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Space Topics: New HorizonsThe Long-Awaited Launch of New HorizonsPersonal Views from New Horizons Science Team Member John Spencer
In anticipation of New Horizons' long-awaited launch to Pluto, science team member John Spencer sent these missives to The Planetary Society, giving us all a window into the life of one of the workers on this daring mission in its final days on Earth. They were originally posted in The Planetary Society weblog. December 28, 2005: Looking forward to New Horizons' launchHi, this is John Spencer, one of the members of the science team on the New Horizons mission to Pluto and the Kuiper Belt. For the last two years I've been a staff scientist at Southwest Research Institute's Department of Space Studies in downtown Boulder, Colorado -- the research group founded by New Horizons Principal Investigator Alan Stern a decade ago. For twelve years prior to my move to Boulder I was an astronomer at Lowell Observatory in Flagstaff, Arizona, where this whole story started back in 1930, with Clyde Tombaugh's discovery of our target planet. I've been working off and on on some version of the Pluto mission since 1993, when Alan invited me to join a team designing a multi-wavelength camera/spectrometer (grandfather of the Ralph and Alice instruments now sitting on top of a rocket in Florida) for one of NASA's earlier Pluto mission concepts. So Pluto has been part of my life for a long time. At the moment, though, my New Horizons work has little to do with Pluto itself. I'm helping to plan the observations we'll make as we fly past Jupiter in 2007 on our way to Pluto (assuming, as we all hope, we launch early enough to use a Jupiter flyby to speed us on our way to our prime target). I'm also working with Marc Buie at Lowell Observatory, and a team of Japanese astronomers, to find one or more Kuiper Belt objects (KBOs) that New Horizons can fly past in the years after its Pluto flyby. For the launch itself, like most of the science team, I'm really just a tourist. The engineers, the real heroes of this and every space mission, are in charge for this most critical stage of the proceedings. Right now my mind is on Pluto's cousins in the Kuiper Belt. I'm sitting in the control room of the 72" telescope back at Lowell Observatory, beginning the first of the night's long exposures on a KBO called 1998 SM165. Despite lacking a catchy name, it's a fascinating beast because it's one of the brightest and nearest KBOs (other than Pluto itself) that's known to have a satellite. From the satellite's orbit we have learned SM165's mass, and in a couple of weeks we'll be using the amazing sensitivity of the Spitzer Space Telescope to measure the KBO's feeble heat radiation and thus deduce its size. Combining those two numbers, we'll be able to determine SM165's density and thus learn valuable clues about what SM165 (and by cautious extrapolation, KBOs in general) might be made of. Here on the ground tonight, I'm measuring SM165's rotation by watching it brighten and fade as it tumbles end over end. From this we'll be able to tell how the KBO is oriented when Spitzer makes its measurements in January, and this will help us make sense of the Spitzer data. So we keep chipping away at the wonderfully rich puzzles of the Kuiper Belt using all the tools at our disposal, from the 80-year-old telescope in the dome next door, to the Spitzer Space Telescope drifting two years out from Earth, to our tiny golden spaceship now awaiting its big moment at Cape Canaveral. January 2, 2006: Happy New Year!Happy New Year! I'm beginning this entry on New Year's Day at the Laughing Horse Inn in Taos, New Mexico (highly recommended) -- my wife Jane and I are halfway back home to Boulder, Colorado after a combined Christmas vacation and observing run in Flagstaff, Arizona. I've been sifting through the data I obtained last week on the lightcurve of binary Kuiper Belt object 1998 SM165 during my three nights on the Lowell Observatory 72" telescope, and as so often happens, the images are proving a bit harder to analyze than I'd first thought. My view was obscured by variable amounts of cirrus cloud most of the time, and the seeing varied a lot, so I'm having to come up with new ways to measure the KBO's varying brightness. The hardest part, as always, is figuring out the uncertainties -- the plausible range of brightnesses that are consistent with each observation. Here at the Laughing Horse we had an impromptu New Year's Eve party with the other guests, and as always, people wanted to know all about the New Horizons mission -- Pluto seems to hold a special fascination for so many folks. Just over two weeks now 'til our first possible launch day on January 17th! I'm working on a slide show to be shown at the pre-launch party at the Cape, illustrating the long history of this mission and the various studies that preceded it, so I'm downloading the best images of the spacecraft assembly from the online image galleries from the Kennedy Space Center and Applied Physics Lab. This is one of my favorites -- the encapsulated spacecraft meeting its rocket for the first time in the pre-dawn light on December 17th.
