One the questions we get pretty frequently is "how do your launches work?". The simple answer to that is we fill large 6ft diameter latex balloons with helium, attach the spar carrying our hardware as well as the shroud that contains the ashes, and then we let go. Of course that is simplifying the process quite a bit but that is the basics.
The first thing we do is fill our balloons. The balloons are made from latex very similar in thickness to latex gloves. For a typical launch about 300 cubic feet of helium is required. The process to fill the balloons with the helium takes about 10-15 minutes. While one of our technicians fills the balloons the others are walking through our launch checklists ensuring the cameras are on, gps is on and receiving signal, cameras are at the right angle, and our hardware that controls the release of the ashes is prepped and ready to go. All of this hardware is housed in or on what we call our spar, which you can see is the black rectangle shape in the picture below. Hanging below the spar is the shroud which a one time use container which houses the ashes that will be scattered. Once the balloon is full we seal it and attach it to our spar. We are now ready for launch!
Once we let go the balloon will climb at a rate of about 1,000-1,200 feet per minute. During the course of the balloons journey upwards it will experience temperatures of -40°F and wind speeds greater than 100mph. The extreme temperatures and winds are typically experienced 30,000-40,000 feet above the ground. At 30,000 feet the balloon is above 70% of the Earth's atmosphere. The balloon will continue to rise experiencing very little wind for another 40,000-60,000 feet where it will reach its peak altitude. During this final ascent the balloon experiences very little wind and where you begin to see the curvature of the Earth. The range for our ash releases is typically 80,000-100,000 feet, this is predetermined before launch and is a function of weather and the quantity of ashes being scattered. At this altitude the ashes are above 99% of the Earth's atmosphere as known as the edge of space.
The balloons we use keep expanding as they climb in altitude. This is due to the pressure difference between the upper atmosphere and the helium inside the balloon. This will eventually cause the balloon to burst. Fortunately it is easily predictable when a balloon will burst and therefore we can ensure we've released the ashes before the balloon burst. In the video below you can see how turbulent the balloon bursts can be and therefore we've moved to a system that allows us to cut away from the balloon so that we start falling more gently.
After cutting away from the balloon the hardware starts to fall from the edge of space. It will fall very quickly until about 30,000 feet where the parachute will finally start to function due to the air finally being dense enough. The hardware will drift down under parachute until it reaches its final landing spot.
During the whole flight we have three redundant GPS systems that are relaying their location. Since we have their current location as well as predicted flight paths we are typically in the "neighborhood" of where the hardware will land. We then recover the hardware and ensure everything worked properly.
Below is a an example using Google Earth of the path one of our balloons would take for a launch in Colorado.