The Pod Bay

There's a question that I know for a fact how something went, because reasons. I've got a number of downvotes, and some scathing replies, posting how things actually went...

Of course, I don't want to explain how I know said piece of information, but...

Feeds

2:06 PM

The Brutal Lifecycle of JavaScript Frameworks

Ian Allen on January 11, 2018

JavaScript UI frameworks and libraries work in cycles. Every six months or so, a new one pops up, claiming that it has revolutionized UI development. Thousands of developers adopt it into their new projects, blog posts are written, Stack Overflow questions are asked and answered, and then a newer (and even more revolutionary) framework pops up to usurp the throne.

Using the Stack Overflow Trends tool and some of our internal traffic data, we decided to take a look at some of the more prominent UI frameworks: Angular, React, Vue.js, Backbone, Knockout, and Ember. …

kim holder

3:02 PM

PearsonArtPhoto

Yeah, that's about right.

kim holder

the fun thing there is i went to reddit just now, thinking 'what is it about reddit that causes this problem?', and actually found that thread in under 2 minutes by randomly opening something.

PearsonArtPhoto

I've been over it all pretty thoroughly.

I think I've added a good summary of what the facts are to the question on the matter here.

kim holder

@ReactingToAngularVues yeah, this is the sort of thing where the SE format shines. and space.se has a number of people who are perfect for answering this kind of question. Pearson and geoffc were both bound to answer and do a good job.

@PearsonArtPhoto are you telling me you waded into discussing Zuma on reddit? oh dear...

PearsonArtPhoto

More observation, and pointing at the few bits where I know something.

I have no inside knowledge whatsoever of Zuma, but I do have a tinsy bit about SpaceX.

kim holder

3:19 PM

Oh sure. Just, isn't that the kind of thing where - how shall i put this - the people who thrive most on reddit were bound to start yakking and spouting? Speculating about Zuma is fun, and there is a wealth of ways to point fingers about it without any evidence.

PearsonArtPhoto

Yeah. Reddit, like here, is often pretty good at sorting the wheat from the chaff, but they definitely fail quite a few times, I think more then we do.

kim holder

i'm almost never on reddit, i do know they occasionally produce stellar stuff. it's just to chaotic for me.

PearsonArtPhoto

I've spent more time then I should there recently.

The funny thing about Reddit is it will be the first place to admit about what a cesspool it is.

If you can sort out the good from the bad, you can learn a lot from Reddit. But...

uhoh

5:09 PM

I don't normally post about "evil dictators", but... twitter.com/locuta/status/950080583111204865

geoffc

5:23 PM

@uhoh Fiction is fun to read. That is pretty funny.

Yay! Rep-capped again today already.

@uhoh How did you include the tweets as the full tweet? I know if we post a Tweet link in here, it renders as:

Falcon 9 first stage has landed at Landing Zone 1.

Tweeted by SpaceX on January 8, 2018 at 1:09 AM

But when I link in a question it does not. Are you screen shotting as an image?

Edlothiad

5:59 PM

@geoffc (sorry for being nosey, but) you could look at the source of the post (click edit or go through the revision history) and see how they did it, however as far as I recall you need to take a screen cap of it.

PearsonArtPhoto

I hit 60K.

Edlothiad

It seems the standard method of linking tweets on Scifi&Fantasy is to use a screen so and quote the contents

ReactingToAngularVues

Sadly, there’s a certain presence of elitism in all the SpaceX communities that I’m aware of that’s really offputting. It’s probably at its worst on NASASpaceflight and the Facebook group (of whom we recently had an admin join).

PearsonArtPhoto

There are certain things I will trust such groups with pretty heavily.

Booster tracking is one.

ReactingToAngularVues

The moderators of the reddit group aren’t much better.

PearsonArtPhoto

6:06 PM

But I've had enough times I do know something, and the truth doesn't match up with what I know, that I know they aren't all that reliable.

