Alan Stern (2014)

Haven't seen it since the 90s to be honest, and I don't remember too much of what happened. I think we have it on VHS at my mom's house. Good soundtrack.

-AZ

Simon here. Guiding in space is a two-part problem. First, we need to know where all the objects are, and second is knowing where the spacecraft is. For the first problem we use telescope observations from Earth taken over a long time to see them move. For Pluto, we scanned in old-fashioned photographic plates of Pluto going back to its discovery in 1930. For the spacecraft, we use high-precision radio tracking from Earth, as well as optical navigation using the spacecraft's on-board telescope (LORRI).

Alex here. I did a quick calculation for you. Using the most up-to-date model of the Kuiper Belt (CFEPS L7), 50% of 100 km or larger Kuiper Belt Objects (KBOs) have another 100 km KBO within 1.3 AU (1.3 times the Earth-Sun separation) at any given time.

This, of course, neglects binary KBO systems. In one part of the Kuiper Belt (the Cold Classical Kuiper Belt), binary systems are extremely common - in fact, there may be more large KBOs locked in binary systems than there are solitary large KBOs.

When New Horizons reaches Pluto it will be about 33 AU from the sun (i.e. 1 Earth-Sun distance). The intensity of light falls off by the square of the distance from an object, so the sun on Pluto appears about 1/1000th (i.e. 1/33^2) the brightness on Earth.

1/1000 is about the difference between full sun at noon, and inside your house, which your eyes will have no trouble adjusting to.

-AZ

We're looking for ancient KB objects to fly by, assuming NASA approves an extended mission after Pluto.

Wheeeeeeee!

I talked to Alan about this question. It's not the answer you are looking for, because the most sorely-missed instruments were invented before the 2006. It's actually money that's the limiting factor.

The first instrument that we'd like to add is something that images in the far-infrared. This would have enabled us to get true thermal maps and detect sulfur.

The second instrument would be a cube sat that we would launch from the spacecraft. We could image the other side of Pluto. Or we could put a magnetometer aboard (we don't have one). Having the magnetometer be a separate thing inside the spacecraft would eliminate need to clean the craft (a pain).

-AZ

About 8.5 hours round trip, at the speed of light.

We'll be taking hundreds! And we plan to make them public as hey arrive, same day, each day, on approach!

That's Pluto! Don't worry, we'll miss it by 10,000 kilometers.

-AZ

We'll get only one hemisphere at really high resolution. We will be imaging Pluto and Charon as it rotates in the days leading up to closest approach.

After flyby, to get some more of the surface, each day we'll be taking a few pictures where Pluto will be a crescent with about 15 degrees of the surface visible.
-AZ

The answer depends on how good a radio system you have. In our case, we can communicate even farther out than Voyager is now.

We don't do the coding for the flight software, that's SciOps.

However here's what I know, each set of spacecraft commands is put up as a "command load", which has a name that's the year plus the day of year. So the 15188 load runs on July 7, and has commands for nine days.

Each load has a multi week coding and vetting process and is simulated on the ground, on a system called "NHOPS", pronounced "nops".

-AZ

I emailed some folk, here's an answer to #3, from Jillian, one of the members of our SciOps team.

3: We have a program called Statesim that checks to make sure constraints are not violated. For instance the Alice aperture door shouldn't be open within 20 degrees of the Sun. We also have something called NHOps which is a software EM of New Horizons and the commands are executed on it and data is downloaded and reviewed by the instruments. We also had a rehearsal in 2013 for the Pluto Closest Approach load.

-AZ

Okay, here's an answer from Helen Hart at Johns Hopkins University Applied Physics Lab (AZ):

1. We do not program New Horizons flight software. We store commands,
   packaged into macros, in the portion of C&DH memory designated for command
   storage, and execute the macros via a Time Tag.

2. See #1.

3. How are we sure that it¹s gonna work? That¹s a really, really big
   question, involving multiple layers, multiple platforms, and a lengthy,
   intensive Load Build and Review process. For more details on the process,
   talk to the Science Sequencers.

The command load is simulated in SEQGEN, which is also where it gets
built. The Seqgen Modeling File contains hundreds of checks for problems
with commands vs. the state of the spacecraft/instrument. The Seqgen
modeling file also contains the Mission Operations Playback Data Volume
models.

We have a SOFTWARE SIMULATOR called stateSim which models the response of
the spacecraft and payload to the command sequence. stateSim generates
the file that Mission Operations Command Sequencer turns into the Command
Sequence Timeline - the excel spreadsheet that is distributed as part of
the load review process.

