Insulated Falcon stage 2?

The discussion of the LOX problem with the Falcon 1 launch says that
the stage 1 LOX tank is not insulated.

Is the stage 2 LOX tank insulated?

Thanks

Henry

Henry wrote:
The discussion of the LOX problem with the Falcon 1 launch says that
the stage 1 LOX tank is not insulated.

Is the stage 2 LOX tank insulated?

Probably not, unless there is some insulation between
the LOX and kerosene tanks. The second stage tank
wall might be slightly thicker than the first stage tank
because the second stage is pressure fed. But maybe
not. The second stage is of Aluminum Lithium, which
is stronger for its weight than the Aluminum used in
the first stage. Ice forming on the outside of the LOX
tank during prelaunch provides some insulation - and
the ice usually shakes off right at liftoff.

- Ed Kyle

Ed Kyle wrote:

[snip]
not. The second stage is of Aluminum Lithium, which
is stronger for its weight than the Aluminum used in
the first stage. Ice forming on the outside of the LOX
tank during prelaunch provides some insulation - and
the ice usually shakes off right at liftoff.

Last thing I read was that the upper stage is made from normal
aluminium alloy, because they could not find a reliable source for the
required LiAl alloy (translation: Somebody put some pressure on LiAl
manufacturers not to sell to spacex if they want to continue being
suppliers for the LiAl Shuttle ET).

That has reduced the payload by something like 100kg.

To answer the question of the OP: yes, the upper stage is uninsulated.
That was one of the reasons for their problems with LOX boiloff.

Rüdiger Klaehn wrote:
Ed Kyle wrote:

[snip]
not. The second stage is of Aluminum Lithium, which
is stronger for its weight than the Aluminum used in
the first stage. Ice forming on the outside of the LOX
tank during prelaunch provides some insulation - and
the ice usually shakes off right at liftoff.

Last thing I read was that the upper stage is made from normal
aluminium alloy, because they could not find a reliable source for the
required LiAl alloy (translation: Somebody put some pressure on LiAl
manufacturers not to sell to spacex if they want to continue being
suppliers for the LiAl Shuttle ET).

That has reduced the payload by something like 100kg.

Hmmm. The SpaceX web site still says that the Falcon 1
second stage "tank structure is made of aluminum-lithium".
It says that the Falcon 5 and Falcon 9 second stage tanks
are going to be aluminum.

- Ed Kyle