transfer into the Starship in orbit.

[@AnonymousFreakYT]

That’s basically what NASA’s use will be. Only with Orion on top of SLS to reach lunar orbit and meet Starship/HLS in lunar orbit. Which is fine for the smaller crew trips - but for things where they want to carry 10+ people, you’d need multiple Dragon launches. The theory is that Starship will be more reliable than Dragon, so (again, in theory) it should be safer to launch, say, 28 people on one Starship than on three Falcon+Dragons.

[@michaellee6489]

Our fearless communicator touched on that. Briefly.

[@aarondavis8943]

@@AnonymousFreakYT Agreed. This is just one of the many problems with Starship: The entire economic underpinning is space tourism, in which case you're talking about large numbers of people which as you just touched on will not be practical to launch separately. Which means no emergency escape. So, if one of these things explodes on launch or misfires and crashes, there'll be a large death toll. And with those 33 engines AND a reusable system making many, many trips, at least one catastrophic failure is highly likely.That will be the end of the tourism program for Starship, which is the end of profitability. And this is just _one_ of the _many_ diabolical challenges. I just can't see this program working out.

[@bluestraveler2980]

Will stable Lagrange points fill up with "garbage"? If so will this make putting something there prone to damage from "garbage"?

[@lazarus2691]

The L1, L2, and L3 Lagrange points aren't stable. They're areas of very low gravity, so you can stay there for a long time with only a little bit of fuel, but if you stop making small corrections, you will eventually slide out of the point - either into Earth's gravity, or into the Sun's gravity. So any junk will clear itself out. The L4 and L5 Lagrange points are stable, so this would be a problem there, but they're also not very useful. To the best of my knowledge we've never sent any spacecraft there. Although there is an asteroid called 2020 XL5 that has gotten 'stuck' in the L4 point, and lots of space dust is caught in both the L4 and L5 points.

[@schedusa]

Hi Fraser, love your show and so does my 7 month old baby! She gets upset if I try to remove her from watching. I have a question for you: are there any KZbin channels on science/space/astronomy for kids that you recommend? Thanks!

[@oberonpanopticon]

I think crash course’s astronomy series might be good. That being said, maybe hold off on showing it to your baby for a while. I’m far from an expert on learning and development, but I’m not sure how much info your baby is absorbing from Fraser’s videos at their age!

[@wdfusroy8463]

I just wish to say here, that, pace the common belief that M31 is as far away as the human eye can see, in fact, M33 can also be fairly easily seen, even from a "exurban" locations, provided your eyes are completely dark adapted and you view from a location that shields you from all stray light. For example, I was quite surprised one early pre-morning in Montana in August when I awoke to go to the bathroom. When I entered the room, I took a quick glance up through the room's glass "skylight" and immediately saw two familiar faint blobs of light in the sky, which I knew from my long experience of observing, and by their relative locations, had to be M31 and M33. And more surprising still, M33 was at least as bright as M31! That seemed very odd to me, since the skylight was composed of double or triple pane glass thick enough to insulate the room during the very cold Montana mountain temperatures of January and February. We are hardly talking optical glass quality, of course, but the view was quite clear, at least to the naked eye. Stranger still, my eyes, although stronger then than now, -- after a retinal detachment, -- were still limited by my severe myopia and astigmatism, neither of which can be fully compensated for by eyeglasses. So I would estimate my vision to have been roughly 30/20, hardly anything like the

[@Matthew-by6vl]

@frasercain Fraser, what were your favorite discoveries of 2023, and what are you most excited about for this coming year?

[@colinp2238]

Yes, I do think that your observable universe is very different to mine. I live near Heathrow Airport in London. We get to see many lights moving in the night sky. They are called planes. You have all that wild land with dark skies and sasquatch.

[@odranoelmusicremixes8453]

in regards to the best sci fi book iv ever read. i have to say thats "Rendezvous With Rama" by Arthur C Clark. about humanities first encounter with an extra terrestrial intelligence. that book changed the way i see the universe.

[@markwhitney555]

Gemini had ejection seats. The first shuttle mission had ejection seats as well.

