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Author Topic: SpaceX (general discussion)  (Read 227343 times)

Online sferrin

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Re: SpaceX (general discussion)
« Reply #1425 on: January 12, 2019, 05:44:29 am »
Blue Origin is hiring.  ;D
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Offline kitnut617

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Re: SpaceX (general discussion)
« Reply #1426 on: January 12, 2019, 07:09:40 am »
The article in Microsoft News says the layoff is partly because of the downturn in companies wanting to launch satellites.
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Online sferrin

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Re: SpaceX (general discussion)
« Reply #1427 on: January 12, 2019, 07:36:47 am »
The article in Microsoft News says the layoff is partly because of the downturn in companies wanting to launch satellites.


I am skeptical of that.  SpaceX is going to be putting up a lot of satellites all by itself.
"DARPA Hard"  It ain't what it use to be.

Offline kitnut617

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Re: SpaceX (general discussion)
« Reply #1428 on: January 12, 2019, 08:21:01 am »
The article in Microsoft News says the layoff is partly because of the downturn in companies wanting to launch satellites.


I am skeptical of that.  SpaceX is going to be putting up a lot of satellites all by itself.

Should have added that each launch is capable of multiple deployments (the SpaceX launch before the New Year had 60 satellites on board), which means there would be less launches. At least that's what the article insinuated.

EDIT: a bit later:  https://a.msn.com/r/2/BBS8whw?m=en-ca&referrerID=InAppShare
« Last Edit: January 12, 2019, 11:21:44 am by kitnut617 »
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Offline Flyaway

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Re: SpaceX (general discussion)
« Reply #1429 on: January 12, 2019, 12:14:35 pm »
https://twitter.com/kimitalvitie/status/1084170058715283457

Quote
Ask and you shall receive! Here's an image with the mighty #SaturnV compared to the @SpaceX's upcoming #Starship and #Superheavy stack! Really gives a sense of scale how truly massive the rocket will be! 🤯

This and many of my other renders are now also available at my shop!

New drone photos of the hopper.

https://twitter.com/rogerlewisholt/status/1084178936555282432

https://twitter.com/rogerlewisholt/status/1084179354190516227
« Last Edit: January 12, 2019, 01:39:05 pm by Flyaway »

Offline Flyaway

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Re: SpaceX (general discussion)
« Reply #1430 on: January 14, 2019, 01:28:55 am »
Confirmation on the bulk head:

https://twitter.com/bkin87/status/1084599978297868288

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Extra pieces or the start to something else??

https://twitter.com/elonmusk/status/1084737144394903552

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Yes

Offline Flyaway

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Re: SpaceX (general discussion)
« Reply #1431 on: January 14, 2019, 04:12:33 pm »
RGV Aerial Photography has uploaded a drone video of the Launch Site to Youtube. Located via NSF.


Offline TomcatViP

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Re: SpaceX (general discussion)
« Reply #1432 on: January 14, 2019, 04:59:39 pm »
A short summary of spotted activities at Boca Chica by NASA Spaceflight.com

https://www.nasaspaceflight.com/2019/01/spacex-starship-tests-boca-chica/



I wonder why they don't seem to share the idea that the tank are integral and that then the spotted bulkhead must fit directly inside (it also explains the wrinkles on the outside skin). The hopper doesn't need to get to orbit or carry heavy load on its top. The more modest needs in structural rigidity offer plenty of room to go lightweight. There is also the amplitude offered there by their cryogenic  process.

Imagine this thing as a big water rocket.
« Last Edit: January 14, 2019, 05:14:14 pm by TomcatViP »

Offline Dragon029

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Re: SpaceX (general discussion)
« Reply #1433 on: January 14, 2019, 07:00:46 pm »
I personally doubt they'll use any more than the lower portion as a tank:

Doing a very rough estimation of the Starhopper's internal volume there's roughly 1600m^2 potential tank volume, which, if filled with a 4:1 ratio of LOX & Methane, would give a fuel mass of about 1,600 metric tons. A single Raptor engine meanwhile (noting that figures are subject to change) puts out about 203 metric tons (1993kN) of thrust; 3 of them simply could not lift the entire Starhopper if it was filled.

Also, while this is just speculation, some have suggested that the Starhopper may have 3 engines in order to test engine-out landing capability, which would require 2 engines to still achieve a >1 T:W.

