Installing the Optical Electronics Enhancement Kit (OCEK) EVA 2 February 15, 1997 Daily Updates from NASA Space Walkers:     Greg Harbaugh     and Joe Tanner     Overview Replacing the FGS Replace ESTR-2 Replace OCEK Summary: What is it like to be in a spacesuit? What is your biggest challenge of the day? The second EVA day, FD 5, will involve the replacement of the Fine Guidance Sensor (FGS), the Engineering/Science Tape Recorder-2 (ESTR-2), and the Optical Electronics Enhancement Kit, (OCEK).These tasks, as well as the clean up and daily close out of the payload bay, are timelined for six hours. Replacing the Fine Guidance Sensor (FGS)

In His Own Words
The mission as seen by
NASA Astronaut Steve Smith
STS-82 Mission Specialist

Overview		The second day, Greg and Joe will go outside and I will stay inside with Mark and kind of orchestrate. Everyone else's roles remain the same. Of course, this will be Joe's first walk in space, so that'll be exciting. Joe will be on the arm to start with, and Greg will be the person free-floating. And they will do 2 tasks. The first is to replace one of the fine guidance sensors on Hubble. There are 3 of those on board. They're used to point Hubble very carefully. They're the ones that basically lock on to stars so that we can observe what we want to observe. Of the 3 on board, all 3 are working, but we are concerned that one is going to be degrading very quickly. So we want to put a new one in there that has new features on board. That won't necessarily operate too much, or won't offer us too many new options, but should be more dependable.
Replacing the FGS		They'll take the old one out, park it on the same fixture we used the other day, and get the new one and bring it in. And it's the third of 3 big box tasks and should take about 2 hours again.
Replace ESTR-2 ESTR		So once FGS is done, we'll go replace one of the tape recorders on Hubble. It's about the size of a little, oh, portable television. It's a mechanical tape recorder that's used to record the data observed that Hubble observes. We don't always get data from Hubble right away. Sometimes we aren't in contact with it. So it needs to record data on 3 tape recorders. One of the 3 mechanical tape recorders is broken, so we're going to put a new tape recorder in.
Upgrade OCEK OCEK		And this is the installation of a cable basically. And this cable will help us take advantage of some of the new features that the FGS will allow. So we put in this new FGS that does offer us some new capability and to take advantage of that capability, we had to put this harness in somewhere else on the Hubble space telescope.
Inside a Space Suit		As you orbit the earth every 90 minutes, of course you spend 45 minutes in the brilliant sunlight and then 45 minutes in darkness. And you continually go through that transition. And the temperatures in Fahrenheit go from about, oh, 100°, 130°, 150° on the sunny side of the earth to -100° on the dark side of the earth, on the shaded side. So in 45 minutes, your suit that you're wearing goes through a 200-250° range. It turns out it's really well designed. It has an excellent environmental control system in the background that we wear. We have this special underwear on that has tubes running through it with water to either cool us on the sunny side or to heat us on the other side. So, if you manage that, it's excellent, and you feel very comfortable.
Steve's Challenge of the Day		On this day, FGS clearances are very small. When you put this box into Hubble. That'll be exciting to have Joe do his first space walk. And, of course, my role on this day will be the orchestrator and the front conductor inside, basically running the space walk. So that'll be neat for me. So that's the first and second day.