Alan Stern (2015)

This is Michael Vincent. The next step in higher rate communication at long distances is laser comm. Instead of sending a broad beam of X-band energy, send a very focused light, preserving a lot of the power. Take a look at the demonstration NASA did with laser comm to the moon: http://esc.gsfc.nasa.gov/267/271.html

Howdy! 1) A few weeks before the closest approach on July 14th should be the transition between geological object and astronomical object :). Pluto is already not a point source (a few pixels across - new pictures will be released later today!) and a few weeks before we will start being able to make out the albedo patterns, and then actual geologic features as we get closer and closer!

2) That would be a great comparison to do, we haven't yet though :P. ~Kelsi

Just to reiterate, here are the new images :)
http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150204

We have mission simulations of different kinds. We have operational readiness tests where we go through a process that involves different subsystem teams working together. We have simulated the closest approach sequence on the spacecraft to make sure it does what we expect. --Cathy

Michael Vincent: Not easy at all, and we don't have laser comm on New Horizons. The first demonstration was Earth-to-moon, and that was successful. The next step is Mars.

We're on a trajectory to Pluto that only needs corrections to home in. We're on original course.

This is Michael Vincent: We are going to be spending a long time downlinking the goods for sure. After that, we have identified two potential Kuiper Belt Objects if we get an extended mission approval.

There will be!

There are several aspects to this. These include when the downlink is planned (can be up to weeks or months after the image is taken), then 4.5 hours or so to get the data to the ground, and then same day image processing by our computers. Following that we decide which noteworthy images to release.On a typical day now, zero to one or two images come down. Watch for an image release today.

Michael Vincent: 10-100 times faster!

We're all incredibly busy. We have mission sims, encounter planning, dat analysis, software tool building, and outreach activities to keep us busy, and it does, usually 7 days a week.

This is Michael Vincent: The short answer is almost all the instruments can play a part. Long answer: we are going to be imaging clouds with LORRI and MVIC (the "cameras"). With Alice, we are going to look through the upper atmosphere by tracking the UV light from stars we are looking at as we are moving (like looking at the Moon through moving clouds). Similarly with REX, we are going to be looking at the lower atmosphere by having the DSN send us a signal at X-band, and have REX record how that signal wobbles through it. We can even "sniff" the atmosphere with our in-situ plasma instruments PEPSSI and SWAP.

We have software tools for different purposes including helping to analyze the science data, checking the sequences of commands that we send to New Horizons to take data, and managing the downlink of the data. We have tools written in IDL, python, C.

We do. And yes, we're working on that, no news for a while though....

The colors you see in the Hubble maps are as close to real as I could do. There's a range of color from neutral and bright, red/brown colors, and black. It's going to be very interesting to see if all that work was right or not. (Marc Buie)

We won't get close to any of the other dwarf planets. (Marc Buie)

Our flyby targets after Pluto are all much smaller than dwarf planets like Pluto and Eris, etc.; they are specifically desired to be the building blocks of dwarf planets, so objects 30-50 km across.

Michael Vincent: The typical rate we can downlink at is 1kbps. Just a trickle, really. There are a couple tricks we can play, though. First off, we can transmit with both our transmitters at the same time. That can nearly double our rate. Also, as the DSN station looks higher and higher in the sky, it gets less thermal interference from our own atmosphere here on Earth. At maximum elevation angles, we can get almost twice the data rate again. So, the maximum rate we downlink at from Pluto is 4kbps.

Michael Vincent: Thankfully, all the geometry is known ahead of time, so we do program the spacecraft to "rate step" through the pass. Our receiver is sensitive enough to lock to a signal as low as -160 dBm, though our commands are usually received at -120 dBm. That is what you get when you use a DSN antenna almost as big as a football field, and transmit at 20 kW.

That's something we have to manage too.

Leslie here. We're already seen signs of WEATHER on Pluto from ground-based stellar occultations. Pluto's atmosphere defocus starlight during an occultation, and waves in the atmosphere locally refocuses the light.

Michael Vincent: We are doing great on fuel. After Pluto encounter, and all the downlink, we will still have ~130 m/s left in DeltaV.

This is Michael Vincent: Keep your eyes on the New Horizons website: pluto.jhuapl.edu. There should be a new image posted shortly.

