Winter time launch

[Hugues]

Hi everyone. I am curious about winter launches. Here in Quebec, Canada we have a lot of frozen lakes offering great recovery space but the temperature could also drop to -15 celcius (5 fahrenheit).

Other than cold fingers and possible electronic/battery issues, what are in your opinion the biggest challenges for those launches ?

Also, I am no engineer, but will there be significant results discrepancy in term of flight speed and altitude ( better or worst ). The air must be different. How does it affect aerodynamics ?

Let us know your toughts on this.

Thank you

 

[Bat-mite]

Definitely battery health, as you mention. Keep them warm in a vehicle right up till launch. Hopefully the LCO doesn't leave things sitting on the pads for long.

I had a rocket with redundant DD and motor back-up fail to deploy a drogue in very cold weather. Both alts were smashed, so I still don't know what caused it. Three charges armed, and no deployment. Lawn dart and carnage.

If you have mixed materials, like FG tubes and wood rings/plates, you might get different amounts of contraction, resulting in stuck couplers, etc. That may be what happened to me.

Aside from that, I don't think there is any impact in altitude or speed, as you asked.

 

[dhbarr]

Air's drier and thicker. Condensation can be an issue.

Some folks ( I've heard ) keep their motors and/or batteries in a baggie inside their coat.

 

[dr wogz]

Salut Hugues.

je pence on a parlez du club CRMRC!

• We fly in the winter. Apart form what's mentioned above, plastic 'Estes' type chutes can freeze 'closed' meaning they don't deploy as expected. (They stay rolled up)
• The ground is usually harder, as it's frozen, so you run a better chance of breaking a fin on landing.
• Snow is soft, and some snow that enters the rocket may melt on the warmer surfaces and may delaminate the paper tubes. Haven't had it happen yet, but I have gotten 'wet spots' on the inside of a few rockets.
• Flying off a lake is easy & fun, but can be windier that expected. I have thought of flying off lac St. Louis a few times! or the seaway. But you don't know about the ice, unless it's the middle of February. The ice may be thin, too thin to walk on. And, the chute can catch the wind and make the walk longer!! (dragging it across open ice..)
• PML 'Quantum tube' rockets are prone to shatter on landing.. and the piston can get very stuck inside.
• bring a shovel. not for recovery, but to dig out the car!

 

[Hugues]

Salut Hugues.

je pence on a parlez du club CRMRC!

• We fly in the winter. Apart form what's mentioned above, plastic 'Estes' type chutes can freeze 'closed' meaning they don't deploy as expected. (They stay rolled up)
• The ground is usually harder, as it's frozen, so you run a better chance of breaking a fin on landing.
• Snow is soft, and some snow that enters the rocket may melt on the warmer surfaces and may delaminate the paper tubes. Haven't had it happen yet, but I have gotten 'wet spots' on the inside of a few rockets.
• Flying off a lake is easy & fun, but can be windier that expected. I have thought of flying off lac St. Louis a few times! or the seaway. But you don't know about the ice, unless it's the middle of February. The ice may be thin, too thin to walk on. And, the chute can catch the wind and make the walk longer!! (dragging it across open ice..)
• PML 'Quantum tube' rockets are prone to shatter on landing.. and the piston can get very stuck inside.
• bring a shovel. not for recovery, but to dig out the car!

Thank you for your comments and tips dr wogz. It's good stuff. I looking forward to go fly with you guys at CRMRC if the weather collaborate.

 

[Jonathan 7]

Plastic parachutes don’t open! Bricks!

 

[stealth6]

I've flown a bunch in winter....totally a doable thing.

Cardboard airframes are generally not good....they get a bit wet sometimes on landing, which causes damage. Fibreglass airframes are definitely the way to go.
If snow is deep, it's possible for a landed rocket to get a bit lost, but generally even if a rocket "goes under" the chute rarely does so this is not a big issue.

s6

 

[Buckeye]

Also, I am no engineer, but will there be significant results discrepancy in term of flight speed and altitude ( better or worst ). The air must be different. How does it affect aerodynamics ?

Temperature has an effect on altitude. Low temps = higher air density = more drag = less altitude. Nothing to worry about for sport flying, though.

Not sure what temp does to motor burn. As always, motor performance is the biggest variation.

However, temps much lower than 15C will cause a barometric altimeter to over-predict altitude. This is a good thing if you are in a competition!

Bottom line, don't let the weather deter you. The best time to fly is when you have the time to do so! Here is in Midwest USA, most flying is done in cold months when fields have no crops.

 

[ANair]

Air's drier and thicker. Condensation can be an issue.

Some folks ( I've heard ) keep their motors and/or batteries in a baggie inside their coat.

I didn't know about this hack! Thanks for sharing this man!

 

[Ryan Gillette]

I fly mostly in the winter just like Buckeye mentioned when the crops are out. Hard, frozen ground and cold epoxy can be hard on fin fillets is the only real issues I have noticed. I have up sized my parachutes and been using the Chute Release to keep the drift to a minimum. We normally don't fly due to comfort when its below zero deg F.

 

[djs]

Not the answer you were seeking, but more important. Take care of yourself first. Rockets are fun to fly in the winter, but it's easy to get hypothermia or worn out. Trudging through the snow to find a rocket is hard, and you don't realize until it's too late what you're doing. Dress in layers, wear waterproof stuff, and don't go somewhere where people can't see you or don't know where you are. Realize when it's time to stop. Drink enough water, because even though you're not sweating, you dry out much faster in the cold.

This is a picture of me wiring up a cluster rocket when it was -16F windchill out. I had to take off my gloves to get the motors wired up. What you don't see in this picture is that I lost feeling in the tip of one of my fingers after this launch for two weeks. Minor injury, but reminded me that I'm not indestructible. And FWIW, only one motor lit. Rocket flew ok and was recovered, but probably not worth it in the end.

 

[tightwad]

Your lucky that you didn't freeze your coccyx off!

 

[djs]

Trust me- my rear was not happy about the whole arrangement.

 

[dr wogz]

I bring a foam floor mat pad for when I need to sit (or lay) in snow..

 

[smugglervt]

I bring dr wogz if I need to sit or lay in snow. [emoji16]

 

[58pan]

Just got this email.

Michiana Rocketry Members and Friends

Just a reminder that we will be having our scheduled February 9th launch this coming Saturday at our field in Three Oaks, MI.

STATUS IS CURRENTLY A GO
Go to https://www.michianarocketry.org/ for the latest launch update and map to field

 

[Glasspack]

I can second the concerns Dj had. My launch in South Dakota in November was great, but we had to cut it short due to rain and sleet/snow.
Be prepaed tp clean up quick. You dont want to damage any models or equipment due to moisture. And please make sure you are safe on that frozen lake.
It would really suck to go through ice! On the plus side ....
the fire danger is drastically reduced, especially here in South Dakota