We have HARDWARE SIMULATORS, called NHOPS-1 and NHOPS-2, which contains
HARDWARE modules for the onboard processors, including C&DH-1, C&DH-2,
SSR-2, SSR-2, G&C-1, G&C-2, P-Alice, LORRI, PEPSSI, Ralph, REX-1, REX-2,
SDC, and SWAP.

The NHOPS and stateSim simulators have different weaknesses; for example:
a: NHOPS gets all the details of slews correct; stateSim gets the slew
start time and duration correct, but does not track the exact path of the
track because that part of the CG&C cannot be modeled in software.
b: stateSim correctly predicts C&DH Thermal Control, but NHOPS does not
predict this at all
c: SSR usage: stateSim does not model SSR usage. NHOPS does, but gets the
wrong answer for anything that gets Compressed or Packetized. SEQGEN is
tied directly to commanded data downlinks, and cannot be manipulated to
produce interim data volumes; it correctly models downlink data volume TO
THE ACCURACY OF the Compression Ratios specified by the Science Sequencers
(lately, DataTrack).

-- Helen

upvoted. Ask your Sci-Ops questions here!

-AZ

Hello! We will also get tons of other information about composition of the surface, the atmosphere, and the interaction of Pluto with its space environment. There are a whole host of capable instruments on the spacecraft, each with a scientific goal.

it is exciting! we will get the first better-than-hubble picture in mid-May! Some pictures will come down right away (day of and a few days after the encounter on July 14th) - and all will come back in a lossy format by mid-November :). Then we will get all of them back in a lossless format over the next year :).

Half of the planet will be in darkness, we will still try to get some pictures of it anyways :).
~Kelsi

Yep, that's the best scene in the movie. John Hurt rocks.

• Simon

:) ~Kelsi

We will be shocked no matter what I think - it is impossible to predict what the most significant find will be - that is why we are going there! I think we would be really shocked though, if Pluto was very cratered, and Charon was not - we expect the opposite :). ~Kelsi

I've never played KSP, but I have friends who love it. It sounds like a great way to get a feel for the actual physics involved. Movies hand-wave away so much physics that people don't really have a feel for what can't be done (i.e. sharp turns and fast breaking). I'll buy it eventually, but I have a very big Zelda backlog.

Cosmos is great. Humanity has gone from "what are these these stars that move against the background" and "this comet means we are all going to die" to flying by planets and landing on them like with Rosetta. It's super-important that the information we've learned actually gets out to as many people as possible, and Cosmos is a means to do that.

-AZ

There is an almost 100% chance more planets will be found farther out, but it's hard because our technology only lets us search a little ways out to the Oort Cloud so far. BIG new telescopes of the 2020s will do much better.

Alex here - there are interesting dynamical signatures in some of the populations of small worlds we know about in the outer solar system that suggest something is lurking further out. However, these signatures remain pretty ambiguous at present.

We do have strong limits on how big a planet can be at any given distance from the sun and still have evaded detection in our all-sky surveys (such as the WISE mission). Our technology is constantly improving - new instruments (like Hyper Suprime-Cam) are coming online all the time, and they all help open up new ways of searching for distant worlds in our solar system.

It's Alan, I was drawn to this because it's raw exploration, not the 10th mission to here or there, but first time, farther, faster, into the unknown. There's nothing else like it for me, I love it!

Hello, this is Kelsi - I did my undergrad in astronomy, and my graduate work in planetary geology on the icy Moons of Jupiter and Saturn - so that is what set me up to work on Pluto - another icy body :). The skills you want are critical thinking, being able to write and communication (believe it or not ;) and working on your math and programming skills. I say working on, because you can always get better, but it helps to get a good start. :)

It is helpful if you can get involved in missions as a grad student or post-doc (work for an advisor who is on a mission) but if you get good at what you do - then people will want you on a mission :).

Alex here - I have a primarily astrophysics background, though my first published work was on Martian geology. My PhD work was on the small and numerous worlds of the Kuiper Belt, particularly those in binary systems.

As part of that research I developed some techniques for efficiently detecting extremely faint moving objects in digital images, and these techniques were needed for the search for a post-Pluto Kuiper Belt target for New Horizons. After completing my PhD I immediately joined the KBO target search effort as a postdoc, and have been working on that ever since.

