Aero-Hi Iris

The Aero-Hi is a cute little flier using 13mm T engines. It is a pseudo-scale sounding rocket design.  This normally uses a tiny 8-inch parachute but was converted to a streamer, which was later converted back into a parachute recovery when I realized it will never go too high to drift away forever. I actually have two of these, one painted green and this one red.

One of the unique features about this design is a conduit attached to the side of the body tube and running along its length. This I believe is to simulate a sounding rocket design with a wiring conduit mounted outside the fuel tank/body of the rocket. It is simulated with a strip of balsa wood, and could serve to strengthen the rocket.

This rocket was later given my Iris modification, which extends the body tube about 5 inches above the streamer/parachute bay, and allows for a payload with an Altimeter One or Two to measure altitudes. It's a shame I "ruined" it by adding the payload, she was a cute little bird. (I can always remove the payload in about 8 seconds though.) I like to send this, or the EAC Viper rocket up first on launch days, it's a good and economical way to get an idea how the winds are blowing without risking a lost rocket.  As a result, this has flown many times.

Iris is named after the Greek god of the rainbow. She is a messenger of the gods, linking the gods with humanity. This rocket has flown as high as 282 feet with the A motor, which is higher than the Cape Hatteras Lighthouse in NC, the tallest lighthouse in the USA.


This rocket holds a special place in my rocket history. It is the first rocket I launched this century after being "Born Again" into the rocketry hobby. That was before I added the Iris payload.

SPECIFICATIONS

Series Number: 7
Number of Stages: 1
Stock Length: 11.6"
Iris Payload Additional Length: 4.25"
Total Length with Iris: 15.85"
Diameter: 0.736"
Fin Span: 2.875"
Stock Empty Weight: 21.4 grams
Iris Payload Weight: 5.8 grams
Total Empty Weight: 27.4 grams
Liftoff Weight Range: 39.7 - 42 grams
Motor Diameter: 18 mm
Motor Length: 45 mm
Motor Retention Method: Clip
Payload Interior Length: 3"
Payload Interior Diameter: 0.71"
Payload Volume: 1.2 cubic inches
Altimeter Capable: Yes
Recovery Method: 10" Plastic Parachute
Alternate Recovery: 48" Plastic Streamer
Typical Descent Speed (Streamer): 16 mph
Recovery Protection Method: Wadding
Shock Cord Mount: Paper
Nosecone Material: Balsa Wood
Number of Fins: 4
Fin Material: Balsa
Launch Lug Size: 1/8"
Unique Features: Balsa Conduit along side of body tube
Paint Used: Pactra Aero Gloss Dope
Kit Brand: Estes
Completion: about 1976

FLIGHT LOGS

(Estimated about 14 flights on this rocket back in the 1970's)

2010, November 13: Tanguy Soccer Field, Light wind

A3-4T:  First flight in 31+ Years!!! Good Flight & Recovery, One shroud line detached from canopy. Altitude was an estimated 265 feet, there was no altimeter onboard.

2011, July 2: Indiantown Gap, Light wind

A3-4T: Perfect flight, first test with added altimeter bay. Apogee measured 274 feet.

2011, August 7: Halifax, Light wind

A3-4T: Perfect flight and recovery.  This first flight of the day was a good test flight to see how the winds were behaving up there.  Altimeter returned 284 feet.

2011, October 2: Penn Manor, Breezy, cold, drizzly

A3-4T: First flight with an Altimeter 2 on board! Breezy winds but didn't seem to affect the liftoff very much. Reached a top speed of 71 mph with a motor burn of 0.8 seconds.  The average acceleration was 3.9 Gs with a peak of 11.6 Gs. It coasted to an apogee of 201 feet in 2.8 seconds, then headed back down for another 1.1 seconds before ejection of the 3' plastic streamer. The ejection was 15 feet below apogee. The model then descended at 15 mph and landed nearby in grass. Total flight time was 12.3 seconds.

Overall a good flight and a nice trial of the Altimeter Two, but too cold that day so I packed up and left with a smile on my face, hoping for many more flights with detailed information to analyze.

2011, October 8: Penn Manor, Calm to light wind

A10-3T: Beautiful day, the kind pilots describe as "severe clear". There were very light winds. Since I usually like the slower flights, this was a change for me launching on an A10 instead of the usual A3 (due to Hobbylinc shipping the wrong motors, they were supposed to be A10-0's for a booster stage.) This motor did shoot up fast, but still attained about the same altitude as the A3 motors. It reached a similar speed of 74 mph, with a 900mSec burn time and a coast to apogee of 3 seconds. Although the average acceleration was only 3.9 Gs, it peaked at 23 Gs!

