 subunit 3.7 phase E. Okay now let's talk about phase E, the operations phase of the life cycle. So once the system's been verified and validated both on Earth prior to launch and then after it's been put on orbit to make sure it'll meet all of its high-level requirements and objectives, now the nominal operational phase commences. So it defines the system operational life expectancy was set early on so you know when you're going through the initial development of the system you're saying okay I expect this system to be able to last for five years on orbit or two years on orbit so that was how the stakeholders approved the project. So when they set aside money to operate the satellite they said okay your mission should be able to be accomplished in two years all your signs should be able to be collected. We're going to give you a two-year mission life and so you budgeted for two years of operational activities. Let's use that as an example. So when you went through your life cycle you made sure that all your components could be verified to operate for that period of time. So you wanted to make sure that nothing would put them you know you're trying as much as you can make sure that all of your system components should be able to last at least for that operational period. Now you're going to go through and now that you've launched it you're going to have an operations team that's trying to maintain the system operationally and make it last for those two years and they're looking to make sure that all the systems are staying healthy all the science is being returned and if anything goes wrong they're trying to operate through that period. So this is all phase E is operations. So at the end of that operational period though you might still have a healthy spacecraft a lot of satellites last a lot longer than they originally planned for. So at that point you could go back to the stakeholders and say geez I still got a really good operating satellite and I'm still getting really good science data and there is more data to be had if you'll allow me to operate for longer and so you can continue to get approval if it looks like the science value of the satellite is still you know contributing scientific value to the community and the system is healthy enough you can get approval to continue on for longer and longer usually in two-year increments NASA will give you approval so that you can operate for at least a few more years and then come back again and have to show that you are still healthy and still providing good science value to get approval to proceed even further. So you have to keep in mind that at the end of the operational phase of a system especially a space system you have to consider that some form of passivation is going to have to happen to end the system's life gracefully and in a way that won't interfere with other satellites and we'll talk a little bit more about that in in phase F but in phase E you're trying to make sure that you operate the system successfully through its mission life and then if it's operating well you can continue to ask for extensions of that life and this global precipitation mission its goal is to get on orbit as quickly as possible because if you go to the next chart you'll see the tropical rainfall mission the tropical rainfall measuring mission trim was launched in 1997 that mission is currently in phase E phase E is the operational phase begins after launch when the spacecraft is checked out it officially transitions into the operational phase and during this phase it's now collecting its science data or whatever its mission is sending that data to the ground and successfully hoping it's being processed and scientists are getting the data now in the case of the tropical rainfall measuring mission it has a similar radar unit you see here on the bottom and that unit is collecting data mostly a lot of it is about hurricanes and so during hurricane season it turns out that this mission is very critical to collecting data on hurricanes to build up how strong they are and where they're moving and so even though it's just a NASA research satellite it also has a lot of operational implications to folks who are monitoring weather and severe weather so so the global precipitation mission they are in a hurry to get it up into space because trim is getting older launch in 97 and when you design and build the spacecraft you are designing it for a certain amount of time so all the designs are based on a five-year mission life or whatever the original mission life was all the components are tested the reliability analysis done for that mission life and so in the case of trim it's lived well beyond its expected mission life so there are no guarantees of how long it will last and so the goal is to keep it operational at least until the next satellite gets up that can perform that function that's that's required the primary technical review in phase e is a post launch assessment review this kind of marks the beginning of phase e the technical reviews are not always at the beginning or the end of a phase they kind of come at a point where the system should be at a certain level of maturity and so in this case the post launch assessment review is an assessment of the activities that were done to verify and validate on orbit that the system successfully meets its requirements and objectives and so this review includes a review of the results of on orbit system verification and validation that shows that the spacecraft that's been launched and the science payload that it's carrying perform in a way that was expected and they meet all of their high level requirements and then any non nominal results anything that came out in its verification and validation that wasn't what was expected that you've been able to characterize those non nominal performances and you've been able to figure out a way to operate successfully even in that kind of non nominal state so any anomalies have been investigated and the impact impacts have been assessed you're also getting reviewed to see that the there's a completeness of all of your operations plans including your detailed procedures and staffing to make sure that the system really is ready to go into into normal operations and again any actions assigned back at the phase earlier phase operational readiness reviews and flight readiness reviews have been closed out successfully and so that would mark the entry in this case into phase E normal operations is by passing through your post-launch assessment review there are no additional resources for this subunit feel free to skip ahead to the next video