Amanda here- I did my undergrad at Wellesley College where I majored in Astrophysics and minored in math. I did my PhD at MIT in Planetary Science with Jim Elliot (discoverer of the Uranian rings) and later Rick Binzel, who is also a Co-I on the mission.

Working in Astronomy was a surprise to me. I got hooked on Astronomy at Wellesley, and just kept getting jobs.

As a grad student, I started this project where I cataloged the use of longitude and latitude for Pluto for every paper written since Charon's discovery in the late 70s. I guess that qualifies me.

-AZ

Simon here. I caught the planetary bug in second grade, but I never thought I would be able to do it for a living until I got to do an internship at NASA JPL in Los Angles. After that, I worked in grad school (at ASU and Lowell Observatory) on the physics of Pluto and Kuiper Belts Objects, before I got be part of this mission earlier this year.

Last one here -- I got here through a lot of school, like everyone else. I knew I wanted to be an astronomer when I started high school. I attended Boston University for undergraduate school and got a BA in Astronomy & Physics (1995-99). While there, worked with Pluto and Triton data trying to detect carbon monoxide (CO) in their respective atmospheres. It was difficult data and we could only provide an upper limit. I knew then that I wanted to stick with Pluto. It was also at this time that Pluto missions were being approved and subsequently cancelled. From there, I went to Arizona State University for my PhD in Astrophysics (2007) and I focused on near-infrared spectra of Charon for my thesis. I also played with spectra and images of various comets .. but Charon was always calling. As I was within sight of finishing my degree (1.5 years away), New Horizons was nearing launch. I was lucky enough to present some of the work at the New Horizons launch science team meeting. And a year later, fate brought me to Colorado where I was lucky enough to land a post-doc position on New Horizons. That lasted two years, I then went to NASA Ames for bit before returning back to Colorado. So what brought me here? A bit of luck and a lot of drive. --Jason

We've found many unreachable KBOs. These will be mostly points of light at closest approach, but we're trying to figure out what sort of science could be valuable, anyway.

Our spectrometers only work on bright objects.

-AZ

We plan to make the first exploration of the Pluto system-- no mission has ever been there. In fact, no mission has been to a Kuiper Belt planet. We are exploring the unknown, the surprises nature present will be the most exciting parts!

About 1000 bits/second.

-AZ

To paraphrase Douglas Adams: "Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."

There's a lot of worlds in the Kuiper Belt, but the volume the Kuiper Belt occupies is absolutely HUGE. The risk of impacting a previously unknown object beyond the Pluto system is vanishingly small.

• Alex

Here's your serious answer.

Our minds would be blown, since Pluto's the absolute worst place for aliens to visit and stick stuff there. It's ... cold, hard to find unless you are looking for it, and Saturn's moons provide cooler views. We have rehearsed many scenarios, but this isn't among them.

There's not really we can do or change, because our imaging plan is locked and the flyby trajectory is set. Our last chance to change anything is at P-13, where we can choose a different (already written) sequence that uses the antenna as a shield to protect the spacecraft, or pick from a handful of pre-planned trajectories based on what we think is safest, but that's still really far out. By the time we are close enough to see images that unambiguously portray intelligent life, it will be much to late to do anything. When the best images come down, New Horizons will be past Pluto.

However, we will have no trouble getting a second mission to Pluto approved, if we did see aliens!

-AZ

Huge satisfaction that we did something good-- inspiring people, developing new knowledge, exploring!

At Nix we'll get images as good as on Pluto's global maps. For the others, not so well, since we have so little time and they all pass by the same day.

And we will be searching for new moons and rings on the way in to the Pluto system, both for science and to make absolute sure we don't hit anything.

Simon

We don't have the speed to slow down much, and we don't want to, it would hurt the chances of flying a KB mission after. And besides, to really slow down we'd need a rocket the size of the one we launched with-- 227 feet tall!

1. We can't get a full map because it is not "equinox" on Pluto. Just like the south pole is completely shadowed in northern hemisphere summer, Pluto's south pole (determined by Pluto's rotation and the right hand rule) is permanently in shadow. We are going to try to image it using illumination from Charon. So we'll have one hemisphere at high resolution, and the other side at lower resolution.

2. We get this question all the time, We don't have the fuel. Simon did a quick calculation, and it would take about 60x the mass of the spacecraft worth of fuel to stop it. Needless to say, we couldn't launch that.

Even though an orbiter can do a lot more than a lander, we've got the most sophisticated payload of any first-reconnaissance flyby spacecraft.

