Chasing New Horizons Page 14

  The biggest problem Todd’s reviewers found was with the Ralph instrument, which was very much the centerpiece of the scientific instrument payload. Ralph was responsible for accomplishing more of the scientific objectives at Pluto than any other instrument onboard. Ball Aerospace was having major difficulties developing it. As a result, the instrument was behind schedule and far over budget. In aerospace, classified projects have higher priority over civilian ones, and Ball kept changing out key personnel on Ralph, taking the better engineers over to other projects. Every effort Alan, Glen, and Bill Gibson made to get Ball to quit poaching engineers, to get back on schedule, and to rein in cost increases failed. For example, as the cost escalated, the APL/SwRI team looked for ways to simplify Ralph’s design. But Ball said that there would be a steep bill for the simplification since it meant redesign and reanalysis of many aspects of the instrument, and that it would actually end up costing New Horizons more. Alan once told Todd about it: “I feel like we’re in a hostage situation with Ball. We can’t launch without Ralph, and they know we’ll have to pay whatever it costs, no matter how high it goes.”

  Todd’s review found other problems, too. Nuclear launch approval was being held up at a number of agencies. Plutonium fuel production was also behind because of a work shutdown at the Los Alamos National Labs (more on that in the next chapter). Costs were also increasing for the spacecraft’s propulsion system, and the development of the special-purpose third stage to top out the Atlas V rocket was running late.

  Alan remembers at the end of Todd’s review process a very painful conversation about how many “alligators in the water” the New Horizons team was fighting. Alan:

  Todd basically told us, “My team has looked the project over a lot deeper now, and I’m pretty convinced you guys really aren’t going to make it. You are submerging the various problems by trying to solve them yourselves. You need more money and some serious come-to-Jesus persuasion of some of your contractors by us at NASA, and you haven’t been asking for either.” Then Todd told me, “I’m going to tell NASA Headquarters that you can’t make it as is.”

  For anyone who had been involved in NASA projects, “alligators in the water” was a clear reference to the gators that lurk in the ditches, streams, and marshes around Kennedy Space Center, where New Horizons was to launch. Those giant reptiles lend a bit of a menacing air to the causeways leading to NASA’s launch pads, but they’re also a metaphor for problems. “You know, if you have one alligator in the water and you know where it is, you can keep an eye on it and maybe outrun it,” Todd explained. “But if you’ve got a whole bunch of them, man, it’s hard to fight them all off.” Alan:

  It was clear that Todd’s analysis was correct—that we had sort of normalized ourselves to these kind of problems because the project had long been a NASA stepchild that we had kind of forced on the agency when it didn’t want to do Pluto, when the “Clydesdales” at NASA had left us to fend for ourselves while the project’s funding was uncertain. And even after the political and funding battles were over, we’d never had the kind of “we’ve got your back” support that NASA normally gives its projects. Now Todd had made it clear to us, and then to NASA Headquarters, that New Horizons had five or six serious problems, any one of which could sink the project schedule, unless NASA stepped in to help.

  So Todd went to work to remedy the situation. Todd:

  We put a little team together and went systematically through each one of those problems. For each one, we ranked how severe its risk was and made a detailed plan to propose to NASA Headquarters for how we would resolve it.

  From his vantage point as liaison between the New Horizons project and NASA leadership, Todd could see clearly that the success of the project was endangered by its history of having a lack of full support from NASA Headquarters. Todd:

  When we started, New Horizons just wasn’t getting the attention it needed from the Agency. I told NASA Headquarters, “These guys are in a crisis. They’re working as hard as they can, but they cannot get from A to B unless you give them more resources and some serious backing. They’re not going to make it. And when they don’t succeed and this mission fails to launch or misses its Jupiter window, it’s going to be a huge black eye to NASA. New Horizons and the exploration of Pluto is a highly visible project, and when you can’t get it to the launch pad on time, it’s going to be viewed as NASA’s failure.”

