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Chapter 3: Flying in Space Shuttle

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Contents

Launch

The simulator starts the user off in the launch phase of the shuttle mission. Here, the user can simply watch as the launch is run. Displayed throughout the launch are the Shuttle’s speed, altitude, time into flight, and time until orbit. The simulator will accurately recreate how long it takes for the Shuttle to reach orbit (eight and a half minutes) and the maneuvers that it goes through on the way there. This kind of visualization isn’t normally possible—after all, the Shuttle is out of range of the cameras within about two minutes of launch, so we never see the whole flight to orbit. In Space Shuttle, though, the entire path to orbit is faithfully reproduced, so users can see what really happens, as fast as it really happens.

It is fascinating to watch the indicated air speed (found in the HUD view—see Chapter 2) slowly fall to zero knots as the Shuttle climbs into space and the air pressure drops to nothing. Also, watch the take off from the HUD view and note how the shuttle only climbs vertically for the first 40 seconds or so, after which it begins to tip over on its back. The shuttle then climbs inverted for the next 300 seconds or so (nearly five minutes), until the spacecraft rolls upright at about 330 seconds after liftoff.

The simulator also puts into perspective the duration of the main engine burn after the solid rocket boosters burn out and are jettisoned. This shows visually why the external fuel tank is so gigantic in comparison to the Shuttle.

Selecting Another Mission

In addition to watching the Shuttle attain orbit, users can choose to fly all or part of the craft’s return to Edwards Air Force Base. To do this, click the Settings button, as shown below.

Image:Settings_menu_space_shuttle.png

When the Settings window opens, the Mission tab (shown in the following image) will be selected. Here, the user can choose to perform a launch, final approach, full approach, or complete re-entry. After selecting the desired portion of the Shuttle’s flight, tap the Go! button to begin.

Image:Mission_tab_Space_Shuttle.png

Let’s walk through the three remaining options. Unlike the launch, users don’t get to just sit back and watch these—it’s time to fly!

ISS Dock

In this segment of the mission, the user will dock the Space Shuttle with the International Space Station orbiting the earth.

To do this, the user must monitor quite a few controls at once.

First, the Shuttle's pitch and roll (controlled using the device's tilt) as well as its yaw (controlled using the YAW slider at the bottom of the screen) must be used to properly align the shuttle with the docking hatch in three dimensions.

While keeping the pitch, roll, and yaw on target, the user must carefully use the throttle control (found on the left side of the screen) to bring the Shuttle in. This slider goes from full forward (at the top of the screen) to full backward (at the bottom of the screen), and releasing it will reset it back to zero thrust (in the center of the screen). Be sure to have the craft's velocity under 1 meter per second when it meets up with the ISS.

Finally, while keeping the pitch, roll, yaw, and throttle where they need to be, use the translational thrusters (labeled TRANS) to align the body of the Shuttle with the space station. The orange circle in the center of the screen and the moving orange dot show where the translational thrusters need to push the craft. Simply drag the thruster control in the direction of the dot relative to the circle to properly align the Shuttle. For instance, if the dot is above the circle, drag the TRANS control up, and if the dot is to the right of the circle, drag the TRANS control right, etc. When the Shuttle is right on target, the orange dot will be inside the orange circle.

Keep all of these controls where they need to be and docking will be a breeze.

Final Approach

First, select the Final Approach. This is the easiest of the mission segments. The Shuttle will be placed on an eight mile final approach to Edwards, and the user will have to glide down to the runway as in any glider (this one just happens to have a pretty poor glide ratio). The speedbrake (the slider in the upper right of the screen, labeled SBRK) will likely be required to get the craft’s descent profile just right. The Shuttle should be slowed to about 250 knots as it approaches the runway, and it should be descending on about a 20 degree glide path until the VASI lights beside the runway turn from white to red. At that point, raise the nose (this is called the “pre-flare”) and follow that shallow 3 degree glide path in for the final bit of the approach for touchdown. Don’t forget to lower the brakes at the last second!

If the approach is flown correctly, the pilot will

1) follow a 20 degree angle down,
2) adjust the speedbrakes to slow to 250 knots,
3) raise the nose as the lights beside the runway start to turn red,
4) lower the landing gear,
5) follow a path in that keeps two of the lights beside the runway white and two of them red (if more are red, the craft is too low, and if more are white, it’s too high),
6) touch down in a nose-high attitude,
7) lower the nose,
8) hit the brakes, and
9) be stopped well before the end of the runway.

That is, at least, how the pros do it.

Full Approach

The full approach provides a greater challenge than the final. It starts the aircraft off at 83,000 feet and moving at Mach 2.5, 40 miles downrange of landing. This approach is a bit trickier: The pilot will need to raise or lower the nose to hold the desired angle of attack (thus keeping a proper drag profile) while slaloming back and forth to get rid of surplus energy. The Shuttle will be slaloming back and forth through the stratosphere at Mach 2, trying to dissipate just the right amount of energy to arrive over Edwards at the right speed and altitude to land.

Onscreen instruction is given during the flight to help guide the user through it. This is the orange text found at the bottom of the screen in the following screenshot.

Image:Hud_space_shuttle.png

In the screenshot, the pilot is commanded to retract the speedbrakes in order to keep the Shuttle moving at a high enough speed to reach Edwards.

As the approach progresses, the little yellow shuttle in the EFIS will glide down the green line to Edwards. If the craft gets below that line, it has too little energy (meaning it is it is either too low or too slow). Pull the nose up and level the wings in order to conserve energy in the thick air of low altitude. If the craft gets above the green line, it has too much speed or altitude. Bring out the speedbrakes (found in the upper right of the screen) and slalom left and right (like a skier) to lose the extra energy. This is what the real Space Shuttle does to dissipate energy. If the user can manage this, he or she is flying very much like the real Orbiter pilots would.

Final Re-Entry

Once the full approach has been mastered, try the "Final Re-Entry" option from the Missions screen. This will start the aircraft 600 miles downrange at 200,000 feet, moving at Mach 10. This is a true challenge.

Worth noting is the fact that the Shuttle starts out 600 miles away, 40 miles straight up, and moving at Mach 10. By the end of the re-entry, it will be sitting on a runway that is only a couple hundred feet wide and a few thousand feet long. Even more remarkable, this is done without a bit of power from the craft’s engines—it gets there on nothing but inertia, drag, and careful flight. The cockpit displays (coupled with the orange help text at the bottom of the screen) do indeed make it possible!

The following is an image of the Space Shuttle simulator that the astronauts actually use. The displays simulated in the Space Shuttle app are circled in red—the layout is fairly close!

Image:Space_shuttle_real_displays.jpg

Space Shuttle for the iPhone and iPod Touch is no game; it is a simulator. If you can handle it, then you would have a real leg up if put in the real Shuttle!

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