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Mike Leinbach, STS-115 Launch Director
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Anita Barrett: From the Kennedy Space Center in Florida, I'm Anita Barrett. Just weeks after the successful launch and landing of Space Shuttle Discovery, NASA is preparing for the launch of Space Shuttle Atlantis on mission STS-115. STS-115 is an International Space Station construction flight and will carry an important truss segment for the ISS. Mike Leinbach is NASA's launch director for the mission. Mike, thank you for joining us and welcome to NASA Direct.

Mike Leinbach: Well thank you very much, Anita. It's good to be with you today as we look forward to another launch of the space shuttle.

Barrett: Why was Atlantis the vehicle of choice for mission STS-115?

Leinbach: That's a good question and it goes back to the early manifesting days of this mission - back before the Columbia accident as a matter of fact. The payload for this mission, the PS/P4 truss is so heavy that it couldn't have flown on Discovery. It could have flown on either Atlantis or Endeavour and certainly not Columbia, but it could have flown on either Atlantis or Endeavour. Endeavour is going through a major modification period and has been for some time and so, Atlantis was chosen for weight considerations primarily. Again, that choice was made many years ago before the Columbia accident.

Barrett: Discovery has flown two return-to-flight test missions in a year. What has Atlantis been up to during this time?

Leinbach: Well, as I alluded to, this mission has been in preparation for quite some time. The crew has been training together as a crew for four and half years together. The vehicle has been in the Orbiter Processing Facility about three and half years - four years about. It had been over to the Vehicle Assembly Building twice and mated to an External Tank in preparation for a mission. In fact, Atlantis was in the VAB preparing for the first mission after the Columbia accident. It would have been the next mission after Columbia's accident. So she's been vertical in the VAB twice before this current flow and after the stand-downs due to the accident we put Atlantis back in the Orbiter Processing Facility and took the time that we had available to us to do some modification to the orbiter. She's gone through over 75 modifications to the ship ranging from very minor bolt change-outs to window change-outs, different fluid systems -- we beefed up -- that type of thing. So, we took advantage of the down time and got some work behind us that we had been wanting to do for quite some time.

Barrett: How does the launch team prepare to launch so quickly after STS-121?

Leinbach: Well, the launch team likes to launch quickly. One of the worst things for us is the stand down period. Once we get into a routine of launching three, four, five times a year it's easier for the team to stay in sync, to keep our skills honed. While we stood down after the Columbia accident for a couple or three years we did extra training cycles every six weeks. I'd assemble the full launch team together and go through training runs where our simulation team throws problems at us and expects us to solve the problems just as we would on launch day. We stayed sharp during the down time, but strictly from the launch team perspective, flying more often is better for us because we stay sharp -- better-- I guess.

Barrett: Does what the shuttle carries inside its payload effect the launch? For example, is there any special monitoring or balance or weight considerations?

Leinbach: There sure is. The weight of the payload is a very critical piece of the whole launch system. This payload is one of the heaviest ones we've flown. It will be the heaviest we've flown in quite some time -- over 35,000 pounds. So, to accommodate that, we are only going to fly six astronauts this time. Some folks may wonder, "Well, don't you usually fly seven astronauts?" and the answer to that question is, "Yes." We're flying 6 this time because of the weight of the payload. For curiosity's sake, each time we fly an astronaut up, we book in about 500 pounds total per astronaut. The weight of the astronaut, the clothes, the food, all the support that goes into putting up an additional crew member all adds up to about 500 pounds. So, the weight of this payload dictated that we could only fly six even though Atlantis is a good light ship. We could still only manage six astronauts this time.

Barrett: Why are there holds in the countdown and what is happening in the firing room during those holds?

Leinbach: Well the holds were put in -- designed in the countdowns from the very beginning of the manned spaceflight program. And they are intended to be points in the countdown where the team can take a breather, essentially. There's not supposed to be much work going on during a hold. Again, it's a point where if work leading up to that built-in hold has run behind schedule for some reason, we can continue to work into the hold and then take the hold itself and then when we pick up the clock again, get back into work. So, really they are points in the timeline that allow catch-up time and also time for the team to take a breather and think about what's coming up next in the count. The last built-in hold we have is at T minus 9 minutes and for the current missions those are 40 minute long holds so that we can make sure that the vehicle is ready to pick up the clock at T minus 9 minutes and counting, because for 9 minutes on down is when the vehicle really starts to come to life. And so we want the team to be focused having just taken a short break as it were. We don't leave the control room, but we look forward to what's about to happen and we concentrate on our jobs. And so, it's really a time of reflection. It's a time to catch your breath and to think about what we're about to go do.

Barrett: Mike, thank you so much for talking with us today about orbiter Atlantis.

Leinbach: It was my pleasure. Thanks a lot.

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