Atlantis will rocket into orbit using a so-called "high-Q" ascent profile that puts slightly greater aerodynamic stress on the spacecraft. "Q" is the letter symbolizing aerodynamic pressure in a variety of calculations.

For Discovery's flight last month, flight controllers approved a low-Q ascent, one the lofted the ship's trajectory slightly to get it out of the thick lower atmosphere faster. The idea was to minimize the stress on the external tank's foam insulation.

But that is not an option for Atlantis because of the heavy weight of the P3/P4 payload.

"As far as we're concerned, it's not an issue," Jett said. "If you look at the difference between a low-Q ascent and high Q, for us the main differences are when we pick up our different abort boundaries. So from a crew perspective, high Q gives us more abort options during the ascent.

"The program has looked at the margins on the tank, they're very comfortable with the margins both structurally and with the foam performance. So we believe it was the right decision to go high Q on 115. With our heavy payload, low Q would have been very, very difficult for us to do."

DATE/EDT.......DD...HH...MM...EVENT

08/27/06
Sun 04:30 PM...00...00...00...STS-115 Launch (flight day 1)
Sun 05:08 PM...00...00...38...OMS-2 rocket firing
Sun 07:00 PM...00...02...30...Post-insertion complete
Sun 07:05 PM...00...02...35...Group B computer powerdown
Sun 07:10 PM...00...02...40...Shuttle robot arm (SRMS) powerup
Sun 07:20 PM...00...02...50...Elevon park
Sun 07:25 PM...00...02...55...SRMS checkout
Sun 08:10 PM...00...03...40...SRMS powerdown
Sun 08:30 PM...00...04...00...Wing leading edge system activation
Sun 08:55 PM...00...04...25...ET video downlink
Sun 09:31 PM...00...05...01...NC-1 rendezvous rocket firing
Sun 10:30 PM...00...06...00...Crew sleep begins

The day after reaching orbit, the Atlantis astronauts will check out a pair of spacesuits, ready equipment for transfer to the space station and carry out the flight-day-two wing leading edge and nose cap inspections that are now a standard part of every shuttle flight.

DATE/EDT.......DD...HH...MM...EVENT

08/28/06
Mon 06:30 AM...00...14...00...Crew wakeup
Mon 07:54 AM...00...15...25...NC2 rendezvous rocket firing
Mon 10:00 AM...00...17...30...SRMS/OBSS unberth
Mon 10:30 AM...00...18...00...Spacesuit checkout preps
Mon 11:00 AM...00...18...30...Spacesuit checkout
Mon 11:20 AM...00...18...50...Starboard wing survey
Mon 12:30 PM...00...20...00...Crew meals begin
Mon 12:50 PM...00...20...20...Nose cap survey
Mon 01:00 PM...00...20...30...OMS pod inspection
Mon 01:30 PM...00...21...00...EVA prep for transfer
Mon 03:20 PM...00...22...50...Port wing survey
Mon 03:30 PM...00...23...00...Transfer preps
Mon 04:50 PM...01...00...20...OBSS berthing
Mon 05:25 PM...01...00...55...Upper surface survey
Mon 06:25 PM...01...01...55...LDRI laser checkout
Mon 06:25 PM...01...01...55...Rendezvous tools checkout
Mon 06:30 PM...01...02...00...Centerline camera installation
Mon 07:00 PM...01...02...30...Orbiter docking system ring extension
Mon 07:35 PM...01...03...05...NC3 rendezvous rocket firing
Mon 09:30 PM...01...05...00...Crew sleep begins

Jett will fly a standard rendezvous profile, approaching the lab complex from behind and below. The terminal phase of the rendezvous procedure begins about three hours before docking with the shuttle trailing the station by about 9.2 miles.

On final approach, at a distance of about 600 feet directly below the station, with Atlantis nose facing forward and its open payload bay facing the station, Jett will carry out the slow 360-degree rotational pitch maneuver, or RPM, that will point the belly of the shuttle at the station.

As the shuttle's underside rotates into view, Expedition 13 commander Vinogradov and flight engineer Williams will photograph Atlantis' belly with handheld digital cameras equipped with 400mm and 800mm lenses. The former has a resolution of three inches while the latter has a resolution of one inch.

