Space X

Westernyelp · 06-05-2021 4:57pm

Beeker wrote:

Pictures of SN16 do show it will have a lot if not a full belly of tiles. Hopefully they can solve the "falling off" problem. Reminds me of Columbia back in 79-80.

Orbital will need the windward side of the flaps protected too. Tricky engineering

Shlippery · 07-05-2021 11:03am

https://twitter.com/elonmusk/status/1390569345361883136

The man's insane! Talking out of his arse, or do ye reckon they'd give it a go?

Cookiemunster · 07-05-2021 11:26am

Shlippery wrote: »

https://twitter.com/elonmusk/status/1390569345361883136

The man's insane! Talking out of his arse, or do ye reckon they'd give it a go?

I don't see any reason why they wouldn't. They test to destruction and SN15 hasn't been destroyed yet!

Seriously though, why would you only do a single flight test an a reusable asset? Seems very wasteful.

jogdish · 07-05-2021 11:40am

Cookiemunster wrote: »

I don't see any reason why they wouldn't. They test to destruction and SN15 hasn't been destroyed yet!

Seriously though, why would you only do a single flight test an a reusable asset? Seems very wasteful.

They said they would refly sn5/6 and then both were scrapped, I also suspect Elon gets bored and tweets crap too.
They said they would want to send the engines back to the factory for insecption as they were the first to fully work which seems sensible, if it's destroyed there is nothing to inspect. I reckon fly SN16 first, then maybe re flys, then onto SN20, July was/is there internal orbital goal. Of course they also have the BN's to fly, at a certain point raptor supply will be a bottle neck if not already. Since higher flights needs more fuel means more weight means more raptors and the BN's need more even for small hops.

Capt'n Midnight · 07-05-2021 1:34pm

Cookiemunster wrote: »

I don't see any reason why they wouldn't. They test to destruction and SN15 hasn't been destroyed yet!

Seriously though, why would you only do a single flight test an a reusable asset? Seems very wasteful.

Space shuttles weren't cheap but Enterprise never went to space.

The original plan was to make it spaceworthy later on but there were so many updates to the program since it's flight tests , IIRC weight issues too, such that it was better to make a new one and use some of the bits.

.42. · 07-05-2021 1:37pm

They may use it to test heat shield setup along with SN16 and others for final setup of SN20

Cookiemunster · 07-05-2021 1:39pm

Capt'n Midnight wrote: »

Space shuttles weren't cheap but Enterprise never went to space.

The original plan was to make it spaceworthy later on but there were so many updates to the program since it's flight tests , IIRC weight issues too, such that it was better to make a new one and use some of the bits.

I don't think your analogy works. Obviously SN15 is never going to orbit and will never fly passenger or freight, but it's functional and can still be reused in the test program.

Capt'n Midnight · 09-05-2021 12:20pm

AMKC · 09-05-2021 2:13pm

Love that picture. As mad as the Space Shuttle was I still prefer it. If offered to go to space in either of them I would take the Space Shuttle.

MayoForSam · 09-05-2021 8:10pm

AMKC wrote: »

Love that picture. As mad as the Space Shuttle was I still prefer it. If offered to go to space in either of them I would take the Space Shuttle.

Space shuttle - cost per launch $450 million https://www.forbes.com/sites/carolpinchefsky/2012/04/18/5-horrifying-facts-you-didnt-know-about-the-space-shuttle/

Starship - cost per launch (expected) $2 million https://www.space.com/spacex-starship-flight-passenger-cost-elon-musk.html

It's all about the money in the end. Plus the space shuttle didn't exactly have an exemplary safety record either.

Capt'n Midnight · 10-05-2021 1:05am

MayoForSam wrote: »

Space shuttle - cost per launch $450 million https://www.forbes.com/sites/carolpinchefsky/2012/04/18/5-horrifying-facts-you-didnt-know-about-the-space-shuttle/

Starship - cost per launch (expected) $2 million https://www.space.com/spacex-starship-flight-passenger-cost-elon-musk.html

It's all about the money in the end. Plus the space shuttle didn't exactly have an exemplary safety record either.

