re- (hot balloon) [Oct. 28]

Since the first trial of the hot balloon experiment was a horrible failure, we were asked to do it again with a different group. This time, we were allowed to bring our own material in order to match different ideas.

        Considering the last failure that the 10 candles could not fly the big garbage bag, we decided to use a relative smaller bag. The bag was relatively thin compared to the garbage bag. The size was one tenth of the big garbage bag, for which we only used two candles instead of 10. Then, we inserted these two candles into the holes that were cut from the straws, and stuck the straws onto the wall of the plastic bag. Therefore, the candles were placed inside the plastic bag.

Depressed, we failed! The hot balloon died right as we lit the candles. The plastic bag was melt because it could not take the heat from the two candles that were put inside the bag. Since the distance between the candles and the top of the bag was very short, it was hotter than the candles that were place underneath the hot balloon.  Plus the smallness and thinness of the bag, the hot balloon failed as soon as the fire touched the candles. The distance where the candles were placed to the top of the bag would be essential to flight. So next time, if we are given another chance (though it is done now), it is necessary try different structure out several times in order to assure the proper distance between the candles and the bag.

 

Star Gazing [Sept. 27]

 

 

This is the photo taken through the telescope. Even though that night was very cold, but the moon fascinates us. This was the first time I have seen the moon like this, very big and clear. We could even see the craters on the moon surface as well as the shadow.

             When enjoying the moon, here is some basic information about the moon. The moon is the only natural satellite of the Earth, and the fifth largest satellite in the Solar System. It is the largest natural satellite of a planet in the Solar System relative to the size of its primary having 27% the diameter and 60% the density of Earth, resulting in 1/81 in mass. The moon is in synchronous rotation with Earth, always showing the same face with its near side marked by dark volcanic maria that will between the bring ancient crustal highland and craters.

The day we saw the moon was a full moon day, meaning that the near side of the moon directly faced Earth, and this was the most beautiful scene.

re-(Egg Lander) [Sept.27]

the part of our egg lander

     Beginning:
      Given the second chances to fix the egg landers seems to build our confidence; however, it did not seem to work very well; at least, it was far from our imagination.

     We focused on using accordions to secure the egg. The spring-like accordion may reduce the pressure when dropped. In short, the accordions were supposed to absorb the big impact due to the gravity.

     It took us, Joyce, Xuelin, and me, a long time to come up with an idea, how to use the accordions effectively. Later, we bent a straw three times to make an accordion, and three accordions formed a triangle spring. This triangle spring was one part (or the top part) of our egg lander (as shown in the picture). After we finished the second half of the structure which was the base, we squeeze the top and the base in order to secure the egg, using tape to tight them. We also protected the sides with six accordions.

Results and reasons:

We failed, meaning our egg died as soon as it touched the floor. Just to comfort ourselves, it was just a little hole. Anyway, our egg lander did not work. It did not fall as we expected, we thought it might fall just onto the accordions. The other main reason that we failed was because that we did not put enough protection around the side of the structure. After finishing the main top and base accordions, we were lack of straws to make an enough strong side protection. Therefore, our egg directly hit the harsh floor.

We failed :(

Further improvements:

Though we are given a second-second chance, there are still some mistakes to fix in future. The biggest one would be that we were lack of side protection. Due to the short of the straw, we were not able to make enough accordions. Our egg hit the ground directly because of no accordion protection. We cannot deny that accordion is an good idea!!!!      

Candle Balloon [Sept. 29]

Proposal:

We were asked to make a candle hot balloon based on the structure of our previous egg lander, meaning we had to make this hot air balloon without deconstructing the egg lander. However, we did. Our design was to simply fit the 10 candles, and at same time, keep balance.

 

Result

We failed again!

Reason 1: The bag was too heavy; ten candles are too weak to produce the hot air to push the bag up.  

Reason 2: We had the candle at the bottom of the structure. However, we needed the heat to go upward to fly the balloon. Therefore, the heat that the 10 candles produced could not reach the top of the plastic bag, and that was why the entire balloon was not able to fly.

Improvement:

In order to have the heat reached the top of the plastic bag, we need to design a structure which can hold the candle at the middle or the top of the plastic bag. Of course, we also have to keep the several candle at the bottom just to keep the structure balance.

Reflection: Egg Lander [Sept.18]

      We supposed to make a container for egg to protect the egg from breaking when dropped from the roof. However, we all failed.
       Orginally we planned to make small cube which could exactly fit the egg. At the same time, we cut the straws in to small pieces. These little straws were stuck onto the cube. We thought these straws could have reduced the force when the container hits the ground. These little straws were made to support the entire structure which could prevent the egg from smashing on the ground.
        However, we forgot one important thing, the corner of the cube. We only covered the sides of the cube, not the corner. I did not realize that until the container hit the ground exactly on the corner where we did not put any protection at all. And then, our egg died.
        For the future constructing, there are few things needed to be correct.
         First, try to avoid the corner, instead, make a spherical container. This way makes it easier to make the protection all around the container.
        Second, the shorter the straws are, the stronger they could take the pressure.

      Hopefully, the structure we are going to make will succeed through these improvements.