  Alan was impressed with how quickly and completely Todd got NASA’s “Clydesdales” to start pulling for New Horizons. Alan:

  Todd really turned it around. He single-handedly got NASA Headquarters on the bus and pulling for us, helping us, taking ownership to make New Horizons succeed. With his help, and for the first time, I felt people at NASA were helping us. Previously, due to all the bruising approval and funding battles to get New Horizons started, I had felt the attitude at NASA Headquarters was more or less “You shoved this mission down our throats—good luck pal; we hope you make it.” Simply put, there had always been either some passive-aggressive behavior going on, or maybe just benign neglect, but either way, that kept us from being able to solve many of our toughest management challenges. Todd’s biggest impact was probably that he got NASA to really change, to help us, and it made all the difference: after that I really felt like we were being lifted on people’s shoulders and carried forward to the launch pad.

  With that help and a year and a half’s hard work, by the late summer of 2005, New Horizons had completed construction. In addition, all its scientific instruments—even Ralph—were also completed, the project had garnered enough nuclear fuel to make the mission feasible, and even nuclear launch approval was on track to complete in time.

  It had been an exhausting eighteen months since Todd May had arrived on the scene, ignorant in the details of robotic solar system exploration. But Todd’s management mojo outweighed his lack of experience. Looking back, without his help, New Horizons almost certainly would not have made it.

  There’s no doubt, Todd May became a hero of New Horizons and a savior of the exploration of Pluto.

  7

  BRINGING IT ALL TOGETHER

  PLUTONIUM POWER CHALLENGES

  As we said in chapter 6, spacecraft that fly far from the Sun can’t be powered by solar cells the way most spacecraft are. Instead, they use nuclear batteries called RTGs, fueled by plutonium.

  As we also described in chapter 6, any rocket launching with plutonium on board is subject to a stringent gauntlet of governmental safety reviews and environmental approvals that take years to complete. The challenge in this for New Horizons was that while most nuclear missions had taken eight to ten years to navigate this complex regulatory process, the Pluto launch schedule only allowed four years to complete the same diligent work. Because there wasn’t the possibility of skipping any of the nuclear launch approval process, the New Horizons team realized at the outset that they could only make the 2006 launch window if they made this complex process a special area of focus and put an experienced and skillful executive in charge of it. As we also noted in chapter 6, APL tapped Glen Fountain for this at the project’s outset in 2001, three years before he became the project manager for all of New Horizons.

  One of Glen’s first tasks in this was to build the nuclear launch approval “data book.” This thick set of documents is a compilation of all the information about the launch vehicle and spacecraft needed to perform the detailed safety, risk, and environmental impact analyses that go into achieving launch approval. The data book describes all the environments that the spacecraft would experience under different ground and launch accident scenarios, and how each could affect the integrity of its nuclear power source—the RTG. In short, the data book provided detailed answers and supporting analyses to determine the chance of a release of radioactive material, and if that occurred, how much material would be released over what area, and what the potential health effects would be. This in turn fed into a meticulous assessment of the probability that anyone would
die due to radiation exposure for the different possible failure scenarios. Glen’s role—bringing the data book together and then orchestrating the entire nuclear launch approval process, right up to the final approval in the White House itself, was perhaps the toughest job on the entire project. Alan:

  Glen is self-effacing about his role, but he literally made spaceflight history by getting New Horizons through this labyrinth in time, allowing us to make the 2006 launch window. What Glen did was legendary.

  In addition to navigating the tortuous regulatory maze, the actual physical production of the RTG nuclear power supply was itself a complex and laborious process, which was performed for NASA by the Department of Energy (DOE). Just as DOE had for previous nuclear-powered deep space missions like Voyager, Galileo, and Cassini, its job was organized in several efforts. For one, DOE’s RTG contractor Lockheed Martin prepared the RTG for flight on New Horizons. Separately, DOE’s Los Alamos National Laboratory produced the RTG’s plutonium dioxide fuel, and formed it into ceramic pellets that would be loaded into the RTG. The RTG and the plutonium dioxide then met for testing at DOE’s Idaho National Lab, a fortified defense lab replete with tanks, barbed wire, control towers, and heavily armed guards who follow visitors everywhere, even to the bathroom. Once the RTG was tested, it was shipped to Florida in a manner befitting a spy story. DOE and NASA sent it cross-country to Cape Kennedy in a covert but heavily armed convoy; in fact, DOE sent multiple convoys to the Cape—all but one containing decoy RTGs—to make it even harder for anyone trying to sabotage or pilfer the plutonium.

