NASA, and its video platform Stream, will launch 100 balloons attached to cameras that will soar 100,000 feet above the Earth’s surface to provide us with live aerial footage of the solar eclipse on Monday, August 21, 2017. Streaming live footage of an eclipse has never happened before.
In addition, some of the balloons will carry instruments to gather data about the effects of an eclipse on our atmosphere. Others will carry samples of bacteria as part of a NASA experiment. These space-based solar observatories and Earth-bound telescopes promise to give a well-rounded coverage of the major celestial event.
“We have spent the last three years researching and building the camera payloads and ground stations in preparation for eclipse day.” explains Angela Des Jardins, Director of the Montana Space Grant Consortium and leader of the Eclipse Ballooning Project.
A total solar eclipse occurs when the moon blocks out the sun as it passes between the sun and Earth, casting its shadow on Earth. Though such an eclipse occurs once every 18 months, it is rare for the eclipse to take place in densely populated land regions of our planet, as most of them occur above water, given that three-fourths of Earth’s surface is water.
The total eclipse of the sun will grace and sweep across the continental United States for the first time since 1979, but it was in 1918 that a similar eclipse had caused a total, (temporary) blackout coast-to-coast. As the moon’s shadow races across the country at about 2,700 kilometers (1,700 miles) per hour, from Oregon to South Carolina, the totality will pass through 12 states, from Oregon to South Carolina in just one-and-half hours, in a 120 kilometers (75 miles) wide path.
The shadow will touch U.S. soil at 10:16 a.m. Pacific time near Oregon’s Depoe Bay and will leave the continent around 2:49 p.m. Eastern time, with Cape Island, South Carolina, as its final stop.
Fifty-five teams from across the country are taking part in the project. Each will launch one or more balloons from within the path of totality, which is a 70-mile-wide area stretching from Oregon to South Carolina. Depending on the wind predictions for August 21, teams may have to adjust their launch locations, because livestreaming works best when the balloons (soaring above 80,000 feet) are closest to the small radio dishes that receive the video signal.
The balloons are roughly eight feet tall when they are partially filled with helium at the launch sites. As the balloons rise through the atmosphere, they will expand as the atmospheric pressure decreases with altitude. They are designed to rise to 85,000 feet, but during test flights the balloons have reached altitudes exceeding 110,000 feet (33 kilometers). “From this edge of outer space, you can really see the curvature of Earth and the blackness of space,” says Des Jardins. “Our project will be the first to show the eclipse video from the space perspective from multiple locations along the path of totality, where the moon totally blocks the sun and it gets dark.”
Balloons will be launched 80 minutes prior to the total eclipse, as it will take that much time for them to rise to the target altitude before total darkness occurs. Shortly after totality, the balloons will pop because of the low atmospheric pressure, or the balloon’s payload will be detached using a remotely controlled mechanical system, and the payload will parachute to Earth. With the payload cut down, the balloon will rise rapidly and burst. The balloons are not reusable.
“Sending live video from high-altitude balloons is tricky though,” says Des Jardins, “because each balloon can lift only 12 pounds, the payloads get really cold potentially causing problems with electronics, the systems to control the video are complicated…I could go on and on.”
And though the exact path of the eclipse can be predicted and it’s possible to have timecodes for switching cameras, “sometimes you hit a violent crosswind,” says Dr. Justin Oelgoetz of Austin Peay State University (APSU) in Clarksville, Tennessee. “so, things can get wild for a few minutes.” That’s why NASA’s kits are also secured by pieces of foam board (used for insulation in walls) and his team uses additional duct tape on it.
Even when the camera is stable, sub-zero temperatures and ice can freeze up the equipment or result in poor image quality. “Sometimes, we get ice around the edges of the image,” says Oelgoetz.
So, Des Jardins plans to have a main web page with the U.S. map and one main feed with thumbnails of other video feeds around it.
The Equipment Payload of the Balloon
What has enabled the project is the miniaturization of computers like Raspberry Pi camera board with cable. It costs $29.95 and weighs 3.4 grams. The primary payload of a balloon consists of a tracking system, a video system and a still-image system, hanging below by a string of nylon cord about 20 feet long. A lightweight modem in the tracking system communicates with a network of satellites, allowing researchers, air-traffic controllers, and others to see the location and altitude of all of the balloons in real-time. The video system has a ring of eight small video cameras hooked to a lightweight computer and radio transmitter. The teams can select which camera to transmit in order to have the most desired view. The still-image system has a single camera hooked to a lightweight computer and radio transmitter. Some of the balloons will carry additional equipment according to experiments that are being conducted.
Each team will use ground-based antennas (it looks similar to a residential satellite TV dish) to receive the video and photo transmission from its balloon. The antennas are connected to a computer, which has an Internet connection. Specially designed software immediately “pushes” the footage from the computer to the Web. Each team will also retrieve the payload(s) once it parachutes back to Earth.
Besides NASA, several research and education entities will look at the data. NASA officials believe the 2017 eclipse will be the most viewed live video since the 2012 landing of the Curiosity Rover on Mars.
From the eclipse and scientific observation, NASA hopes that we may increase our understanding related to the following questions:
How does our atmosphere react to the sharp shadow of the eclipse speeding across the continent at over 1,500 miles per hour? What does the exact surface of the sun look like? What happens to resilient bacteria when exposed to a Mars-like environment? How do we transmit live video with inexpensive equipment from space-like conditions and over long distances? What happens on the Internet when hundreds of millions of people are watching live streams from the same source at the same time?
The Eclipse Ballooning Project was initiated by Montana Space Grant Consortium at Montana State University in 2014 and is sponsored by the NASA Science Mission Directorate and NASA’s Space Grant program, a national network that includes over 900 affiliates. Money for the project comes from the NASA Science Mission Directorate and each team’s local space grant consortia.
SAFETY WHILE WATCHING THE ECLIPSE: Please be safe and wear solar eclipse glasses, while viewing the eclipse. These are affordable and available. Without protective eyewear, you can only safely look at the eclipse during totality, which occurs for about two minutes. Protective eyewear should be worn while viewing the eclipse during all other times and places.
For more safety information: http://eclipse2017.nasa.gov.
NASA’s Live video feed: https://eclipse2017.nasa.gov/eclipse-live-stream