martes, enero 05, 2010

Pluto and beyond: The New Horizons endeavour

An interview with Cathy Olkin, New Horizons's mission to Pluto investigator.

New Horizons is the first scientific investigation to obtain a close look at Pluto and its moon Charon. Scientists hope to find answers to basic questions about the surface properties, geology, interior makeup and atmospheres on these bodies, the last in our solar system to be visited by a spacecraft.

Cathy before one of her occultation cameras mounted at the Anglo-Australian Telescope, Siding Springs.Photo courtesy Cathy Olkin

Launched on January 19, 2006, it swung past Jupiter for a gravity boost & scientific studies in early 2007 and will reach Pluto in July 2015. Then, as part of an extended mission, the spacecraft would head deeper into the Kuiper Belt to study one or more of the icy mini-worlds in the region a billion kilometres beyond Neptune's orbit.

Today, we meet Dr. Cathy Olkin, at the South West Research Institute, to talk about this fascinating mission.

Dr. Olkin, what is your job as Program Manager for the New Horizons mission?
I have a few different responsibilities on New Horizons. I am a Co-Investigator, the Director of the Office of the PI (Principal Investigator) and the Project Manager for the Ralph instrument. The Program Manager for the mission is Glen Fountain at APL (The Johns Hopkins University Applied Physics Laboratory). As a Co-Investigator, I am a member of the science team and participate in the science planning. As the Director of the Office of PI, I am responsible for the day-to-day operations of the New Horizon’s effort at Southwest Research Institute and the subcontractors that we manage.
Finally, as the Project Manager for the Ralph instrument, I work with the other members of the Ralph Instrument Team to make sure that we are taking the data we need to check Ralph’s performance annually, that the sequences planned will execute the science we want, and that the analyses of the Ralph data are done in a timely manner. I have diverse responsibilities and that is one thing that I love about this job.

Early next year, NH will be closer to Pluto than Earth, and so far, the spacecraft has flown by Jupiter and 2002 JF56 (later renamed 132524 APL) asteroid. You even co-authored an article on the later. What have been the main conclusions of these approachingS in terms of both science and hardware

We are looking forward to the halfway point as a milestone on our journey. We will have traveled half the distance to Pluto on February 25, 2010. Interestingly, the halfway point in terms of travel time doesn’t occur until October 15, 2010. That is because we slow down slightly as we go.

We have learned a lot from the Jupiter and asteroid APL flybys. These flybys gave us practice for the big event – the Pluto encounter. We were able to confirm that the spacecraft and instruments are all working well. We got practice commanding the spacecraft during a busy flyby period and we got some new science results (see Science volume 318 for details). Our flight path was unique in that it traversed Jupiter’s magnetotail. This allowed our plasma instruments to probe the magnetotail to a distance of more than 2500 jovian radii. We saw multiple eruptions on Jupiter’s moon Io including the 330-km high plume from the Tvashtar volcano.
The 330 kilometer high plume from the Tvashtar volcano, in the Jupiter moon of Io. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Using our infrared imaging spectrometer, we were able to observe the development of transient ammonia ice clouds in Jupiter’s atmosphere.

Our goals for the Jupiter encounter were to target the correct location to put us on the path to Pluto, to calibrate our instruments, and to do new science at Jupiter. We were successful in all three of these endeavors.

"New work shown at DPS by NH scientist Cathy Olkin show pressure in Pluto's atmosphere still rising as of 2007. Fingers crossed for 2015...." can be read at NewHorizons2015 twitter. Pluto closest approach was originally set to about 10.000 kms. How can Pluto's atmospheric pressure affect the flight path plans? Or is more related to the cooling of the planet and the ability of NH instruments in detecting in an ever cooler world?
The atmospheric pressure does not affect our flight path. That comment was more about our science goal to characterize Pluto’s atmosphere. Pluto has a very eccentric orbit and its distance from the Sun is currently increasing (since perihelion in 1989). As Pluto recedes from the Sun, it receives less energy from the Sun. Models have predicted that Pluto’s atmosphere could condense onto the surface as the insolation decreases. We want to study Pluto’s atmosphere, so we have our fingers crossed that it will not condense out before New Horizons arrives. But there is no need to worry. Recent findings from stellar occultation observations show that the atmospheric pressure has been increasing from 1998 to the present day.

In 2005, the Hubble Space telescope discovered two new moons around Pluto, shortly before New Horizons launch. Now, after celebrating the 5th anniversary of the discovery, how is NH fit to explore these new moons?
New Horizons is well suited to study the newly discovered moons of Pluto. We have a science plan that will take color and panchromatic images of Nix and Hydra as well as near infrared spectra of these bodies so we can learn about the composition of their surfaces. We will be able to see what the surfaces of these small bodies look like. It is wonderful that these objects were discovered in time to incorporate them into our observation plans so we could get a comprehensive look at these bodies.