  Everything the DOE did to prepare the RTG and fuel worked like clockwork, with one very nearly project-killing exception. Its Los Alamos National Lab, which is also involved in the production of nuclear weapons, was forced to halt all operations due to a security breach. The investigation lasted months while New Horizons waited, in agony, waiting for the resumption of its must-have nuclear fuel: not enough fuel—no Pluto mission. Finally, once the security investigation was completed Los Alamos was reopened, with barely enough time left for complete plutonium production. But then, in a new nightmare turn of events, Los Alamos was shut down again. This time it was because an accident elsewhere in the lab led to a safety issue—unrelated to New Horizons—but again putting the mission in jeopardy as it became clear that New Horizons was not going to get a fully fueled generator in time for launch. Alan:

  Our engineering team couldn’t redesign the spacecraft to operate on less power—it was just too late for that. Instead they started to look at ways to run the mission on less power, taking more risks, collecting less data, running fewer instruments at once, and so forth. We really were facing an existential crisis: if we couldn’t figure out how to operate the spacecraft with a lower power level, there would be no exploration of Pluto, so we looked at every possible option.

  They found that by cleverly operating the spacecraft, the mission could accomplish all its goals with as little as 190 watts at Pluto, about 35 watts less than originally designed for. That, and some spare plutonium fuel found from past NASA projects did the trick, because in the end the total plutonium DOE would deliver for the RTG was enough to produce just 201 watts at flyby. It was as close a call with fuel production as any RTG mission had ever had, but New Horizons survived it.

  TESTING, TESTING …

  By the spring of 2005, its Atlas rocket was being assembled, and the mission’s plutonium problems were solved. Back at APL, all the various spacecraft subsystems and the seven scientific instruments were being mounted aboard New Horizons. After each was bolted onto the spacecraft, it was electrically tested to verify its functions. Then, once the entire spacecraft was assembled and functioning, the entire flight system was put through a battery of tests at APL—from launch vibration testing, to launch acoustics testing, to operating it from the New Horizons mission control.

  APL then took the spacecraft—roughly the size and shape of a baby grand piano, south to NASA’s Goddard Space Flight Center in Greenbelt, Maryland, to begin several months of testing. For this, New Horizons was put into a thermal vacuum chamber, where the air gets pumped out to simulate the vacuum of space, then it was repeatedly heated up and chilled to simulate conditions it would encounter in space. This was all to make sure that the spacecraft’s systems, both primary and backup, would function as planned in flight, and to weed out any weak parts that might fail under these conditions.

  And the testing did what it was supposed to do: it revealed problems so that they could be fixed—after all, there would be no fixing things once New Horizons was launched and on its way.

  Most systems aboard the spacecraft passed their tests without problems. But a main computer failed and had to be replaced. And the Inertial Measurement Units (IMUs)—the gyros responsible for determining where New Horizons is pointed—leaked when subjected to vacuum. It took three rounds of replacements, racing against the clock with every replacement cycle, to find IMUs that would not leak. Changes in the thermal blankets were also needed as testing refined how they performed. And of course many software bugs were found and squashed.

  Finally, after months of grueling tests in space-simulation chambers, parts replacements, and software fixes, New Horizons was able to pass all its tests with flying colors, and was certified as ready to ship to Florida for its launch from Cape Canaveral.

  FOUR’S COMPANY

  Something else was going on for New Horizons during the spring and summer of 2005 besides spacecraft testing, a wonderful scientific discovery. That story largely revolves around Hal Weaver.

