It was a nice weekend to fly rockets!  We had warm temperatures, light winds and blue skies all three days.  I arrived on Friday about midday and began setting up camp.  By 6:00pm I had Scorpion on the pad and ready to fly.  It was launched on an Aerotech L850 and reached 10,328 feet. Scorpion deploys the main chute at apogee so it landed 1.4 miles away in the light wind.  Right after touch down, a whole crew of us set out to recover it.  Scott Morrison drove his suburban and took me along with his son Pat, daughter Sarah, Jane Fossen and Chris Beekman right to it. The rocket was only 200 feet from the small two-track dirt road we were on.  There was no damage so we declared victory and headed back to camp.  It was a very good start to the weekend and now it was time for dinner!   Photos and a short launch video of this flight can be found further down this page.  This was the 32nd flight of Scorpion.

On Saturday I launched Angelfire on an Aerotech M1419.  The liftoff was an awesome boost.  It was relatively slow and looked very straight.  This was the first flight of Angelfire after the repairs to the damage suffered on flight #9 last October.  It proved the repaired fin was just fine.  There was not even any roll that could be observed as it climbed into the sky.  Angelfire reached 10,740 feet and deployed a small drogue chute.  My GPS radio downlink electronics were on-board for this flight.  I was able to see the actual altitudes in real time as it came down.   At 1000 feet to go it deployed the main chute and then softly touched down 0.97 miles away. Once again Scott Morrison was kind enough to drive me and Jane out to recover it.  It was 0.21 miles from the dirt road so Scott also helped me carry it back to his vehicle.  Photos and a nice launch video are presented below.  The 3-D flight trajectory captured by the GPS system is also presented below.  You can even view it using Google Earth to look at it from any angle.

On Sunday, I prepped Vulcan to fly on an Aerotech M1315.  It weighed 36.1 pounds ready to fly. Once again there was a breeze coming in from the west. Vulcan left the 12 foot launch rail at a slight angle heading to the west.  It then proceeded to weathercock a bit more as it was heading up-wind. This arc continued throughout the long coast time after motor burnout as Vulcan was making a long gradual gravity turn.  As Vulcan reached apogee it was still traveling pretty fast.  The main chute was deployed right when it should be but the airspeed was too much for it.  The chute snapped open and was instantly shredded.  Vulcan had reached 11,017 feet.  It's highest flight ever, but it was doomed at that point and fell to its destruction during the two minute ride back to the ground.  It landed about one mile due south of the launch site.   Photos can be seen below.  This was the 26th (and last) flight of Vulcan.

Photo by Vern Knowles

This is the view while standing at the high power pads and looking back toward the flight line.  It was taken on Saturday afternoon.

Click here to see a large high resolution panorama.    (1.8 MB file.)

Click here to see a smaller low resolution panorama.  (279 KB file.)

Photos from previous flights of Scorpion can be found here.

This short video clip showing the launch of Scorpion on the L850 motor.  It was captured by Pat Morrison. 

View MPEG2 version   (4.4 MB)

View QuickTime version of the video    (4.4 MB)

View Windows Media Player version   (3.7 MB)

Angelfire was launched at about 10:00 am Saturday morning on an Aerotech M1419.  The boost was a spectacular display of power as Angelfire slowly climbed into the clear blue sky. That sight never gets old!  Angelfire reached apogee at 10,740 feet and then deployed a small drogue chute.  It dropped back down for 1.5 minutes and then with 1000 feet to go it deployed the big main chute. It drifted off to the northeast and eventually touched down 0.97 miles away. This was the tenth flight of Angelfire. 

View photos of previous Angelfire flights.

View Angelfire construction details.

This is short one minute video of the setup and launch of Angelfire on an M1419 motor.

