5 ms·

Looks like there was quite a lot of time for taking pictures[1], 172 second to be exact between parachute deployment and touchdown. [1] http://www.nasa.gov/ima

• 3JPLW 14y ago
  Not really. The MRO is moving fast and at a relatively low orbit. "If HiRISE took the image one second before or one second after, we probably would be looking at an empty Martian landscape," said Sarah Milkovich, HiRISE investigation scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "When you consider that we have been working on this sequence since March and had to upload commands to the spacecraft about 72 hours prior to the image being taken, you begin to realize how challenging this picture was to obtain."[1] [1]: http://www.nasa.gov/mission_pages/msl/news/msl20120806b.html http://www.nasa.gov/mission_pages/msl/news/msl20120806b.html
  • _delirium 14y ago
    Since HiRISE appears to be more of a "scanner" than an instant-in-time snapshot, I was curious why they had to pick a specific second to take a "photo", instead of just scanning across the likely region. It seems that the answer is on-satellite memory: since the images can't be transmitted anywhere near real-time, they have to fit into the 3.5 GiB local storage. That limits the 20,000-pixel wide "scanner" to recording 126,000 pixels along its trajectory before running out of memory, with a long pause for transmission before it can start recording again.