{"id":1468,"date":"2011-05-15T15:16:15","date_gmt":"2011-05-15T13:16:15","guid":{"rendered":"http:\/\/www.verticallimits.nl\/?page_id=1468"},"modified":"2015-02-18T18:10:01","modified_gmt":"2015-02-18T16:10:01","slug":"nero-launch-day-13-05-2011","status":"publish","type":"page","link":"https:\/\/www.verticallimits.nl\/?page_id=1468","title":{"rendered":"NERO Launch Day 13-05-2011"},"content":{"rendered":"

Thursday\u00a012-05-2011<\/strong> –\u00a0What started out to be one of the most relaxed preparations\u00a0turned out to be one of the most demanding last minute propellant casting jobs in years. Because the\u00a0launch campaign in September the year before was cancelled, all grains\u00a0for both the DECA III and the H13A2 were already cast. These were then vacuum sealed\u00a0and stored at room temperature for about 8 months.\u00a0The grains was checked regularly. Therefore the only\u00a0expected\u00a0preparations needed for the DECA III\u00a0were to solder the recovery charges, program the RDAS tiny and pack the parachute afterwhich I would drive to the\u00a0hotel and enjoy a nice cold\u00a0beer in the bar, or so I thought.\u00a0\u00a0At\u00a011:00 I inspected the Thrust grain and\u00a0broke the vacuum seal to\u00a0give the grain a final inspection and not to\u00a0have any unpleasant surprises on the\u00a0launch day itself. It wouldn’t\u00a0be the first time that\u00a0Murphey would pay us a visit. What I\u00a0found out\u00a0was a gummy like grain which was quite tacky indicating that somehow the grain had absorbed a significant amount\u00a0of moisture. It was even possible to peal of \/ delaminate some of the outer layer of the free standing grain. A quick check on the available materials showed that\u00a0a new 1700gr grain could be cast within a couple of hours. A call\u00a0with NERO HQ confirmed that we could not take any risk and a new grain would need to be cast.<\/p>\n

So most of\u00a0the day was spent casting the freestanding grain and prepping\u00a0a new\u00a0booster grain\u00a0with a BP\/Mg charge. The grain turned out to be\u00a0great with a cylindrical length of 217mm and mass of 1707gr which results in a density of 92%. No further machining would be required and the grain could be flown as-is. At around\u00a019:00 the car was\u00a0packed and I drove out to the OTCVust\u00a0shooting range \/ launch site were the motors were prepared. Assembly of the DECA 12 grain motor was straightforward.\u00a0For some reason the forward bulkhead of the Thrust motor\u00a0would not fit through the front end of the motor no matter what was tried (this is a typical example of the “ASK-factor”). It was decided to coat the inside of the casing with some vaseline and push the forward bulklhead into place through the nozzle end.\u00a0This turned out to work\u00a0and after this small delay also the Thrust motor was quickly assembled and placed into the motor shed were several other motors from the NAVRO<\/a> & DARE <\/a>were already stored. At around\u00a021:30 it was time to head to the hotel, get a hot meal and we were able to finalise the work on the DECA III rocket around 1:30.<\/p>\n

Friday 13-05-2011 <\/strong>– Weather was\u00a0comforatble\u00a0with a temperature\u00a0of\u00a020\u00b0C\u00a0and\u00a050% cloudy with clouds\u00a0at 1100 – 1500m. This was the best weather we had seen in years. Wind was 6-7m\/s blowing from the West.\u00a0The launch schedule was revised after a\u00a0swift prep of the DECA III.\u00a01) the DECA III at 11:00, 2)\u00a0French Quark-Meson from GEA<\/a> at 12:00 and 3) the H13a2 at 13:13 on Friday the 13th. JV also visited the launch day to test his liquid\/liquid rocket motor. Quite a crowd had gathered at the NAVRO \/ DARE as tbe combined launch\u00a0had a total of\u00a08 rockets to launch. Furthermore there was\u00a0some national media coverage regarding their Stratos II project<\/a> which\u00a0will sure benefit the exposure of the amateur experimentel rocketry community in the Netherlands. The joint launch day was a succes and organisation + communication\u00a0between both parties works better each year. Maybe next year we can stay in the same hotel again and share ideas? Once again the launch rail was\u00a0again easily erreted and\u00a0set at 20\u00b0\u00a0azimuth\u00a0with an elevation of 84\u00b0.<\/p>\nngg_shortcode_0_placeholder\n