And then lastly, you have to keep in mind that the real Starship will have something like 40% of its forward length as empty / dry mass (with the weight of payload, passengers, etc being significantly lighter than fuel). Although this Starhopper isn't meant to test re-entry or be a 1:1 analogue, it would be beneficial to have a ballpark-similar centre of gravity for getting relevant control dynamics data.

Offline Michel Van

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Re: SpaceX (general discussion)
« Reply #1434 on: January 14, 2019, 10:45:55 pm »
Looking later picture and Videos

I starting to have doubts about this Starhopper purpose

1. it's not build by SpaceX it self, but by a company that build Water-towers 
2. Starhopper is build right next to Mission control center at Boca Chica, too close for flight test
3. were is the launch-pad, fuel tanks and landing-pad for that thing ?
4. this thing stand dangerous close to town of Boca Chica for start and landing

Personal i think Starhopper is merely a water-tower with capacity of 1600 m^3 at Mission control
and Elon Musk is mess around with fandom...
I love Strange Technology

Offline Dragon029

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Re: SpaceX (general discussion)
« Reply #1435 on: January 14, 2019, 11:59:50 pm »
Having the test platform built by a water company isn't that unorthodox; who else has more experience at performing large diameter, high quality, water-tight, steel, welded tanks designed to hold hundreds of tons of liquid?

As for the location; they're building it next to their in-development mission control centre, which in turn is only about 3km / 2 miles from the actual launch pad where they intend to eventually launch the full scale Starship and Super Heavy booster from. While not the simplest thing in the world, it wouldn't be that hard to put the rocket on a flatbed and truck it down the road to that launch pad either:


Offline galgot

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Re: SpaceX (general discussion)
« Reply #1436 on: January 15, 2019, 02:56:47 am »
Is this the real thing ? I want to believe , but the skin look like my kitchen alum foil.
And it seems they are building the rocket before any launching pad, facilities e all,  in a fenced field in the bush.

Offline TomcatViP

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Re: SpaceX (general discussion)
« Reply #1437 on: January 15, 2019, 04:05:28 am »
I personally doubt they'll use any more than the lower portion as a tank:

Doing a very rough estimation of the Starhopper's internal volume there's roughly 1600m^2 potential tank volume, which, if filled with a 4:1 ratio of LOX & Methane, would give a fuel mass of about 1,600 metric tons. A single Raptor engine meanwhile (noting that figures are subject to change) puts out about 203 metric tons (1993kN) of thrust; 3 of them simply could not lift the entire Starhopper if it was filled.

Also, while this is just speculation, some have suggested that the Starhopper may have 3 engines in order to test engine-out landing capability, which would require 2 engines to still achieve a >1 T:W.

And then lastly, you have to keep in mind that the real Starship will have something like 40% of its forward length as empty / dry mass (with the weight of payload, passengers, etc being significantly lighter than fuel). Although this Starhopper isn't meant to test re-entry or be a 1:1 analogue, it would be beneficial to have a ballpark-similar centre of gravity for getting relevant control dynamics data.

I don't think either (tank). But if their intend is to test the specific reentry manoeuvre (horizontal decent + 90deg rotation before starting the boosted recovery), they will need to reach a representative initial speed for the test, hence the high impulse request necessitating the 3 engines. Also, for the Mars mission, a supersonic pitch up + relight would have to be performed, something that could be tested in the higher earth atmosphere. Hence (IMOHO)  the design choices.

Regarding the proximity of the Boca chica village, does it sound extravagant to pay the villager to evacuate their home for a couple of hours out during the test? 
« Last Edit: January 15, 2019, 04:08:30 am by TomcatViP »

Online sferrin

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Re: SpaceX (general discussion)
« Reply #1438 on: January 15, 2019, 05:03:39 am »
They aren't testing reentry with this thing.  Look at the original Grasshopper.  That's about what it's going to do.  As for having a water tank builder build the structure, as long as they're doing it to specification it's fine.  I would not be at all surprised if there were SpaceX engineers onsite looking over their shoulder both to make sure it's done to spec and to learn. 
"DARPA Hard"  It ain't what it use to be.

Offline TomcatViP

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Re: SpaceX (general discussion)
« Reply #1439 on: January 15, 2019, 06:27:19 am »
Not reentry by itself but the dynamic maneoevres that follow it. Sorry if that was not immediately clear.

To be specific, this is what I had in mind:

  - Low viscosity Supersonic pitch-up and boosted slowdown (Mars - simulated on the upper atmosphere by gaining speed - horizontal)
   - High viscosity  slowdown + pitch-up and boosted recovery (earth)