What’s the unistrut rails? The M-impulse went off the back row I’m assuming
and unless the Super Uber was there (and I don’t think it was), there is only
one kind of pad on the back row.
Doesn’t look like drag damage to me. Most of the available rail buttons are
pretty tough and would just plow through the surface of the lakebed. Did the
rocket slide on the rail nicely when it was installed? 46 lbs is a heavy
rocket even for a M. Could the shock cord have caused the damage during
deployment?
Richard
On Jul 22, 2019, at 6:28 PM, Jason Muckenthaler (Redacted sender "jmuck78" for
DMARC) <dmarc-noreply@xxxxxxxxxxxxx<mailto:dmarc-noreply@xxxxxxxxxxxxx>> wrote:
After retrieving the LOC Hawk on Saturday, I noticed that both rail buttons had
been damaged with very little damage to area immediately surrounding the rail
button locations. My initial, knee-jerk reaction was that the rail button
damage was just another consequence of the rocket being carried across the
lakebed, but on further reflection, I wonder if the damage was actually caused
during the launch. The wind was blowing at a healthy pace (while still less
than the 20 mph limit) and the rocket has quite a large fin area. The large
fin area coupled with a potential torque due to the nozzle exhaust hitting the
blast deflector at an angle, may have been enough to shear the outer edges of
the rail buttons off before the rocket cleared the tower.
I have attached pictures of the two rail button locations, and there is a clear
lack of road rash in the vicinity. The other possibility is that the rail
buttons impacted something during its trip along the lakebed, but if that were
the case, I would have expected the rail button screws to show some deflection
or some other impact damage - but there is no such visible damage to the rail
button screws.
I am also now curious if I should have used one of the larger unistrut rails
instead of the 1515 rail tripod. I don’t know where the cutoff for using the
1515 tripod launcher is versus the unistrut rail (and I should have asked prior
to the launch, but it didn’t occur to me until I saw that rail buttons). Does
anyone else have any similar experience with broken rail buttons like this, or
does this look more like damage from wind carrying the rocket across the
lakebed, and I’m just not recognizing it?
Some Data: The Lift off weight was about 46 lbs with the M1297. Velocity off
the rail (according to OR) was about 40 mph.
Greg Smith has a nice video of this torque on his blog from 2016 here:
http://hawtakshun.blogspot.com/2017/01/lucerne-dry-lake-november-2016-l1500-is.html<https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fhawtakshun.blogspot.com%2F2017%2F01%2Flucerne-dry-lake-november-2016-l1500-is.html&data=02%7C01%7C%7C9eaf0f7cf6124a195c7908d70f0d11a7%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636994421126047991&sdata=gpolkN4HKFL%2B3qOmAWYlxo8iD4qAD2QTluaHg6Z0c2M%3D&reserved=0>
Thanks,
Jason
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