Imagery from the station will be downlinked to Houston for detailed analysis.

"The RPM maneuver, or rendezvous pitch maneuver, is actually very visually dramatic," Jett said in a NASA interview. "But from a flying standpoint, it's not really any more difficult than any other type flying we do for rendezvous. The real significance of the RPM is that it allows the station crew to take photos of the underbelly tile areas of the orbiter, which we don't inspect on flight day two. On flight day two, we're looking primarily at leading edge of the wing so this is a whole other area of the thermal protection system, which allows the folks on the ground to analyze for any damage.

"If for some reason we can't do the RPM, it's a significant impact to our mission because we still have to, at some point, go under there and look at the tile. The RPM is a very, very efficient way for us to do a little flip maneuver, as we approach the station and allow the station crew members to use an 800mm lens to photograph all the tile and send it down to the ground and let them analyze it. So it's a real important maneuver."

After completing the pitch-around, Jett will position Atlantis about 400 feet directly ahead of the space station with the shuttle's nose facing deep space and its cargo bay facing the lab complex. He then will guide the spacecraft to a docking with a pressurized mating adaptor attached to the front of the Destiny laboratory module. Assuming an on-time launch, docking is expected around 12:40 p.m. on Aug. 29.

After leak checks, Vinogradov, Williams and European Space Agency astronaut Thomas Reiter, ferried to the station aboard Discovery last month, will welcome the Atlantis crew aboard the station and provide a safety briefing before all nine astronauts get down to work.

DATE/EDT.......DD...HH...MM...EVENT

08/29/06
Tue 05:30 AM...01...13...00...STS/ISS crew wakeup
Tue 07:15 AM...01...14...45...Group B computer powerup
Tue 07:30 AM...01...15...00...Rendezvous timeline begins
Tue 08:19 AM...01...15...49...NC4 rendezvous rocket firing
Tue 09:51 AM...01...17...21...TI rendezvous rocket firing
Tue 10:00 AM...01...17...30...ISS: Verify RPM photo setup ready
Tue 11:15 AM...01...18...45...Begin final approach
Tue 11:35 AM...01...19...05...Rendezvous pitch maneuver
Tue 12:38 PM...01...20...08...Atlantis docks with space station
Tue 01:00 PM...01...20...30...Hatch leak checks
Tue 01:15 PM...01...20...45...Group B computer powerdown
Tue 01:30 PM...01...21...00...ODS preps for entry
Tue 01:50 PM...01...21...20...Hatches opened
Tue 02:00 PM...01...21...30...SRMS P3/P4 grapple
Tue 02:15 PM...01...21...45...Welcome aboard!
Tue 02:25 PM...01...21...55...Safety briefing
Tue 02:50 PM...01...22...20...SSRMS configured
Tue 02:50 PM...01...22...20...Post-docking EVA transfer
Tue 03:20 PM...01...22...50...SRMS unberths P3/4
Tue 03:25 PM...01...22...55...REBA checkout
Tue 04:10 PM...01...23...40...EVA tools configured
Tue 04:40 PM...02...00...10...SRMS hands P3/P4 to SSRMS
Tue 05:00 PM...02...00...30...SRMS ungrapples P3/4
Tue 05:25 PM...02...00...55...EVA camera setup
Tue 05:50 PM...02...01...20...EVA-1: Procedures review
Tue 07:55 PM...02...03...25...EVA-1: EV1, EV2 campout prebreathe
Tue 08:40 PM...02...04...10...EVA-1: 10.2 depress
Tue 09:00 PM...02...04...30...ISS crew sleep begins
Tue 09:30 PM...02...05...00...STS crew sleep begins (EV1/EV2 in airlock)

"What we've elected to do ... is to get right into the payload operations shortly after docking. So about two hours after we're together, hard-mated and the hatches are open, Dan and I are going to extract the payload from the payload bay. Once again, this payload is huge, it occupies the entire payload bay and weighs about 36,000 pounds, so it's no small operation. There are some areas where the clearances get rather tight."

Burbank, operating the arm, will have just one inch of clearance between P3/P4 and the OBSS heat shield inspection boom mounted along the right wall of the payload bay. As he is lifting the payload straight up from its perch in the payload bay, Burbank will have to jog it slightly to the left to avoid the OBSS. It is a delicate procedure because of the payload's inertia and the need to avoid any overshoots that could cause it to hit anything.

