Ron Howard’s “Apollo 13” celebrated its 25th anniversary on June 30. With the help of post house Digital Domain, the 1995 film depicted a 1970 space mission that turned into a fight for survival after an oxygen tank exploded in the service module. 

Variety looked up Kelly Port (“Avengers: Endgame”) and Matthew Butler (“Ready Player One”), two VFX supervisors who worked on the film in their junior years at the house.

What are some of the memorable VFX scenes you worked on for “Apollo 13”?

Kelly Port: This was one of the first film projects I ever worked on. I was responsible for the directional thruster effects, floating debris after the explosion and, if I remember correctly, some parts of the moon.

Matthew Butler: This was a time when we were bootstrapping like crazy. Back then, there weren’t any set procedures or mechanisms at Digital Domain to facilitate the workflow, like there are now. We had so many brilliant minds who were inventing neat tricks, but they were insular and we needed a cohesive plan. I worked mostly on the technical side of things, making sure that the pipeline was well oiled; that included gathering the necessary data on set, mimicking the camera representation, scanning the film, animating and creating synthetic representations of the product, compositing the final image and rendering out to disk. For “Apollo 13,” we would also then output it all back to film.

What were conditions like? 

Port: These were early days of visual effects, and Digital Domain was only a couple years old at the time. We had an amazing miniature department, and they were cranking stuff out like crazy. There was a time where you could go on our big stage and see miniatures for “Titanic,” “Apollo 13” and “Dante’s Peak.” The air was filled with an intense creative energy and just incredible for a person like me just getting into the industry.

Butler: Coming from the aerospace industry, I was so geeked to be involved, albeit at a peon level. I remember how guerrilla our approach was. I’d hear a colleague yell, “Stop writing to stage 26; it’s filling up.” They were referring to physical computer space that was in critical danger of overflowing. These are not issues we deal with today, but back then you had to fix your own carburetor.

Is there anything from the shoot you were especially proud of? 

Port: Rob Legato [VFX supervisor] and Erik Nash [VFX DP] came up with some brilliant motion-control setups with the miniatures using all kinds of interesting passes, like orange matte passes and various UV light passes [to separate light, color, diffusion and reflection within an image before passing them through a compositor to combine them back into a single image]. We also did a reverse blue-screen pass and finally a pass over the model. One of the coolest things they did on the live-action shoot was build a partial set within NASA’s “vomit comet” that simulates zero-gravity effects. 

Was there any moment that stands above the rest? 

Port: Buzz Aldrin had asked what NASA archive was used to get some of the launch footage of the Saturn V [the disposable first stage of the rocket that was used to get the mission into space], because he had never seen it before. We, of course, loved hearing something like that, since it meant we had achieved our goal of keeping it as realistic-looking as possible. We based a lot of the shots on stock footage but made them better. It’s like what our collective memories of those iconic shots are.