{"id":1605,"date":"2012-10-21T21:42:28","date_gmt":"2012-10-21T19:42:28","guid":{"rendered":"http:\/\/www.verticallimits.nl\/?page_id=1605"},"modified":"2015-02-18T18:10:01","modified_gmt":"2015-02-18T16:10:01","slug":"nero-launch-day-19-10-2012","status":"publish","type":"page","link":"https:\/\/www.verticallimits.nl\/?page_id=1605","title":{"rendered":"NERO Launch Day 19-10-2012"},"content":{"rendered":"

Thursday 18.09.2012<\/strong> – The day started out with rocket preparations and assembly of the motor. Prior to this, the recovery charges had been prepared and a new 9.6 battery inserted. The old battery dropped its voltage after one year to 8,0V. So although common practice it really\u00a0pays off to replace or recharge the flight control battery before every flight. The parachute was\u00a0folded and the cable tie cutter was\u00a0placed by means of 3x 2,5x100mm cable ties since I ran out of the preferred single 2,5x200mm cable tie. The propellant grain\u00a0for the Thrust motor of the H13cwas checked and looked perfect. An old booster grain was used which I had lying around. Assembly of the DECA IV took placed at the designated area on the military shooting range OTCVust from 17:00 till 19:30. Previous to this we had some troubles of the Beeline GPS tracker not transmitting its position and only working intermittent. This was not until the last moment tracked down to a loose cable connection\u00a0between GPS receiver antenna & the\u00a0BRB unit and was fixed\u00a0by taping the cable\u00a0under slight tension.\u00a0Rocket inspection of the DECA was finished and some comments were made with regards to the intentionally high static margin of 4.83. However the weather forecast predicted light winds from a favourable South-Eastern direction and clear skies. Around 19:30 a we joined the other NERO members at the hotel for a pleasant rocketry-talk infused dinner and we ended up for drinks in the bar till the small hours. Topics passed like static tests of: 45kg ZnS motors, the occasional close call in the \u201970s & \u201980s to remind every body \u201csafety first\u201d and lesson learned the hard way.<\/p>\nngg_shortcode_0_placeholder\n

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Friday 19.10.2012<\/strong> – With the much deserved bacon & eggs breakfast, the aftermath of the beers quickly disappeared and we headed out the the OTCVust shooting range. Since the launch site is only being a mere 8km away from the hotel we arrived there at around 9:30. Final preparations and payload integration of the rockets DECA IV (aka H14d) and the H13c were easily completed.\u00a0\u00a0After receipt of\u00a0the latest meteo forecast, the launch rail was erected and set at 65\u00b0 azimuth and 85\u00b0 elevation. First up would be a 4500Ns static test of a single use Glass Reinforced Polyester PVC KNSB motor from MU of the DARE. Motor was designed to actually test the limits of the motor to increase reliability of subsequent milder versions of the motor. Test set was a simple wooden rig, a person scale, mirror and video camera recording the analog scale output. After the range was cleared and a 10s count down the motor ignited and spectacular CATO-ed spitting out the forward closure and sending the rest of the motor 20m skywards leaving lots of clear white smoke and a damaged test rig.\u00a0This also shows that\u00a0the OTCVust is a perfect place to test such motors.<\/p>\nngg_shortcode_1_placeholder\n

DECA IV \u2013 joining of the recovery & payload section to the motor was done near the launch rail and consisted out of taping two 8mm (tested with 10mm tapes)\u00a0wide aluminium tapes to hold both sections and would sheared upon ignition of the 2gr BP apogee separation charge. The GSM GPS tracker & Beeline GPS tracker had been powered up upon arrival at the OTCVust to locate as many satellites as possible. Once again the rocket was inserted into the lower third of the rail with ease. Payload and the outlooking Turnigy camera were activated and secured with three screws. The down looking key chain camera was subsequently activated. The RDAS Tiny flight control altimeter was powered on and started\u00a0beeping once a second indicating all systems \/ igniters were\u00a0functioning. The motor igniter was inserted but got stuck at \u00be way. This was\u00a0becasue\u00a02 of the 8 bates grains had a reduced core diameter. Likely caused of early core removed while not fully hardened. Keeping in mind that the grains are produced under spring pressure and trapped air is compressed. By not allowing it to fully harden the propellant likely expanded a bit thereby reducing the core diameter. This phenomenon was discovered during coating and concluded not to effect motor performance. However inserting of the motor igniter was not considered.\u00a0Since the motor igniter was designed to direct the hot BP\/MG gasses \/ particles to the forward closure it was decided (what else was to do) to launch any way as the down side would be neglectable.<\/p>\n

Again after the range was cleared and “Bureau Veiligheid” confirmed to proceed\u00a0the 10s count down began at 11:39. After near instant ignition the rocket leaped out of the rail travelling straight up, no weather cocking and soon to be out of sight leaving everybody surprised. The only thing remained was a\u00a0white smoke trail while\u00a0every body wat looking at the sky for a parachute. Meanwhile the BigRedBee tracker kept sending positions. Apogee was expected to be at T+22s. In case of\u00a0a ballistic trajectory it was expected that\u00a0after 44s no packets would be received. However more then a minute into the flight positions were still coming in, indicating successful apogee separation. After two minutes or so the Bigredbee messages stopped coming in. However the GSM GPS tracker was\u00a0also sending every 20s its position which didn’t changed indicating successful soft recovery. Nobody spotted the rocket under parachute nether did the\u00a0three military spotters in the field. With everybody puzzled whether this was a successful flight GPS positions kept coming in. Soon the GPS coordinates were put into Google Maps which resulted in a landing spot 1800m away from the launch rail but perfectly centered in the width of the field. This position was translated to a more workable position for the spotters in the field. The position was near \u201c pink panther\u201d a pink painted target tank and a dummy house right next to the road. Sure enough within 5min I\u00a0got the rocket back in my possession with the military being impressed that\u00a0two modern rocket locating systems gave the rocket positions while nobody saw the rocket actually\u00a0landing. Quick inspection showed rocket had functioned perfectly. The outside mounted camera was still attached and the main parachute had deployed as designed. RDAS Tiny beeped out 8.968ft. Soon the files from the camera\u2019s were downloaded and were played back on my laptop. Below a summary of the flight can be found on Youtube.<\/p>\n