NASA provides first image from record-setting flyby of Ultima Thule

[KY_EnviroGuy]

12. Low data rate to save power....

Last edited Wed Jan 2, 2019, 04:09 PM - Edit history (1)

Spacecraft only has a 15 watt transmitter to conserve fuel and Deep Space Network ground station use is shared with many other users.

See: https://eyes.nasa.gov/dsn/dsn.html (New Horizons' ID is "NHPC" )

I just checked the DSN page and New Horizons was transmitting to the Goldstone facility at 841 bits per second. This is a much slower rate than previous events from this mission (see below).

From Johns Hopkins APL:

The Data Rate Challenge

A major challenge for the New Horizons mission is the relatively low "downlink" rate at which data can be transmitted to Earth, especially when you compare it to rates now common for high-speed Internet surfers.

During the Jupiter flyby in February 2007, New Horizons sent data home at about 38 kilobits per second (kbps), which is slightly slower than the transmission speed was for acoustic computer modems which operated over telephone lines. The average downlink rate after New Horizons passed Pluto (and sent the bulk of its encounter data back to Earth) was approximately 2,000 bits per second, a rate the spacecraft achieved by downlinking with both of its transmitters through NASA's largest antennas. Even then, it took until late 2016 to bring down all the encounter data stored on the spacecraft's recorders.

NASA's New Horizons home page is here: https://www.nasa.gov/mission_pages/newhorizons/main/index.html

APL's mission page is found here: http://pluto.jhuapl.edu/

APL mission summary, technical details on spacecraft powering, and complete technical summary PDFs are found here:

http://pluto.jhuapl.edu/News-Center/Resources.php#Fact-Sheets

As an interesting side note, this mission was almost canceled by W's administration but thank goodness NASA's scientists put up a hell of a fight and got it funded.

..........