Space shuttle Endeavour launched to the International Space Station on Monday, lifting off on its final spaceflight 19 years to the day after its first landing from space.
"Looks like a great day to launch Endeavour for the final time," radioed launch director Mike Leinbach to the shuttle's crew. "So on behalf of the thousands of proud Americans who have been part of her journey, good luck, godspeed and we'll see you back here on June 1."
"As Americans, we endeavor to build a better life than the generation before and we endeavor to be a united nation," Endeavour's commander Mark Kelly replied from onboard the vehicle. "In these efforts we're often tested. This mission represents the power of teamwork, commitment and exploration. It is in the DNA of our great country to reach for the stars and explore. We must not stop."
"To all of the millions watching today including our spouses, our children, family and friends, we thank you for your support," said Kelly.
Out of sight, but still minded
Endeavour lept off Launch Pad 39A at NASA's Kennedy Space Center in Florida at 8:56 a.m. EDT (1256 GMT) to begin the STS-134 mission.
For just over 20 seconds the vehicle's rocket plume lit up the sky, giving the estimated 500,000 spectators who came to see the launch the show they had desired. The shuttle then disappeared behind the clouds.
"As you can see, we don't have any flight rules or launch commit criteria that dictate how long you can see the launch before it goes out of sight," said NASA's mission management team chair Mike Moses. "[I] apologize that the view was not the best, but the data we were looking at in the control center was absolutely perfect."
That data revealed a few minor issues during Endeavour's climb to orbit, but nothing of great concern.
"The vehicle looked very good going up hill," Bill Gerstenmaier, NASA's associate administrator for space operations, said. "We had a little thing on [Endeavour's] center main engine, a [sensor] that is used to calculate some offline performance, it went out of calibration or out of range and then went back in and worked fine the rest of the way."
Gerstenmaier also said that video transmitted from the shuttle revealed that insulation had fallen off Endeavour's external tank, which had earlier been damaged during Hurricane Katrina in 2005 and repaired.
"We saw a couple little foam events on the external tank. I think we saw two small losses just prior to the aerodynamic sensitive time — that is when we're worried about foam coming off the tank and potentially having enough velocity to damage the orbiter," Gerstenmaier explained.
"Those were very small losses. They didn't look like they went any where near the orbiter. They were very, very small and looked pretty benign."
"We [also] had two losses very late on the tank, around five minutes and 12 seconds and five minutes and 39 seconds, and again those look like they are no problem to us at all," said Gerstenmaier.
As a matter of course, Endeavour's crew will spend most of the first full day in space inspecting their spacecraft's heat shield for any damage it may have sustained during liftoff, including, oddly enough, from insects.
"On this mission, we will probably have some extra stuff to look for. If you've been driving around the area, you know we have had a little bit of an explosion in the Lovebug population. So, we want to make sure the [orbiter's] nosecap doesn't have any extra Lovebugs on it," said Moses.
Challenging final mission
"The mission in front of us is no easy mission," said Gerstenmaier.
During its final 16 days in space, Endeavour will deliver to the station the Alpha Magnetic Spectrometer, a state-of-the-art particle physics detector designed to search for unusual matter by measuring cosmic rays.
Also on board Endeavour are spare parts for the station. The ExPRESS Logistics Carrier 3 (ELC3) carries two S-band communications antennae, a high-pressure gas tank, a replacement ammonia tank assembly, circuit breaker boxes, a computer for Canadarm2 and a spare arm for the Dextre robot.
STS-134 commander Mark Kelly, whose wife, wounded Congresswoman Gabrielle Giffords, traveled to Florida to watch him launch, led his crew of five into space. Joining him on Endeavour is pilot Greg H. "Box" Johnson and mission specialists Michael Fincke, Andrew Feustel, Greg Chamitoff and European Space Agency astronaut Roberto Vittori.
Feustel, Chamitoff and Fincke will perform four spacewalks that focus on station maintenance, experiment swap out, and transferring Endeavour's orbiter boom sensor system (OBSS) to the station. The crew will leave the boom as a permanent fixture to aid future station spacewalk work, if needed.
The spacewalks will be the last performed by shuttle astronauts.
STS-134 will also see Endeavour perform a rare flight test, reapproaching the station after it undocks to test sensor technologies that could make it easier for future space vehicles to dock to the orbiting laboratory.
Two for the show to go
Endeavour's last liftoff came on its second try.
On April 29, an electrical short in a hydraulic system heater resulted in a scrub for Endeavour's first attempt at launching on STS-134. Subsequent analysis traced the cause of the short to a test performed on the heaters' thermostat last June.
The Aft Load Control Assembly-2 (ALCA-2), the switchbox containing the wiring for the faulty thermostat, was changed out and new wiring was run to circumvent any possible damaged power lines. Testing confirmed that the heater system, which prevents freezing of the fuel lines providing hydraulic power to steer the shuttle during ascent and entry, was working properly.
During the final countdown to Endeavour's liftoff, the heater circuitry was again tested and was in working order.
And then there was one
The 25th trip to space by NASA's fifth and youngest orbiter, Endeavour's STS-134 mission is the second-to-last for the space shuttle program.
Sister ship Atlantis, which preceded Endeavour into service as NASA's fourth built orbiter, is slated to fly the final mission of the shuttle program, STS-135, in July.
As currently scheduled, weather permitting, Atlantis will begin its journey to the launch pad on Tuesday with its rollover from the orbiter processing facility where it has been prepared for this flight to the Vehicle Assembly Building. The next day, it will be lifted by crane and mated with its solid rocket boosters and external tank.
Should schedules hold, Atlantis will rollout of the VAB on the evening of May 31, arriving at Pad 39A just as Endeavour returns from space.
"So if it does happen that way, it will be a very, very special night," said Leinbach. "We'll be rolling out to the pad... then here comes Endeavour back to [Kennedy Space Center]. It will be a nice night to witness and be part of."
Four hours after launching, space shuttle Endeavour's primary cargo, the Alpha Magnetic Spectrometer (AMS) particle detector, was turned on by ground controllers to make sure that it survived the ride intact.
"AMS is in space and activated," mission specialist Mike Fincke radioed from Endeavour.
The state-of-the-art science experiment will be added to the International Space Station on Thursday.
To be ready for that and their other STS-134 mission objectives, the crew spent several hours configuring Endeavour for life on orbit. They opened the shuttle's payload bay doors, inspected the cargo bay and the forward windows for any impacts from launch and checked out the robotic arm for the next day's heat shield survey.
The crew also performed the first of several trajectory maneuvers to bring them to the space station for a docking on Wednesday.
The astronauts retired for an eight hour sleep period at 2:56 p.m. CDT.