New Horizons - Are we there yet?

Helen Hill | EAPS News
Monday, June 1, 2015

The New Horizons spacecraft has been on its way to Pluto for almost ten years - and on July 14, 2015 it will be at its closest to the “icy dwarf”. While we wait, EAPS alum Cathy Olkin ’88(XVI), PhD ’96(XII), Deputy Project Scientist and Team Leader for the PI on New Horizons, talks about the mission and its deep connections to EAPS. Cathy’s mentor, EAPS Professor Jim Elliot (1943-2011) was the pioneer of the stellar occultation technique that led to the discovery of Uranus’ rings and Pluto’s atmosphere, and current EAPS Professor Rick Binzel is a Co-Investigator on the New Horizons Team.

EAPSpeaks: What excites you most about New Horizons?

Olkin: What excites me most is being one of the first people to get a close up look at this new realm of the solar system - somewhere we've never seen before. The New Horizons Pluto encounter will be the first time we have seen a Kuiper Belt object (KBO) close up. The Kuiper Belt is a completely different planetary regime from anything we have visited before - not the terrestrial planets, nor the gas giants we have become familiar with, but this great ring of hundreds of thousands of rocky and icy bodies out on the edge of our solar system: a great million year old debris field, the remnants from when our solar system formed. It can’t help but be a revelation to see this new class of bodies close up.

When I was an undergraduate at MIT in the 1980's, we didn't even understand that there were objects in the Kuiper Belt - people had postulated that maybe there was something out there but that wasn't confirmed until the discovery of the first KBO (after Pluto) in 1992. 

Of course, Pluto, discovered in 1930 by American astronomer Clyde Tombaugh, famously was, for most of the 21st century, considered to be the solar system's 9th planet (if a slightly oddball one). It was only in 2006, with New Horizons already many millions of miles into its journey, that it was formally reclassified as a dwarf planet, but I still consider Pluto a planet and refer to it that way. So I have been the witness of a transformation of our understanding of the structure of the solar system just since the time I was in college. 

EAPSpeaks: What discoveries are you most eagerly anticipating?

Olkin: New Horizons has a really capable payload - we've got seven instruments on board that can look from the ultraviolet to the near infrared and also, using radio science, to investigate the atmosphere. We'll be looking at Pluto with everything we've got and, while I don't know what we're going to find, I, for one, am very excited to learn more about its atmosphere. While Earth based stellar occultation measurements have allowed us to look at the pressure and temperature of the atmosphere as a function of altitude, we simply can't see the lowest levels of Pluto's atmosphere from Earth. With New Horizons, we'll be able to probe those lower levels with the on-board radio science experiments.

My EAPS advisor, Jim Elliot, was the first person to definitively observe that Pluto has an atmosphere. We used the same stellar occultation technique when I was in graduate school to look at the atmosphere of one of Neptune’s moons, Triton. At that time, we also tried to look at Pluto but Pluto wasn't cooperating so we weren't successful until the stellar occultation in 2002, work that ultimately indicated Pluto’s atmosphere was expanding. 

EAPSpeaks: How did your training in EAPS prepare you for this mission?

Olkin: Foremost, my training in EAPS gave me a rock solid foundation in scientific investigation. I was an engineer prior to coming to EAPS as a graduate student (my undergraduate degree, also at MIT, was in aeronautical engineering, and I had spent some time working at the Jet Propulsion Laboratory) - of course I had science classes but what I learned about being a scientist I learned in Course XII. I also learned so many lessons from Jim as well as my fellow graduate students, among them Leslie and Elliot Young, Amanda Bosh and Mike Person.

A particularly valuable lesson I learned was, when you have time on a telescope, you can't waste it, especially when making occultation observations where timing is so critical. It's not enough to simply be at the right place at the right time, although that can be tough in and of itself: You have to be ready to dependably take data. There was obviously very little you could do about clouds (apart from go fly on the Kuiper Airborne Observatory, KAO) but certainly you did not want to miss an opportunity simply because you weren't prepared. I think that's a huge lesson for working on a spacecraft mission. We build very carefully designed sequences of observations to collect the data to answer the scientific questions we are interested in. We develop contingency procedures. We do lots of checks and validation on the sequences, and I believe that comes naturally to me because of how I learned to be an observer in Course XII.

EAPSpeaks: Is there still a place for the small hands-on observing experience you get at the Wallace Observatory?

Olkin: I was a teaching assistant (TA) for the observing class for a number of years, so I was at Wallace often. I would say it's even more important now than it used to be because we need to train the next generation of observers with hands on experience. A lot of times these days you're observing remotely, which is excellent, and I love having the opportunity to do that, but in order to learn the craft nothing replaces physically being there. So I really believe Wallace has an extremely important place in education, and in science.

EAPSpeaks: What are your best memories of EAPS?

Olkin: I loved being a TA. I loved working with the students, and teaching them, and the excitement when they were able to put it together and understand what was being taught in the classroom and connect that to what they were actually doing at Wallace. The observing class is an excellent class because it teaches so many things and that made it very exciting to TA. Besides that I really enjoyed the camaraderie of the graduate students. Sharing ideas, working together, the spirit of the group was just really great.

EAPSpeaks: What comes after Pluto?