ReactingToAngularVues

Hah, funny you mention booster tracking. Two of the reddit moderators are very much into that. If definitely affects what gets posted there.

PearsonArtPhoto

Yeah, the list of what boosters have been used for what missions they have there is amazing.

PearsonArtPhoto

6:22 PM

So, we are in the window now...

> The Falcon Heavy's static fire test has been scrubbed for the day after SpaceX's launch team loaded propellants into the heavy-lifter for the first time at pad 39A.

NM

geoffc

@Edlothiad I did go look at the source, and it looks like he screen capped it. Alas.

@ReactingToAngularVues Every thinks they are elite to some level or other. I for one, am an elitist when it comes to quoting bad Python jokes, mangled to be barely recognizable! (I'm not!) You get used to it. All my coworkers are like this, I live in NYC region and everyone seems to be like this. You get used to it.

@PearsonArtPhoto That Reddit is doing well.

@PearsonArtPhoto Ah drat.

But they loaded, and then stopped. Good. If they find an issue, they can fix it, till the next issue. We knew this was likely. (I still wanted to see the static fire, darn it).

PearsonArtPhoto

Would rather have them analyze things a bit then have a failure on the first firing.

geoffc

Of course.

Just found Retrocomputing SE. Oh the memories...

NASA Space Flight

6:53 PM

NASASpaceFlight.com: SpaceShipTwo begins 2018 test campaign in preparation for powered flight

posted on January 11, 2018 by Michael Baylor

Virgin Galactic’s SpaceShipTwo has begun the latest round of test flights for 2018. Most notably,…

PearsonArtPhoto

8:14 PM

The Falcon Heavy has another attempt at a static fire tomorrow, a bit earlier, starting at around 10:00.

We have a lot of old questions that are perfectly answerable out there...

I think I'm going to try and keep answering old questions. It should help me hit the rep cap, gain tag badges, and help the site statistics, all at once!

ReactingToAngularVues

8:27 PM

DIV launch webcast is up. youtube.com/watch?v=3rCjIaCBldY

If you're into that sort of thing.

PearsonArtPhoto

LOL, you are asking if we are in to that kind of thing?

I mean, it's not SpaceX, but still...

geoffc

@ReactingToAngularVues Alas my wife is learning that I am into that thing. But not in that way - get your mind out of the gutter. They don't make Falcon 9 lingerie. Though, you know, they should...

Delta 4 medium! RS-68 one of the last LH2 engines developed in the US. Sad, how long ago that was, and how little use it got really. 35 launches, 9 of which are heavies, so add 35+19 and only 55 or so engines flown (Counting todays before it hatches). SpaceX has now flown ~450 engines.

This year, if they hit 30 launches, that includes 2 Heavy missions, maybe 3, that is over 330 this year, in all likelyhood.

PearsonArtPhoto

8:43 PM

Well, when you have 10 engines/ flight...

geoffc

Shuttle with 2SRB + 3 SSME and 135 flights, only burned 675 times total. SpaceX should pass that in 2018...

@PearsonArtPhoto vs 1 on a Delta (or 3 on a heavy) I get the point. But there is something to be said for more smaller engines.

PearsonArtPhoto

I mean, if you are counting times the engine burned, they fired one of the spent boosters, what, a dozen or more times?

geoffc

Space Shuttle took 1981->2013 minus 6 or so years of downtime, 25-30 years VS spaceX hitting that milestone in about 8 years.

@PearsonArtPhoto I know. And SSME's were on the test stands alot too. I mean in use for orbital flight.

PearsonArtPhoto

Ahh.

geoffc

Plus static tests at the pad, per engine fire at McGregor, all up static test at McGregor,

I was thinking even run time shouldbe caught soon...

