Tandems

The new airships have been rolled out and are up on the website.

www.jpaerospace.com

JP

Video of the launch of the little (14 foot) MicroTandem is up.

www.jpaerospace.com

It's at the log section.

JP

nice! it looked from the video as if one baloon had more initial lift or something, like the vehicle flew tilted with one side higher than the other. was this the case? and how can you control something like that?

Great Work!
Good to see another great video again also!

Rob G

We're still looking at why it was angled in the first few thousand feet.
We meter the gas so there is the same amount in each balloon. We also check the balance of the vehicle about an hour before liftoff.

There are two leading candidates:

1. Uneven launch. We did some low altitude flight with a 18 foot test truss.
When we launched intentionally at an angle it would take a while for the vehicle to level out.

2. Different shaped balloons. We have found on the smaller balloon the inflated shape is not consistent. You can see in the video that the balloons look very different even though they have the same amount of helium. That has a big effect on the vertical airflow around the balloon during climb.

MicroTandem did level out after after about 3,000 feet above the ground. This implies number 1 however, I'm not sure that's the whole story.

The full size Tandem has a pumping system that can transfer gas between the balloons. This way we can correct any pitch problem in flight.
The pump will be on the second full Tandem flight. It's a little too much to have on the first flight so we'll need to very precise about weights and fill.

JP
www.jpaerospace.com

Talking about the shapes of the balloons, do you worry that environmental factors will hinder progress?

If small balloons are changing shapes and sizes on fairly good days at low altitudes there must be a huge worry about what will happen higher up and with more balloons. It must be hare to get coherent data if each balloon is performing differently?

Also how did the documentary go ?