Space Lasers

NASA’s Goddard Space Flight Center uses lasers in a wide range variety of applications; everything from measuring ice to tracking satellites is done with lasers.


When I first arrived at the Goddard Visitor Center, the rest of the NASA Socialnauts and I jumped on a bus and went to hear Dr. Thorsten Markus (the Chief of the Cryospheric Science Laboratory) and Dr. Tom Neumann (Deputy Project Scientist) talk about ICESat-2. ICESat-2’s main objectives are to: measure global icesheet elevation changes, global sea ice thickness, global vegetation height, ocean wave height, and atmospheric profiles. To do this, ICESat-2 is armed with a laser. It fires a laser, which is then split into six beams, at the Earth and times how long the photons take to leave, bounce off the ice, and come back. (Here’s a cute video made by students at SCAD demonstrating this.) Using those times, scientists can figure out the elevation of the ice and then compare that data to past years to see how much is changing. The laser is visible (and green), but it’s moving so quickly you could blink and miss it. Speaking of blinking, ICESat-2 times 300,000 photons in the amount of time it takes you to blink. Unfortunately, we didn’t get to see ICESat-2, but we did get to see the thermal vacuum chamber and the acoustic chamber where it, and other satellites, are tested. In space, ICESat-2 could go from very hot to very cold very quickly due to the amount of sun light that reaches it. To make sure it can handle that, the thermal vacuum chamber and move the temperature between the two extremes as quickly as possible. It’s not as fast as it occurs in space, but it’s close enough. In the acoustic chamber, the recording of a rocket launch can be played to make sure the satellite can withstand the vibrations. ICESat-2 is currently listed for a 2018 launch.


Next we learned about GEDI (pronounced like Jedi). GEDI will produce the first high resolution laser ranging observations of the 3D structure of the Earth. GEDI will use its three lasers that fire 242 times a second to provide precise measurements of forest height, canopy structure, and surface elevation. The data will be used for habitat mapping and management, studying the water and carbon cycles, as well as possible weather forecasting advancements. GEDI will launch to the ISS in late 2018.


The Restore-L project will allow NASA to service old satellites instead of destroy them. The robotic arms currently in use for testing are intended to be used to assemble IKEA bookshelves. Those arms will use tools to cut away the gold foiling to expose various components, meaning NASA can refuel or complete small repairs on older satellites. The first target, Landsat 7, launched in the late 90s and Restore-L is hoping to refuel it. 


This was not on the original schedule, but was an amazing addition nonetheless. The building is beautiful. Dozens of photos from the Hubble hang on the walls, there is a large model of the Hubble in one room, and several display cases showcase artifacts. We didn’t get to go in the room, but just getting to look through the window and chat with the Deputy Project Manager, Dr. James Jeletic, was awesome. 


The GGAO was by far the highlight of my trip to Maryland. At GGAO, they use satellite laser ranging (SLR) to measure the round trip time of flight of ultrashort pulses of light to satellites equipped with special reflectors. We got to go inside MOBLAS-7, the most accurate SLR system in the world, and see it in action as it tracked Galileo 107 across the sky. MOBLAS-7 serves as the network standard, is a test bed for upgrades to SLR, and helps NASA track the movement of the North American plate. Seeing that green laser in the sky was breath-taking and I still can’t believe I got to see it. 


I really enjoyed my time at the NASA Social and it won’t be my last time (hopefully). I recommend to anyone giving it a try. You can learn more and apply here. A couple of things I wish that I had done differently were: 

  1. Bring an external battery or two. Or twelve.  I would have been much more active in sharing everything that was going on if I hadn’t been worried about my battery dying. I made it through the day with it not dying, but barely and that was after charging during lunch and dinner. If you go, be prepared with extra juice. 
  2. Business cards. I’ve never worked someplace where I had my own business cards, so they aren’t something I’m used to handing out. Throughout the day, I kept realizing I was forgetting to give them to people and I should have handed out more than I did. 

I really want to thank y’all again. I wouldn’t have been able to get to this point without your continued support of Science with My Cat and I’ll never be able to express how much it means to me. Thanks, y’all!  

- Clear skies!