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Athos & Porthos Fly Again, Motors Max'd
Xavier Reaches New Heights

We finally got a chance to put both Athos and Porthos back up fully clustered, with as much AP as both could take.  We also found time to put Xavier back up, also in a maximum motor configuration.  We had hoped to get our Aramis Two-Stage project in the air as well, but with winds on Friday and Saturday, we ran out of time.  Athos' second flight was reminiscent of some of Aramis' earlier flights, and once again helped us tune our recovery design.   Xavier's altimeter switched off on descent, but she suffered no damage.  And Porthos' second flight was picture perfect, and very impressive.  Below is a summary of the various flights.  Read on for details.

Springfest Flight Summary,  March 2001
  
Specifications Projected Performance
Time Rocket Event Dia. Length Rail Weight Motor Electronics Settings Altitude Speed Apogee
Saturday
3:20 PM

Athos

Dual
Recovery

First Triple Air Start Cluster Flight

Subsonic

Altitude Waiver

7.5" 144"

12 ft

114"

9 ft 6"

97 lb M1315W

6 x
J570W

Blacksky AltAcc2

Drogue/Main

9500 ft 570 ft/s 30 sec
Blacksky Timer2 32 sec Actual
Olsen FCP-M2 1200 ft  3400 ft 280 17
Cluster Timer2
(x2)
8 sec
11 sec
14 sec
Only 1st 2 outboards lit.
Olsen altimeter failed on take-off.
Main didn't clear deployment bag.
 
Saturday
4:20 PM
Xavier

Dual
Recovery

Transonic
Flight
3" 76"

6 ft 4"

54"

4 ft 6"

 

12 lb K250W Missile Works Co-Pilot 800 ft
SID 12 sec
14200 ft 1060 ft/s 29 sec
Actual
?    
Altimeter switched off on descent
No damage.
 
Sunday
11:20 AM
Porthos

Dual
Recovery

Clustered Flight

Subsonic

11.5" 186"

15 ft 6"

80"

6 ft 8"

220 lb N2000W

6 x
K250W

Blacksky AltAcc2 Drogue/Main 9300 ft 700 ft/s 26 sec
Blacksky Timer2 28 sec Actual
Olsen FCP-M2 2000 ft 9000 ft 700 ft/s   25 sec
Cluster Timer2  
Perfect flight
No damage
 

 

Springfest Launch Report,  March 2001
  

Introduction

We arrived at El Dorado dry lake bed Friday afternoon with the winds gusting 5 to 10 mph.  The winds  started to die down around 3:00pm, but none of the big rails had shown up yet, so we decided to prep Xavier (our glassed PML Sudden Rush) and throw it up on a K250W.  The launch advertised windows to 15,000 ft, and this flight sim'ed to 14,200ft., so we should be in good shape.   We got Xavier ready to fly at 4:05pm, 5 minutes after the waiver had expired for the day.  If the flight wouldn't have exceeded the standing 7,500ft waiver, maybe we could have flown.  But when you need to call in for the big window, no can do after the waiver has ended.  Well, there was always tomorrow.

  

Athos, 2nd Flight

  Athos_2nd_Flight_Business_End.JPG (401775 bytes) Athos_2nd_Flight_Iwo_Jima_Move.JPG (535303 bytes)
The business end of Athos loaded with
a central M1315W and six J570Ws

