New Horizons Phones Home After Pluto Flyby -- Craft Healthy, Data Recorded

Tablizer was one of several readers to note that the New Horizons probe has completed its flyby of Pluto and radioed home to confirm that it went without incident. Mission Ops manager Alice Bowman said the spacecraft was healthy, full of data, and sharing telemetry. The images New Horizon collected haven't been downloaded yet, but NASA decided to tide us over by releasing this high-resolution view from the day before. It was taken when the probe was still 768,000 kilometers away with a resolution of 3.8km per pixel. (Closest approach was approximately 12,500km.) They also released an exaggerated-color image of Pluto and Charon which highlights the non-uniformity of both worlds.

Pictures from closest approach are not yet available. Expect another post late Wednesday or early Thursday with those images. The reason for this is that New Horizons can't take pictures and send them to us at the same time, so imaging activity is interspersed with downlinks to Earth to transmit data. Emily Lakdawalla has posted a downlink schedule. On Wednesday afternoon (ET), the probe will transmit three images of Pluto that were taken from 77,000km away, with a resolution of 0.4 km per pixel. They'll be the first three pieces of a mosaic of Pluto's surface, and the dwarf planet will fill all three frames. It will take a full 16 months for New Horizons to transmit all the data it collects. (Lakdawalla also added Pluto to a montage of the biggest non-planets in the solar system. New Horizon's measurements indicate Pluto is slightly larger than we thought. It's now considered the largest of the Kuiper Belt objects.)

Comments

It's larger than we thought, lets call it a planet

[youn]

lol, that surely won't wake up any old controversy :)

anyway, awesome to see images coming through

Re:It's larger than we thought, lets call it a pla

[Crashmarik]

Still say they should have named Charon, Goofy.

need for delay befor the images are released

[frovingslosh]

You can bet that, after NASA recently cut out of a live broadcast of the earth from space when 3 UFOs suddenly appeared in the video, that this data will be thoroughly picked through to make sure that there are no more unwelcome photobombs in these pictures.

NASA's amazing capabilities

[chipschap]

NASA's staff does amazing things and this is another one. Imagine what they could do with adequate funding, non-politicized leadership, and freedom from overwhelming bureaucracy. It's a huge credit to the staff that despite enormous obstacles they do a lot of great science.

After 5:00 AM EDT

[mbone]

The first data download with pictures from the encounter (the "New York TImes" download) will start at 5:00 AM EDT Wednesday. Expect some in the morning, and a lot during the 3:00 PM EDT NASA Press Conference.

largest already

[arth1]

,

It's now considered the largest of the Kuiper Belt objects.

It already was considered that. Eris, the previous contender for largest dwarf planet, has not been considered a Kuiper Belt Object for a long time now, but a Scattered Disk Object.

Downlink

[Solandri]

Downlink speed is limited to 1 kbps (bits, not bytes). 2 kbps if they use a trick involving shutting down power to instruments to boost transmit power.

Reminds me of the early 1990s when JPEG images first started showing up. Full-color 640x480 GIF photo scans were a couple hundred kB and could take 10+ minutes to download over my 2400 baud modem. I was astounded that a 30-40 kB JPEG could look just as good to the eye. Course the JPEG took over half a minute to decode and display back then, but combined with download time it was still faster. (Yes computers and network speeds used to be that slow - it's why the early web made extensive use of thumbnail pics.)

Re:Downlink

[mbone]

Downlink speed is limited to 1 kbps (bits, not bytes). 2 kbps if they use a trick involving shutting down power to instruments to boost transmit power.

That's actually a dual polarization mode - this is the first spacecraft with a dual-polarization data transmit capability. (And, yes, it does require more power, and so won't be used until they are well past Pluto and can put things on standby.) Even with that, it will take 16 months to get all of the data back.

Re:Downlink

[stud9920]

What a waste of time. In these 10 years since launch, they could have precomputed every possible picture, hash them, and then the probe could have simply sent the hashes instead of the full size pictures.

Re:Downlink

[Lord Crc]

In these 10 years since launch, they could have precomputed every possible picture, hash them, and then the probe could have simply sent the hashes instead of the full size pictures.

Just for fun, let's see what it would take for them to pull this off. The LORRI image sensor is 1024x1024 pixels with 12 bits per pixel.

So the number of distinct images divided by the timespan available gives 2^(12*20) / (10 years) = about 5.6 * 10^63 hashes per second.

Let's say you had a CPU capable of computing one such image hash per nanosecond (very optimistic), you'd need 2^(12*20) / (10 years) / (1 nanosecond) = about 5.6 * 10^54 CPUs to pull this off.

For comparison that's an order of magnitude or so more than the number of nucleons in our earth.

If those CPUs consumed 50W of power computing these hashes (again very optimistic), the entire project would consume 2^(12*20) / (1 nanosecond) * (50 watt) = 8.8 * 10^64 joules.

For reference that's two orders of magnitude more than the total mass-energy (including dark matter) of the Virgo supercluster, the supercluster which contains our Milky Way galaxy.

Unless I messed up the calculations that is...

I was really excited about this

[jez9999]

I'd been waiting for this and following New Horizons so obviously it's great to see, but what slightly tainted the coverage for me was all the freaking USA flag-wavin'. Do you guys really always have to do that? Obama called it "American leadership". Look, I know it was launched and managed by NASA but it involved various non-US technology and experts, not to mention plenty of non-US interest (and non-interest from most US citizens who won't even have heard of New Horizons until yesterday).

I do think your nationalism ruins things a bit. At one point a NASA guy said it was "all about America" in a room full of US flags. Funny, I thought it was all about Pluto. Can't it just be a victory for human ingenuity and curiosity?

Re:I was really excited about this

[jez9999]

In fact the core technology of the 2 main imaging devices, LORRI and RALPH, was British.

Re:It's larger than we thought, lets call it a pla

[bunratty]

They did name Charon, Doofus.