That link said Over the life of the programme, this increases to about $1.5 billion per launch

Shuttle could only carry at best about 10%-20% more payload (27.5 tonnes) than a common or garden Falcon 9 (22.8 tonnes) Yes it could land with satellites but in practice this was very rare, and none of them was worth the cost of the launch.

Both shuttles were lost because the lessons of near misses weren't learnt. ANY damage to the o-rings meant the main silicon putty safety barrier had already been breached.

Shlippery · 10-05-2021 12:27pm

AMKC wrote: »

Love that picture. As mad as the Space Shuttle was I still prefer it. If offered to go to space in either of them I would take the Space Shuttle.

Space Shuttle is cool - but Starship can look fairly impressive once fully decked out a la renders below!! It'd be like a little cruise ship for space. Think of all the room for activities!

https://twitter.com/ErcXspace/status/1386059531839361030/photo/1

Also discovered this daily comic on twitter which I'm thoroughly enjoying set at Starbase!
https://twitter.com/daily_hopper/status/1391157756846084099

Shlippery · 11-05-2021 4:03pm

https://twitter.com/BocaChicaGal/status/1392127958207410176

:O

jogdish · 11-05-2021 6:04pm

Shlippery wrote: »

https://twitter.com/BocaChicaGal/status/1392127958207410176

:O

Will be interesting to see if there will be a raptor swap out, and or inspection of the raptors (x rays etc, could be something as dull as just a handy stand to have a poke at the underside)
please hop!

jogdish · 13-05-2021 8:02pm

Exciting times! I really really really hope there are cameras!

https://twitter.com/nextspaceflight/status/1392915876643438592

AMKC · 13-05-2021 10:08pm

https://www.facebook.com/UNILADTech/videos/1477788989232663/?d=null&vh=e

Really cool story there. I hope he completes his dream but for now it is nice to see someone documenting Space X history as much as he can.

AMKC · 13-05-2021 10:10pm

jogdish wrote: »

Exciting times! I really really really hope there are cameras!

https://twitter.com/nextspaceflight/status/1392915876643438592

When will this happen and is that what is planned for SN20?

jogdish · 13-05-2021 10:40pm

AMKC wrote: »

When will this happen and is that what is planned for SN20?

The internal goal is by end of July and yes with SN20, you would imagine they try a booster hop first. BN3 seems to be ahead of BN2 according to the various people who track these.

FFVII · 15-05-2021 3:17am

https://thomas-godden.medium.com/how-spacex-lands-starship-sort-of-ee96cdde650b

Itssoeasy · 16-05-2021 12:08am

Space X starlink launch just happened and they got into a nominal orbit and they had the camera on the first stage on through the landing on the recovery ship and it was much better than previous ones where the camera was on the ship and would lots of times cut out due to vibrations.

Ghost Train · 16-05-2021 12:32am

The video of the landings has been good the last few times with the downward video angle. The sea looked rough for todays landing hopefully they got it secured with the octograbber before there is any risk of it falling overboard

Poulgorm · 09-06-2021 5:45pm

One thing that I find puzzling: I understand that Starship is just a single stage rocket. I thought all rockets heading into orbit had to have a second stage (as the Falcon 9 does) - something to do with a different nozzle shape required when the atmospheric pressure reduces to almost zero, at a certain altitude.

donspeekinglesh · 09-06-2021 5:50pm

Poulgorm wrote: »

One thing that I find puzzling: I understand that Starship is just a single stage rocket. I thought all rockets heading into orbit had to have a second stage (as the Falcon 9 does) - something to do with a different nozzle shape required when the atmospheric pressure reduces to almost zero, at a certain altitude.

No, it'll have a booster stage called Super Heavy - which hasn't been test launched yet that I know of.

Capt'n Midnight · 09-06-2021 7:30pm

Poulgorm wrote: »

One thing that I find puzzling: I understand that Starship is just a single stage rocket. I thought all rockets heading into orbit had to have a second stage (as the Falcon 9 does) - something to do with a different nozzle shape required when the atmospheric pressure reduces to almost zero, at a certain altitude.

Having a second stage means a lot less dead weight to carry to orbit.

