Today I upload some more detailed photos of the DIY egg-shaped balloon. The first test sample was designed as 70% of the intended size. This "baby" balloon is of volume of 11 cub.feet. Its seam was more rough, since I was experimenting and not certain "how to".
The photo below is of the "adult", more advanced version. Its volume is 33 cub.feet. The diameter in cross-section is 1 meter. The seaming technique is a bit more mature. The "appendix" -- also the "repair sleeve" is inaccurately left to fly loose.
Fig. 1 The "simple balloon" test-flying with the dummy payload of 200 g. At night.
As sometimes we fly the balloon system with the low-purity helium, it is helpful to use a tandem configuration "adult + baby", for additional lift. This was an ad_hoc idea, but since then we see it as "a solution", practical enough.
The photo below shows the balloon system flying with the payload, i.e. photocamera. At this configuration the camera is shooting the video at oblique position to the horizon. The frame at the belly of the balloon is almost horizontal (please don't mind the photographs orientation).
You can notice one other feature of "how we do it Ukrainian style" -- the frame at the belly of the balloon. It is made with the finest "end" sections of the fishing rod, these spare parts are available at the local market.
Apologies, the baby one has the rude untrimmed seams!
Fig. 2 The tandem of the balloons with the attached camera (Canon A-490)
The next photos were shot at the sunrise, and one can see the most significant feature of these balloons -- the internal suspension system. It consists of the "curtain" with the parabolically-indented lower edge, and of the lines (strings) which go down to the frame on the belly of the balloon. In the real-sized airhips the internal suspension system may consist of two or more "catenaria curtains", along the back of the envelope.
Fig. 3 Tandem of the balloons at the sunrise, side view.
Fig. 4 Tandem of the balloons at the sunrise, front view.
Several nice photos of the balloon system flying with camera were made from the ground by the team member Mikhail 'Mike' Blinov. Below is one of them.
Fig. 5 Tandem balloon system flying with the photocamera. Eastern Ukraine, July 2013.
This egg-shaped balloon is called here a "simple balloon", as opposite to the "aerostat" shape. The aerostat-shape was tested earlier, from the summer 2012. It was intended to model the shape of the historic airships and aerostats. Such an approach required 4 pairs of differently-shaped gores. It is a task not to misplace one for that! So year 2013 the new approach was intended, with 8 identical gores. It is much simplier for seaming the whole construction.
The "aerostat" shape will be a subject of the separate post -- hopefully, I'll upload it today.
Below is one more photo of the tandem system of "simple balloons". May 1, 2013. We are starting our first balloon-mapping expedition in the Dvorichansky National Park. My plan is to report the results (of that and other field experiments) in one more separate post.
By the way, on the photo below you can see even more features of "balloon mapping Ukrainian style" -- 1) the fishing rod for piloting, and 2) the gas-holding bag for reused helium.
Fig. 6 Off we go to air-photograph the wild nature!
I get more familiar with how the PublicLab' server works, and now larger-sized versions of the photos can be seen, when clicking