totm nov 2023 SpaceX Discussion Thread

[insert_name]

Here's a picture of a faring in port Canaveral from Tess's fb

Looks pretty intact

[YNM]

On 4/26/2018 at 9:46 PM, tater said:

 

(for anyone job-hunting)

Is there an equivalent vacancy in Boring Company or something ?

[CatastrophicFailure]

56 minutes ago, insert_name said:

Looks pretty intact

Much better shape than the other one. So this one soft-landed and the other actually just crashed, that's encouraging at least.

[kerbiloid]

Spoiler

Why don;t they make this shroud inflatable rather than aluminum?

Deflated, it's a shroud.
Inflated, it's a boat. 
Inflated with helium, it's a blimp.
Equipped with Cessna motor, it's a Reusable Self-propelled Rocket-Conformal Protective Airship.

Upd.

Spoiler

Let we suggest a toroidal inflatable shroud.
Instead of splitting the shroud like a coconut shell, the rocket will just sneak through the central hole of the inflating shroud.
Then it will be it's own toroidal ballute/blimp/boat/airship. This would be handy.

 

Edited April 29, 2018 by kerbiloid

[DAL59]

 

 

[tater]

 

[tater]

Normally I'd not have watched a video like the gateway one above, but it makes some interesting points, and I honestly think that tourism will be the "killer app" for human spaceflight in the foreseeable future.

Worth a watch, even if it's pretty aspirational.

[Cunjo Carl]

I was a little non-plussed. Basket ball in LEO sounds dramatically further out to me than most goals presently being discussed, including getting out to Mars and back.  And the whole "The pages of this book are written in blood" with the airplane stalling, and tragically crashing also didn't do much to win me over. I feel like 'people will have urpy tummies in space' is a hard banner to wave for a several-ten-billion dollar project! Maybe it's just me

That said, space stations are cool,  so I guess best of luck to them.

And thanks for sharing, @DAL59!

Edit: Wait, wasn't the plan for Moon-bound BFR to do their refueling and transfer to trans-lunar injection through a high eliptic orbit? That'd mean the gateway station would need to be high eliptic, too? Eh...

Edited April 29, 2018 by Cunjo Carl

[DAL59]

1 hour ago, tater said:

Normally I'd not have watched a video like the gateway one above

Me neither, because that guy's voice is so monotone. 

[Bill Phil]

Hmm... I guess BFR would technically count as one of these:

http://www.sarna.net/wiki/DropShip

With propellant it's definitely above 200 tonnes and even without if we count payload. Just a shower thought, but I think it's cool.

More about SpaceX, does anyone know the BFS SSTO payload?

[cubinator]

53 minutes ago, Bill Phil said:

More about SpaceX, does anyone know the BFS SSTO payload?

"Very small"

[tater]

The number I heard was ~10 tons to LEO. I assumed this was the cargo version, as well. Unsure if that includes any reserve props for landing.

[Scotius]

Still comparable (roughly) to Falcon 9. If flight costs turned out to be comparable too, i wouldn't be surprised if SpaceX decided to quietly phase out F9. Logistically it would be much simpler to deal with one type of ship and not two.

[hms_warrior]

Well the numbers from the last speech was 5-6 million per BFR launch... wich i find a bit optimistic

[cubinator]

I suppose we'll see gradual improvements to BFR after flights, similar to Falcon 9. Initially they may not be reusable 100 or 1000 times, but as SpaceX learns the nuances of the spacecraft they will surely find ways to improve performance and reusability.

[tater]

4 hours ago, hms_warrior said:

Well the numbers from the last speech was 5-6 million per BFR launch... wich i find a bit optimistic

The math is that the propellants only cost several hundred thousand dollars for a launch of the whole stack.

If the 2 stages together cost ~300 M$, then the question is reuse, and you'd divide that cost by the flights to get the amount of vehicle used up per flight. at 100 flights, that's 3 M$ per flight. Add a few hundred grand for maintenance, and you get 4 M$/flight as the cost. At 50 flights reuse, then we're at 7 M$/launch.

[wumpus]

27 minutes ago, tater said:

The math is that the propellants only cost several hundred thousand dollars for a launch of the whole stack.

If the 2 stages together cost ~300 M$, then the question is reuse, and you'd divide that cost by the flights to get the amount of vehicle used up per flight. at 100 flights, that's 3 M$ per flight. Add a few hundred grand for maintenance, and you get 4 M$/flight as the cost. At 50 flights reuse, then we're at 7 M$/launch.

There's a lot more than the vehicle and the fuel.  Every technician needed to bring the thing from barge to pad and on hand to launch the thing needs to be paid.  When Spacex charges $60M to launch a used Falcon, it isn't clear how much is profit.  Certainly nearly 90% of the rocket is saved, but there is also certainly a lot of money getting the payload integrated into the first stage, and getting the whole thing into space.  With Spacex pushing into launch cadences only previously dreamed of by Shuttle propaganda, they might see just how low these costs can go (low, but certainly much higher than fuel costs).

[XB-70A]

11 hours ago, Bill Phil said:

Hmm... I guess BFR would technically count as one of these:

Out-of-topic, but I just read your profile's location for the first time. Pretty fun that it's happening while you posted a link to the wiki of BT.