View MPEG2 version   (9.6 MB)

View QuickTime version of the video    (9.5 MB)

View Windows Media Player version   (12 MB)

Angelfire carried a GPS receiver and a radio transmitter in the nosecone.  The transmitter sent  the GPS coordinates as well as speed and altitude data to a receiver on the ground.  This data was then recorded in a small hand held computer for later analysis.   Click here to see more details about this system.  After the flight, this data was combined with the data from the onboard ARTS recording altimeter. This allowed the GPS trajectory to be color coded for each phase of the flight by using timing information from the altimeter.  The section for motor burn is shown in red.  The coast phase is in blue.  The drogue chute was deployed at the point where the blue turns to yellow.  The yellow trace shows the path Angelfire fell while on drogue.  The green trace is the path while on main chute.  Four images of this trajectory were generated by Google Earth and are shown below.

The vertical scales in these images have tic marks every 1000 feet.  They help show the 10,328 foot apogee reported by the GPS system.  The scale also drops straight down to the ground from apogee so it shows the point on the ground where apogee occurred.

Angelfire

Flight Trajectory

Looking West

Motor Burn

Coast Phase

Drogue chute deployed

Angelfire

Flight Trajectory

Looking North

Motor Burn

Coast Phase

Drogue chute deployed

Angelfire

Flight Trajectory

Looking East

Motor Burn

Coast Phase

Drogue chute deployed

Angelfire

Flight Trajectory

Looking South

Motor Burn

Coast Phase

Drogue chute deployed

You can view this trajectory in simulated 3D by downloading the data file at the link below and loading it into Google Earth.  You can then use all the standard pan, tilt and zoom controls in Google Earth to see it from any angle.  (Google Earth is a FREE program available here.) 

If you already have Google Earth installed, then you should be able to simply click on this link and it will "fly you" to the Brothers launch site and display the Angelfire trajectory.  If that doesn't work, then right click on the link, save the file to a convenient place and then open the file from within Google Earth.

The charts above show the altitude and velocity data reported by the GPS system.  Each point in the plot represents one GPS reading.  This GPS unit updates at five times per second. (Readings are spaced apart by 200ms.)  The peak altitude was 10,328 feet above the ground.  The peak velocity reported by the GPS was 537 mph. (The peak velocity reported by the ARTS recording altimeter was 515 mph.)   The sink rate on the drogue chute was 66 mph. The sink rate on the main chute was about 13 mph.

Click here to view Angelfire GPS data plots in PDF format

Six pages of analysis of the data from the ARTS recording altimeter are presented below.  You can click on each page individually to see an image of it, or you can get all six pages at once in a higher resolution PDF document.

Click here to view Angelfire Flight Data in PDF format

Angelfire carries enough electronics that it was possible to determine the peak altitude in five different ways. The two MissileWorks altimeters reported the peak altitude to be 10,552 and 10,928 feet.  The ARTS altimeter reported the peak altitude as 11,164 feet based on the accelerometer and 10,215 feet based on the pressure sensor.  And lastly, the GPS reported the peak to be 10,328 feet. The accelerometer reading is the one that differs the most from all the others.  It disagrees by about 9% or so.  The other four readings all agree within -3% to +4%.  The average of all five readings is 10,637 feet.

Maximum acceleration was 5.4 G's.  Peak velocity was 755 ft/sec (515 mph).  Angelfire reached apogee in 27.1 seconds.  After that, it dropped on the drogue chute for 1.56 minutes at -97.0 ft/sec and then fired the main chute ejection charge at 1065 feet.  It dropped on the main chute at -17.6 ft/sec for 41.2 seconds.  Total flight time was 2.75 minutes.

This shows the body tube that got zippered by the recovery harness.  Vulcan was built in a "zipper less" configuration but it still suffered a massive zipper as well as impact damage to the body tube. The onboard cameras and the electronic altimeters survived the flight.  The motor case and plastic nosecone were fine too.  The airframe was a total loss.         

Vulcan was designed to be a single deployment system. It was intended to deploy the main chute at apogee along with the cameras in the payload bay.  To help avoid the kind of failure mode suffered on this flight, it might be a good idea to pack the main chute in a deployment bag that delays the opening of the main chute for at least a short while.  During that time a drogue chute could be used to slow it down a bit.  The drogue could then pull the main chute out of the deployment bag.  This type of system has it's own set of failure modes, so it's not clear if it is a net improvement in overall reliability or not.  However, it probably would have prevented this particular failure mode.