-AZ

Yes: mooooooons. Months before launch, two new moons were discovered around Pluto (Nix. In the years since, we have discovered two more (Kerberos. The Pluto system is absolutely lousy with moons.

• Alex

Yes! Just months before launch, two more moons of Pluto were discovered, Nix and Hydra. Several years after launch, moons Kerberos and Styx were discovered.

Since launch, Pluto's atmosphere has also been more extensively discovered via stellar occultation.

-AZ

No need to remake the trajectory due to gravity. We did try to squeeze in some images of them though.

-AZ

No, we don't want to burn the cameras out on the Sun-- and the Earth in July is <1 deg away from Pluto, also too dangerous.

-Alan

We haven't seen any non-gravitational forces on the spacecraft that can't be explained by known forces like the solar wind and RTG thermal emission. Part of that is that we have a much better thermal model of New Horizons than the faulty Pioneer 10 model that led people to think they saw the "Pioneer Anomaly".

Hello! This is post-doc #4 - I can answer your question as I worked on Icy Satellites for my dissertation work. You are correct that we think Triton might be one of the best analogues to Pluto and that is why we feature it on the website :). Triton does not have very many craters, and that is because other geologic landforms have resurfaced it, including possible cryovolcanic features, funky terrain called "cantaloupe terrain" and tectonics. :) Pluto probably won't look exactly like that, but it we think it probably doesn't have a ton of craters (as in, it will not look like the Moon!)

2001: A Space Odyssey, Apollo 13, Gravity, Silent Running, Her, Moon, can't wait for Interstellar!

The cameras (Ralph and LORRI) are really sensitive, so that we can take pictures as fast as possible at Pluto. In fact they were almost blinded trying to look at Jupiter when we flew past in 2007.

Simon

We are taking all the pictures and measurements as fast as possible and saving them on two big solid-state drives. Then we'll slowly trickle them back over the next year and a half.

We are not doing a "slingshot" (technically a "gravity assist") around Pluto, because we are going so fast and Pluto's gravity isn't strong enough.

However, we able to get that fast by doing a gravity assist at Jupiter. Before Jupiter, we were just in an orbit around the Sun, but Jupiter's gravity put us on trajectory to leave the solar system entirely.

Simon

Ground-based occultation data say no, but we will look anyway!

-AZ

Nope, longer than 9 years. We get to go so fast precisely because we aren't slowing down.

Also, I don't remember where Jupiter is these days, but we'd another slingshot from it. Had we missed our launch window, years would have been added onto our travel time. I forget when it reopens.

-AZ

Some ways yes, some ways no. It sure was beautiful eye candy though!

Yes, Love New Horizons more. And yes, it's single!

Alex here - New Horizons has a few cameras, but it does have one pretty serious telephoto: LORRI, the Long Range Reconnaissance Imager. It is a 208mm-aperture telescope with a 2630 mm focal length. This is one of my favorite instruments because of what it can get us as New Horizons continues on into the Kuiper Belt.

Simon here. New Horizons is going slower than both of the Voyagers, because they had two and four giant planet flybys, respectively, while New Horizons only had one. That means the New Horizons will never pass them. However, New Horizons is a much smaller spacecraft and was launched on on rocket that was only a bit less powerful than the Titan-Centaur that launched the Voyagers. So, New Horizons was the fastest powered spacecraft ever when the Atlas V launched it in 2006.

For comparison, missions to Jupiter that intend to stay there (like Galileo and Juno) take many years to slowly reach Jupiter and softly go into orbit. We screeched through the inner solar system and reached Jupiter in a year. NH is a speed demon!

Yes! Pluto isn't much bigger than Charon, and their common centre-of-mass is about a Pluto radius above Pluto's surface. So, New Horizons doesn't see just Charon orbiting around Pluto, but also Pluto wobbling back and forth as Charon pulls it around. Charon is actually bigger all of the main belt asteroids, including the dwarf planet Ceres. Plus, there are least 4 more small moons that orbit around Pluto-Charon; it's like a miniature circumbinary solar system.

• Simon

It's a challenge we love! Truly! -Alan

When the Pioneers and Voyagers were launched, we didn't even know the Kuiper Belt existed. In fact, when Voyager 2 did its last planetary flyby in 1989, we still didn't know the Kuiper Belt existed! Plus, Voyager 1 went completely out of the plane of the Kuiper Belt (in order to fly past Titan).

Alex made up a plot of how close our four outer system predicessors went to known KBOs; not very close! https://plot.ly/~alexhp/56

Simon

Alan says the competition for getting funding.