Terra, you were so beautiful. If only these filthy Blakers were eliminated sooner...

[NSEP]

12 hours ago, Bill Phil said:

More about SpaceX, does anyone know the BFS SSTO payload?

I tried the Delta-V calculator and if we assume the Delta-V required is 9.5km/s for Earth orbit, the BFR could send 15 tons to LEO. This is using the 375s ISP of the Raptor vacuum however, and because the BFR might use its SL engines during the first part of launch, the payload could drop to 10-12 tons.

The BFR SSTO could probably re-used, assuming they are going for a 150m/s de-orbit burn and a 350m/s suicide burn. Again, using the Delta-V calculator,  i calculated the BFR could technically send 2t to LEO, but because of they might use the SL engines during the first stage of launch, the payload might drop to zero.

I would also assume the BFR SSTO would have more fuel. The gigantic cargo bay is way too overkill for its payload capacity, wich is the opposite of Falcon Heavy's volume to mass ratio.

Im making alot of assumtions here.

Edited April 30, 2018 by NSEP

[tater]

2 hours ago, wumpus said:

There's a lot more than the vehicle and the fuel.  Every technician needed to bring the thing from barge to pad and on hand to launch the thing needs to be paid.  When Spacex charges $60M to launch a used Falcon, it isn't clear how much is profit.  Certainly nearly 90% of the rocket is saved, but there is also certainly a lot of money getting the payload integrated into the first stage, and getting the whole thing into space.  With Spacex pushing into launch cadences only previously dreamed of by Shuttle propaganda, they might see just how low these costs can go (low, but certainly much higher than fuel costs).

The goal of even Block 5 is rapid turn around. 24 hours in the case of Block 5 F9. That is not about time, but about money. There will not be time for much labor in a short turn around.

6-700k in propellant costs, and a few hundred thousand in labor seems like plenty of slop. If the vehicle stack is 300 M$, then to get the launch cost <6M$, you need 60 reuses of the whole stack (which could be more reuses on the booster, and fewer on the spacecraft, or whatever). That's 5M/launch in vehicle cost, then 1M/launch in props and labor.

[Bill Phil]

4 minutes ago, NSEP said:

I tried the Delta-V calculator and if we assume the Delta-V required is 9.5km/s for Earth orbit, the BFR could send 15 tons to LEO. This is using the 375s ISP of the Raptor vacuum however, and because the BFR might use its SL engines during the first part of launch, the payload could drop to 10-12 tons.

The BFR SSTO could probably re-used, assuming they are going for a 150m/s de-orbit burn and a 350m/s suicide burn. Again, using the Delta-V calculator,  i calculated the BFR could technically send 2t to LEO, but because of they might use the SL engines during the first stage of launch, the payload might drop to zero.

I would also assume the BFR SSTO would have more fuel. The gigantic cargo bay is way too overkill for its payload capacity, wich is the opposite of Falcon Heavy's volume to mass ratio.

Im making alot of assumtions here.

Maybe it won't SSTO, but could use a small kick stage or even an F9 second stage in a reusable configuration?

[NSEP]

3 minutes ago, Bill Phil said:

Maybe it won't SSTO, but could use a small kick stage or even an F9 second stage in a reusable configuration?

Adding a kick stage to the BFR SSTO sort of defeats the purpoise of the BFR SSTO. But they without a doubt could give it a small kick stage/upper stage. They could revive the Falcon 1, and maybe add wings to it for reuse, kind of like what the Soviets wanted to do with the Energia boosters. Its probably not going to be easy however.

Hmmm, they could still do long-distance transport with only the BFS, right? Im pretty sure BFS could send maybe 100 people across the atlantic, for god knows what kinds of missions, without having to use the booster. 

[Bill Phil]

40 minutes ago, NSEP said:

Adding a kick stage to the BFR SSTO sort of defeats the purpoise of the BFR SSTO. But they without a doubt could give it a small kick stage/upper stage. They could revive the Falcon 1, and maybe add wings to it for reuse, kind of like what the Soviets wanted to do with the Energia boosters. Its probably not going to be easy however.

Hmmm, they could still do long-distance transport with only the BFS, right? Im pretty sure BFS could send maybe 100 people across the atlantic, for god knows what kinds of missions, without having to use the booster. 

They want to replace the Falcon 9 family entirely, and if they also want to reuse the BFS with that much payload they'll need an upper stage.

[NSEP]

1 minute ago, Bill Phil said:

They want to replace the Falcon 9 family entirely, and if they also want to reuse the BFS with that much payload they'll need an upper stage.

Are we talking about my suborbital transport thing or the BFS SSTO? Then yes, BFS 'SSTO' could use an upper stage/small kick stage.

If we are talking about the suborbital transport thing, then say every passanger masses in at about 100kg (75kg human, and 25kg luggage), 100 people weigh only 10t. If they can in theory send 10t to LEO without reuse, then they could without a doubt do 10t across the atlantic with reuse. BFS could also use the atmosphere to get an extra kick and go further.

[Elthy]

Is there anything official regarding the usage of BFS as a SSTO? I know SpaceX stated it could SSTO, but thats also true for the Falcon 9 first stage.