NASA's Jet Propulsion Laboratory was a magical place to be last night, as engineers, flight specialists, NASA administrators, space celebrities, and scientists from many fields gathered to witness the landing of the Mars Science Laboratory (MSL) Curiosity rover. Those seven minutes of terror ended in a picture-perfect landing: an amazing machine went through a crazy Rube Goldbergian descent sequence, and plopped down about two meters away from its planned destination on the Red Planet's surface.
We witnessed history. It seemed impossible. It was awesome.
I sat in on the post-landing press conference, and live-tweeted the evening at @boingboing. During the press conference, after the high-fives and screams of joy subsided, I asked MSL engineer Adam Steltzner a question about those first two all-important thumbnail images Curiosity sent back—critical because the data they contained would tell NASA if the rover had touched down in a safe spot.
Given the great distance and technical challenges involved in transmitting timely data back from Mars, what file type and image compression algorithm(s) did they use for those first "rush" thumbnails? There's a 14 minute delay involved for any signals from Mars to Earth.
A dorky question, perhaps, but I was curious, and figured nobody else would ask. Things like, "Hey how do you guys feel right now," and "What will Curiosity do next," I knew others would tackle.
Mr. Steltzner didn't have details handy about the image file types used, and he referred me to Mars mission image specialist Justin Maki. Today I checked in with Mr. Maki and his JPL colleagues whose work focuses on data compression and interplanetary data transmission. Here's what I learned.