Wednesday , June 16 2021

The moment we first saw Ultima Thule Up Close



You plan an exploration trip for over three years and the time comes when you see a new world for the first time. This is an informal sketch of how I experienced this during the Ultima Thule encounter by NASA's New Horizon spacecraft. The setting is a simple conference room on New Year's Day 2019 in building 200 on the campus of the Johns Hopkins University Applied Physics Laboratory, which operates the New Horizons. The room supports the analysis activities of the New Horizons Geophysics and Geology Investigations team, one of the three divisions of the general science team established to investigate Ultima Thule. The other scientific divisions are housed in similar rooms in other parts of building 200. Other APL buildings house the two navigation teams, the operations team, a diverse set of instrument engineers and spacecraft, and a variety of management and support personnel which enables more than 100 people to blend their efforts into common cause. Alan Stern is the principal investigator and responsible for the mission above all else.

It took all of us to make the meeting happen. Each of us has a story to tell, a role to play, a unique perspective. The credit for success goes far, far more people than those shown in the photos of this article, not to mention the few that I call in the narrative. In the end, however, the experience of the meeting is always personal – where you are, what you were doing at the moment, who you were with, and the shared reactions of those on the team with whom you worked more closely. This story is simply what I saw from the point of view of the small part of the team I was with at the time.

The arrival of Ultimate's first high-resolution image in physical terms could be more mundane.

In emotional terms, it could not be more electric.

The Deep Space Network spent an hour capturing the telemetry of the New Horizons spacecraft, all of it sending the image line by line to a server and a reduction channel in Boulder, Colorado. We hope, we'll see, we wait a little longer for a given file to be created in a specific directory. Who really sees the image first is who first identifies the key file update or is the fastest typist.

Credit: NASA / JHUAPL / SwRI / Henry Throop

It's Stuart Robbins who finally shouts, "Get it!" and we immediately mobbed his work area in the back of our analysis room. This is my back in the lower right corner of the image above. I see nothing! I doubt many of us can. We have a big screen in front of the room, so the question is: how fast can Stuart remember how to type the command to connect to it?

Credit: NASA / JHUAPL / SwRI / Henry Throop

We put the image on the screen and everyone goes crazy. This is Marc Buie giving a victory turn, above. Marc was the one who discovered Ultima Thule, and with immense skill, focus, determination, blood, sweat (and tears), fought a four-year campaign recruiting teammates (and others) to throw everything they had on the object to determine your precise path through space. Thread a needle as it flies into the galaxy – let's see – only 42 times the speed of sound. There has never been a spacecraft that needs navigation so accurate so far.

Oh, look, this is Brian May on his back. He walked in about 30 seconds before the fourth exploded with three years of repressed energy. It's showtime except we're all on stage now. We're all in the area. We all have our parts and instruments to play, but always with attention to each other as we listen to where the music is going. See people with their hands on keyboards? They are not coming back to work, they are not calming down from the show. They started the beat, and we'll play the night. A quick first reading at Ultima Thule is the task ahead of us. All contribute. I look around the room at one point and see Brian working quietly with another team member using stereo images to visualize Ultima Thule.

Credit: NASA / JHUAPL / SwRI / Henry Throop

But first John Spencer has a solo. This is John standing on the right. (I'm in the right corner, almost certainly carrying the image myself). John led the team by defining the entire observational sequence for Ultima Thule. Three years ago, a few months after we passed Pluto, we dismissed New Horizons' thrusters to set their course for Ultima Thule. John got up at a team meeting in November 2015 to put the question, "Well, OK! So what do we do when we get there?" Countless telecons, meetings, PowerPoint presentations, simulations, inquiries followed. In the middle of one of them, I thought, "God, John is trying to order Chinese food for 100!" The trick is to ensure that everyone has enough to be happy, even if they do not get what they want. Oh yeah, John also working side by side with Marc to make sure we got to Ultima Thule OK first.

So, the ground! While we are all going crazy, John in his undisturbed style remembers to ask Stuart the exact position of Ultima Thule in the image and instantly knows that we discard it in money. The navigation seems perfect – we should get everything we ask for. He sings about the room. In a concert, the crowd applauds and screams – and so do we.

Credit: NASA / JHUAPL / SwRI / Henry Throop

Marc hugs John or John hugs Marc. It worked. Everything worked.

I'm on the right, smiling, and Simon Porter is back on the left. The four of us were BORG – the Binary Object Reconnaissance Group. As part of a larger risk-taking team, we used long-range imagery on the spacecraft to see if the path to Pluto was safe in 2015 and again as we approached Ultima Thule. The risk team (led by Mark Showalter, who is in the lower left corner of the previous photo) stated that the road to Ultima Thule was free of dust and debris a few weeks away.

But if the spacecraft were likely to be safe from physical damage, the project team still feared that as we approached we might find that Ultima Thule was actually a two-object binary system, potentially requiring a sharp adjustment in our preprogrammed segmentation . We stayed in the "raven's nest" almost all the time, supporting the efforts of the two shipping teams. I was more than a little nervous that we could really stick the needle.

Credit: NASA / JHUAPL / SwRI / Henry Throop

So I have to hug John too! But there is more. Two years ago, John commissioned me to lead the project of the highest resolution image sequences to be made. The fact that we could target Ultima Thule with the New Horizons high resolution camera was an open question at the beginning. I was always pestering John about a trick or another we could do to make it all work. And so it happened, then it happened.

Credit: NASA / JHUAPL / SwRI / Henry Throop

Here is Ultima Thule! Can you "read" that image? (Full disclosure: here we are looking at an even closer picture that came much later, not the first one to come down.) I try to learn from my time with the team, but I am not trained as a planetary scientist. As an extragalactic astronomer, I can read galaxies, star clusters, what you have, but that is beyond my experience. But beyond that, it is beyond the experience of all others, and that is the essence of discovery. I know Ultima Thule is nothing like what we saw before. Is it special, though? We hope not! We've never been so far before. The entire Kuiper belt was unknown until the early nineties. We hope that Ultima Thule is not strange, but rather a typical inhabitant of a strange new place.

Each team member will analyze the Ultima Thule differently based on their own experience, intuition, knowledge and influences. Let's share all these ideas among ourselves, with various discussion disputes, jaws, calculus, simulation, gesticulation. We will be wrong about some things, certain about others. Intelligent ideas will emerge, often from those not on the team, but waiting patiently (or waiting not so patiently) to see what we can extract from the outer solar system.

But for now, imagine yourself here with us in the dark room. Be quiet, look, think, imagine, reflect on how far we travel and what we will learn from the journey. It's your adventure too.


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