To get to the Pluto system in only 9 and a half years, we sent a small spacecraft on a large rocket. New Horizons is traveling at about 14 km per second. New Horizons launched on a huge Atlas V rocket to get to that speed. To slow down, we'd need the fuel of another Atlas V! But to carry that, we'd need more fuel, and then more fuel to carry that fuel.
-- Leslie

We will be taking color pictures. The big moon, Charon, will be mostly just shades of grey. Pluto really will have different colors on the surface. We just want to know how the colors relate to different geologic regions. (Marc Buie)

This is Michael Vincent: Because the location of the heliopause "breathes" with the activity of the sun and moves by many AU, so the exact date is impossible to determine. It won't be until the late 2030s at the earliest.

This is Michael Vincent:
1) We aren't really braking on approach. It is more important to fly through the system at exactly the right point, so that all our pre-planned observations are looking in the right place to find Pluto and its moons.
2) The prime mission will be over when all the data is to the ground, somewhere around the end of 2016. The RTG power supply will be able to keep critical systems powered until the late 2030s.
3) New Horizons is a Pluto and Kuiper Belt mission, so if we are approved for an extended mission, we will target another KBO (Kuiper Belt Object) and head thataway.

NASA receives less than 1% of the federal budget each year.

Everyone gets free stuff: we post all of the data from our spacecraft to the web for everyone to see.

I have never been to a meeting where I did not learn something new!

There are zero non-terrestrial residents in Idaho. (source: US Census Bureau)

• Curt

We're still evaluating between possible KBO targets. About Charon, it's Pluto's biggest moon, no problem there. It's also a planet in it's own right by my standards, just like the big moons of some closer planets. Sometimes things fit into multiple categories, even on Earth you can be both a city and a state. Just ask Google!. -Alan

Hate to say this, but when we name something after people, they are always deceased.

This is Michael Vincent: In the Kuiper Belt, it is unlikely there are more than a few more that we haven't already detected. Further out in the Ort cloud, however, there could be many more (could be hundreds or thousands).

There will be strong contrast on the surface, really dark and really bright, and other areas in between that will be red/brown colored. Inside, Pluto is mostly rock and water ice. On it's surface it has ices made of nitrogen, methane, ethane, and carbon monoxide. There must be a lot of carbon rich stuff around as well.

Nope.

New Horizons was the fastest spacecraft ever launched, but Voyager had more gravity assists than New Horizons so it is now faster than New Horizons.

Alan here. Shape was decided by many design aspects and requirements, but loosely based on the Ulysses probe to Jupiter which also had just 1 RTG, unlike Voyager's 2 RTGs. The instruments were chosen to answer NASA's request for certain data sets and scientific objectives and to be most competitive against other proposals. I chose the name to symbolize the exploration as aspect of the mission.

Leslie Young here. Three of here at the reddit (me, Cathy Olkin, and Alan Stern) have all worked on how Pluto's atmosphere varies over its season. New Horizons will give a highly detailed snapshot which can be used to understand decades of telescopic observations and to fine-tune computer models. These all together will give us a much better understanding of how Pluto's atmosphere varies, and how similar atmospheres vary on Triton or other volatile-covered Kuiper Belt objects.

It's the whole package! Many moons, surface activity, complex and changing atmosphere, clear surface markings, none of the others we know have all those in one system!

we do have some chemists! They also have a specialty in some sort of planetary-related field, like spectroscopy, or surface ice chemistry, or atmospheric chemistry :) If you could find a space-related project at a big lab, like the Applied Physics Lab or the Jet Propolsion Lab, that could be a way in :) - Kelsi

This is Michael Vincent: The best way is to start looking around for internships while you are still in school. As far as degrees, it takes all types. Pick something you like and are good at, then keep looking for openings.

This is Kelsi: You could look for internships with a big lab like the Jet Propulsion Lab or the Applied Physics Lab - you can contact people there and ask if there is any internships/work that you could do there as a student or new graduate - or look for a place local to you where any space-related science is done and ask there! There are tons of ways that computer science graduates can be of use to space programs, so don't be shy asking :).

The sunlight at Pluto is about a thousand times fainter than it is at Earth. This is about as faint as dusk or dawn here. Just as that isn't much of a challenge for your camera to adjust between noon and dusk, it was not much challenge for the New Horizons visible-wavelength imagers, LORRI and MVIC. For the New Horizons infrared camera, LEISA, and its ultraviolet camera, Alice, we planned our encounter to allow these observation to have long-enough exposure times to gather enough light from Pluto and its moons.

Alan here, there is SO LITTLE we know, its hard to guess what would be most surprising. I guess most surprising would be to find there are no surprises.

We should start to be sensitive to seeing additional moons in June.

