Back To School With Planet: Week 2 | Doves in Space
This is the second installment of our Back to School with Planet series, a weekly update for K-8 students interested in learning more about the science we do with Earth and Space. Learn more about this series here.
You can find this entry in Spanish here. / Puedes encontrar este texto en español aquí.
You can find this entry in German here / Hier findet ihr den Blogpost auf Deutsch
A Planet Dove is small, measuring 30 cm by 10 cm by 10 cm. As members of the CubeSat family of small satellites, a Dove’s size and shape has a lot in common with satellites built in schools, even elementary and middle schools! Read more about CubeSats here.
The launch vehicle helps the Dove satellites arrive at their place in space. Here’s a video of several new Doves right after launch, ready to watch the world from above.
Career Spotlight: Space Operations
Engineering Manager in Space Operations
This week, Planeteer Deanna is going to explain the job of people who operate the Doves in Space, and how the design and operation of the satellites keep them imaging and flying.
What is your job at Planet?
I keep the satellites on-orbit healthy to make sure they can take as many pictures as possible! Because there are so many satellites and a much smaller number of engineers managing them, we develop a lot of automation code to help do the work for us. For example, if a satellite is unhappy, we have tools to detect issues and alert us to investigate.
What did you study to learn your specialty?
I studied Aeronautical and Astronautical Engineering. This type of engineering uses courses across all disciplines of engineering, including mechanical, electrical, software and thermal, to name a few. In addition, there are courses specific to this type of engineering including Aerodynamics (“How does this object move through air?”) and Orbital Mechanics (“How do celestial bodies move in space?” “How do I get from one Planet to another?”).
What inspired you to start a career in spacecraft?
Some of my favorite movies growing up were Back to the Future, Contact, and Apollo 13. I loved stories about exploration and discovery, and how those things can be accomplished through technology! That’s what keeps me excited working at Planet. The images that our satellites take are showing us all of the dynamic changes that we didn’t previously know about with our planet. What can we discover and help with using this information?
Are Doves visible from Earth?
No, our satellites are about the size of a shoebox so we won’t see them normally. However, I have seen a video on the internet of a space enthusiast capturing a streak in the sky that matched up with one of our satellites deorbiting and burning up in the atmosphere!
How long does it take the solar cells to charge?
As soon as the satellite is deployed from the launch vehicle in space, and it is in view of the Sun, it will start charging its solar panels. The panels start out in a stowed configuration and will deploy the wings out as part of its commissioning process.
So how do you know if a launch worked?
We have ground stations all around the world that we use to communicate with the sats once they are launched. We schedule contacts when the satellite is flying over the ground station and send commands to check on the health of the satellite and to tell the satellite when it should deploy its panels, run calibrations and take pictures.
What puts the Doves into the right place to orbit the Earth?
We work closely with the rocket launch folks to make sure they insert our satellites into our desired orbit. Once they are in space, we verify with telemetry that they are where we expect them to be.
How do you prevent a Dove from colliding with another satellite?
Some satellites have onboard propulsion to adjust their position. Because Doves don’t have any onboard propulsion, we use parts called magnetorquers and reaction wheels to point and rotate to put as much room as possible between the Dove’s area and the other satellite we are at risk of colliding with.
How fast does a Dove fly?
Our satellites are in Low Earth Orbit (LEO), which describes satellites up to an altitude of 1000 km. Our satellites are at about the same altitude as the International Space Station, all flying at a rate of 4.76 miles per second, orbiting the entire planet every 90 minutes!
How do you get the images off the satellite?
Planet has over 45 ground stations around the world, ready to receive data from the Doves. When a Dove flies over one of the ground stations, the ground radio and the satellite radio connect and the satellite sends down the latest pictures. A single pass with a ground station can send up to 20,000 images.
The ground stations even have art on them!
What keeps a Dove from falling back down to Earth?
Satellites stay in orbit by balancing their speed with the gravitational pull of the Earth. A satellite orbiting further from the Earth feels the pull of Earth’s gravity less, and therefore doesn’t need to travel as fast to stay in orbit. [Video: Why Don’t Satellites Fall Out of the Sky?]
How long does a Dove keep working?
A Dove satellite is typically in service for three years. Once it’s no longer useful for imagery, the engineering teams may still use them as on-orbit test satellites, running experiments and testing new software. We try and maximize our use of these sats before they deorbit!
Activity
This week’s activity is about art.
Just like the ground stations, every single Dove in orbit is decorated with its own unique art. Together, the Doves make up the world’s first art exhibit in space.
If you could design any art to go to space, what would it be? Use this template to design your own Dove and show us.
Send your design to backtoschool@planet.com for a chance to have your art featured on a real Dove that will go to space!
Where on Planet Earth is Ziggy?
I am a thick cloud of tiny droplets suspended in the atmosphere.
I come when I want to conceal the tall towers and surprise all the citizens of San Francisco, California.
I even have a Twitter account.
Who am I?
(Answer)
Further Inspiration
Reading (Grades K-3): Satellite Space Mission by AnnMarie Anderson
Reading (Grades 4–8) You wouldn’t want to live without satellites (Ages 8–12)
Movie to Watch (Rated G): Apollo 11
Vocabulary
Telemetry: “A measurement that takes place on a far away or hard-to reach instrument.” It sounds like a space-age word, and it’s often heard in the Apollo 11 movie. In short, it means something far away doing a measurement, and then sending it back to you. The word is derived from the Greek roots tele, “remote,” and metron, “measure.’ For Doves, telemetry is measuring the positing and angles of a satellite. Telemetry is also used to measure deep-ocean temperatures, cloudiness on Mars, and healthcare devices.
Calibration: A process to confirm that measurement tools are working correctly. For example, if Dove sensors measured something on the ground and classified it as aqua colored, then someone could check the spot on the ground and confirm it’s reporting the right colors. Or, if the atmosphere is messing it up, make adjustments so that the images report the truth.
Commissioning: The process of getting a satellite listed as ready for service. This includes calibration, adjusting and perfecting the orbit and position and running quality checks on the new satellites’ images.
Orbit: The position an object takes in rotation around another object. Satellites and the Moon orbit the Earth, the Earth and other planets orbit the Sun.
