Who Should We Send to the Stratosphere?

We’re getting ready to launch in August and it’s time to select a new LEGO minifigure. We’ve narrowed it down to three options: Merida from the movie Brave, Hermione Granger from Harry Potter, and Amelia Earhart, the first pilot to cross the Atlantic. We think that all of them were strong, empowering, girls. What’s your opinion about which of them should be on the Loki Lego Launcher 3.0? Let us know here!

We look forward to the final results!

Loki Lego Launcher 3.0: Into the Eclipse!

We plan to launch the Loki Lego Launcher 3.0 this summer, hopefully in the path of the August 21 solar eclipse! We’ll be launching in East Wyoming hoping to capture footage of Earth during the eclipse. We’re also interested in what our solar data will show too.

We’re still thinking about which LEGO minifigure we want to include as our co-pilot. For the first launch we sent R2-D2, for the second launch we sent Rey, and now our criteria is for it to be a strong female who is recognizable and can be found in LEGO.

There will be more to come later. Stay tuned!

Published in Scholastic Magazine

We loved reading Scholastic and Ranger Rick and Highlights and other magazines like that in our early elementary grades.  So you can imagine how excited we were when Scholastic contacted us and told us they would like to publish our project in their SuperScience magazine.

We did an interview with them and answered a few questions through e-mail.  Dad sent them a few photos that they asked for.  Then, they turned our project into a learning unit in their November 2016 SuperScience article.  They wrote it using language that was easier for younger kids to understand.  They also had an Investigate It! sidebar, and an online skills sheet, and they also linked to our video online as well.

It was really cool to be in a magazine that we had read for many years.  Thanks Scholastic!

Appearing in President Obama’s Issue of WIRED Magazine

President Obama is guest editing the November issue of WIRED magazine. We are very excited because he specifically asked for us to appear in it. We are honored to be asked and we are so grateful that he even remembered who we were.

A few weeks ago, we set up a Skype interview with Elise Craig, a writer for WIRED.  We enjoyed talking to her about our project. WIRED also brought us to New York to get our pictures taken for the magazine by a professional photographer named Platon. He has taken pictures of leaders from all over the world, which was amazing. We had to keep it all secret because we weren’t allowed to give away the surprise about the President being a guest editor.

When we got to the studio, there were people there who were helping with the photo shoot. They included a really nice guy who was in charge of hair and makeup, a producer, and a photographer assistant.  It was an interesting experience because we’ve never had a professional photo shoot before.

Platon was really nice to us and he asked us to do different poses for the pictures.  It was really fun, but it was hard not to smile and it was also hard to hold a pose for so long.

The digital version of the WIRED issue came out today, but the print version will come out next week.  We subscribe to the magazine, so we can’t wait to see the issue!

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Barack Obama: Now Is the Greatest Time to Be Alive

Our Interview with Adam Savage from Mythbusters

In April, we were invited to present our project at the White House Science Fair and many people came to see our project. We had the honor of being asked to present our project to the President of the United States.

We also presented our project to many members of the media and science celebrities. Adam Savage, the co-host of Mythbusters, also came to the White House Science Fair to check out the science projects that were on display.  He was funny and really nice to us. He seemed to be really interested in what we were talking about, and he was very animated when he talked.

It was really exciting for us to get to meet him and talk to him about our project, especially because our family are really big fans of his show!

 

More Data Analysis

Our data came from our flight computer and was recorded in a .TXT file. The column headings include:

Date, Time, Latitude, Longitude, Head, Km/h, Alt-m, mV, mA, mW, Temp C, and Pa

We then imported the .TXT file into Microsoft Excel and deleted all the information from before the launch and after the landing. Then Dad imported the Excel file into Tableau, a graphing software program. We then came up with a bunch of different graphs to display our data.

Click images to enlarge.

Altitude vs Pressure

As the balloon ascends, the pressure decreases because the density of air goes down. As our spacecraft approaches 30,000 meters above sea level, the atmospheric pressure approaches zero pascals. This lack of pressure is what eventually causes the balloon to pop.

Alt-m vs Pa

Altitude vs Temperature

We learned about the changes in temperature shown in this graph in our last launch, which is very similar to this graph, which is good, since we don’t think the layers of the atmosphere have changed since our last launch.

The first layer of the atmosphere is the troposphere. While traveling upward through the troposphere, the temperature gets colder. But as soon as it reaches the second layer of the atmosphere, the stratosphere, the temperature becomes warmer. We will have to do some more research to find out why.

Alt-m vs Temp C

Altitude vs Current

We attached a solar panel to our spacecraft and it measured the solar current that it was collecting. This graph shows the current that the solar panel absorbed from the sun. The lines are very jagged because of the motion of the spacecraft, but the trend line we created shows very clearly that our hypothesis was correct: As we get higher, there is more current generated by our solar panels and we think that this is because there are less particles in the air to block the suns rays.