The ejection was a bit early, at 246 feet, traveling for another 1/2 second before apogee of 260 feet. It then came down fast on the small streamer at 16 mph, landing within 10 feet of the launch pad!  Total flight time was 13.4 seconds. They should all be this good. The only thing unusual is that the wadding was still left in the
tube - probably packed a little tight.

A3-4T: This second flight of the day was a test to compare the A3 with the A10 motor.  Under calm winds, the A3 reached a usual height of 256 feet and a max speed of 76 mph. The motor burned for 0.9 seconds and generated a maximum of 7.5Gs (the average G force was 3.8), and then the Aero-Hi coasted for another 3.5 seconds while turning into the winds aloft. After apogee, while still moving fast, it lost only 2 feet in 1/10 of a second before ejection.

It descended under a streamer at a fast 21 mph, and landed nearby after a total flight time of 12.6 seconds. All was well.  Although the acceleration was much less than the A10 motor, it reached a very similar maximum speed and altitude. The plastic streamer works well with this model, although for some odd reason this same type gave me constant problems with my Astron Sprint. Go figure.



2012, November 23: Penn Manor, moderately strong wind, no gusts

A3-4T:  It was getting very windy, but the Aero-Hi Iris is not bothered too much by wind and doesn’t go too high, so I chose this rocket to end the day of flying.  Again I was going to compare the A3 and A10 motors to measure the difference. For these flights, the streamer was changed out for a 10” parachute. Note that this is the original parachute supplied with the Estes kit, one of the few survivors over the years.

I fired up the A3 first, and it burned for 8/10 seconds, accelerating off the pad at 13.8 Gs and averaging 4 Gs during the boost. It reached a speed of 71 mph, turning just a moderate amount into the wind before coasting for the next 3.1 seconds. At 221 feet it reached its apogee and started back for another 6/10 seconds, falling 7 feet. At 214 feet the parachute ejected after a 3.7 second delay, and the rocket descended at 9 mph, landing in the grass a good 300 feet downwind in 19.7 seconds.  A successful flight, but a long walk with the wind.

A10-3T:  The second flight of this test used the A10, which I expected to fly faster but not quite as high.

The motor lit and she tore off the pad, pegging the G meter at 23 Gs.  The burn averaged 3.3 Gs for the 9/10 second of thrust.

The launch was so straight up that I was a bit surprised in the strong winds.  The rocket reached a max speed of 68 mph, which was slower than the A3 motor.

After 3.1 seconds while at 233 feet the ejection fired just 1/10 second early, slowing the rocket to reach an apogee of 244 feet. Oddly, this was higher than the A3 flight, even though it had less speed and a shorter delay time. It then descended with a good parachute at 7 mph.  Flight time was 23.6 seconds, a duration record for this rocket. 

There was a very long walk to recover the rocket, about 450 feet downwind.  That was a good way to end the day and probably the last flight of the year!
(It wasn't, I later decided to fly the Bullpup, and flew again the following week!)

2012, December 2: Penn Manor, 7 mph wind, no gusts

1/2A3-2T:  I started today with the Aero-Hi.  The wind prediction for stronger winds fortunately did not come to pass, and the sky was mostly clear and in the 50’s (great for December).  I followed thru with my “windy” flight schedule for today anyway, since I didn’t bring my other high-altitude rockets. At the top of the list was the Aero-Hi with the 1/2A motor.

This was my first test flight with the 1/2A motor for any rocket, although I used these motors back in the 1970s.  I had just removed 3.3 grams of nose weight on the Aero-Hi, which was left over from when this model didn’t have the 5.8 grams of additional payload.

The 1/2A engine burned for 4/10 seconds, peaking the acceleration at 10.3 Gs and getting this rocket to a speed of 45 mph. It then coasted for 2.2 seconds to reach an apogee of 96 feet. After turning over and falling 14 feet in the next 9/10 seconds, the parachute deployed only 1/10 second later than spec’d.  From 88 feet the rocket coasted back to earth at 11 mph with a good parachute, landing about 40 feet downwind. This was a very good flight, lasting a mere 8.8 seconds.

***

Here is an interesting coincidence. I was photographing the descent of the Aero-Hi. I didn't notice it at the time, only saw this upon reviewing the images. Here we see a jet flying under the Aero-Hi. My altimeter is out of calibration, I didn't mean 96 feet, I meant 96 miles of altitude.

A10-3T:  I flew this rocket again with a much stronger motor this time, expecting 260 feet or 300 at the most.