[@sja45uk]

@frasercain - Does the stage 2 Starship have enough delta with 6 or 9 Raptors to achieve hot staging soon after launch? Is it possible if the stage 1 Booster is still under 33 Raptor power, or how far would they need to be throttled back to allow hot staging and avoid the stage 1 crashing back on to stage 0?

[@Liberty2358]

T + 00:02:40 is a relatively long burn then Super Heavy booster engines cutoff, by this time the whole system is many kilometers downrange therefore it has zero chance of crashing back on to stage zero, When SpaceX flippe the booster and try to fly it to the splash down area (not stage zero) it exploded. So much for a reusable booster There is simply too much forward momentum and it would take a lot of Delta V for fly it back to the launch site, it is not an airplane.

[@sja45uk]

@@Liberty2358 I assumed a worst case of an emergency shortly after ignition, when the upper stage would need to get clear. It seems likely that any incident later in the flight would be more like normal hot staging.

[@Liberty2358]

@@sja45uk It is all about getting away from the blast radius, it is almost impossible to design a system that would work well both at zero speed to mach 1 and beyond.

[@sja45uk]

@@Liberty2358 so what is the Crew Dragon optimized for, up to Mach 1?

[@mikeg9b]

I wonder if a Starship crew escape system could be made out of the pez dispenser. The astronauts could be in a cabin with parachute attached that could shoot out the side of Starship if anything went wrong during ascent.

[@dumb_Timberbeast]

Orion can't do LLO? And, can you animate lunar orbit (number of days of light on the dark side, etc.) ?

[@dumb_Timberbeast]

Thank you! It was worse than we thought. Everyone involved signed up and knew the risks. At the same time- they deserved more respect. And maybe one more redundancy (parachute) 😢

[@badrinair]

Hi Fraser, What makes me wonder is what's the purpose of the Orion capsule? The hls has to go from LEO to LLO anyway. Why not use a safe vehicle like a crew dragon to get to the HLS in LEO and from there to go the gateway or land straight on to the surface of the moon.

[@Hevach]

Because HLS can't come back, and even if we ensured it had a full tanker for the return burn, it couldn't return all the way to LEO and would be forced to attempt a translunar reentry, which far exceeds it's structural limits. Orion at the minimum is needed to get the crew home (Dragon can't manage it either, hence the Dragon variant that will supply the lunar gateway will be expendable, not recovered), but also enables a single HLS lander to support multiple landings.

[@badrinair]

@@Hevach thank you. That does add clarity.to paraphrase. 1. Even if HLS has enough propellant to get back to LEO, it's structurally not sound to do that. 2. since it can't get back to LEO it cannot rendezvous with an orbiting crew dragon capsule.

[@Rorschach1024]

In the case of greenhouses on Mars, one possible means of dealing with it is multilayered glass with phospors on the outside surface that are activated by that cosmic radiation and leaded glass below to absorb that radiation.

[@MrDmadness]

No, the soil is literally toxic on Mars. And every word salad you tossed was nonsense

[@Disasterina]

I vote Nimbus! Also, would it make any sense to explore above and below the plane of the solar system? Or is it essentially empty of the fun stuff?

[@realzachfluke1]

Remus. It's gotta be that one, both question and answer.

[@1000dots]

Will the matter in a galactic disk eventually clump up like planets forming in an accretion disc?

[@jklappenbach]

I don't get the focus on an escape system. The Shuttle had an escape system. It was never used. And, in fact, the escape system that the shuttle had was of no use in either of its two fatal missions. If they survive re-entry, give them a clear method of individual egress, and parachutes they can strap on.

[@paintballercali]

❓ can you explain light curves. Why are they called that? What can we learn from them? How are they created?

[@rickgilliland8995]

Why does the Rover and Probe creators do not put dust wipers on the solar panels? Or at least make them rotate to dump the dust?

[@absalomdraconis]

Wipers would damage the panels by dragging dust over them (liquids are not solids!), and there's always a concern that added complexity will cause a mission failure that otherwise wouldn't have happened. Also, neither option does anything about the occasional year-long dust storm, nor do they reverse the actual degradation of the solar cells themselves (which sadly is a thing- the power industry considers them useful for only about 20 to 30 years, depending on how much capacity loss they're willing to accept). That having been said, there have recently been some interesting developments (electrostatic dust removal and super-critical fluid dust removal are the ones I'm thinking of) that might result in dust removal being incorporated into future landers.