PearsonArtPhoto

8:46 PM

They do a number of engine fires sometimes at McGregor.

geoffc

Shuttle had SSME's at under 9 min X3 per launch. Plus SRBs at 2.5 minX2. So 33 min of engine run time on a Shuttle launch. Falcon gets 2.5 min X 9 so 22.5 + about 8 min for second stage, barring GTO missions. So about 31 min engine run time rounding for a Falcon launch.

I am ignoring OMS engines.

So 135 X 33 = 4455 m of run time for Shuttle. That would only take 144 launches of a Falcon 9. And if they hit 30 in 2018, then that is 75 by the end of 2018, which is only 2-3 years away if they keep that rate up.

Throw in a couple of heavies a year and it comes up even faster.

PearsonArtPhoto

Do you really think there will be 30 launches this year?

geoffc

@PearsonArtPhoto If they hit 18 this year. As they recovered, with a single pad in FLorida. Now they have a second one for the cry babies to waste time on. (Air Force/DoD/NSA, looking at you guys) at LC-39A. Heavy won't block because of 40 and 39A availability.

Iridium has a couple more Vandy launches. And there are actually several Vandy flights on the manifest for this year.

PearsonArtPhoto

I doubt Zuma will affect much, but still...

geoffc

Block 5 is due to fly real soon now. (I know, I know, but they are flying Block 4's now, and Block 3's are not even being landed on second mission anymore, since where would you put them).

PearsonArtPhoto

8:52 PM

I actually wonder if they will get the backlog cleared soon.

geoffc

So bottlenecks seem like how fast a Block 4 can be turned around, fairing build times (and how soon they get fairing recovery working). And if they are correct about how easy Block 5 will be to reuse, then Block 5 by the summer, fly out the rest of the Block 3's, use new Block 4's till Block 5 is ready, and it seems like a higher cadence is likely.

I suspect payload delays will be a bigger problem than booster availability. getting 30 payloads ready on time seems almost impossible.

PearsonArtPhoto

I'm wondering if the bottleneck might start to be the payloads before too long.

geoffc

But with 2 Florida pads, can be moved around if they delay. Like Zuma did.

@PearsonArtPhoto Concur.

PearsonArtPhoto

And they can actually process at least 2 payloads at 40 at a time.

They've been doing that for some time.

The final payload preparations have to happen where the rocket is assembled, but they can do some of the prep work like fueling the satellites in another close by building.

geoffc

And LC-39A HIF has room for 3 cores or Heavy + 1 F9. So they can process more. They have that extra space at Port Canaveral next to where OCISLY docs.

So they are setting themselves up for success, one hopes.

PearsonArtPhoto

8:55 PM

I mean, 30 launches is about 30% of the entire global market for satellite launches today.

A big part of the problem no doubt will become that the payloads just aren't finished.

There's what I've heard to referred as the game of "Launch Chicken".

Basically, the payload and the rocket keep telling each other that they are good, while neither one is good. They just don't want to be the one to delay things any...

SpaceX is going to have to change the game of building satellites, or they will effectively own the market, but not be able to grow.

I guess that's part of why they are building the internet satellite network. Wonder how that is going.

geoffc

Paz launch Jan 30th is supposed to carry two Starlink demo sats as secondary payloads.

PearsonArtPhoto

theinquirer.net/inquirer/news/3021558/…

And there should be a second one soon.

geoffc

Unless they redesign the fairing, majorly, it is gonna take a "CRAP LOAD" of F-9 launches to get 4400 into service.

PearsonArtPhoto

That being the case, maybe SpaceX will be launching a ton...

ReactingToAngularVues

Put me under the "skeptical it will ever happen" bucket.

geoffc

9:00 PM

And they need 800 for revenue service. Estimates seem to suggest between 25 and 40 in the current fairing. Which seems unworkable. 110-176 launches.

ReactingToAngularVues

Like with Falcon Heavy crossfeed, point to point suborbital flights, Red Dragon, propulsive Dragon landings, etc

PearsonArtPhoto

The goal could be to clear out the backlog so they can start doing a launch every week of a dozen satellites for the internet service.

geoffc

Volume limited not mass, so F-H does not help.

