What Flew

[Rocketjunkie]

Attached is a Raven file for a recent flight. Can you guess what it flew on? Motor(s) are certified. The flight was nominal and nearly straight up.

View attachment Rocket01.FIPa

 

[JDcluster]

I'll put my money on Warp Nine motor of some sort...



JD

 

[cjl]

I'm going to go with a 38mm warp 9 - H699, H999, or I1299 specifically. An F240 is also a possibility, but that would have to be a fairly light rocket.

 

[G2Rockets]

I am going to guess a cesaroni G80 sk.

 

[Rocketjunkie]

First hint :smile:

Look at the accelerometer velocity curve and the acceleration at the same time. Remarkably accurate. Also look closely at the liftoff burn time:wink:

No fair if you saw the flight :wink:

 

[rocketkyle]

Looks like there were airstarts or a second stage. No idea on the motors.

 

[mannyskid]

I'm going to guess a CTI K2045 in a short fat rocket, possibly a polecat thumper?

Manny

 

[Rocketjunkie]

I'm going to guess a CTI K2045 in a short fat rocket, possibly a polecat thumper?

The K2045 burns too long. Look at the burn time. There is only one certified motor with this burn time. :smile:

 

[cjl]

The K2045 burns too long. Look at the burn time. There is only one certified motor with this burn time. :smile:

The burn time is 0.3 seconds, which is a pretty close match for the F240, as well as any of the aerotech 38mm warp 9 motors. Thus, there are several motors with that burn time.

(You're right about the 2045 though. It's a fun motor, but it burns substantially longer than this)

 

[Sandy H.]

I'm going for an H669 first stage going to a G79 (Cessaroni Smokey Sam - not AT).

Sandy.

Edit: This thing lost velocity really fast between burnout of motor 1 and ignition of motor 2 and my estimate doesn't. Tons of drag on the first stage?

 

[Rocketjunkie]

Hint #2:

The rocket is 2.6" diameter and weighed 39 oz on the pad.

 

[Adrian A]

At that mass, the average thrust was around 600 Newtons, so I'd guess the first motor was an Aerotech 669. There was an airstart with a really wimpy motor, probably black powder based on the shape of the thrust curve, but the Raven didn't light it.

 

[Rocketjunkie]

At that mass, the average thrust was around 600 Newtons, so I'd guess the first motor was an Aerotech 669. There was an airstart with a really wimpy motor, probably black powder based on the shape of the thrust curve, but the Raven didn't light it.

Close, but not quite.

The rocket is a LOC Viper 4.

 

[Adrian A]

Ah. With a 4-motor cluster, I'll go with 2 F240s to start, followed by 2 D12s as an airstart.

 

[Rocketjunkie]

Ah. With a 4-motor cluster, I'll go with 2 F240s to start, followed by 2 D12s as an airstart.

You got it! The D12's were started with Thermalite. I was amazed at how well the D12 burn showed on the accelerometer data.