January 8, 2006: Music for New HorizonsI'm at home on a Sunday morning, five days before leaving for the Cape (assuming the current launch schedule, with the first launch opportunity on January 17th, continues to hold). I'm musing on space songs, as I listen to David Bowie's Space Oddity, which recaptures for me the romance of spaceflight as I felt it as a teenager in the 1970s, and as I feel it still. That other classic astronaut song, Elton John's Rocket Man, also comes to mind, along with two powerful memories it invokes. First, from the summer of 1975, just before I went to university to pursue my dream of an astronomy career, listening to records while polishing the floors of the Scottish hotel where I was working. Second, from just a couple of months ago on my first ever visit to Kennedy Space Center at Cape Canaveral, listening to the car radio as I explored that hallowed place after a New Horizons Science Team meeting. The song has maintained its appeal through all those years -- the teenage space nut lives on within the middle-aged planetary scientist. So what if "Rocket Man" is about disenchantment with space travel -- it's a song about space and that's good enough for me. Both those songs focus on the human experience of spaceflight -- it's hard to imagine a Top 40 song about one of our wonderful robots. Too bad. The late Jonathan Eberhart, folk singer and space correspondent for Science News, wrote some great songs about Mars and the Viking mission in the 1970s, though I think only one, Lament for a Red Planet, was ever recorded, on his album Life's Trolley Ride. But thanks again to the enduring appeal of our enigmatic target, Pluto and (by extension) New Horizons have their own song popular enough to be available via iTunes -- Christine Lavin's hilarious 1997 ditty Planet X, about the discovery of Pluto, the debate over its status as a planet, and NASA's plans to explore it. As the song says, "for a little guy, you've made quite a splash".
My slide show for the pre-launch party is almost complete. It weighs in at over 400 slides -- yikes. I suppose I'll have to trim it if I expect anyone to watch the whole thing at the party. But we'll keep the unedited version too -- it's pretty cool to have a pictorial history of the project at this level of detail, to organize all those fading and blurring memories of 13 years of e-mails and teleconferences and proposals and team meetings into some sort of coherent order, and to fill in some of the engineering story from our own Rocket Men (and women) -- the folks who actually designed and built the spacecraft. Amazing to watch all those years of abstract planning turn into something very real, to watch a CCD array millimeters wide integrated with a camera a foot across, bolted onto a spacecraft about the size of its designers, and finally to see that spacecraft hoisted atop its massive rocket, the whole 200 foot tall edifice poised to hurl itself off the planet very soon. Nine days and counting... January 11, 2006: Thinking about New Horizons scienceThis is probably my last missive before Jane and I leave for the Cape on Friday in preparation for the launch. Our pre-launch schedule includes a New Horizons Science Team meeting on Saturday 14th, the pre-launch party on Sunday, and our first shot at the actual launch on Tuesday afternoon -- the 2-hour window opens at 1:24 pm Eastern time. Adding to the excitement for me personally, my sister Frances will be flying in from England to join us for the festivities. From Saturday evening onwards there's also a continual series of media and public events -- I'll throw in a shameless plug here for my talk about Pluto and the mission at 7 pm on Saturday at the Brevard Community College planetarium near Kennedy Space Center, though as I write this, I see that they don't yet have a notice of the talk on their web site. There will also be public talks at Kennedy Space Center, featuring Andy Cheng on Sunday afternoon, Bill McKinnon on Monday afternoon, and Marc Buie on Tuesday morning, shortly before the launch. Having linked to my friends' web pages, I now have an excuse to include a link to my own: here it is. We continue to plan for the Jupiter encounter, which (assuming we launch on February 2nd or before) occurs, astonishingly, a mere 13 months after launch. For comparison, it took Pioneer 10 21 months, and Voyager 1 18 months, to cover the same distance in the 1970s, while Galileo, being heavier and needing to arrive more slowly to get into orbit, followed a roundabout trajectory and took 6 years to get to Jupiter between 1989 and 1995. Detailed planning of our observations of Jupiter and its satellites must wait till after we launch, because the launch date determines the Jupiter flyby date, and that in turn determines the orbital positions of the satellites during the flyby and the timing of many of our observations, including critical events like satellite eclipses by Jupiter. We're planning a team meeting in late February where we'll hash out the details, once the spacecraft is safely on its way and we know the geometry. The Jupiter plan will be a balancing act between many conflicting factors. We'll need to turn the main antenna to the Earth periodically to download data and track the spacecraft's trajectory (after all, the primary purpose of the Jupiter flyby is to speed us on our way to Pluto), but this will interrupt our observations, because all instruments are fixed on the spacecraft and pointing the antenna at Earth means not pointing the instruments at Jupiter. We'd love to make high resolution movies of Jupiter's turbulent storms, but our spacecraft data system is designed for the Pluto encounter, where we fly rapidly past a couple of relatively small targets and have months to play back the data, so we don't have the storage or downlink capacity for the enormous number of images we'd need to do full justice to Jupiter's hyperactive meteorology. And so on. We will do wonderful things at Jupiter, but we can't do everything, and we'll make our choices carefully. In the meantime, we have another important date on the calendar -- proposals for time on the Hubble Space Telescope are due on January 27th. There are some things that Hubble can do better than New Horizons during the Jupiter flyby (for instance, New Horizons can take ultraviolet spectra of Jupiter's moons, but not images, while Hubble can take images, but not spectra). The combined efforts of the two spacecraft will thus tell us more than either can do on its own, and at our team meeting on Saturday we'll discuss how to make the most of this synergy, and finalize our plans to condense the potential Hubble science into pithy telescope proposals. January 13, 2006: We're at the Cape!We're at the Cape! More properly, we're at Cocoa Beach just down the coast, having flown in from Denver today. We all have return tickets to wherever we came from, but for some part of us, this is not a final destination, merely a transfer stop. Our hopes and spirits continue on from here, to Pluto and beyond. The spacecraft has passed its launch readiness review, the weather forecast looks favorable for Tuesday, and no obvious barrier stands between us and the Kuiper Belt. I can't actually believe any of this. All my life, Pluto has been inaccessible. Yes, we've been working on this mission for more than a decade. But we work on so many mission proposals that come to naught. It's hard to grasp that this one, to the most outrageously faraway destination of all, has become something real, and is sitting at a launch pad a few miles from here. I guess it will all seem real enough very soon. That's all for tonight, except for a quick update for the thousands of you who anxiously await news of 1998 SM165, that Kuiper belt object that I was watching at Lowell Observatory just after Christmas. I mentioned that I was having trouble making sense of the data, but the more I've worked on the images the more I believe what I'm seeing. What I seem to be seeing is that this KBO is rotating at a speed about 5% different than its published rotation rate. Maybe the gravitational influence of its moon could have temporarily altered its rotation period, but four out of four dynamicists that I've consulted think this is highly unlikely. More likely there's still something wrong with my analysis, or with the analysis that led to the original rotation period estimate. Once we complete our little bit of business here in Florida, I'll get back to the problem. January 15, 2006: Looking forward to New Horizons' launchAnother quick post from the Cape. Yesterday was our final pre-launch meeting of the Science Team. The mood was quite different from previous meetings, which are normally enjoyable but fairly sober affairs. People were breaking into applause for the engineering team as they described the success of the final tests before launch, and congratulations were being passed around. We're all pretty high. Project Manager Glen Fountain always shows a chart at these meetings, describing his list of top worries -- things that might still go wrong and jeopardize the mission. Yesterday, the list was empty. Our Principal Investigator, Alan Stern, the driving force behind this mission, gave his own retrospective at the end of the meeting, starting all the way back when he started pushing for this mission while still a graduate student in the late 1980s. Much laughter as people recognized their much younger looking selves and colleagues on the screen. What will we look like when we finally get to Pluto, nine years hence??? Tomorrow morning is the rollout. The science team will have the great privilege of watching New Horizons take the first step in its journey, the few hundred yards from its tall narrow hangar, the Vertical Integration Facility, to the launch pad, just over 24 hours before our first launch opportunity. It's hard to avoid breaking into clichés, so I won't try- all systems are go! January 16, 2006: Less than 24 hours to New Horizons' launch
