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Chasing New Horizons: Inside the Epic First Mission to Pluto

af Alan Stern, David Grinspoon

MedlemmerAnmeldelserPopularitetGennemsnitlig vurderingOmtaler
1464144,629 (4.18)9
Shares a behind-the-scenes account of the science, politics, egos, and public expectations that shaped the New Horizons' mission to Pluto and beyond, citing the endeavor's boundary-breaking achievements and how they reflect the collective power of shared human goals.

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Love me a good space exploration tale. What these folks do is amazing and very cool. Loved the detail on what they went through to get the mission launched. Nice photos as well. ( )
  bermandog | Mar 20, 2021 |
This is a selection from "Chasing New Horizons" by Alan Stern and David Grinspoon. When NASA sent a spacecraft to Pluto, there was no room for error or after the fact corrections. So NASA did its software testing the correct, thorough way:

"As leader of the mission, Alan Stern felt as though it was part of his job to look for weaknesses in the flyby plan, ask a lot of questions of his teams, probe their assumptions, and ask for changes to fortify the planning. One of the many weaknesses he spotted and changes he asked for concerned NHOPS (New Horizons Operations Simulator).

"About the time that the seven various flyby phases were being laid out and architected, Alan became concerned that the NHOPS spacecraft simulator, which was used to test all spacecraft command sequences to weed out bugs, could become a showstopper if it failed in 2015. He just wasn't comfortable with the fact that an NHOPS failure in 2015, when there was little time for a repair, could risk the team's ability to fully test the flyby sequences. A backup, called NHOPS-2 was al­ready in place, but it was a stripped-down version of NHOPS that lacked much of the simulation capability and fidelity of the original. So at Alan's direction, Glen put plans and budget in place to convert NHOPS-2 into a full-up spare to NHOPS, and to test it as thor­oughly as had been done with NHOPS, to be sure it would be ready if there ever was a need. Little did he know then, this was a decision that would prove crucial in the final days of the approach to Pluto.

"As each of the dozens of command sequences that together com­prised the entire flyby were designed and had passed their peer re­views, the MOPS team began running them on the NHOPS spacecraft simulator to see if they would work as expected. Bugs were often found, corrected, and then new NHOPS runs would be sched­uled. MOPS repeated this again and again, until every sequence ran completely error-free. For the Core load -- the crucial nine-day-long chain of sequences that instructed the spacecraft how to execute all actions during the close flyby -- that took eight tries. Each of these eight NHOPS runs of the Core load took the full nine days. Version 1 was called V-1, version 2 was called V-2, and so on. Every time the team found bugs it rewrote the errant parts of the sequence and started the NHOPS run again, from scratch. When the Core finally ran bug-free on V-8, the eighth of these nine-day-long NHOPS runs, Alan cele­brated by buying a couple cases of little cans of V-8 juice and handed the cans out for each team member to keep as souvenirs of the time­consuming battle to create a completely bug-free Core load.

"Once that error-free milestone was achieved, the Core sequence was 'locked down' under a rigorous 'no change without careful re­view and approval' process, called 'configuration management' (or CM). CM's job was to ensure that an extra level of scrutiny and test­ing rigor went into any change, no matter how minor. Weekly meet­ings of a group called the Encounter Change Control Board (or ECCB), were held to evaluate change requests to the Core load and half a dozen other sequences that would run on New Horizons dur­ing the period from May to July of 2015. The ECCB was chaired by Alan and staffed by chief engineer Chris Hersman, project manager Glen Fountain, MOPS lead Alice Bowman, senior project scientist Hal Weaver, PEP lead Leslie Young, and encounter manager Mark Holdridge.

"At the same time that all the Pluto flyby command sequences were be­ing developed, the project team also took a look at everything that could possibly go wrong during the encounter and how they or the space­craft would have to react in order to fix any given situation. This kind of 'malfunction procedures' development is common to space mis­sions, and it was crucial for a one-shot opportunity like a Pluto flyby.

"The largest effort to prepare for potential problems was led by spacecraft chief engineer Chris Hersman. Hersman, incredibly sharp and meticulous in his attention to detail, and incredibly knowledge­able about all aspects of the bird, made plans for each of 264 potential spacecraft, ground system, and other problems that might arise."
  AntonioGallo | Oct 30, 2019 |
I love reading science-by-scientists books, where we learn the questions modern scientists are asking and the day-by-days tasks and troubles they face to find the answers. This book follows the inspirational New Horizons mission to Pluto (and now, in 2019, to the Kuiper Belt object Ultima Thule), from the very beginning of planning any mission at all, to securing funding for this mission, to building and launching New Horizons, to its final Pluto flyby. It is a great story.

Compared to other books in this genre, I'm rating this one a bit lower, for two reasons. First, the authorial structure is a bit weird. The book seems to mostly have been written by David Grinspoon, who is a scientist but not directly involved with New Horizons, based on interviews with Alan Stern, the project's PI. It also includes long quotes from Stern. This one level of indirection is suboptimal, and the way they paper it over can be awkward. Secondly, I did find it interesting to learn how a project leader manages to get $700 million from NASA to lead a team of thousands—a long ordeal that includes lots of politics, and it is cool to get a behind-the-scenes perspective on the politics, strategies and bickering (especially between JPL and APL). However, that's not really what I came for. I wanted to learn more of the science, but I guess there's another level of indirection between the PI Stern, who manages everything, and the scientists who are getting their hands dirty studying Pluto. I missed a first-hand perspective on the science.

Still, the book takes off in the second half, where we learn some details of managing a space mission, the considerations that have to be made and the problems that arose. (There could still have been more details.)

I don't think the authors do a great job surfacing the interesting factoids that I wanted. For example, they compare getting New Horizons to Pluto as like hitting a hole-in-one from Los Angeles to Washington, DC—or some similar utterly nonsensical comparison. What does that even mean? It's *impossible* to hit a hole-in-one at that distance. New Horizons made course corrections the whole way, so maybe a better comparison would be to flying a plane from LA to Washington, DC? I have no idea. The authors could have tried to teach us something, for example, how precise did the initial aiming of the rockets have to be, before going beyond the limits of what could be corrected en route? But instead, they made the lazy and meaningless golf ball comparison. This is just one example, but with more work, and more direct involvement from Stern and, especially, other people on the project, readers could have learned so much more.

Quote, from after the Bush administration tried to cancel the Pluto program: "I was so mad I couldn’t see straight, and I smelled something fishy. If Europa went forward, JPL would be guaranteed to get the work, because that mission had simply been assigned to JPL—without competition—and it was also a far bigger monetary prize than winning Pluto would be. Alan speculated that JPL had worked behind the scenes to persuade the Bush administration more or less to trade the Pluto mission for a new start on Europa. He also believed that JPL had another interest in killing Pluto, because if APL actually won, APL’s hand would forever be strengthened as a powerful competitor in all future outer solar system exploration." ( )
  breic | Mar 3, 2019 |
A really fascinating look into the behind-the-scenes of a NASA planetary exploration project. This book goes through the science, the politics, and the personality behind getting a mission like this funded and executed. None of it is trivial. I very much appreciated how many women scientists were included in this project, and I was super thrilled to see the inclusion of at least one LGBT scientist as well. Highly recommended if you're into NASA, space exploration, or the solar system's cutest planet. ( )
  lemontwist | May 24, 2018 |
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Grinspoon, Davidhovedforfatteralle udgaverbekræftet
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Shares a behind-the-scenes account of the science, politics, egos, and public expectations that shaped the New Horizons' mission to Pluto and beyond, citing the endeavor's boundary-breaking achievements and how they reflect the collective power of shared human goals.

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