Our best estimate of the risk of a dangerous impact is now less than 1%. The New Horizons team has done a lot of work in the last two years to understand the risk better, including more sophisticated models of how dust would move in the system. It is always prudent to be prepared: New Horizons is taking pictures when we get close to search for dust, and our team has prepared and tested an alternate set of observations that turns the antenna toward the direction we're moving for a few hours.

• Leslie

Michael Vincent: So am I! Our typical received power at Pluto is around -120 dBm. Our receiver is so sensitive it would lock to something as low as -160 dBm.

Yes, it is heading out and out. It does not contain a greeting to other civilizations, but it does contain a CD filled with names of people who wanted to send their names to Pluto.

One of the main uncertainties we're working with is planning the final details of DSN (Deep Space Network) planning.

We have an opportunity for a trajectory correction maneuver (TCM) March 10. We are still refining our plans but may have a TCM that would be about a 1 m/s burn. Without this TCM we could be off by ~10,000 km.

We have intensive imaging of Pluto and Charon planned through July. After that, we haven't decided. As we are flying away from Pluto, the Sun is ~15 degrees away from Pluto as seen from New Horizons and we can take images of Pluto with the Sun that far away. -- Cathy

This is Michael Vincent. I have been lucky enough to work on the RF and REX instrument for the last 10 years! In broad strokes, the DSN sends up a 20 kW X-band signal that is very very stable in frequency and amplitude. Onboard, we have an ultra-stable oscillator that the RF system uses to down-convert the signal and send it over to the REX instrument. REX has a digital filter (also referenced to the oscillator) that splits the signal up into in-phase and quadrature components, and then records it on the Spacecraft. By analyzing that signal, our scientists can look for any faint wobbles in amplitude and phase, and determine the nature of the atmosphere the signal had to travel through.

Michael Vincent: bacon

definitely waffles, with granola in them, obviously

Our mission objectives are really about exploration-- no mission has even been to a Kuiper Belt planet before. So we will be going with eyes wide open to map Pluto and its satellites, map their surface compositions and temperatures, assay the composition and temperature/pressure structure of Pluto's atmosphere, look for new satellites and rings, and to search for an atmosphere around Charon too.There's more, but that's the basics...

My #1 thing I was to see is what the exact size of Pluto is. The atmosphere makes it hard to measure the size directly. (Marc Buie)

Cool you're up at 2 am! We'll be imaging a lot in May, we haven't decided yet which images will be the best to send back or exactly when, but you can bet we'll be the most excited people on this planet to get cool new pics to the public!

Since Pluto's discovery in 1930, we have learned many different things about Pluto including it has 5 moons (that we know of today), a thin atmosphere (about one million times less dense than earth), Pluto has a surface with a lot of contrast (dark and bright patches), there are ices of nitrogen, methane, and carbon monoxide on the surface.

There could be lots, particularly far from Pluto. In close, the system is gravitationally jammed packed, so we expect at most only a few. But then again, this is first time exploration, so we could be really surprised!

We're moving about 14 km/sec at Pluto, do the math for km/hr or day! We will image Pluto and its biggest moon Charon best, with the very best images having better than 100 meter resolution. For reference, that's MUCH better than many first exploration missions, we're proud of that!

It's almost as easy as printing a picture out and using a ruler. But we need to get the images from right at closest approach to get the best answer. In reality it will take some months to get a definitive result. (Marc Buie)

New Horizons is flying two instruments that observe in visible wavelengths (LORRI and MVIC), and six other instruments besides. The Alice ultraviolet spectrograph will mainly study Pluto's atmosphere. The REX radio experiment will also study Pluto's atmosphere and measure the temperature of its surface. The LEISA infrared imaging spectrograph will mainly study the composition of the surfaces of Pluto and its moons. The two plasma instruments, SWAP and PEPSSI, will measure Pluto's escaping atmosphere and its effect on the solar wind. Finally, the Student Dust Counter will measure the dust environment of the outer solar system.
-- Leslie

Observations with LORRI, our high resolution camera, have typical exposure times of 0.1 sec. Our color observations, with the Ralph instrument, have exposure times of ~0.6 seconds. -- Cathy

Pluto's rotation period is ~6.4 days and we will have time to image the whole surface multiple times over.

You knew this was coming-- our extended mission!

We could have done that, but we carefully studied which date would optimize the positions of Pluto and its satellites and July 14 came out far better than any other mid-2015 date.

Michael Vincent: All our data will become publicly available!

I hope to see how the bright and dark regions plus the surface composition relate to geologic features on Pluto's surface (Marc Buie)