But that also means you have a real problem if the second stage doesn't start. And in zero g fuel doesn't sit at the bottom of the tank. (Russian rockets usually start stage 2 while stage 1 is still firing, that's what the gap is for)

There's a lot of 1.5 stages to orbit.

The Americans had Atlas rockets that put the single seater Mercury capsules into orbit were derived from ICBM's. At take off they'd have three engines firing. Half way to orbit they'd drop two of them and just the remaining one to get there. To save weight the tanks were made of really thin metal like they had to be pressurised like a balloon or they'd collapse under their empty weight. So light that dropping the engines dropped most of the weight.

There was a plan to do the same with the Saturn V third stage , they'd parachute back 4 out of the 5 engines as they were the heavy, expensive bits.

The Russians like Falcon Heavy fired up all the engines and then throttled back the central one to 25% or so. Half way up the outer boosters were dropped and the core would ramp up to full power with remaining 75% fuel remaining.

The Space Shuttle and the Chinese rocket that's putting up their space station do similar. For both the weight of the external tank or core stage weighed the same on thr ground as the payload.

Having a second stage means a lot less dead weight to carry to orbit.

Capt'n Midnight · 09-06-2021 7:41pm

Poulgorm wrote: »

One thing that I find puzzling: I understand that Starship is just a single stage rocket. I thought all rockets heading into orbit had to have a second stage (as the Falcon 9 does) - something to do with a different nozzle shape required when the atmospheric pressure reduces to almost zero, at a certain altitude.

Space Shuttle Main Engine produces a specific impulse (Isp) of 452 seconds (4.43 km/s) in a vacuum, or 366 seconds (3.59 km/s)

You get about 16% more thrust in a vacuum from the same engine because there's no air to slow down the exhaust.

For Falcon the engines used at sea level use a turbopump to supply fuel at high pressure and a small nozzle because atmospheric pressure stops keeps the flame small. The second stage engines work in a vacuum so flame can expand more. So a bigger bell is needed, and you can use a pressurised tank which is a lot more reliable than a turbopump.

Poulgorm · 09-06-2021 8:49pm

donspeekinglesh wrote: »

No, it'll have a booster stage called Super Heavy - which hasn't been test launched yet that I know of.

The Starship can get into orbit by itself - as far as I know. And carry a sizable payload into earth orbit too - more than the Falcon 9.

Put the Super Heavy rocket under it & it becomes the second stage of the combined unit. The combined rockets can put much a heavier payload into earth orbit (100 tons?) and the Starship portion will be capable of going to the moon or Mars.

That's my understanding, anyway.

jogdish · 09-06-2021 9:21pm

Poulgorm wrote: »

The Starship can get into orbit by itself - as far as I know. And carry a sizable payload into earth orbit too - more than the Falcon 9.

Put the Super Heavy rocket under it & it becomes the second stage of the combined unit. The combined rockets can put much a heavier payload into earth orbit (100 tons?) and the Starship portion will be capable of going to the moon or Mars.

That's my understanding, anyway.

Starship can get itself to orbit, but would not be able to land itself(extra fuel for that), at which point its not really starship as we know it.

Capt'n Midnight · 09-06-2021 9:57pm

Starship can land and then get back into orbit from Mars or the Moon, provided it's been refuelled in Earth orbit. Because it can't use air to break on the Moon it will use a lot on the way down.

IIRC they can transfer 100 tonnes of propellant to orbit and carry a max of 950.

Poulgorm · 10-06-2021 3:46pm

I am still not clear on the answer - the Starship (in the guise that reached 10 km and returned to earth a few weeks ago), will that be capable of putting a payload into orbit and then return to a soft landing on earth?

Shlippery · 10-06-2021 5:16pm

Poulgorm wrote: »

I am still not clear on the answer - the Starship (in the guise that reached 10 km and returned to earth a few weeks ago), will that be capable of putting a payload into orbit and then return to a soft landing on earth?

My understanding is yes, if launched on top of the super heavy booster it can return to soft landing on earth.

I think for SN20 the plan is to sacrifice the booster and SN20 with a planned splashdown.

But Starship -without the booster, would not be capable of going into orbit & landing again as it would not have enough fuel to pull off the whole trip?

Space X

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