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Comment by jcims | Hacker News Reader

>This isn’t the end of the mission for NH.

At ~1:30 in the video interview with Alan Stern he says they have ~20 years of power in the RTG and 'plenty of fuel' to get around. Sounds like there could be a lot of science yet to come!!

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Sounds like there could be a lot of science yet to come!!

From Wiki: at Pluto's distance, a rate of approximately 1 kbit/s per transmitter is expected. Besides the low data rate, Pluto's distance also causes a latency of about 4.5 hours (one-way).

Scientists have a lot more patience than I do!

In a lot of ways, science and patience are the same thing.

Not in all ways. But a lot of them.

I wonder if they watch their planet porn arrive one scan line at a time.

There's a lovely photo of scientists manually painting the scan lines coming in from Mariner 4, like a paint by numbers picture

https://www.nasa.gov/multimedia/imagegallery/image_feature_1...

I can tell you stories about the days of 300 baud dial-up modems.

And 110 baud before that (Model 33 Teletype).

When 256 colors was good enough...

For high res displays. The rest of us got by on 16 colors.

The Hubble scope had to spend many hours to find this target, basically taking "before" and "after" images to find changes: dots moving against the background stars seen via subtracting the pixels values of before and after. Once they find rough candidates, they take more pics to narrow down their orbits. Any new targets will be further away and thus probably dimmer to Hubble than Thule. Also, New Horizons only has so much fuel to change direction. Its room to operate is a very narrow cone, kind of like a long lopsided straw. It will be challenging finding new objects to visit. I wish they didn't have to depend on Hubble so much.

Interestingly, we'll solve this problem just about when it won't matter anymore for New Horizons. In the 2020s the Large Synoptic Survey Telescope will come online, which will (among other things) catalog tens of thousands of KBOs/TNOs.

Isn't TESS kind of built to do the same thing? Wide field analysis? Presumably it's looking for dimming rather than relative motion, but that seems more like a software issue than a hardware one?

Not exactly. TESS monitors bright objects. It uses actually quite small telescopes (only 10cm aperture or so), but the it has 4 such telescopes and uses very wide fields of view to monitor a large number of stars continuously. To see KBOs/TNOs requires more light gathering power.

Ah! OK, makes sense. Thank you!

Time to send a telescope into distant orbit?

Considering the size of the Kuiper belt it wouldn’t make much difference if you observe if form earth orbit or from within an orbit in the belt.

There would be no reason to do that. Putting telescope into distant orbit will not make it easier to observe anything except for the thing you are orbiting.

The problem with kuiper belt objects is not that they are far away but that there is not much light reflected from them. The belt is huge, and if you put say Hubble in there you have no guarantee you would see anything.

Putting space observatory is costly project, money are better spent by putting it in Earth orbit as it is much cheaper to put it there and possible to service while in orbit. If history teaches us anything it is that being able to service the telescope in orbit is very important for getting as much bang for the buck as possible.

Re: There would be no reason to do that.

In general, probably; BUT I'd qualify that to say it depends on the mission. As I mentioned nearby, visiting the bigger known Kuiper objects seems a bigger priority than finding new smaller ones (and finding them is better done near Earth).

However, if something unusual were found at Thule such that a mission to study lots of smaller Kuiper objects were deemed warranted (like being made of gold or clear signs of life), then a probe with a relatively big telescope could be sent into the Kuiper Belt to hunt such objects in its approximate vicinity. That may still be cheaper than building larger-than-Hubble scopes near Earth to guide New-Horizons-like probes. But the math on that may depend how sparse smaller Kuiper objects are.

That probe would be worse than a Hubble like telescope at an earth or near SOL orbit.

Firstly due to their relative small size their angular size wouldn’t make much difference at those distances.

Secondly you essentially limiting your search envelope to a small section of the belt as most of it would be further away form the telescope in the belt than from earth.

And lastly you can launch a much bigger telescope to a near earth orbit than to the belt and you can also get the data much more rapidly so you can actually search for candidates in hours not in months and readjust the telescope as you see fit.

Is there any reason to think of an array of telescopes, like the VLA? Like, multiple smaller telescopes scattered at large distances? Or is that too difficult to coordinate?

This has a lot of sense and shouldn't be too difficult to coordinate. This has already been tested by LISA Pathfinder (https://en.wikipedia.org/wiki/LISA_Pathfinder) and proven to be feasible. Still, the reson here to get something far away from Earth as a general is not to have closer observation point but to have large distance between array nodes.

You mean send a Telescope to the Kuiper Belt? I believe resources would be better spent sending a probe to one or few of the bigger Kuiper Belt objects, such as Eris and Sedna. New Horizon's "target problem" is rather specific to that probe. Pluto was its primary mission. Other bodies were considered a bonus, and the probe doesn't have enough fuel to target the bigger (known) objects. Perhaps that was a mistake; but many of these were discovered after the probe was budgeted.

Their biggest problem atm isn’t time but speed, they have fuel but they can only do limited course correction as they don’t have that much specific impulse available to them.

So they need to find interesting things on their way bwfore they fly off.

“Plenty of fuel” is a PR spin. They have enough fuel for an additional flyby, but it has to be an object that is pretty much along their path anyway, or far enough out that a little tiny nudge will correct their course over a good portion of that 20 years. Hopefully such an object will be discovered once they start looking.

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