2.6" Competitor 2 Stage - Configuration

[markg]

Here's a copy of my two-stage checklist, recently updated as I replaced the airstart Quantum with a Proton. First two-stage flight with the Proton this weekend at URRF. The Proton has already flown 3 times in single stage mode.

AT THE PAD
Load booster
Load sustainer onto booster (no igniter in motor)
Arm sustainer TRS (Sustainer deployment)
Arm booster Quantum (ABA8B3) (Deployment + Separation)
Insert sustainer igniter into motor
Insert booster igniter
Back off
Check Proton Status (All AQUA)
Arm Sustainer Proton

Changing this after accidently deploying the charges while on the pad while attempting to fly this at NY Power. When following this order, I am arming the booster Quantum, then removing the sustainer to insert igniter. When I pulled the sustainer off the booster it pulled a vacuum on the booster AV bay through the hole in the coupler for the separation charge which fired off the ejection charge. New order :

AT THE PAD
Load booster on PAD
Insert sustainer igniter into motor (pointed away from flight line)
Load sustainer onto booster
Insert booster igniter
Arm sustainer TRS (Sustainer deployment)
Arm booster Quantum (ABA8B3) (Deployment + Separation)
Back off
Check Proton Status (All AQUA)
Arm Sustainer Proton

I abandoned the flight attempt for the weekend as I did not have extra ejection charges with me.

 

[markg]

After a bit of a hiatus, I was finally able to get a couple of two stage flight attempts this past weekend at URRF. First up was a nominal flight #7 for Red Tenacity. I need to figure out why my flights are not lining up with my sims. Booster sims correctly but sustainer is a mystery.

Settings	Actual
Flight #7, H550ST -> H144W	06/10/2023 - URRF
Booster		Apogee	2506 ft
- Aerotech H550 ST (0.6s burn), delay 7 seconds	0.60 secs	Time to Apogee	14.40 s
- Quantum Drogue - nose over (1g) for parachute	10.9 Gs AVG	Max Velocity	290 ft/s
- Quantum Main - timer - 1.0s (0.5g) for separation charge		Max Accel	12.2
- Apogee 669ft (sim)	574 ft	Time to Max Accel	0.05
Sustainer		Flight Time	68.4
- Loki H144W w/pyrodex pellet, 11 second delay	1.45 secs @2.85 seconds
- TRS Main - 700 ft (1g) - primary
- TRS Drogue - Nose-over (1g) - primary
- Proton CH2 Drogue - Nose-over + 1 s (1g) - backup	2445 ft
- Proton CH1 Main - 600ft (1g) - backup	581 ft
- Proton Ch3 - air start, timer burnout+1.0s, min velocity 100ft/s (anytime), alt off, dev 15%, 2 sec pulse	290 ft @ 1.65
- Apogee 3120ft (sim)	2506 ft

 

[kjhambrick]

Beautiful shots and Data markg !

Thanks for posting them !!

-- kjh

 

[waltr]

I need to figure out why my flights are not lining up with my sims. Booster sims correctly but sustainer is a mystery.

What is not matching between sim and flight?

Can you post graphs of the sim and the Proton data?

Great photo of sustainer burning after separation.

 

[markg]

What is not matching between sim and flight?

Can you post graphs of the sim and the Proton data?

Great photo of sustainer burning after separation.

Sustainer sim'd to 3120ft but only flew to 2506ft. My previous flight sims have been very close. Maybe this H144 was a under performer. Flight appeared to be vertical. Velocity slowed normally to apogee, doesn't look like an early separation.

cheers - mark

 

[kjhambrick]

markg --

Interesting stuff ...

I ran your OR sims and I got the same results as you.

I have some Qs but no As.

Q1: is the acceleration derived from the Pressure Altitude ?

Q2: Did the Loki H144 really ignite around t=2.5 instead of t=1.5 ?

Looking at the actual data curves that looks about right.

I changed your ork file for Sustainer ignition at t=2.5 and that only reduced the altitude at apogee to 2973 ft or so ( delta z ~ -150 ft ).

Q3: What were the temperature and pressure at the launch site for this launch and for your previous launches ?

I wonder if adjusting the Pressure Altitude for the Launch Site Temperature would bump the Density Altitude at apogee closer to the sim data ?

-- kjh

P.S. I meant to add that the area under the curve of the acceleration -vs- time of the booster motor is relatively smaller than it is in the sim'd data ...

 

[waltr]

Thanks for posting the plots.
kjh has good observations and questions.

Maybe this H144 was a under performer.

This is certainly possible.

On sim for one of my rockets, the altitude sims high for one motor but low for a different motor compared to altimeter. This has been consistent over multiple flights with each motor.

The other is that the 'Thrust Curve' is from the original 'Certification' and is not accurate with current production.