ASK 't Harde, 2 October, 2009 - Thursday 1 October was the usual preparation day. Three towers were build: NAVRO's 6 meter and 3 meter (HPR) launch towers and NAVRO's motor test stand. While preparation en certification of the rockets and their motors took place several motor tests were done by the NAVRO. These were motor tests CMT0901-CMT0903 (CMT0904 was done Friday). These test motors have our Kalinitrox as propellant and have just a single Bates-grain. The flight motor will have six grains. CMT0901-CMT0903 were all similar in composition, but each had a slightly smaller throat diameter. This could be seen in the results of the tests, as the motor pressure steadily rose.
The next day we woke up with very rainy weather. After preparations were done the last motor test was done. CMT0904 was a rerun of yesterdays CMT0903, thus having the same throat. After a little more than 3 seconds the safety membrane gave way. This means that the pressure in to motor had reached a value of more than 8000 kPa (80 Bar) and to safe the equipment the brass safety membrane breaks, which creates a second, much wider throat that lowers the pressure in the motor. Later is was discovered the throat was not cleaned after the last test and thus probably was clogged up with residue from the third test. More information can be found on the CMT0901-CMT0904 pages.
The first launch of the day was that of Pleun Punt's classic UFO. It's flight was successful and its onboard altimeter registered a maximum altitude of 80.5 meters (265 foot). The red flare of its Ceseroni Pro38 H120 Red Lightning could clearly be seen. Next was the flight of SRP15 "Menhir's". Although successfuly flown last May and thereby having won the 2008-2009 season of DARE's Scrambled Eggs competition, in flight it soon became unstable. It crashed after in erratic flight.
The next pair of rockets were Fred van Arkel's somewhat familiar locking rocket "Geinig Jolig Luchtvaartuig Beta" (Great Jolly Launcher Beta) and senior DARE member Hein Olthof's Aeolus. Before either was launched Aeolus fell partially out the launch tower as one rail guide broke lose. The rocket was quickly made safe, but could not be repaired to be launched this day. It was replaced by Olga Motsyk and Bryan Tong Minh's The Princess. Which was launched after the "Geinig Jolig Luchtvaartuig Beta" had a misfire. The Princess' flight was also very unstable and it too crashed. After an other attempt the AeroTech H128W of the "Geinig Jolig Luchtvaartuig Beta" misfired again and hereby it ended NAVRO and DARE's launches.
One the other side of the field one other launch took place. For a jubilee NERO had made their H12 rocket at the a last minute. The rocket had a great flight and reached some 1200 meters (4000 foot) and successfuly parachuted. Fortunately NERO finally ended their string of failed parachute deployments of recent years.
The bad weather, the day was interrupted several times because of the rain, and the failed launches made for a miserable day. The altitude record on a NLD launch for a successful flight of 80.5 meters will probably stand for some time to come. DARE's SRP-motor of 2009, which was used in all three DARE rockets, proved to be a highly unreliable motor. The problem was most likely bad alignment of the Bates grains in the motor. At the last launch many SRP rockets also were unstable too, but then the strong winds were given blame (which was not the case at this launch). Looking back, most would probably have flown better with another motor.
The combined thrust curves of CMT0901, 02, 03 and 04.
Photos
DARE had used NAVRO smaller tower and returned it at this launch. The question is: Is it a car with launch tower, or launch tower with car?Assembling NAVRO launch tower and motor test stand.The hardest part assembling NAVRO's launch tower is the beam, which takes some people.Hein Olthof's Aeolus is being certified.SRP15 "Menhir", which was granted an extra flight after having won DARE's Scrambled Eggs competition of 2008-2009 last May, is awaiting certification.Fred van Arkel's somewhat familiar locking rocket "Geinig Jolig Luchtvaartuig Beta" (Great Jolly Launcher Beta) is being certified by Mark Uitendaal and Peter Leemker.While The Princess is being certified, it builders Olga Motsyk and Bryan Tong Minh look on. Olga Motsyk and Bryan Tong Minh and their rocket The Princess.Simultaneously with certifying some small scale motor tests were prepared. Peter Heeren and Kees Jan Groenendijk prepare the first test.Peter Heeren connects the igniter of the first test motor.The first test.The audience of the first test.A nice study of how the test motor sits in the test motor stand.The second test.The third test seen from where the rocket are certified.The third test seen from close by.Friday morning the weather changed from okay to quite wet, as can be seen by the water in the motor test stand.The fourth motor test soon after being ignited.The fourth motor test seen from afar.The fourth motor test just after the brass safety membrane gave way, which can be clearly seen by the black smoke.The fourth motor test after almost all propellant is used.The gaping hole where the brass safety membrane used to be.The day was interrupted by periods of rain.Pleun Punt (left) with his classic UFO. The small white box left on the UFO holds a simple altimeter.Pleun Punt's UFO in the launch tower. For propulsion it has a Ceseroni Pro38 H120 Red Lightning.SRP15 "Menhir" is brought to the launch tower.Placing SRP15 "Menhir" in the launch tower.The UFO lifts off.The UFO in flight.The UFO in flight.The UFO's motor is almost used up its propellent, as can be seen by the darkness of the smoke trail.At their top, all UFO's turn and descent top down. This UFO reached an altitude of 80.5 meters (265 foot).The UFO's descent, no parachute needed.SRP15 "Menhir's" launch.Although successfully flown last May, it soon became unstable.SRP 15 "Menhir" performed some nice aerobatics.A very extreme angle: the nose points towards the smoke trail!The rockets are recovered by the safety personal of the shooting range. Pleun Punt's UFO made an original hood ornament.Fred van Arkel's "Geinig Jolig Luchtvaartuig Beta" in the launch tower.Synchronised connecting of igniters by pyrotechnicians Olga Motsyk and Mark Uitendaal.The launch procedure of Hein Olthof's Aeolus was stopped, as one of the rail guides broke. The rocket's break wire is still attached to the tower.Olga Motsyk and Mark Uitendaal then place The Princess in the launch tower.The launch of The Princess.The Princess too became unstable.The Princess behaved more like a prima ballerina.She made a nice pirouette.And then descended horizontally.Fred van Arkel's "Geinig Jolig Luchtvaartuig Beta" has it's igniter replaced as it failed earlier.And it failed again, obviously a rocket with fear of heights.Following NERO launched the H12 rocket.Which flew successfully to 1200 meters.The Princess dancing days are over.The combined thrust curves of CMT0901, 02, 03 and 04.