New Horizons just experienced what we hope will be its last ever sunset on Earth. There will be three more sunsets to come. The next will be about 20 minutes after launch, as the spacecraft plunges into the Earth's shadow and prepares for the final rocket burn that will take it out of orbit. Its last-ever pair of sunsets will be behind Pluto and Charon nine years from now, as we use the setting Sun as a probe of their atmospheres. After that the rapidly diminishing sun will shine on our spacecraft forever, though the Sun will eventually be indistinguishable from the billions of other stars in our galaxy. Heady stuff. This has been a day that I'll never forget. This morning the science team and some press folks gathered at a viewing area near the launch pad to watch the spacecraft slowly make its way from its hanger to the pad, a process that took about half an hour. Once the rocket was in place, and the work to configure it for launch got under way, we were able to approach within a few hundred feet, and pose for pictures that we'll always treasure. Here's mine (thanks to Rick Binzel for taking the photo). I could barely take my eyes off the rocket -- an astonishing thing to see. I've worked on planetary missions for most of my career but I've usually become involved after launch, so I've never before seen this stuff up close. Just awesome. Tomorrow should be even more memorable. The weather forecast still looks good and so far there are no technical hangups. Wish us luck! January 17, 2006: Philosophical after the first day's launch attemptOh well, the Sun sets on an earthbound New Horizons at least one more time. The first day's launch attempt was a strange experience in retrospect -- lots of excitement but nothing to show for it at the end of the day. We feel sorry for all the people who have to leave tomorrow, who will never see a launch that they came within 2 minutes and 40 seconds of experiencing this afternoon. But those of us who can stay a few more days can afford to be philosophical -- delays like this are a normal part of space flight, and there's a decent chance that we'll be able to launch tomorrow, and an even better chance the day after. Like most of the science team, I had no role to play in the launch, so I watched with my wife Jane, sister Frances, and a few hundred others at the Banana Creek viewing area near the building that houses Kennedy Space Center's Saturn V. There were a few temporary technical problems with our rocket and the ground stations, but it was the weather that got us in the end -- a restless wind that kept the mosquitoes away from the bleachers but never stayed below the "red line" limit for long enough to let us off the launch pad. For two hours we sat and waited, our hopes rising as the end of each planned hold in the countdown approached, and falling again as another delay was announced. Despite the tension, it was quite a party atmosphere -- we were surrounded by friends, and it was a beautiful day to watch history almost being made. There was a big post-launch party planned for the evening, and by the time the launch was scrubbed the food was already prepared, so we held the party anyway. The mood was relaxed, not much disappointment. We'll try again tomorrow. January 19, 2006: Here we go!Wow! Now it's real. We'll probably be past the Moon by the time I mail this off to Emily. We just got back from the real post-launch party, following two non-post-launch parties on the last two evenings. This was more like it. Whoops and hollers and congratulations all around, but especially for the launch team. This was their day -- they performed magnificently, launching the most-powerful-ever configuration of Lockheed Martin's Atlas V rocket, and the third stage built by their arch rivals Boeing, faster than any rocket had gone before, and doing it flawlessly. Though I haven't seen any actual numbers yet, provisional reports suggest we are very close to our planned trajectory, which is great news for the science team, because less of the spacecraft's fuel will be needed to fine-tune the trajectory to Jupiter, and more will therefore be available to steer us to a Kuiper Belt object after the Pluto encounter. We have also, as they say, "retired a lot of risk" -- the most dangerous part of the mission is over and the spacecraft is in the environment it was born for (as Arthur C. Clarke once wrote, space is a benign environment, at least for ships designed to sail in it). One of the ceremonies at the party was to burn copies of the very detailed contingency plans that had been developed to cover all possible launch failure scenarios. We won't be needing those any more. I'm still processing the actual launch experience. We were twice as far away from the rocket as we had been two days earlier, due to shifting winds, but we had a fine view of the rocket across the lagoon. The spectacle was brilliant, amazing, and over very quickly as the rocket disappeared into the clouds. Everyone said "don't try to photograph the launch, just experience it", but I'm a die-hard photographer and my instincts to point my camera at anything amazing got the better of me. So I saw too much of the launch through my viewfinder. Still, my memory of the event is mostly of the emotion, not the spectacle. The joy was overwhelming as we saw our baby go. We were all hugging each other very hard until the buses revved up to take us back to the visitor center. Now the engineers have done their work so magnificently, it's time for us scientists to get to work. Once the trajectory folks can spare the time from making sure we're pointed in the right direction, we'll be getting the details of the Jupiter flyby geometry from them. Then we can finalize our plans for the Jupiter encounter now only thirteen months away.
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