E, D, D's son Evan, & fellow ROC'ers
 Brent and Jeff, load Athos on the rail

The winds at El Dorado dry lakebed were pretty steady through the day Saturday, again blowing at 5 to 10 mph in gusts, just enough to make you think twice about flying.  And just as they had on Friday, they started to die down around 3:00pm, so we decided to brave flying Athos.  We loaded up Athos with a central M1315W and 6 outboard J570Ws.  The plan was to airstart the J570Ws in pairs at 8, 11, and 14 seconds, pushing Athos to around 9500 ft.   Athos took off perfectly on the M1315W and climbed straight into the sky.  At 8 or 9 seconds, as planned, the first pair of J570Ws came to life, in sync, and kept her moving.  At 11 seconds, nothing.  At 14 seconds, nothing.  And not much later Athos arced over and the drogue popped at a Blacksky reported 3400 ft.  Down Athos came.  No main.  No main.  No main.  Finally at 600 ft. the Blacksky AltAcc2A popped the main.  We had dropped the use of a pilot chute on the deployment bag for the three 14 ft chutes after our tangle on Porthos at ROCStock, and unfortunately, from 600 ft. the chutes had no chance to open.  Athos hit hard with all three 14 footers still in the deployment bag, ouch!  Fortunately, Athos landed in the very same mud that our trailer had gotten stuck in the night before and suffered almost no damage.  The on board video camera, on the other hand, didn't do as well.  It may be a total loss.  Unfortunately we had to nearly disassemble the entire camcorder to retrieve the tape, but it was worth it.  Once again the on-board footage was spectacular.  You can view it in our Movie Theater.

  
Athos_2nd_Flight_Lift_Off_4.JPG (277007 bytes) Athos_2nd_Flight_Recovery.jpg (674085 bytes)
Athos climbs into the sky on
it's central M1315W 
A sad Athos sits in the mud,
chutes still in the deployment bag

Athos, 2nd Flight Post Mortem

We learn something every time we airstart.  It turns out that a Blacksky Timer2 fires each channel at it's designated time for one second.  If the charge opens, all is fine and the unit keeps on timing.  In our case the igniter wires didn't completely burn away and were left shorted dangling behind the rocket.  Well, if you short the Blacksky timer while it's firing, it brings the 9V battery down low enough to reset the unit, and voila, no second channel event.  Lesson learned: with the Blacksky timers don't try 2 airstarts on the same timer.  There is some probability the second won't occur if the first shorts.  We also appear to have lost the third pair of outboards to a charred igniter wire that left it open, even with the wires wrapped in Teflon tape.  This brings up another good lesson reinforced: wire those outboard igniters in series.  If one fails, the whole cluster doesn't start.  You wouldn't want one or two motors out of an airstarted 2 or 3 motor cluster not to light.  Can you say "left to Albuquerque"?  It also turns out on the flight, the Olsen FCP-M2 failed completely.  It didn't record a thing.  It looks like the battery popped out at take off (why do they have the battery pointing up in the unit anyway?)  We had the right beeping noises on the pad, but no data afterward.  The unit still said it was in "Record On" mode and the main charge never blew, it was still intact on the ground.  We needed the Olsen to fire the main at 1200 feet for the chutes to have time to open.  Lessons learned: tie wrap the Olsen battery in and a stock Blacksky AltAcc2A can't work as a back-up, 600 ft is just too low to pop the main on this kind of project.  We need to get the main out at 1500 feet or above, with the back-up kicking in well before 1000 feet.   We've since talked to Scott at Blacksky and he's getting us a couple of custom AltAcc2As that pop the main at 1500 ft.  Now we can set the Olsen to either 1800 ft. to pop high with Blacksky as a back-up at 1500 ft., or we can set the Olsen to 1200 ft. as a back-up to the Blacksky at 1500 ft.

  

Xavier, 3rd Flight

  Xavier_3rd_Flight_at_the_pad_2.JPG (469140 bytes) Xavier_3rd_Flight_Lift_Off.JPG (314637 bytes)
E & daughter Jessica place
 Xavier on the rail with D's 
brother, Kris, & son Evan's help.

Xavier takes off on a K250W, 
flying to an estimated 14,000 ft.

