Plait: Hi, this is Phil Plait, the NASA Education Resources Director, or NERD, for GLAST at Sonoma State University, and I'm here with Peter Michelson from Stanford University. and he is the top dog, head honcho, big cheese, he is the principal investigator for the large area telescope, or LAT, which is the primary instrument onboard GLAST. Now Peter I don't think a lot of people understand how a multimillion dollar observatory like this can come to be. So, can you please clue us in on that? 

Michelson: Yes, well, it...my experience with multi-million dollar observatories is limited to GLAST, but I was also part of the Gamma-Ray Obseravtory mission, which was a precursor to GLAST, and which flew in the 1990s and made a number of important discoveries but also opened up a huge number of questions. And it was clear that we needed better instrumentation and more capability. So, my background is astrophysics, it's not high energy physics, but in this experiment we use the technology that really comes from high energy experiments and we adapt it to space. And... [sound of an airplane] there's an airplane flying over, but never mind. Anyway, we adapt the technology to space and that's how..ah..that's the legacy of Egret. But for GLAST it was clear that we needed a major leap in capability. And where would that come from? 

Being at Stanford University, on the Stanford campus, I have colleagues at Stanford who sit in the Stanford Linear Accelerator Center which is on the Stanford campus. Happens to be a Department of Energy National Laboratory in high energy physics, and if there are experts anywhere in the world, some of the best were just up the road from it. So I went up there and gave a seminar on results from Egret, the Gamma-Ray...GRO experiment, and got them interested in thinking about what would come after Egret. And one of my closest collaborators and colleagues, Bill Atwood, who was at SLAC at the time and was now at University at Santa Cruz, literally over night came up with a design that's effectively what we're going to fly. I should say it was a design concept, there was a lot of engineering detail which took many years to fill in. But, Bill had this idea for what we're going to fly and amazingly enough after ten years of development what we're going to fly is pretty close to what Bill first conceived of. 

So that's the beginning of the story. Then there was the question how do we get this in orbit, how do we get a mission, and it was clear to me, at least, that the scientific, as well as technical interest of people in high energy physics like Bill Atwood and others overlaps substantially with this community in astronomy that does high energy gamma-ray astronomy. So the idea was: bring the two together into a collaboration and then seek the support from both NASA and the Department of Energy in the US. So I had this model of interagency cooperation in mind, between those two agencies that had never worked together on any large scale. And with the help of then-SLAC director Burton Richter, who was very  enthused about this and the subsequent director Jonathan Dorfan, we convinced the Department of Energy this was a good idea. NASA had its process of reviewing the project and they were also enthused about the science as well as working with NASA...er working with the Department of Energy. 

So that was the beginning of the mission concept, and we had two agencies in the U.S. that were interested and a lot of discussion took place. There was also a down-side to this that the two agencies work in very different ways. So, in terms of managing the project, there were lots of, at times, heated discussions and misunderstandings. And being the PI and getting it from both sides was sort of a challenge. But, in the end it all worked out and the two agencies now can both be proud that they've co-sponsored this instrument. Part of that legacy is also that, which is typical in particle physics and to some extent in space astronomy, that was we enlarged the collaboration beyond the U.S. and brought in major contributions from France, Italy, Japan, and Sweden. And they all played key roles in various aspects of the hardware. And so we were able to coordinate all the development of this instrument around the world and bring it together at SLAC, where it was integrated together. And now we're done, and we're going to fly this thing in about a year. 

Plait: So that's amazing. Besides different agencies in the United States and different scientists from across the country, and engineers as well, there were also other governments involved, scientists in other countries, so this must have really been like herding cats and its kind of amazing that this all came together for such a magnificent observatory. 

Michelson: Yes. There's a certain aspect of herding cats involved, and its taken me about ten years to figure out how to do that. We should have started earlier, but with our collaborators we've basically merged into one interactive, coherent team that's very international. It didn't start that way - it took a long time for people to figure out how to work together, not so much over international boundaries, but across the boundaries of the different the cultures of traditions in astronomy and particle physics. They're very different. They both have positive points about them, but we had to come up with a collaboration that respected those different cultures and could, in fact, create a new one. And that's what we've done. And we've also done that, to a large extent, with the agencies involved. In every country involved there's sort of the mirror image of DOE and NASA. So we had in France two agencies involved, in Italy two agencies involved, and in Japan, actually, several agencies involved. And coordinating all that and getting everybody on the same page, that was at times challenging. But its worked out. 

Plait: That great, and we're looking forward to the launch of GLAST and the fantastic science it's going to bring back and show us how collaborating across agencies and cultural and international boundaries will actually further our knowledge of the universe. So thank you, Peter. 

Michelson: Thanks Phil