Author Topic: SpaceX Starship/Super Heavy Engineering General Thread 3 (Read 364849 times)

Chris Bergin · « **on:** 08/07/2019 03:02 pm »

New thread (Thread 3)

Thread 1:
Starship (BFS) Engineering Thread (#dearMoon edition + Musk Stainless Update)
https://forum.nasaspaceflight.com/index.php?topic=46395.0

Thread 2:
https://forum.nasaspaceflight.com/index.php?topic=47052.0

L2 Section:
https://forum.nasaspaceflight.com/index.php?board=60.0

Be on topic. Don't wander into areas already covered on other threads and make sure your post is useful.

cuddihy · « **Reply #1 on:** 08/08/2019 01:18 pm »

Kind of a dumb question, but I'm very curious about it: Star hopper has been loaded up with all kinds of tanks, valves, pipes & electronic hardware hanging off in every direction, but especially welded to the top.

Obviously for Startship, even prototypes, most of that business will be going under the 'fairing' or nose cone, but the question is, how are they going to access/ work it? Is there any indication of a port or door going into the fairing? I can't think they'd want to do fairing mate / demate operations very often.

Surely they would also mount most of the hardware to flat steel decks, rather than welded to the upper tank dome the way Starhopper was. Especially if they're going to mount substantial batteries as some have proposed for fin /avionics power.

I'd expect some of those pieces to already be in work now, just as the harder-to-hide thrust mountings are.

Any ideas or stray mounting hardware anyone else has spotted?

capoman · « **Reply #2 on:** 08/08/2019 01:35 pm »

Obviously, production versions will have significant access via a large bay, and possibly have access on lower decks as per some renderings we have seen. For this prototype, I am making a guess that it will have a hatch similar to the ones used for the tanks. I do think there will be some type of spider structure or deck above the tanks though for both stiffness and hardware mounting points. Hard to say whether they will put a bay door in the prototype or not.

ThomasGadd · « **Reply #3 on:** 08/08/2019 10:25 pm »

Is there enough interest to create a new thread to discuss Starship refueling/tanking/depots.

One of the things that's hard for people to get use to is the flexibility in mission planning Starship with on-orbit refueling. Starship without refueling has limited options.
There a lot talk in this thread and others on tanking and fuel depots (mostly old space threads).

Slarty1080 · « **Reply #4 on:** 08/09/2019 02:39 pm »

Quote from: ThomasGadd on 08/08/2019 10:25 pm

Is there enough interest to create a new thread to discuss Starship refueling/tanking/depots.

One of the things that's hard for people to get use to is the flexibility in mission planning Starship with on-orbit refueling. Starship without refueling has limited options.
There a lot talk in this thread and others on tanking and fuel depots (mostly old space threads).

Yes its an interesting point. IMO one of the more difficult elements is trying to figure out how many refueling flights would be required. Even with multi use Starships the difference between 3 flights to fully refuel and 12 flights is huge in terms of risk, cost and time.

Cheapchips · « **Reply #5 on:** 08/17/2019 06:25 am »

It looks like the tiles will be alumina-silica based on this job posting?

https://boards.greenhouse.io/spacex/jobs/4345369002?gh_jid=4345369002

Quote

- Develop state of the art manufacturing site for low density alumina-silica refractory insulation
- Optimize tile factory in terms of layout, scrap rate, material utilization, energy consumption

Upper continues heat limit for alumina-silica fibre is 1600C

FutureSpaceTourist · « **Reply #6 on:** 08/17/2019 07:21 am »

twitter.com/harrystoltz1/status/1162595874561617920

Quote

Will spaceX eventually need to use a continuous spiral welder to make super heavy? 🚀 Much faster than making individual ring segments, but I’m not sure it would be necessary given the amount of super heavies that will be produced. 🚀 ✨

https://twitter.com/elonmusk/status/1162601447235604480

Quote

No, as better to vary thickness with vehicle height, but this is the right way to go for Boring Co tunnels reinforcement imo

rsdavis9 · « **Reply #7 on:** 08/17/2019 12:38 pm »

I can imagine it now.
Stainless supplied from rolls continuously and welded.
No need for placement of concrete segments which would seem to require stopping or high automation to place.

aero · « **Reply #8 on:** 08/17/2019 12:45 pm »

Quote from: rsdavis9 on 08/17/2019 12:38 pm

I can imagine it now.
Stainless supplied from rolls continuously and welded.
No need for placement of concrete segments which would seem to require stopping or high automation to place.

