Space! You can reach it!
Two Seattle girls, aged 10 and 8, decided it would be fun to plan the construction and launch of a weather balloon into space. They achieved their goal, took a video of the whole process and launch, and have even impressed NASA.
Designed to Rise:
They learned how to create a design for their spacecraft from the web and created a design using materials bought and some from home. Trial and error changed the design from using PVC pipes to old arrow shafts to keep it light weight. Overall, the design of the craft resembled a triangle, or pyramid. They planned for the craft’s landing and even added styrofoam balls in the event of a water landing. The standard weather balloon they used for the ascent was filled with Helium, and the whole spacecraft was strategically launched from a specific point where they would be most likely to recover the craft upon its return to earth’s surface.
Pop Goes the Weather Balloon:
As the weather balloon traveled further from the Earth’s surface, the air pressure around the balloon decreased drastically. As the air got thinner, the balloon’s casing got tighter. This is due to the gas expanding within the balloon. The expanding gas caused the balloon to reach full capacity and it popped. This is how weather balloons work, and these girls planned for its popping to initiate the spacecraft’s return to earth.
The girls collected data during the launch. The Balloon ascended at a very constant rate – an average speed of 35 kilometers/hour. There was a peak speed recorded, of 110 kilometers/hour as the craft left whats called the Tropopause, right before entering the Stratosphere. They noticed a temperature drop as it got higher up, but then it changed at got higher as the craft left the Troposphere and got into the Stratosphere.
The Earth’s Atmospheric Layers:
The atmosphere is divided into five layers. It is thickest near the surface and thins out with height until it eventually merges with space. The troposphere is the first layer above the surface and contains half of the Earth’s atmosphere. Weather occurs in this layer. Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs harmful rays from the Sun. Meteors or rock fragments burn up in the mesosphere. The thermosphere is a layer with auroras. It is also where the space shuttle orbits. The atmosphere merges into space in the extremely thin exosphere. This is the upper limit of our atmosphere.
The girls’ spacecraft’s weather balloon popped at 78,000 feet, or about 15 miles into the atmosphere, which puts into the Stratosphere.
This picture above is the girl’s notes following their successful mission – inspiring! – from GeekWire
The Higher Up, the Lower the Pressure:
Atmospheric pressure is the pressure exerted by the weight of air in the atmosphere of Earth. In most circumstances atmospheric pressure is measured by the hydrostatic pressure caused by the weight of air above the measurement point. On a given plane, low-pressure areas have less atmospheric mass above their location, whereas high-pressure areas have more atmospheric mass above their location. Likewise, as elevation increases, there is less overlying atmospheric mass, so that atmospheric pressure decreases with increasing elevation.
These girls took all of these factors into consideration when planning their weather balloon spacecraft. It’s amazing what careful planning, passion, and ingenuity can do, even at a young age.
The girls – Rebecca and Kimberly Yeung – photo by GeekWire