What if your phone was built to last 15 years without being plugged in or repaired? It might be hard to imagine, but it’s exactly how spacecraft operate.
Once a spacecraft blasts off, it spends its entire mission outside the reach of human hands. Which means it has to work perfectly. That’s why engineers perform extensive tests before launch, because once it’s launched, you can’t bring it back to fix. So who’s in charge of building perfection? We talked with a few of our engineers who are responsible for shaking, blasting and freezing our spacecraft to get insight into what they do. Take a look and see how you can join the team below:
Structural Testing: Dan Qvale
During a launch, rockets often top speeds of up to 20,000 mph, nearly 10 times faster than the top speed clocked by the record-holding SR-71 Blackbird jet. This pace can generate a few bumps.
Every spacecraft must undergo structural testing to ensure it can withstand the forces, vibrations and noise of a launch.
Q: What is structural testing?
Dan: This test validates the structural design of the spacecraft by physically assessing it against what our design analysis shows it can withstand. We conduct these tests by applying loads to the spacecraft that are 1.4 times what we expect it to encounter during its mission.
Q: Any advice for future testers?
Dan: Test engineering is in many ways similar to a sports team where there is many different positions, but your work supports something or someone down the line. You have to be willing to jump in and get your hands dirty. You do a lot of hands-on work with the spacecraft, so it is exciting work.
Acoustic Testing: Katie Oakman
Acoustic testing can look a lot like a rock concert. That’s because for some types of acoustic testing, speakers are rigged together to blast a spacecraft with noise. What’s pumped through the speakers isn’t music though. It’s sound that replicates what the spacecraft will be exposed to during launch.
Q: So what’s acoustic testing?
Katie: For most spacecraft, the launch is the most extreme environment it will experience. The sound is so loud that it produces vibrations that can impact solar panels, fused joints and avionics. When we test the spacecraft, we power it up just like it’s going to launch and expose it to vibroacoustics it will experience during the real thing. The sound is louder than standing behind a jet engine.
Q: What do you look for in particular?
Katie: One simple way we verify that a structure withstood testing is to make sure there isn’t anything on the floor of the chamber when you go in after testing. We put down white paper that catches any small pieces that may come off the spacecraft during the test. For electrical systems, we make sure that anything powered on during launch stays on throughout testing.
Q: What do you love most about your job?
Katie: What gets me to work every day is the people and the fact that we’re working toward a common goal together. I get to work on spacecraft from their birth all the way through graduation when we send them off into the solar system!
Thermal Vacuum Testing: Justin Mortara
Thermal Vacuum (TVAC) testing is the most comprehensive testing you can perform on a fully assembled satellite prior to its launch. Using a special depressurized chamber, TVAC stresses the very design and production of each satellite, validating its integrity and operational capabilities in a simulated, harsh, space-like environment – all part of “test like you fly.”
Q: What is TVAC and why is it important?
Justin: The GPS III TVAC test phase consists of reducing the air pressure to a near-vacuum and simulating the temperature of conditions in space. During the thermal cycles, the team performs various tests to verify that the all the subsystems on the satellite perform as expected with temperature extremes (302⁰F to -238⁰F) similar to near and far-side Earth-orbital conditions.
Q: What do you love most about your job?
Justin: While there are many aspects to my job that I enjoy, I love being able to take a satellite through its test flow. I truly look forward to participating in my first launch of a satellite that I have helped take through its entire system level testing.