@ReactingToAngularVues Which part? 30/year?

PearsonArtPhoto

I'm sure SpaceX can fix things, but the last I heard, 12 was the max number of satellites/ launch.

That is pretty old info, however.

ReactingToAngularVues

@geoffc satellite constellation.

geoffc

9:01 PM

12! Ouch. 367 launches? That is just unworkable.

ReactingToAngularVues

Or at least, at the scale Musk is talking currently.

PearsonArtPhoto

Well, the limitation was SpaceX's own, so presumably they could increase that number.

There is plenty of room.

geoffc

@ReactingToAngularVues Fair point. Hard to now. The size seems unworkable, with current launches. Even if F-9 launch is just cost of fuel, by the time they 800 in orbit lifetime of satellites suggest they are replaceing soon as well as launching new ones.

PearsonArtPhoto

Seriously though, SpaceX seems to be changing the game of Earth launches.

ReactingToAngularVues

My suspicion is that LEO constellations will be killed off by more cost effective drones, the likes of what Facebook is testing currently with Aquila.

lower latency, faster turnaround, reuse.

PearsonArtPhoto

9:03 PM

They probably will be doing a launch of at least a grouping every week, if not faster.

ReactingToAngularVues

and a fixed dish, too. SpaceX will need to seriously develop a ton of expensive transmitting and receiving tech for it to be cost effective.

PearsonArtPhoto

Maybe.

ReactingToAngularVues

Downside to drones, is of course, power requirements are currently lower.

s/rerquirements/envelope.

PearsonArtPhoto

My cost estimate for Starlink assumes 12/ launch.

Maybe they would use a heavy, which could support more, but...

14

A: How much will SpaceX's constellation of Internet satellites cost?

First of all, let's figure out how many satellites per launch vehicle. The estimate of the mass of these satellites is 386 kg. The mass for a launch of a Falcon 9 is 5500 kg. That means one could launch 13-14 satellites per rocket. I suspect 12 is more realistic, because part of the payload mass ...

Well, I've got to run, so...

geoffc

@PearsonArtPhoto Reddit folk were estimating, and 25-40 seemed the cap. Even with the fairing 2.0 design that rounds out some corners making room.

@ReactingToAngularVues A satellite is more reliable, runs for many years, for the most part. Drones, just are not. Weather gets in the way. So I dunno. Time will tell us.

@PearsonArtPhoto I think your 5500Kg per launch is incorrect. These are LEO launches, not GTO. 5500KG is GTO ASDS reused. 8000KG expendable. The PAF is mass limited but it is almost 11,000 Kg. See:

ReactingToAngularVues

9:38 PM

Nah, weather doesn't get in the way. These things hover continuously at FL900. Well above most of the atmosphere. I'd also wager that drones will end up being more reliable due to quicker iterative design and the ability to get the vehicle back if necessary.

geoffc

@ReactingToAngularVues Be very interesting to see how this plays out. I am very curious to see what ends up winning!

ReactingToAngularVues

Satellites will probably have the initial advantage. It's very true that drones aren't there yet.

Buuuut, I wouldn't invest in a satellite constellation mutual fund, mind you :)

geoffc

@ReactingToAngularVues I hear you. It is a gamble. But to be fair, so are drones.

ReactingToAngularVues

Sadly such a question is probably off topic for space.se. Maybe Engineering.se.

PearsonArtPhoto

10:20 PM

@geoffc You might be right, but the published numbers I saw didn't distinguish between LEO and GTO.

Obviously it takes more fuel to get to GTO, but the price was listed as the same, oddly.

NASA Space Flight

11:27 PM

NASASpaceFlight.com: China launches latest Beidou-3M satellite duo

posted on January 11, 2018 by Rui C. Barbosa

A new pair of navigation satellites was successfully launched by China on Thursday, using a…

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