Two Weeks Until the Eclipse!

There are only two weeks left until the eclipse, and we have been busy preparing for the upcoming launch. We’ve done several tests, ran a number of calculations, and done research on the eclipse.

This launch is going to be much more challenging than our previous launches. The shadow of the solar eclipse is moving across the surface of the earth at over 1600mph (2500 km/h), which gives us a time window of approximately two minutes and forty seconds. This means we have to time our launch so that our launcher is at the right altitude and location when it enters totality.


We want our launcher to be at roughly 80,000 feet when it hits totality. If it is too low, we won’t be able to capture the blackness of space with the shadow of the moon and the curvature of the earth. If it is too high, we risk the balloon bursting before the launcher can film totality.

The lift of our launcher is affected by the lifting force of our balloon and the weight of the payload. The University of Montana is generously providing us with a 2000g balloon and the helium, which will give us more lift than our previous two launches. Because of our additional lift, we’re able to to include more weight on our payload than previous launches. We’ll be able to include an additional GoPro as well as an Iridium satellite tracker (more on this later).

Calculating our ascent rate is complicated due to these changes in lift and the weight of our payload. This is further complicated by the fact that we want to hit 80,000 in a 2 1/2 minute window of time.


The width of the shadow of the moon on the earth in totality is approximately seventy miles. Since we will be launching from near the center of the path, that means we have about 35 miles of leeway in a north-south direction. We have no way to predict the wind two weeks in advance, but wind directions a week from now indicate wind is blowing in a east-west direction. In previous missions, our launcher travelled approximately 50 and 70 miles from launch to landing. So, we have the added complication of trying to launch in the correct location so that our launcher stays within the path of totality.

So this is why our calculations this time are much more complicated than previous launches.


We have been offered an Iridium satellite tracker which communicates through a network of Iridium satellites in orbit around the world. This provides us with an additional redundancy in tracking and retrieval in addition to our SPOT GPS tracker and our APRS Radio Bug. Thank you Montana Space Grant for offering this to us!

We have recently been featured in some media, and we’d like to give our thanks to the Seattle Times, GeekWire, and Q13 News.

For the first time, our project isn’t just our family alone, but we’re now part of something bigger. We’re very grateful to be part of the Eclipse Ballooning Project, and are looking forward to sending our data to NASA. It’s thrilling to be working with real scientists from different educational organizations around the country. We’ve been e-mailing with people that we’re soon going to be working with, and every time we receive a new e-mail it feels very humbling.

We’re really looking forward to this launch!


2 thoughts on “Two Weeks Until the Eclipse!

  1. Keep up the good work Rebecca and Kimberly! Keep asking questions, keep learning and stay humble. There is sooooo much more to learn. Love you, Auntie Barb


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