HOUSTON – Atlantis smoothly glides up and around the International Space Station (ISS) and commander Terrence Wilcutt pulses the orbiter’s thrusters as the craft docks without a hitch.
No, there isn't a mission in progress, just a simulation exercise held on Wednesday, August 23, of the first crucial steps that will prepare the station for its first occupants this fall.
Wilcutt, along with pilot Scott Altman and mission specialists Ed Lu and Rick Mastracchio, spent about three hours practicing docking and undocking with the station inside a Johnson Space Center (JSC) simulator that reproduces the orbiter’s rear flight deck. Video projectors inside the domed structure give a realistic depiction of Earth along with the docking mechanism in the orbiter’s payload bay and the ISS.
Atlantis and its seven-person crew are slated to launch September 8 at 8:31 a.m. Eastern Daylight Time (12:31 GMT). Once in orbit, the crew will make one spacewalk, deliver supplies and install equipment to the station during their 11-day mission.
"If I do it right, we won’t feel anything at all," Wilcutt said of the actual docking. Atlantis will close in on the station at a few inches (centimeters) per second, with Wilcutt and Mastracchio watching out the orbiter’s windows. They will use an electronic gun-sight-type device and a video monitor showing the station’s docking target.
Lu operates a computer running a program that graphically shows where the orbiter is in relation to the station and where it is likely to drift. Mastracchio operates a laser range finder that he uses to compare the data from radar readings and other devices and passes the information on to Wilcutt. Altman assists and is also ready to dock the orbiter.
Altman will do the undocking, as well as a fly-around inspection of the station, to give him practice for the next time when he will likely return as a shuttle commander, Wilcutt said.
Wilcutt, a U.S. Marine colonel, also visited the Russian space station Mir twice – once as a pilot and a second time as a shuttle commander.
The laser range finder aboard the shuttle is the most accurate of the range-finding devices, but Wilcutt said it still takes a human decision to interpret the data.
"I’ve got complete trust in Rick, he’s doing the math in his head and calculating the difference," Wilcutt said.
To dock with the station, Atlantis comes up from underneath the ISS and curves around to the top for the docking. During the final docking process, the orbiter’s thrusters are fired gently to bring it closer to the station. The station’s solar arrays are pointed away to prevent any potential damage from the thrusters.
On Friday, the crew works an "integrated simulation" with Mission Control’s flight controllers participating. Wilcutt anticipates the exercise won’t be as smooth as Wednesday’s.
"It’ll be an interesting one," he said. "They’ll give us some failure scenarios to work through."
Wilcutt said the crew is ready to go and looking forward to the mission.
"It’s going to be busy, but fun with the launch, docking, EVA (extravehicular activity), delivering supplies and undocking," he said.
Along with the docking simulation, the rest of the crew that includes Dan Burbank and cosmonauts Yuri Malenchenko and Boris Morukov, will practice launch and reentry simulations, orbiter-escape drills and take a last flight physical before heading to Florida.
Wilcutt and Altman will fly to El Paso, Texas next week to make practice landings in the Shuttle Training Aircraft, a modified Gulfstream 2 business jet that mimics the shuttle’s flight characteristics.
Lu said he and Malenchenko would train one more time for their spacewalk in JSC’s 40-foot- (12-meter-) deep pool in the Neutral Buoyancy Laboratory.
He said mission managers are considering adding one task to their 6.5-hour spacewalk – a docking target aboard the Zvezda service module didn’t extend after docking. The spacewalking duo may see if they can get the target to open.
Lu, making his second flight, said he’s ready to go and visit the station. He flew previously on a shuttle mission that docked with Mir.
"We’re going to go from being a shuttle crew to being a station crew and back to being a shuttle crew," he said.