-AZ

Not sure across the whole mission, but in this room the arithmetic mean age is 30.

The time it takes for a signal to get from one end to the other is about 4 hours. BUT, the rate at which the full resolution images are returned is slow. We won't have all of the data from the flyby down until October 2016. This will sort of make the flyby feel more like an orbiter, because we will be releasing new discoveries for months after July 2015.

I personally hope we find that Pluto and Charon are not dead frozen worlds, but ones like Triton and Enceladus with plumes and geysers. --Jason

If I were king, I'd love to see more New Horizons mission using Uranus and Neptune flybys to go on to other planets in the Kuiper Belt, like MakeMake, Eris, and Orcus. -Alan

Outer solar system exploration dead? Nope. There is the Juno mission which is currently on its way to Jupiter. JUICE, a European mission, is also going to Jupiter with a launch around 2022. Cassini is still going on until 2017. There are plans for a mission to Europa to examine the recently discovered plumes. And there are proposed missions to get back to Titan. Depending on where you draw the lines for the outer solar system, Dawn will reach Ceres in April 2015 and Rosetta is orbiting Comet 67P/Churyumov-Gerasimenko .. and comets tell us a lot about the outer solar system and the environment it formed in.

Yes there is a lot of focus on Mars, but that is all for good reason. Mars is close. When a mission takes 9 years to get to its target (compared with several months or 1 year to get to Mars), a lot of things can go wrong. And because Mars is relatively easy to get to, we can learn a lot about the solar system in general, the likelihood of forming life, and what made Mars so different from Earth.

Mars will probably be an object of interest for some time. But so will Europa, Titan and Enceladus. --Jason

From ground based observations, we know that its surface is covered in nitrogen (N2), methane (CH4) and carbon monoxide (CO). There are also traces of (at least) ethane (C2H6) with predictions of other hydrocarbons and possibly nitriles (e.g., HCN, hydrogen cyanide). One thing we haven't seen on Pluto's surface is water ice (H2O). Pluto's near-twin, Triton, does have detectable water ice. The difference might have to do with how ices/frosts migrate over different seasons on each of the objects. I should also add some perspective here .. our detection of these ices is done at near-infrared wavelengths (generally 1.0-2.5 microns) and that only measures the top millimeter of ice or so. So it would not take much to bury water ice. New Horizons may find small, isolated patches of water ice during its flyby. This is, of course, one of many things we don't know that I (Jason) personally will find interesting.

We've already sent spacecraft to Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune, some multiple times. This will be our first and possibly only visit to Pluto.

-AZ

Encounter begin in January, but we will not have imagery able to detect new moons until late spring when we're closer. That's bcs Hubble has done such a great job so far.

-Alan

New Horizons should remain alive until late 2030s.

I am not aware of what kind of data it will return past the Kuiper belt. But I can imagine the SDC (Student Dust Counter) will remain in operations. If we happen to get a chance KBO within range (1 AU?) maybe we'd get a few images of it, but it wouldn't be anything like the Pluto images. It would be a pixel or two.

There are images planned that will be specifically for the Kodak moment. You'll have to wait and see what they are.

--Jason

In my headcanon, a self-aware N'zons returns to Earth alive and well in the 2270s.

Alex here - astrodynamics is a buzzkill. Humanity got very lucky with the timing of the Voyager missions, given an arrangement of the planets that made for that sequence of encounters practical. New Horizons used a Jupiter flyby to boost its speed and make the cross-solar system cruise relatively short (~9 years), but trying to target other outer planets in a grand tour-style mission would be extremely hard given the current arrangement of the planets.

Hi Charles,

We are going to try to look for hazards and unseen moons as often as we can to avoid any collisions with an unseeable ring system. Our last chances to do see rings and do something about it to adjust our trajectory are at P-13 days and P-18 days.

However, after the Pluto encounter is the best time to see rings. Think of how when driving into the sun you can see all the dirt on your windshield. So after it's on the other side of Pluto, New Horizons will point back to look for unseen objects. Voyager discovered Jupiter's rings this same way.

-AZ

hello! the resolutions for the some of the best images will be ~70 m/pixel, great for looking at high resolution of the surface.

The range at closest approach is 10,000 km, or 6,200 miles, and it will be traveling at 14 km/s (31,300 miles per hour!)
~Kelsi

Doctor Who -- Jason

Star Wars
-AZ

Doctor Who

What? Battlestar Galactica.

Please. Space: 1999.

I can't believe I'm sitting in the same room as y'all.