A few months ago, during a break at a conference, I met a very interesting young engineer. She told me she worked for Space X (you know, the Elon Musk ones, with the reusable rockets); particularly, in the team that takes care of painting the rockets. Our conversation was brief and left me wondering: do rockets need engineering teams just for the paint?
As it turns out, they always have.
In the old days, paint was used to keep an eye on the rocket’s roll (its spin around its length). Instruments on board don’t necessarily realize, amidst the phenomenal launch forces, the enormous acceleration, and the vibration.
Looking at how the large white and black checkered or striped patterns moved, you could check on it, just by looking, from the control center.
Different parts were also painted differently. Should any problem arise in flight, technicians could see in what part of the rocket it originated. Also, the rocket probably exploded as a result of the breakdown, so they only had a few seconds of grainy footage to go on. So they took any and all help.
Nowadays computer image analysis got much better (probably better than humans) and paint lost part of these functions. NASA still uses paint schemes at times, but most recent ESA and SpaceX rockets are just white.
A 2009 picture of a piece of NASA’s Ares. The Z-pattern is particularly useful to track roll. credit: NASA
Discovery launching, now you know why the tank is orange. credit: NASA, via commons
Why white? Because the rockets have to stand a long time in (hopefully) good weather in typically warm locations—like Florida. The white coat of paint keeps the frigid fuels from boiling off the tank. However, if it’s not strictly necessary, the tanks stay unpainted to save weight. It was the case, for example, of the iconic orange tanks for the shuttle.
When it’s used, paint must withstand being close to the freezing fuels, then the launch, then the rough conditions in space, and finally the extreme heat of reentry.
New materials must be designed for the job, and techniques must be developed to apply them so that they don’t shed or burn off.
That’s why, to paint a rocket, you needed—and still need—engineers, like the young lady I met.
If you want more
- Wanna know more than you ever need on SpaceX? There’s a subreddit for that! It gave me many useful tips for this post
- As for so many things space, NASA has a very interesting page about painting rockets too
- Why should a rocket want to roll? Vintage Space explains that
Cover photo: CC0 kaboompics/pexels.com