BFR or BFS first or both?

[JamesH65]

Prototypes launched, some failures, not yet ready to take over from F9/H.

So what kind of failures do you see happening?

Carbon fibre tanks are going to take some work to get right (and I am sure they will figure it out), so I expect some ruptures. Probably during ground testing but they could still lose a vehicle in flight - after all, there is a lots of new stuff (to them) in the BFx system.

[Norm38]

The BFS is a truck. It's got to be reliable and be able to take a beating. It's got to land on rough terrain on Mars so you'd better believe it'll do the same here. Later they should launch in New Mexico and land in a random patch of desert.
They only have to place the three landing engines. They can use heavy legs as ballast for the vacuum engines and launch with partially full tanks. Work their way up, just as Grasshopper did.

[meekGee]

It's very basic...

BFS is unlike anything that's ever been done before. An actual interplanetary ship, and a surface-to-surface one at that. Straight out of sci fi.

BFR is merely a larger rocket.

So of course they have to stat with BFS.

[Lar]

I think this thread is closeable. SpaceX have said multiple times, including Elon himself more than once, BFS first.

While we could play "let's outsmart SpaceX engineers and the CTO", let's not.

[speedevil]

Perhaps appropriate to let Elon have the last word.

From the transcript at https://forum.nasaspaceflight.com/index.php?topic=43154.msg1784964#msg1784964  _{edited for clarity and topic}

if we get lucky, be able to do short hop flights with the spaceship part of BFR maybe next year.

By hopper tests I mean kind-of-like the grasshopper program for falcon 9, where we just had the rocket take take off and land in Texas at our Texas test site so we'd either do that at our South Texas launch site, near Brownsville or or do ship-to-ship. We're not sure yet whether ship-to-ship or Brownsville, but most likely it's gonna happen in our Brownsville location because got a lot of land with nobody around and so if it blows up, it's cool.

By hopper test I mean it'll go up several miles then come down. The ship is capable of single stage to orbit if you fully load the tanks. So we'll do flights of increasing complexity. We really want to  test the heatshield material so,  like you know fly out turn around accelerate back real hard and come in hot to test the heat shield, because we want to have a highly reusable heat shield that's capable of absorbing heat from interplanetary entry velocities. So it's really tricky.

The ship part is by far the hardest because that's going to come in from super-orbital velocities. Mars transfer velocities these are way harder than coming in from low-earth orbit. There's some of the heating things that scale to the eighth power.  I diddn't think there's anything that scales to eight power but turns out on reentry certain elements of reentry heating scale to the 8th so just testing that ship out is the real tricky part.
The booster I think we understand reasonable boosters. Reusable spaceships that can land propulsively that's that's harder, so we're starting with the hard part first.
I think it's conceivable that we do our first full-up orbital test flight in 3-4 years including the booster.  inaudible question on moon/mars
 We'd go to low earth orbit first but it would be capable of going to the moon very shortly thereafter it's designed to do that.

[Lar]

Yep. Locked.