[@mr.ackermann807]

I am a little confused about starship payload. Can someone explain how it can increase its new capacity to 300 metric tons? I heard they were wanting to expand the tanks to hold more fuel but will that really allow large capacity for payload? Also now that i thought of it, if mars atmosphere is only 1% thick as our own, wouldn't that mean it would use the vacuum raptors for most of the descent and maybe sea level for landing and take more atmosphere to slow it down properly or just burn longer in orbit to help with slowing down?

[@topandeneil]

Re: The first segment: I think Jon Kelling's question might have been in reference to the Gemini seat ejection system

[@BlenderForDocumentation]

"Observable fog of us." Thank you, Fraser.

[@frasercain]

Fogiverse

[@BlenderForDocumentation]

@frasercain yep, I know; both ideas made me happy and I wanted to share that.

[@MrBrukmann]

The book was awesome.

[@frasercain]

Agreed!

[@bigfatbearhouse2284]

Hey, have you checked out “for all mankind”? Thoughts on how scientifically realistic it is?

[@GreatAwakeningE]

Yes, The Martian (film) is great, even tho they they got the Martian Atmospheric Pressure and Wind completely wrong. Is the book more accurate?

[@doncarlodivargas5497]

24:48 "...infinite universe..." if the universe are infinite, the matter in the universe are also infinite, and if the universe was created in a big bang, what "banged" must also have been infinite, and if the universe have expanded for ~13,7 billion years, at what speed if it is infinite?

[@neliotuga]

Random question: If we could stand on the surface of the sun, how far away would the horizon line be in comparison to earth's?

[@charleslivingston2256]

Remus. Great book and movie

[@scottschlueter916]

Nimbus, very interested in the next batch of telescopes.

[@simonlang2001]

Right now its more concept vechicle avout 5 to 10 more flights before any kind of human cargo goes on board, there will be three phases yet to happen phase one will be sub orbital flight on try two now may take 3 more flight attempts, phase two will be LOE, LOW EATH ORBIT, phase 3 will be landing of starter pack, and return of main vechicle to orbital stand, then phase 4 will be material to orbit, and lunar landing, where we would be today if there were no regulatiry requirements set on spaceex restricting launches

[@TeeTekTrab]

Sorry i left a response to a 9 month video earlier. Here is my question. "What if you could take a significant portion Earth's mass like dirt and rock and gather it in one place(like the north or south pole)? Would that change the Earth's orbit, rotation or tilt?" Thank you for reigniting my passion and wonder for astronomy!

[@918Boyz]

The Earth's crust is less than 1 percent of the total mass of the earth. It moves and the tectonic platea are always crashing into one another forming mountain ranges and leaving behind rifts.... even had supercontinents... yet everything indicates Earths orbit has been essentially stable for billions of years. The entire crust isn't significant enough to change our orbit even if you make the earth wobble slightly more on its axis or spin backwards it'll still be doing all that in its eame orbit. You would have to slow or increase the speed of our orbit around the sun to change the distance at which we orbit.

[@_PatrickO]

The water held back by the three gorges dam in china has actually slowed earth's rotation a tiny bit. "Raising 39 trillion kilograms of water 175 meters above sea level will increase the Earth’s moment of inertia, and thus slow its rotation. However, the impact will be extremely small. NASA scientists calculated the shift of such a mass will increase the length of day by only 0.06 microseconds, and make the Earth only very slightly more round in the middle and more flat on the top."

[@absalomdraconis]

Thanks to conservation of motion, the orbital parameters wouldn't measurably change at all, and the tilt & rotation would be somewhat limited as well.

[@zapfanzapfan]

"Remus". Yes, The Martian was very realistic, only a few nitpick details like having an RTG power the system to make the fuel for the return vehicle. A 100 kW reactor would be more realistic. Edit: The audio book is very good, excellent accents.

[@djblackprincecdn]

How would time dilation affect interstellar communication?

[@locutusofzork4630]

On lagrange points: Has there been surveys to see if there are objects in the sun/milky way lagrange points?