Ed Kyle wrote:

Murray Anderson wrote:

I'd count it as half a failure, and try to do that consistently.
There was an Ariane flight like that, I believe.

I count these "partial" failures as failures simply
because they fall short of being called successes.

You're unreasonably pessimistic, IMO.

In the case of the Sea Launch Apstar 5 launch, for
example, the early DMSL stage shutdown cost the
satellite a delta-v of about 345 meters/second.
Apstar 5 must have had enough contingency propellant
to allow it to recover from the launching error
without shortening its planned lifetime (but its
potential for an extended life has almost certainly
been reduced).

Other comsats would not have been so lucky.

So while the mission was a success it should count as a failure, because
if the launch vehicle had been flying a different mission it wouldn't have
succeeded? That doesn't make sense.

I haven't been able to find a partial success/failure
figure of merit that I can be comfortable with.

Generally I use the criterion that if the payload made it into an oper-
ational orbit under its own power it's a success, and it's a failure if
it didn't. I'm not the only one to use this, since I picked it up from
someone (but don't recall who).

So the first Pegasus launch was a success, since the payload wasn't
particular about what orbit it needed and could operate just fine from
the one it got put into. The first Titan IV Milstar mission was a
failure, since though the payload made orbit, it couldn't operate from
the orbit it made nor get into an operational orbit under its own power.
Also, the Intelsat VI launch was a failure for this reason, since while
it did eventually reach an operational orbit, it required the intervention
of a shuttle crew to do so.

It's not a perfect metric, since the pass/fail mark depends on whether
non-fatal anomalies happen to robust payloads or to "fragile" ones. But
I haven't seen one I like better at this stage of the industry's evo-
lution. (Eventually dispatch reliability will have to enter into it but
not yet, in my opinion.)

Mike

-----
Michael Kent Apple II Forever!!
St. Peters, MO