In article ,
says...

Jeff Findley wrote:
In article ,
says...
How long can the second stage "wait" before performing a second (and I
presume final?) burn?

Speculation on ARocket is that the burn was canceled more because of
the NASA imposed rules to prevent anything from hitting ISS.
Supposedly this off-nominal situation was so far off nominal that it
wasn't covered by the analyses done for this reason. Because of
this, they had to go to the backup plan.

So the second stage of the rocket system that has a first stage which
can supposedly "complete the mission" if it loses two engines,
ended-up without enough propellant to complete the mission? Or is the
second stage's lack of sufficent fuel/oxidizer for the burn not a
result of the first stage's loss of an engine?

The Falcon 9 first stage has nine engines (hence the origins of its
name). One first stage engine failed in a somewhat spectacular way. To
compensate, the first stage burned longer, but due to the lower thrust
of the first stage, it surely incurred more drag and gravity losses than
on a nominal launch. Because of the first stage losses, the second
stage must have also burned longer in order to make it into the proper
"parking" orbit for Dragon release. So, the launch was a success for
Dragon.

The second stage only has one engine, so burning longer left it with
less fuel than a nominal mission. This meant that there wasn't enough
fuel for the next burn. This burn would have placed the secondary
payload into its final orbit. This was at least a partial failure for
the secondary payload any way you look at it.

Unfortunately, because of the ISS constraint, SpaceX wasn't allowed to
perform any additional burn using the fuel remaining in the second
stage. So, the backup plan was initiated which released the secondary
payload into the parking orbit, which is a far cry from its intended
orbit.

If it weren't for the ISS constraint, SpaceX surely would have done the
second burn (likely to fuel depletion) in order to place the secondary
payload into as favorable of an orbit as they could. But they couldn't,
which is a shame for the secondary payload.

The bottom line is that this was a successful launch of the primary
payload (Dragon), but a nearly complete failed launch for the secondary
payload. Sucks to be a secondary payload when "stuff happens".

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer