 subunit 3.6 phase D. Now you've got all these components that you've purchased or you've built. They've all been verified. Now phase D is going to involve integrating all those components and creating a system out of them and testing the system and preparing it for a launch. So all along the way here in phase D all those components are going to be connected together and as you're connecting each one to another component you're going to check that you can verify that the requirements for that now integrated set of components can be met and at each higher and higher level of integration you're going to be able to check out that higher and higher level of requirements are being met by this newly developing integrating system as you go along the way. So the system is now being built up and it's being verified at higher and higher levels that all the requirements can be met. So at the end the completed integrated system is verified and validated to make sure that all of those high level remember at the beginning here back in pre phase A and phase A we were working on things like high level requirements top level that take the stakeholder objectives and start to define underneath of them requirements at a very high level. Now that I've got this fully integrated system I can check that that fully integrated system can actually perform the functions and have the capability to meet those high level requirements that were defined way back at the beginning of the process. So once this process is completed you've now got a system that's ready to deploy and put into operation. So at the end of phase D for a satellite you're going to be able to launch the system and you're going to do some on orbit verification and validation to say that okay I tested on the ground and I thought the system would perform the way it needed to to meet the objectives of the stakeholders. Now that it's actually on orbit and I'm in the real space environment does it really still meet all those requirements and so they'll be on on orbit verification and this will kind of mark the end of phase D where you're now saying the system is ready to go. I've evaluated that it can meet all the requirements and it's ready to be put into its operational phase which is phase E and so this is the end of phase D. So detailed activities that happen in phase D include you're going to integrate components into a larger and larger kind of in a building block fashion into larger and larger components to subsystems up to the big system level until you've got this final integrated system. You're going to verify and validate along the way that the capabilities, the performance and all the interface requirements that you define early on in the process can all be met by the system that's it's developing. You're going to perform most for satellites you're going to perform some kind of environmental testing that simulates both the expected launch environment, the vibration, the acoustics of launch and the space environment, the lack of the vacuum, the heat and the cold and all the other environmental factors that you might find in space. You're going to simulate as best you can on the earth what those environments will be by putting the spacecraft through a series of tests to make sure that it should work the way it's expected to when it gets into that environment. You're going to complete all your plans and procedures for the commissioning of the satellite and operating the system. You're going to train all the operations personnel to again make sure that the folks that are going to be involved in this next phase of operations all are properly trained on how the system works and all the contingencies that they might have to use if something doesn't go well and you want them to be totally prepared to operate the system on a good day and on a bad day. You're also going to verify that all external interfaces interfaces to things like the launch site and the launch vehicle that you're going to be on, the communications ground antennas that you're going to be talking to that all those external interfaces have been tested and verified so that you know that everything will work when you actually launch the system. You're going to integrate the system that in this case we're talking mostly about a you know we're talking about a satellite integrate that system with the launch vehicle and you're going to go ahead and launch it into orbit during the end of phase D and the end of phase D really is the commissioning and establishing of a baseline operational system where you've verified on orbit that the system meets all the high level requirements and verified that it can meet the stakeholder objectives. You'll see an example of a mission that's in phase D. This is the global precipitation mission, a joint U.S. Japanese mission that's going to focus on measuring rainfall around the world in the tropics where I think most of the rainfall falls, 80% or so the rainfall falls. You'll see that on the bottom of the space, it's got a complex radar instrument that's provided by the Japanese Space Agency. It has to be brought over from Japan and integrated into this spacecraft and so that's what's happening in phase D is that you're bringing all those components together and you're building one unified spacecraft and so this is the most exciting part. Any project I've ever worked on, you've worked for years and now you finally get to see the spacecraft come together. It's no longer a bunch of computers and fuel tanks laying around on the ground. It's now being put onto the structure. You're testing each component as it goes on. You're actually seeing those designs come to fruition and you're seeing the spacecraft being built up. That's a really exciting part of the project. So when they get the final spacecraft built up, it now has to go through system level testing where you're going to make sure that that full system that you've built up can operate in its environment as well. You'll put it through the shaking process to make sure it can survive launch. You'll put it through heat and cold cycles in a depressurized environment to make sure it can survive on orbit environments. You'll do all kinds of testing to make sure that it will survive and then you'll also do some connectivity testing to make sure that data coming from that integrated satellite can be brought down through the antennas and processed in the control centers and that the whole integrated system, which not only includes a spacecraft but all the other components that make this an integrated system of science data and scientists that want to look at that data and operators who have to command the satellite, all that can be done and tested on the ground before launch. And that all happens in phase D as you're prepared to go to the launch pad. The primary technical review in phase D is the operational readiness review. There's also a flight readiness review. We'll talk about both. So the operational readiness review, the technical review team will come in and they're going to assess things like your system is matured, it's all your enabling products for operations have been developed and it looks like you're ready to enter the operations phase. That all your lessons learned have been captured through the development phase to make sure that anything that the team has learned about the nuance of how the satellite might operate in space and any specific constraints that it might have on how it operates have all been documented and passed on to the operations team and that same lesson learned information has been given back to developers of other satellites so they can learn from the lessons that you have on your project and maybe do things a little differently in their development cycle. You're also going to look to see that all the waivers and anomalies have been addressed maybe during some of the testing as you were getting the satellite integrated. Some of the test didn't go that well. Maybe in some cases the system failed the test, meaning that maybe a requirement couldn't be verified. Maybe the thruster didn't perform its plan. In a lot of cases a waiver might be considered where you might say well gee that thruster didn't perform its plan once we integrated the system together but we're willing to live with that. The performance that we'll get out of it should be at least 95% say or whatever the analysis shows and that we're willing to go forward and we'll sign a waiver saying okay it didn't meet its requirements at an integrated system level but we're willing to go ahead and launch but there might be some constraints on how you have to operate. Again those have to be documented and passed on to the operations team. You're also going to be assessing that all the hardware, software, personnel and procedures are all in place to support the operations activities and you're going to look to see that the results of all activities performed earlier back in the previous phase where we went through the system integration review have all been closed out. The flight readiness review is the second technical review that happens in phase D and a flight readiness review is done usually very close to launch at this point. So the spacecraft is evaluated to make sure that it's all ready for flight. All hardware and software have been verified and validated at the system all the way up to the system level. Any operational constraints and again these are things where the development team may have identified some problem with the satellite that it has to be operated in a certain manner to be successful and so those constraints on how it has to be operated need to have been documented and passed on. They've been identified. There's process in place for safely addressing them to make sure that you can safely operate the satellite through its life and that all external interfaces have been verified and so you'll see an operational readiness review again usually comes a little bit earlier before launch and then a flight readiness review you'll see a lot of common things that are being assessed here but again you're a little bit closer to launch at this point. Things should be even a little bit more mature and this is usually the last major review to give you the okay to go ahead and launch the satellite into operations. There are no additional resources for this subunit. Feel free to skip ahead to the next video.