New Horizons mission to Pluto & Kuiper Belt

[carosio]

Makes one wonder what signal strength is being received from the craft, and also how it manages to pick up signals from earth, and what frequencies they're using.

[RiffRaff]

Makes one wonder what signal strength is being received from the craft, and also how it manages to pick up signals from earth, and what frequencies they're using.

 

Crazy, isn't it?!

I can't even get a DAB signal in my front room!

[carosio]

Some details here from Wiki:

 

Telecommunications and data handling

New Horizons* '​ antennas

 

Communication with the spacecraft is via X band. The craft had a communication rate of 38 kbit/s at Jupiter; at Pluto's distance, a rate of approximately 1 kbit/s is expected. Besides the low bandwidth, Pluto's distance also causes a latency of about 4.5 hours (one-way). The 70 m (230 ft) Deep Space Network (DSN) dishes are used to relay commands once it is beyond Jupiter. The spacecraft uses dual redundant transmitters and receivers, and either right- or left-hand circular polarization. The downlink signal is amplified by dual redundant 12-watt traveling-wave tube amplifiers (TWTAs) mounted on the body under the dish. The receivers are new, low-power designs. The system can be controlled to power both TWTAs at the same time, and transmit a dual-polarized downlink signal to the DSN that nearly doubles the downlink rate. DSN tests early in the mission with this dual polarization combining technique were successful, and the capability is now considered operational (when the spacecraft power budget permits both TWTAs to be powered).

[Anarchon]

Makes one wonder what signal strength is being received from the craft, and also how it manages to pick up signals from earth, and what frequencies they're using.

 

I've read on Geek.com that New Horizons currently has a 1 kilobit per second download rate. For a 1024x1024 pixel picture (300k uncompressed size), it would usually take 42 minutes to stream. In reality given the distance of Pluto at 30 astronomical units it takes around 4.5 hours for New Horizons to stream the data back to Earth.

[carosio]

Thanks, just spotted some of it earlier on Wiki!

[truman]

Latest picture

 

Pluto

[johncocker]

So what's the point of sending it on? Wouldn't it be better orbiting round Pluto to give more info or does it not have the capability.

 

 

 

I believe they have at least one other Pluto sized planetoid object they wish to study.

 

https://en.wikipedia.org/wiki/New_Horizons#Future_mission_objectives

 

After passing Pluto, New Horizons will continue on to the Kuiper belt. The goal is to study one or two other Kuiper belt objects (KBOs). Because maneuvering capability is limited, this phase of the mission is contingent on the presence of suitable KBOs close to New Horizons* '​ flight path.

 

quote/On October 15, 2014, it was revealed that Hubble's search had uncovered three potential targets, provisionally designated PT1 ("potential target 1"), PT2 and PT3 by the New Horizons team. All are objects with estimated diameters in the 30–55 km range, too small to be seen by ground telescopes, at distances from the Sun of 43–44 AU, which would put the encounters in the 2018–2019 period. The initial estimated probabilities that these objects are reachable within New Horizons* '​ fuel budget are 100%, 7%, and 97%, respectively.....

 

 

as for orbiting round pluto, the probe is traveling at such a high rate of speed that it would take over 1000x the the amount of fuel it can hold to slow it down enough to enter orbits. It took new horizon nearly 10 years to get to Pluto, and is the fastest probe we have ever launched. So we would have to make a probe to travel much slower meaning much longer to get to Pluto.

Edited July 14, 2015 by johncocker

[hyper]

Makes one wonder what signal strength is being received from the craft, and also how it manages to pick up signals from earth, and what frequencies they're using.

I'd heard that the power needed to transmit these signals is less than that of a domestic light bulb. To me, that's amazing

[johncocker]

It's "try and get your head round that!" time....

Talking to an astronomer on Breakfast this morning, he was asked "what next?" for the craft passing Pluto sometime today.

Apparently travelling at 14 kilometers a second - which is mind-boggling enough - it will head off towards the Sagittarius constellation.

Bill Turnbull then asked the obvious next question, to which the answer was that it will take "billions of years to get there...."

"Billions of years"!

It's enough to send you mad, just thinking about it...

 

Indeed, anytime I need some perspective I just watch this:

 

 

Space, the only place where you can see the past in real time.

[RiffRaff]

Another little gem from the TV astronomer this morning was that, by the time the craft "gets to" the sagittarius constellation, mankind will probably have got there first...

Now there's a thought!