DECA III <\/strong>– As stated above\u00a0the assembly of the DECA III was quick and easy. It\u00a0comprised of connecting the motor to the recovery section with a small d-shackle,\u00a0power on the GPS tracker, slide the recovery section over the motor coupler and secure it with 2 small 5mm wide aluminium tapes. A test SMS was received to check the function of the GPS tracker and proved to be\u00a0accurate within a 2m range. It was soon inserted into the launch rail, recovery charges armed and the motor igniter was connected by the LCO. A 8 gram ignter (with 5 gram BP\u00a0abd 3gram magnesium) charge was used to ignite the DECA 12 grain KNER motor. After a 10s count down right at 11:00\u00a0the\u00a0 motor igniter popped and after the initial spike the motor slowly came up to pressure with\u00a0the rocket\u00a0leaving the launch rail\u00a0at 20 m\/s and only 4G acceleration. Due to the wind\u00a0it changed\u00a0trajectory\u00a0a mere meter above the rail\u00a0after which\u00a0the motor came up to full pressure with the rocket heading in the wrong East – SouthEast way. This slow start up\u00a0phenomenon is typical for KNER propellant and was also observed during the static test<\/a>\u00a0<\/a><\/span>. However calculations showed that if the start up delay was similar to the static test the rocket would have reached a sufficiently\u00a0high enough speed to stabaly exit the rail.\u00a0The start up delay was slightly longer than anticipated and unfortunately took place above the rail. Observers stated the rocket was not stable and\u00a0cork screwed\u00a0agressively when under power. It was soon lost in the clouds.\u00a0I could not get a position SMS from the GPS tracker\u00a0and concluded that the rocket would have made a ballistic trajectory\u00a0and\u00a0was considered a loss considering the wide spash patern. However Friday the 13th pulled a trick and rather\u00a0having bad luck I had a healthy dose of good luck and the rocket was recovered only 3 hours later from the middle of nowhere. Chances of finding the rocket were\u00a0about one in a milion. It had parachuted as designed and was recovery with minimal damage. The minor damage\u00a0was inflicted to the payload and likely occured when the motor and payload clashed while under main parachute. The RDAS indicated that apogee was reached at 2300m and missed its simulated apogee of 2990m by 700m due to its erratic course change.<\/p>\n

Click here for a video clip of the onboard camera: DECA III – Flight I – Onboard web – 13.05.2011<\/a><\/p>\n

Click here for a video clip of the lift off as seen from launch control: DECA III – Flight I – Ground video web – 13.05.2011<\/a><\/p>\n

Click here for an interesting post flight analysis DECA III by BO – H14C flight analysis presentation (7)<\/a> the reports includes an interesting analysis of the RDAS, IR sensors & onboard camera.<\/p>\nngg_shortcode_1_placeholder\n

Quark-Meson<\/strong> – The French had their own minor assembly problems and it\u00a0took a lot longer than expected to prep their rocket.\u00a0So they postphoned the launch to the next time window. The Quark-Meson\u00a0was a\u00a0beautifully crafted rocket with a rather unique design: the recovery & payload section were mounted on a tower above the motor. This time the\u00a0APCP motor had a revised forward closure. Back in 2004 I had seen the motor\u00a0to\u00a0burn through at the forward closure right after ignition. This time the forward closure held and the rocket had a perfectly straight flight to approximately 1km. The single stage parachute\u00a0deployed on time by means of a pyro bolt actived lateral ejected hatch and landed close to the rail without a scratch. The flight was celebrated with a\u00a0magnum bottle of triple beer which was much appreciated. Hopefully this bright spirit group will be back in September to fly again.<\/p>\nngg_shortcode_2_placeholder\n

H13A\/2 <\/strong>– Because the Quark-Meson was not launched in correct launch window the NERO\u00a0missed it’s oppertunity to launch the H13 at 13:13 on Friday the 13th.\u00a0Nonetheless, assembly was straight forward and again test SMS was received to check the function of the GPS tracker. After a quick countdown the H13\u00a0made a perfect flight. The freshly casted grain worked fine although there was a short start up\u00a0delay. Likely caused due to the a slightly tacky grain which was not de-hydrated over a week. Motor functioned normaly<\/p>\n

Click here for a video clip of the lift off as seen from launch control: H13A2 – Flight 2 – 13.05.2011<\/a><\/p>\nngg_shortcode_3_placeholder\nngg_shortcode_4_placeholder\n","protected":false},"excerpt":{"rendered":"

Thursday\u00a012-05-2011 –\u00a0What started out to be one of the most relaxed preparations\u00a0turned out to be one of the most demanding last minute propellant casting jobs in years. Because the\u00a0launch campaign in September the year before was cancelled, all grains\u00a0for both the DECA III and the H13A2 were already cast. These were then vacuum sealed\u00a0and stored<\/p>\n

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