What I see is a complete re-design of that welding machine since it all has to fit inside the pipe that lines the tunnel, the pipe that it is designed to weld up.

spacenut · « **Reply #9 on:** 08/17/2019 02:53 pm »

They could use rolled stainless to make the individual hoops before stack welding the hoops together. It would only have one vertical weld per hoop. A little lighter from fewer welds. Also use wider hoops.

Question about the alumina-silica.

Will it be applied on the entire re-entry side of the Starship or just on the points of highest heat?

Will it be easy to replace burned out ones, or are they highly resistant and will last for several re-entries? Heat tiles on the Shuttle is what cost a lot to repair-replace, and ones that fell off on the wheel well doors caused one to burn up upon re-entry.

Then you have the folding fins/legs, that will take a lot of heat. It seem there will be problems there to address/fix.

Maybe if they air-brake in several orbits to drastically slow down before re-entry to have less heat.

speedevil · « **Reply #10 on:** 08/17/2019 03:34 pm »

Quote from: spacenut on 08/17/2019 02:53 pm

Question about the alumina-silica.

Will it be applied on the entire re-entry side of the Starship or just on the points of highest heat?

We have almost no specific information as to the actual hardware that will be placed on the flight vehicles.
It has recently (this year) gone from carbon fiber, to shiny stainless, to stainless tiles, to more mention being made of ceramics.

We've seen test hardware including some that is now placed on Hopper.
What's actually going to be on the flight version isn't known. More may be revealed next week in the press conference Elon is planning on holding.

Slarty1080 · « **Reply #11 on:** 08/18/2019 05:26 pm »

Elon said that he would be describing the various options and the different trade offs in his talk so we should know more soon.

livingjw · « **Reply #12 on:** 08/19/2019 02:07 am »

alumina-silica refractory insulation. Saffil fiber insulation under metallic hex tile, or some form of light weight solid insulation under ceramic hex tile? Inquiring minds want to know.

garidan · « **Reply #13 on:** 08/19/2019 02:45 pm »

I see renderings of Superheavy think it is made of steel as Spaceship, but is there any confirmation it is not made like Falcon of aluminium ? There is no thermal need to have superheavy made of steel. If made of aluminium the tooling should have been already bought, but there is no news on that.
Did I loose some news ?

mmeijeri · « **Reply #14 on:** 08/19/2019 02:48 pm »

Wouldn't it be easier to make it out of steel at least in the near term even if they didn't need it?

spacenut · « **Reply #15 on:** 08/19/2019 02:54 pm »

Since Superheavy and Starship are the same diameter, they will probably make both of stainless steel. Even F9 has to have some type of heat resistant material around the engines and on the bottom. With a Stainless bottom, there may not be a need for any type of heat resistant material, thus being easier to turn around and re-launch.

Starship may require more heat resistance at certain points. Hopefully whatever they use will be easy to replace if necessary to keep launching.

envy887 · « **Reply #16 on:** 08/19/2019 03:06 pm »

Quote from: spacenut on 08/19/2019 02:54 pm

Since Superheavy and Starship are the same diameter, they will probably make both of stainless steel. Even F9 has to have some type of heat resistant material around the engines and on the bottom. With a Stainless bottom, there may not be a need for any type of heat resistant material, thus being easier to turn around and re-launch.

Starship may require more heat resistance at certain points. Hopefully whatever they use will be easy to replace if necessary to keep launching.

Musk confirmed this:

https://twitter.com/elonmusk/status/1107382673012486144

Bananas_on_Mars · « **Reply #17 on:** 08/22/2019 01:59 pm »

Didn‘t know where to place it best, so i‘ll put it here

Interview with Dr. Garrett Reisman on „The Space Show“

Some tidbits from the interview relevant to Starship design:

SpaceX has of course identified tasks like ECLSS and Radiation protection etc. but doesn‘t have them on their critical path right now. It’s part of the way they do development to tackle those problems in time during their development and not everything right from the start, which reduces the redundant work because of design changes.

SpaceX has a flight surgeon on their team that they lured away from NASA.

livingjw · « **Reply #18 on:** 08/23/2019 09:56 pm »

I see 4 leading edge fin mounts and one trailing edge fin mount. What do other people see?

John

livingjw · « **Reply #19 on:** 08/23/2019 10:05 pm »

What kind of material and or surface treatment might look like this? Weird.

- Doesn't look like sheet metal stamping.

- Doesn't look like shuttle type tiles, they were smooth.

- plasma sprayed metal over ceramic block?

- other ideas?

John