After recovering from the emotional distress of crashing Athos and losing one of our camcorders, we decided to fly Xavier. It was still prepped from the day before, so we hustled out to the rail right around 4:00pm, less than an hour before the range was to close.  We held our breath as the waiver was called in, but not to fear, it was a go.  Wow, the K250W burned for an entire 10 seconds, and Xavier was gone.  We never saw an apogee event, or the main, but thankfully, we had installed the Walston retrieval transmitter.  We whipped out the tracker and started looking.  And sure enough, we found Xavier about half a mile away toward the highway.  Unfortunately the Missile Works Co-Pilot had switched off somewhere on the descent.  Not only did the main not deploy, we didn't even get an altitude reading!  It turns out that on the ride down from 14,000ft on the 18" drogue, the two halves on the rocket collided in such a way as to hit the external on/off switch for the Co-Pilot, breaking the switch, and turning the altimeter off.  Lesson learned: tape those external on/off switches ON!  Or perhaps more important: don't use external switches.  And oh yes, use recording altimeters so no matter what happens, you can get your data.  And one more thing, the rocket suffered no damage.  With enough glass a 7 lb rocket CAN come down on an 18" drogue.

  
Porthos_2nd_Flight_Business_End_2.JPG (343452 bytes) Porthos_2nd_Flight_Iwo_Jima_Move.JPG (680469 bytes)
The business end of Porthos loaded with
a central N2000W and six K250Ws 
D, E, and fellow ROC'ers Ron, Dave,
Carl, and Kurt lift Porthos into position.

Porthos, 2nd Flight

After two crashes on Saturday, we retired to the Hacienda to perform our post mortems and plan for the following day.  We decided to fly Porthos on the N2000W because we couldn't do that in California.  Additionally, we decided that instead of airstarts (which we still needed to work on), we would bang everything on the ground.  This would give us the best altitude, and besides, we weren't all that crazy about trying to take a 220lb (at lift off) rocket off the pad on just an N2000W.  So we spent hours that evening and the next morning readying Porthos, and by 11:00am Sunday, under beautiful blue, windless, and cloudless skies, she was ready to launch from Ron's McGough's rail (thanks again, Ron, for bringing it, and for getting the new one ready for Athos, too)   Just before 11:30am, Porthos took off on all 7 motors: An N2000W and six K250Ws.  All the motors lit at the same time producing the equivalent of an O3500 with 30,000NS total impulse!  You should have heard the noise.  It was your usual big motor noise, plus a low frequency thrumming from having all seven motors going at the same time.  And those motors must have caused some serious vibrations: all six 54mm outboard motor retainers vibrated off.  They were there at take-off, but gone when Porthos was recovered.  Next time a little Locktite should take care of that.

  

Porthos, 2nd Flight Recovery

  Porthos_2nd_Flight_Lift_Off.JPG (263785 bytes) Porthos_2nd_Flight_7_Motors_Blazing.JPG (23257 bytes) Porthos_2nd_Flight_Recovery.JPG (184108 bytes)
Porthos lifts off on all 7 motors:
an N2000W and six K250Ws.

All 7 motors push
Porthos into the sky

Porthos floats back to earth
under three 18 ft. chutes.

At an Blacksky reported altitude of around 9000ft (a 220lb rocket going to 9000ft!), the 12ft drogue popped.  And right on schedule, at 2000ft, the main popped pushing out the three 18ft recovery chutes.  We went back to using a pilot chute to get the mains out of the bag, and it worked.  We also add a 20ft. section to the recovery harness to get the nosecone away from the chutes to avoid the tangle we had last time.  This also worked.  Two of the 18ft chutes started out wrapped around each other, but after a few seconds they cleared themselves and we had a glorious landing under three 18ft chutes.  The only bad news is the on board video didn't record.  The same issue we had on the maiden flight of Athos occurred again.  E swears he started the camcorder,  but nothing recorded (D highly suspects pilot error :-)  The main body tube also happened to fall over on the camera side, and this camcorder got pretty banged up, but hopefully not a total loss.

  

Conclusion

All in all, a couple of good flights.  And a great flight.  Lots of learning.  And lots of fun.  We headed for home to start preparing for the April launch and the first flights of the X-Rockets.  And beyond that, the first flight of Athos II at Delamar in May.  We had lots to do.

 

 

 

 
 

Gates Brothers Rocketry   © 2001-2007 D & E Gates        

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