Although I’ve seen this rocket launch on the A10 twice before, I was still very surprised at the extreme speed of the launch, with the rocket virtually disappearing from the launch pad. It accelerated at a peak beyond 23 Gs (higher than I can measure), breaking the Aero-Hi record, and averaged 3.7 Gs for the full second of thrust.  That brought the rocket to 77 mph, a record high for this rocket. It then coasted for 2.8 seconds and the ejection charge was 2/10 seconds early, ejecting at 296 feet.

The rocket continued up for another 4/10 seconds to an apogee of 312 feet, also a record high for this rocket with any motor.  With the parachute deployed fully, it drifted down at 6 mph.  Apparently there were much stronger winds a few hundred feet aloft, as this rocket then quickly sailed far downwind perhaps 600 feet or more before being caught by a tree about 16 feet up.  Flight time for this was 37 seconds, the longest flight of the Aero-Hi.

I rescued the model with a long pole, but had to break the shock cord and shred the original 1970’s Estes parachute to get the rocket and payload back. Sad because I think this was the only surviving original parachute that still worked.

















The bitter end...

OK, that was overly dramatic. I have the Aero-Hi back again and it has been repaired and ready to go - hopefully before spring.

2013, January 13: Penn Manor, 5 mph wind, drizzly and damp

1/2A3-2T:  For the first flight of the new year, I wanted to wrap-up flight testing of the Aero-Hi. It was foggy with low visibility, so high flights were not a good idea today.  It also made for lousy photographs, so I didn't bother to photograph the Aero-Hi today.

The rocket lit up and accelerated at 9.5 Gs, averaging 4.5 Gs for the 4/10 second burn. It reached a top speed of 41 mph and coasted for 2.2 seconds to an altitude of 87 feet, turning over and dropping 10 feet in the last ½ second before ejection fired.  The 7/10 second too-long delay of the motor was useful in this flight to allow the rocket to coast for more altitude.

At 77 feet the new parachute opened up and the rocket came down at 10 mph for a good landing. The flight was low so the rocket landed within about 15 feet of the launcher.  Though it was only a 7.8 second flight, it was a perfect first flight of the new year!

1/2A3-2T:  The second flight used the same motor.  This motor seemed to have more energy and accelerated at 13.1 Gs, averaging 5.5 for the 4/10 second burn.  It flew slightly faster, reaching 44 mph and then coasted for another 2.1 seconds.  The ejection delay was only slightly too-long at 2.1 seconds, and ejection occurred while still coasting up at 93 feet, so the rocket stopped its upwards climb 1/10 second later at an apogee of 97 feet - still ten feet higher than the last flight.

The parachute did not deploy, and wadding was stuck in the tube, so the rocket fell at 21 mph and the flight was over in 5.2 seconds. There was no damage to this small, light rocket though, just to my ego.  The good part about this flight was that I literally had to take only one step forward to retrieve the rocket, as it fell right in front of my feet!  That has to be some sort of record!

2014, July 20: Gloucester College, 85 degrees, 8 mph winds

1/2A3-2T:  The Aero-Hi Iris was my first rocket to fly when I was reborn to rockets back in 2010, and now it is the first flight with a new rocket club in south New Jersey almost 4 years later.  Co incidentally it is also the 45^th anniversary of the landing on the moon.

I chose the 1/2A motor and the Aero-Hi because it was windy and I wanted to stay low at first, thinking the winds would subside through the day (they didn’t and got stronger).  This was likely to be the last 1/2A motor for a while since I only bought a 4-pack.  I’m not really into power this low.

The motor burst into life and the small, lightweight rocket shot up with 11.1 Gs, averaging 5 Gs for the 4/10 second burn time.  At burnout it was moving up at 40 mph, then coasted for 2.1 seconds to reach a top apogee of 78 feet.  The fast acceleration prevented this rocket from turning in the wind very much.  It turned over and began to fall for the next 3/10 seconds, dropping 5 feet to 73 feet for ejection of the parachute after an only slightly long delay of 2.4 seconds.

Is that a chunk of burning wadding? I've seen little bits of flame before, but that is huge!

My small homemade 10.5” parachute with a spill hole opened cleanly, allowing the Aero-Hi to settle to the ground at 6 mph.  Flight time was 10.6 seconds.  This was quite a low-power flight, with speed and altitude a record low for 1/2A motors, although accelerations were normal.

Ejection timing was nearly perfect, and the slow descent speed made this a record long flight for 1/2A motors. Granted, not the most impressive rocket or flight to introduce to a new club, but it couldn’t have been a more successful flight.