Jump to content

SpaceX Discussion Thread


Skylon

Recommended Posts

Proposals for supersonic jets are in the news every now and then. Maybe two or three companies are even reluctantly working on something, but i think the market is limited and it'll never be a service for the masses if it is much more expensive than a normal flight. But idk, maybe just a marketing gag ...

Link to comment
Share on other sites

On 25/02/2018 at 5:44 PM, sevenperforce said:

Aircraft have engine failure abort modes on landing. It's called "glide".

Wing loss and other incidents say "hello". Most craft have some failure mode options. For example, should an engine fail while in orbit, the BFR upper stage will be the most "safe" vehicle ever* with an engine failure... it would orbit safely forever. :wink: No wings or gliding needed!

Perhaps we can go full Kerbal and have a system that can land fine without any power. Like this: 

 

 

*Even a car in a drive way with a failed engine can get stolen. No chance on an orbiter. Try sneaking up on it!

Edited by Technical Ben
Link to comment
Share on other sites

13 hours ago, Technical Ben said:

 

*Even a car in a drive way with a failed engine can get stolen. No chance on an orbiter. Try sneaking up on it!

Hmmm. *hatches evil plan* would it be economically feasible to steal satalites and ransom them back to the owner? (You don't have to move it, just wrap it in alfoil till they pay up) :wink:

Link to comment
Share on other sites

1 hour ago, Antstar said:

Hmmm. *hatches evil plan* would it be economically feasible to steal satalites and ransom them back to the owner? (You don't have to move it, just wrap it in alfoil till they pay up) :wink:

Every superpower states have effective warning systems for ICBM launches. Therefore it is practically impossible to launch secretly rockets to orbit. Every launchpad would get some cruise missiles soon after launch. Such mobility would be quite hard and expensive. Probably it would be more productive to sell honest launch services if you have such resources.

Link to comment
Share on other sites

IT'S BEAUTIFUL 

I've heard that Musk said somewhere that Block 5 would look different... and there are quite a few distinct features on this core.

The interstage looks like it's made of some carbon fiber- reminds me of the falcon 1.

The logo has been moved up as well.

I wonder what it will look like after reuse? Will the "thermal covering" do anything to keep the paint on?

Link to comment
Share on other sites

19 hours ago, Green Baron said:

Proposals for supersonic jets are in the news every now and then. Maybe two or three companies are even reluctantly working on something, but i think the market is limited and it'll never be a service for the masses if it is much more expensive than a normal flight. But idk, maybe just a marketing gag ...

Which is why the latest attempt to make a supersonic business jet is aimed at sheikhs.

%D0%A2%D1%83-160-original.png

https://www.rbc.ru/society/13/11/2017/5a095c0d9a7947768772759a

Edited by DDE
Link to comment
Share on other sites

8 minutes ago, DDE said:

Which is why the latest attempt to make a supersonic business jet is aimed at sheikhs.

%D0%A2%D1%83-160-original.png

https://www.rbc.ru/society/13/11/2017/5a095c0d9a7947768772759a

There is much room for extended runways in the desert. Not so much room in London or Paris, New York or Los Angeles. They can design an aircraft that can haul passengers at Mach 3 (80000 feet ceiling) making any destination on Earth 4 hours away. The problem is that you would need a runway 5 nMiles in length to make it safe to take off and land.

Link to comment
Share on other sites

4 minutes ago, sevenperforce said:

Not possible. The interstage is black because it is unpainted carbon fiber; the core is painted aluminum. Ya gotta paint the aluminum but carbon fiber is good on its own.

But the core is painted anyways. Is black paint just substantially heavier than white paint, or is it an electrostatic thing, like the side of the SpaceX logo on the side of the booster?

Link to comment
Share on other sites

7 minutes ago, IncongruousGoat said:

But the core is painted anyways. Is black paint just substantially heavier than white paint, or is it an electrostatic thing, like the side of the SpaceX logo on the side of the booster?

The core is painted white to help keep the subcooled LOX and RP-1 cool. Black paint would cause solar heating.

Link to comment
Share on other sites

22 minutes ago, IncongruousGoat said:

According to NasaSpaceflight, the first Block 5 launch will be for Bangabandhu-1, which according to r/SpaceX's launch manifest is set to launch March 30th.

I find that launch date completely unbelievable in the best way possible.

CRS-14 is supposed to launch on April 2 on the same pad...

That would mean that they would achieve like a 3-day turnaround or something!

(Or maybe one of these would launch from LC-39A...)

Link to comment
Share on other sites

5 minutes ago, IncongruousGoat said:

But the core is painted anyways. Is black paint just substantially heavier than white paint, or is it an electrostatic thing, like the side of the SpaceX logo on the side of the booster?

Best guess is that white paint absorbs less solar radiation, keeping the LOX just a little bit colder.

Link to comment
Share on other sites

3 minutes ago, sevenperforce said:

"just a little bit" is understating it. White paint keeps the LOX (and the RP-1, for that matter) MUCH colder than black paint would.

But unpainted orange tanks were preferred for shuttles (although they started out with white paint).  It depends on how much you need the mass of that paint.  Remember, those orange tanks held LH2 as well as LOX.

Link to comment
Share on other sites

2 minutes ago, wumpus said:

But unpainted orange tanks were preferred for shuttles (although they started out with white paint).  It depends on how much you need the mass of that paint.  Remember, those orange tanks held LH2 as well as LOX.

Orange tanks were orange because they were covered in insulation, which kept the contents quite cold regardless of external temperature. SpaceX uses uninsulated aluminum tanks.

Link to comment
Share on other sites

25 minutes ago, wumpus said:

But unpainted orange tanks were preferred for shuttles (although they started out with white paint).  It depends on how much you need the mass of that paint.  Remember, those orange tanks held LH2 as well as LOX.

That probably had more to do with the sheer amount of work and time it took to paint the tanks. Remember, they wanted to fly pretty often (about 14 times per year was the goal). Painting the tanks proved to be a waste of time, since the insulation worked just fine without it and it incurred a small mass penalty. It just wasn't worth doing. The mass penalty was actually very slight and could've been easily overcome by making other modifications to the external tank (this was later done anyways, shaving off tonnes of unnecessary dry mass, compared to the few hundred kilograms of paint). Since the vehicle took this tank almost to orbit, the payload increase was roughly one to one if you could reduce the external tank's dry mass.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...