Jeff Findley wrote:


"Craig Fink" wrote in message
thlink.net...
FALCON DemoFlight 1* Q1 2006 Falcon 1 Kwajalein
+0
FALCON DemoFlight 2 Q1 2007 Falcon 1 Kwajalein
+0

To be fair, this second flight was a lot more successful then the first.
On the first flight, the second stage didn't even get a chance to fire, so
it
really wasn't tested in flight. Because of this, it's not surprising that
a
second stage problem might show up in this flight. See the news he

http://www.spacex.com/updates.php

They've fixed the problems found in the first launch attempt, so they got
a
lot further in the flight profile, which uncovered 2nd stage problems.
From above:

Falcon flew far beyond the "edge" of space, typically thought
of as around 60 miles. Our altitude was approximately 200 miles,
which is just 50 miles below the International Space Station.
The second stage didn't achieve full orbital velocity, due to a
roll excitation late in the burn, but that should be a comparatively
easy fix once we examine the flight data. Since it is impossible
to ground test the second stage under the same conditions it would
see in spaceflight, this anomaly was also something that would have
been very hard to determine without a test launch.

So, they've likely gathered good data on what went wrong with the 2nd
stage
and will work to address these problems for the 3rd launch. I see nothing
out of the ordinary here. Look at this "anomaly report" for STS-1:

http://www.jsc.nasa.gov/news/columbia/anomaly/STS1.pdf

A lot of the problems uncovered by STS-1 were damn serious! Look at the
problems caused by the SRB overpressure and the problems related to the
TPS. Also note the foam shedding problem on this very fist flight...

So perhaps Falcon I hasn't been as lucky as STS, but they're working
through the "anomalies" in much the same way.

Yeah, I agree, pretty darn successful first two flights and the third will
probably make it.

http://www.spacex.com/falcon1.php
....Helium pressurization is again provided by composite over wrapped inconel
tanks from Arde. However, in this case the helium is also used in cold gas
thrusters for attitude control and propellant settling when a restart is
needed...

Roll problems, wonder if it's similar to a Delta launch problem, liquids
don't roll with the vehicle. Wrong roll moment of inertia leads to over
controlling, leads to greater propellent usage, leads to...

Helium roll control, tank pressurization, and settling burn. Roll out of
control, might still get there. Lack of tank pressurization, lack of engine
performance, how much??? No settling burn, no ignition.

Nice job SpaceX and good luck with the next one.