Assuming all goes well, Burbank will position P3/P4 over the left wing of the shuttle. At that point, MacLean, operating the space station's more massive arm from inside the Destiny laboratory module, will grapple P3/P4 in a handoff maneuver and Burbank will release the truss with the shuttle's arm.

"I'm out on work site 7, which is as far as you can go on the space station with the station arm, or Canadarm 2," MacLean said in an interview. "I'm prepositioned so I can accept the handoff. Dan will get it into position and then I'll go in for the handshake when both arms are holding it. Dan will let go and we'll park there over night."

MacLean said the handoff will mark a proud moment for Canada, which provided both robot arms and the Space Vision System that will be used later to precisely position P3/P4 for attachment to the station's truss.

"Don't be surprised if you hear a call out on the 'great Canadian handshake,'" MacLean joked at a news conference. "But we are handshaking with a payload that is impressive, very high tech, that's going to carry us forward to having the best orbiting laboratory in the world."

Pulling P3/P4 from the cargo bay starts a 35-hour timer. That's how long the crew has to get the payload attached to the P1 truss and wired into the electrical system to power critical heaters. But the 13 umbilicals needed to route power and data to and from the new truss element will not be hooked up until the next day during a spacewalk by Tanner and Piper.

Instead, P3/P4 will be left hanging out over the left wing of the shuttle, safely attached to the station's robot arm, while the astronauts wind down from a very busy third day in space.

Tanner and Piper will spend the night sealed up in the Quest airlock module as part of a new "campout" procedure. The airlock's pressure will be lowered from 14.2 pounds per square inch to 10.2 psi to help the spacewalkers purge nitrogen from their blood and prevent the bends when working in their 5-psi spacesuits.

Flight controllers in Houston plan to roll the station about 45 degrees to port, dipping the port side of the solar array truss down toward Earth, to improve the thermal environment. The next morning, after a "hygiene break," Tanner and Piper will begin donning their spacesuits, assisted by Jett. MacLean, meanwhile, will return to the Destiny module, take control of Canadarm 2 and move P3/P4 up to a pre-install position just a few inches from P1.

"I'll maneuver the P3/P4 truss around up to the P1 truss, an operation that will take about 45 minutes, to the preinstall position nine centimeters away from the center of P1," MacLean said. "During that time, we have to do this attitude roll. It's tied to the arm operation because once we get to that position, it's a thermally very hot place and that's the best orientation to minimize that thermal case. Then you have to wait for the rates to damp out, that takes about 30 minutes plus or minus five or 10 minute probably, then we move in for the final install using the Canadian Space Vision System, which gives me the guidance data."

The Space Vision System uses television cameras and powerful software to measure the precise locations of large black dots attached to the truss elements. The SVS software computes the relative positions of the dots to give MacLean very precise distance and orientation information. Temperature effects can cause distortions of up to five inches, MacLean said, and misalignments of 1 to 2 degrees. The SVS will help compensate for any such effects.

"It'll take about an hour to get to the pre-install position there, and then we have to wait for an attitude change that we need in order to have the P3/P4 Truss at a thermally viable position," MacLean said. "And then we install. Fergy will come over and back me up with the Space Vision System and he will basically provide that data to me, and then using that data I will guide the P3/P4 truss in to the P1 Truss. And that'll be it. A good day."

The actual attachment is automatic. Once P1 and P3 are in close proximity, four motorized bolts on P1 will drive into attachment fittings on P3, firmly locking the two truss elements together. Three of four bolts must engage to call the operation a success.

At that point, Tanner and Piper, now suited up in the Quest airlock, will float out into space and begin the first of two back-to-back spacewalks to hook up and activate P3/P4.

"Once three of four of those bolts are mated, we'll go ahead and send the crew EVA and perform the activities that we need to do to make the element survivable," McCullough said. "All the power connections, the 13 umbilicals that need to be mated and all the activities to get ready for solar array deploy start on EVA-1. The power hookups all are completed by the end of EVA 1 and the element is completely survivable."

PREVIEW REPORT PART 5 --->