...As Pluto recedes from the Sun, it receives less energy from the Sun. Models have predicted that Pluto’s atmosphere could condense onto the surface as the insolation decreases. We want to study Pluto’s atmosphere, so we have our fingers crossed that it will not condense out before New Horizons arrives. But there is no need to worry. Recent findings from stellar occultation observations show that the atmospheric pressure has been increasing from 1998 to the present day....

Pluto-Charon flyby in mid 2015 will mark the end of the primary mission, and probably the start of another extraordinary voyage to the Kuiper belt that may take the New Horizons team to the year 2020. New targets may be selected by 2011. Is this extension already approved by NASA? How's the selection process for Kuiper belt targets going?
The extended mission is not yet approved. It is too early for that. We have planned that this year and next year we will step up our efforts to search for Kuiper Belt objects along our path. We had done a preliminary search before launch, but this year and next are more favorable because the search area has decreased and we still have plenty of time to find an object and characterize its orbit.

For such a longevous mission, only two project managers have been appointed so far, Tom Coughlin and now Glen Fountain. Is this helping to keep the momentum on an otherwise somewhat boring cruise with a majority of hibernation periods?
Both Tom and Glen are excellent project managers and they have helped us keep on track during busy times or hibernation periods. I wouldn’t characterize the hibernation periods as boring. While we haven’t been operating the spacecraft much, we have been planning a robust encounter sequence for when we get to Pluto. Also as a scientist, the hibernation periods allow me to pursue other projects such as ground-based observing of Pluto.

After flying by Pluto and along with Dawn mission planned visit to Vesta and Ceres, NASA will complete an extraordinary solar system family photo album in a little more than half a century. How do you personally feel about being part of it? Was it becoming a Program Manager for an interplanetary mission part of your childhood dreams?
I love being a part of the New Horizons mission. The people are great and I am thrilled to be a part of the team that will give us our first close up look at these cold icy worlds. The data returned from New Horizons will be a huge step forward of our understanding of the Pluto system.

Pluto was downgraded by mid 2006 to a dwarf planet, but it's still a full ranked world to many people's hearts. And this is not only emotional. NH team often questions "how could Pluto be a dwarf planet, with its mass about 4 times that of the entire asteroid belt, including 1000-km wide dwarf planet Ceres, atmosphere, weather, 3 moons, surface snows, geology, and perhaps an internal ocean and also a core, while Mercury, who lacks all that, is?" What is your personal opinion on that? Did politics come in the middle on the IAU decision, as the book "Pluto confidential" suggests?
My personal opinion on the classification of Pluto as a dwarf planet is that Pluto is a fascinating world and it doesn’t matter what it is called. The physics of seasonal change that we have observed with Pluto’s atmosphere is just as exciting whether you call Pluto a planet or a dwarf planet. One good thing that came out of this debate is that people are more aware of how diverse our solar system is – from terrestrial planets, to giant planets, to cold icy objects in the Kuiper Belt.

I can’t speak to the question of the politics because I wasn’t involved in the IAU decision.

Collaboration with ESA's Rosetta spacecraft has been very intense through Dr. Stern's revolutionary ALICE instrument, developed at the Southwest Research Institute, and its joint ESA/NASA observations of Jupiter. Do you foresee more collaboration from Rosetta in this mission? What's your opinion on these collaborations between national agencies? Would they help pave the way for more intense cooperation between countries in the field of space exploration?
The New Horizons spacecraft is hibernating for most of each year right now and Rosetta also has plans for hibernation so I don’t see any near-term collaboration between these missions. This doesn’t rule out the possibility of collaboration just reduces the need for it right now. I think collaborations between national agencies are very beneficial. When we collaborate, science is advanced and that is good for us all. It very well may help pave the way for more cooperation between countries in the field of space exploration.

Finally, what has been your best moment on this mission so far and the recommendations for the future?
I would say that the best time so far was the Jupiter encounter. The team had spent a lot of time planning the Jupiter encounter, reviewing sequences that would be sent to the spacecraft and hitting the right aim point to be on the path for Pluto was critical. It was great to see the data returned from our instruments and know that we are ready to investigate the Pluto system.

Many thanks, Dr. Olkin, and the best of lucks for this amazing trip to the boundaries of the Solar System and the Human knowledgement!

New Horizons is part of NASA's New Frontiers Program. For more information, visit