Alt-m vs M A

Altitude vs. Power

Power is equal to Voltage times Current (Power = VI) so both voltage and current are factors in this graph. You can see the lines gradually show the curve that the voltage showed during the ascent. Also, the trend line, though it is not quite as pronounced, shows that there was more power as the balloon ascended, which shows the current.

Alt-m vs M W

Altitude vs. Voltage

The voltage measurement is measuring the voltage produced by the batteries powering our flight computer. We were very surprised at the change in voltage because we thought that the battery voltage would continually stay the same and not change. It did not seem that we could make any conclusions from this chart. But by comparing voltage to a different measurement in our next chart was really interesting.

Alt-m vs M V

Voltage vs. Temperature

When we first saw this graph we thought that since the temperature was changing with the atmospheric layers, the voltage levels must be too. However, we did some more research and we found out that the voltage levels actually changed because of the temperature levels, not because of the atmosphere. The temperature changes because of the atmosphere, and the voltage changes because of the temperature.

We did some more research and the reason this happens is because of the chemical reactions inside the battery. When the temperature gets warmer, the chemical reactions happen faster, and consequently there is higher battery performance and more voltage. On the flip side, when the temperature gets colder, the chemical reactions happen slower, so there is lower battery performance and less voltage. This correlates very clearly with our data set from the launch.

M V vs Temp C

Altitude vs Speed

Our speed data was a little bit different from the last launch: see From the Project Binder. Last launch, our speed stayed around 35 km/h until it reached the tropopause, the space in between the troposphere and the stratosphere, the first and second layers of the atmosphere. In the tropopause, there is very little air resistance so the spacecraft was able to move much quicker than otherwise. However, in our second launch our spacecraft’s speed rose steadily to reach its high speed in the tropopause instead of a sharp difference of speed like our first launch.

Alt-m vs Kmh

Mission Debrief for Loki Lego Launcher 2.0

Our mission was successful!  We met all of our primary goals:

  1. Reach a height of 27,500 meters (90,200 feet); we made it to 30,880 meters (101, 325 feet).
  2. Complete the launch and descent in less than four hours; our mission length this time was 3 hours and 23 minutes.
  3. See the curvature of the earth on our video footage; see picture above!
  4. Compare data with our first launch and see if we observe the same temperature changes at the same heights; our temperature/altitude graph looks very similar to our last launch.

However, we might have failed on one of our secondary parameters: Parachute not opening.  Our cord between our balloon and parachute was too long and the balloon got twisted around the parachute lines.  When we found the Loki Lego Launcher, it was totally twisted up.

By the Numbers

Height at highest point (apogee): 30,884 meters (101,325 feet)

Total flight time: 3:23:30; launch to apogee: 2:30:30; apogee to landing: 53:00

Temperature range during flight: -55C to 31C (-67F to 87.8F)

Fastest speed during flight: 127 km/h (78.9mph)

Distance between launch and landing sites: 126.8 km (78.9 miles)

Data is Everything

Our APRS Radio Bug that we added as a second tracker to our spacecraft was awesome.  It was so fun to see where it was in real-time, and we were able to be close to our landing site before it actually landed.  (Chasing the spacecraft in the car while it was coming down was super exciting).  It gave us really interesting data that can be analyzed in several ways.

Raw Data from flight computer:   EAGLEB01.LLL2.0 – Copy

PDF charts: Loki Lego Launcher 2.0 Data

APRS track
From APRS.fi, using the latitude and longitude coordinates
LLL2.0 path 1
Using the KML data in Google Maps for a 3D view showing altitude

Plus, our data from our new VI sensor was really interesting.  There is a lot more to analyze, but we think there are going to be lots of other ways to use use this sensor.  We have a lot more data analysis to do over the next few days and weeks.

Our Solar Experiment Hypothesis was Correct

Our solar panel experiment that was on board was based on the hypothesis that as our spacecraft got higher, then there would be less particles in the air that would block the sun’s rays, so the solar panel would produce more current.  Well, according to our data, this may be true!

Alt-m vs M A
Altitude (meters) vs Current (mA)

As can be seen in the chart (that Dad did for us), as the altitude increases, the trend line showing the current data also increases.  The other cool thing is that all those tests that we did while we were trying to figure out this solar experiment were useful, because this data shows that at least our circuitry wiring was correct!

 

Lessons Learned

Like last time, we talked about what we learned from our launch on the car ride back home from the recovery site.  A few lessons we learned were new, and a few were similar to our first launch.  We referred to our first set of lessons several times during Launch Day.

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