Olkin: Well one thing that's really interesting about the Pluto mission is that it's going to take a while to downlink all the data. The New Horizons spacecraft is very far away from the Earth. At closest approach, we'll be 32 times the distance between the Sun and the Earth away. At that distance it will take ~ 4.5 hours for data to travel from Pluto back to us. In addition, because we wanted to get to Pluto in a reasonable amount of time, we had to have a small but highly efficient spacecraft, however that meant our downlink rates are pretty slow - about 1000 bits per second. For comparison, at that rate the HD version of the new Mad Max movie would take about 555 days to download. For this reason it is going to take until late 2016 to recover all the data, longer still to analyze it. This makes it a little bit different from most earlier missions. Come mid-July we'll be having press conferences, we'll be talking about what we're learning, but more than likely there will still be mysteries up on the spacecraft, things that haven't been sent back to the ground yet, that we won't know about until months later.

Beyond the Pluto encounter, using the Hubble telescope, we have identified two other potential KBOs that we could fly by - one or the other, not both - and so once we have passed Pluto we will write an extended mission proposal to NASA which, if approved, will see New Horizons flying by a second target in approximately 2019. This is not a given, but we are extremely hopeful this post-Pluto mission will be funded. New Horizons historic near-decade long journey has put it on the Kuiper Belt's doorstep. How can we not now carry on, paraphrasing those by now immortal words, to boldly go where no one has gone before? After all this is just our solar system: rumor has it there are quite a number more out there waiting for us to explore!

Meet EAPS alumna Cathy Olkin ’88(XVI), PhD ’96(XII, XIID)

EAPS alumna Cathy Olkin is a planetary scientist with interests in icy outer solar system worlds. Using near-infrared and infrared spectroscopy she studies icy surfaces and stellar occultations to investigate tenuous atmospheres. She is also interested in spacecraft investigations of these worlds and is a member of the New Horizons team which will provide the first close-up look at Pluto.

Olkin began her career in engineering, getting her undergraduate and masters degrees at MIT in Course XVI (Aero-Astro). After working at NASA's Jet Propulsion Laboratory, she returned to MIT for graduate school where, working with EAPS advisor Jim Elliot, she obtained a doctorate in planetary science for her work involving stellar occultation studies of he atmosphere of Triton. 

Image captions: Upper right - Cathy pictured with a large telescope in Tasmania; left - Cathy during hypnoxia training - images courtesy C. Olkin.


NASA New Horizons

Wallace Astrophysical Observatory

MIT Planetary Astronomy Laboratory

Cathy Olkin ’88(XVI), PhD ’96(XII)

The New Horizons Mission

NASA's New Horizons mission will help us understand worlds at the edge of our solar system by making the first reconnaissance of the Pluto system and by venturing deeper into the distant, mysterious Kuiper Belt – a relic of solar system formation. New Horizons launched on Jan. 19, 2006; it swung past Jupiter for a gravity boost and scientific studies in February 2007, and began a six-month-long reconnaissance flyby study of Pluto and its moons in early 2015. Pluto's closest approach occurs on July 14, 2015. If NASA approves an extended mission, the spacecraft could head farther into the Kuiper Belt to examine one or two of the ancient, icy mini-worlds in that vast region, at least a billion miles beyond Neptune's orbit.

Sending a spacecraft on this long journey will help answer basic questions about the surface properties, geology, interior makeup and atmospheres on these bodies. The National Academy of Sciences ranked the exploration of the Kuiper Belt – including Pluto – as being of the highest priority for solar system research. New Horizons seeks to understand where Pluto and its moons "fit in" with the other objects in the solar system, such as the inner rocky or "terrestrial" planets (Earth, Mars, Venus and Mercury) and the outer gas giants (Jupiter, Saturn, Uranus and Neptune). Pluto and its largest moon, Charon, belong to a third category known as "ice dwarfs." They have solid surfaces but, unlike the terrestrial planets, a significant portion of their mass is icy material.

Using Hubble Space Telescope images, New Horizons team members have discovered four previously unknown moons of Pluto: Nix, Hydra, Styx and Kerberos. And in the last few months before Close Approach the team is on the lookout for possible new moons and even a ring system not least because that may prove a threat to the spacecraft.

A close-up look at these worlds from the spacecraft promises to reveal an incredible story about the origins and outskirts of our solar system. New Horizons will also explore – for the first time – how ice dwarf planets like Pluto and Kuiper Belt bodies have evolved over time.

New Horizons is the fastest spacecraft ever launched, and is traveling the farthest to reach its primary target, and is the first mission to Pluto and the Kuiper Belt. The United States has been the first nation to reach every planet from Mercury to Neptune with a space probe. If New Horizons is successful, it will allow the U.S. to complete the initial reconnaissance of the solar system.

From NEW HORIZONS the First Mission to Pluto and the Kuiper Belt, NASA.


New Horizons: Are we there yet?
Video by Helen Hill, EAPS, MIT 
New Horizons Co-Investigator and Professor of Planetary Sciences at MIT Richard Binzel has spent the best part of two decades preparing for this summer. In this interview he reflects on New Horizons place in the history of human exploration, and the intellectual imperative of the boundless frontier.


The Pluto Siblings Nature (about EAPS alumnae Leslie Young (PhD '94) and Eliot Young (PhD '90) written by Alexandra Witze XII BS '92, now a Nature contributing correspondent.)

Postcards from Pluto Angela Zangari (PhD '13)'s blog via EAPS News

EAPS, Physics Professor James Elliot Dies at 67 MIT News 

Remembering James Elliot, 1943–2011 Sky and Telescope Magazine

Jimboree lots of great pictures of Jim Elliot and lab members from the June 17, 2010 "Jimboree" celebration.

Pluto's atmosphere is expanding, researchers say MIT News 2003

Recent WAO News

Shhhh! Remote Observing in Progress EAPS News