  In addition to serving as the mission project scientist, itself a demanding engineering-science job, Hal was also leading part of a long-standing effort that Alan had begun years before to search for additional moons of Pluto. Many on the New Horizons science team suspected that, in addition to Pluto’s double planet partner Charon, the binary pair might be accompanied by some smaller moons that had not yet been detected. If so, knowing about them would be important for the detailed flyby planning, because if there were more moons, the team would need to know about them to choreograph observations of them.

  By far the best tool for searching for small moons around Pluto was the Hubble Space Telescope, but it’s never been easy to get observing time on the Hubble. The selection committees that allocate Hubble observing time typically receive seven to ten times as many proposals to use the telescope as there is available time. Twice during the development of New Horizons, Hal, along with science-team member John Spencer, Alan, and others, had proposed to use Hubble to search for faint satellites of Pluto. But both times they had been turned down.

  It probably didn’t help that the New Horizons team had also been searching for years using some of the best ground-based telescopes on Earth, and hadn’t found anything. These negative results may have made a Hubble search seem a long shot that wouldn’t be worth it. But countering this were computer calculations that Alan had made in the 1990s with his former postdoc, Hal Levison, showing that the Pluto-Charon system held many stable orbits for small moons to hide in, even moons up to one hundred kilometers in diameter.

  In 2004, Weaver and others proposed to search with Hubble for the third time, and were turned down once again. Weaver was really surprised at this, thinking that they had so pared back their request—asking for just three hours of time on Hubble—that logic would be in their favor and their proposal would be approved. After all, the portent of such a discovery would be huge—both for understanding the Pluto system and for planning the Pluto flyby. But alas, even that had not done the trick.

  Then, in the late summer of 2004, something very unusual happened: one of the major instruments on Hubble shorted out, ending its life. Since none of the observations with that instrument could then be conducted, the Hubble project looked around to fill the newly opened observing time. Hal remembers: “Suddenly, I got a call, and it was Christmas in summertime: we’d been awarded those three hours of observing time on Hubble after all. We’d ge
t to make the search!” Naturally, though, that good news came with the usual New Horizons dose of delayed gratification—the Hubble observations would not be possible until May of 2005, due to scheduling constraints.

  While they waited, Hal led the detailed planning for the Pluto satellite search observations. Then, once they got the data, he and one of Alan’s postdocs, Andrew Steffl, began careful analysis to see if they could find anything faint orbiting Pluto. Hal Weaver is a soft-spoken, even-keeled guy. But Hal couldn’t contain himself when the Hubble data revealed not one, but two additional moons of Pluto. Within days, Steffl, not knowing of Hal’s discovery, found the same two new moons.

  What a discovery! The Pluto system wasn’t a binary after all, it was a quadruple, and New Horizons was going to be able to study not just one moon, Charon, but now three!

  Having discovered two new moons around Pluto, the team got to nominate names for them. The way this works in planetary science is that the discoverers propose names that are used unofficially until the International Astronomical Union (IAU) signs off on the official ones. Because the IAU approval process is long and requires detailed naming proposals, the team adopted lighthearted provisional names to use while searching for, selecting, and then proposing what would become the official names that would go in the science textbooks. The temporary nicknames: Boulder and Baltimore, because almost everyone involved in their discovery was from one of those cities.

  When the team later got around to naming the new moons for real, Alan wanted names that made sense with the mythology of Pluto but that also honored the tradition of how Pluto itself was named. Recall that back in 1930, during the effort to find a name for Clyde Tombaugh’s new planet, Percival Lowell’s widow wanted to call the new planet “Percival” or “Lowell” to honor her husband for initiating the search for the new world. Eventually, when eleven-year-old Venetia Burney suggested “Pluto,” the scientists at Lowell Observatory liked it not just because of the underworld mythology surrounding the god Pluto, but also because it began with a P and an L, which could also be used to honor Percival Lowell.