28 replies to this topic

[Icterus galbula]

Colbert talks Pluto with Neil DeGrasse Tyson-

 

[Mackus]

That was awesome

[tennOsfan]

What is really crazy -- I read that the pictures took so long to get back to us, because of the sheer distance from Pluto to Earth, that the satellite is already over a million miles past Pluto already.  I forget the exact distance I read, but it's wild to think about.

[RShack]

What is really crazy -- I read that the pictures took so long to get back to us, because of the sheer distance from Pluto to Earth, that the satellite is already over a million miles past Pluto already.  I forget the exact distance I read, but it's wild to think about.

 

My brother works on Deep Space stuff at Goddard... for a while all he did was make communications with the satellites work... it's not just that distance means the signal has to travel farther... it's also that the greater the distance, the slower the communication rate... so, being far away presents a double-whammy re: communications time...  it's like the diff between driving 5 miles at 100 mph vs. driving 100 miles at 5 mph...

[Mackus]

What is really crazy -- I read that the pictures took so long to get back to us, because of the sheer distance from Pluto to Earth, that the satellite is already over a million miles past Pluto already.  I forget the exact distance I read, but it's wild to think about.

 

It's about 3 billion miles away.  Being an additional million miles away is just a drop in the bucket.

 

NH uses only the DSN 70-meter diameter dishes because the 34-m dishes would only allow for the lowest data rates (all else equal, the 34-m dishes can only support 1/4 of the data rate of the 70-m).

 

I forget how much power the on-board  has, but it's not very much.  The low power combined with the massive distance to travel means a very low data rate, even with the 70-meter dishes being able to collect a ton of signal and recombine it. 

 

In addition to the low data rates being used to transfer a ton of collected data, the DSN only has three 70-meter dishes - in California, Madrid, and Canberra, Australia - and while that would allow for constant contact fo the NH satellite based on where they are on Earth, those dishes are a shared resource that every other NASA deep space mission wants to use as well, so NH does not get constant 24-hour coverage (or at elast won't after a while, it's very high profile right now so I think they've got a couple weeks of constant contact).

[DuffMan]

[BSLChrisStoner]

Time.com: The 5 Craziest Things We Just Learned About Pluto
http://time.com/4264...s/?xid=homepage

[Mackus]

http://www.cnn.com/2...ound/index.html

 

This is another APL-built and operated mission.  Two satellites, everyone thought we lost communications forever with Behind, but operators detected a signal for the first time in almost 2 years (a chunk of that time was when it was in conjunction with the Sun and wouldn't have been able to get a signal even if it was healthy) and are starting recovery. 

[Mackus]

https://www.cnn.com/...-scn/index.html