Space Shuttle Liftoff

[airplane wizard]

Does anyone on here know why the Space Shuttle rolls on it's back during liftoff?

 

[CaravanMan]

The only thing I can think of, which probably isn't correct, is to help those onboard cope with the G-forces since the flight path does seem to be an arc. Again, just a guess.

 

[Rogue5]

From the wikipedia entry:

http://en.wikipedia.org/wiki/Space_shuttle#Ascent

Shortly after clearing the tower the Shuttle begins a roll and pitch program so that the vehicle is below the external tank and SRBs. The vehicle climbs in a progressively flattening arc, accelerating as the weight of the SRBs and main tank decrease. To achieve low orbit requires much more horizontal than vertical acceleration. This is not visually obvious since the vehicle rises vertically and is out of sight for most of the horizontal acceleration.

 

[TrafficInSight]

When it's in orbit it's "on its back." Perhaps rolling on its back right away just prepares it for that so they don't have to expend thruster fuel to turn it over?

edit: nevermind then

 

[FL420]

The only thing I can think of, which probably isn't correct, is to help those onboard cope with the G-forces since the flight path does seem to be an arc. Again, just a guess.

I think you're on to something. I'm guessing the crew would experience positive G's after translation instead of negative G's during the sub-orbital acceleration phase.

 

[kevdog]

I think so they can see the earth during orbit. We already know what happens to it when the fuel tanks explode.

 

[nosehair]

The State of Florida made that a conditional requirement during contract negotiations during the planning phase of Cape Canaveral.
This roll-over is so that the passengers have a full view of the beautiful beaches along the Florida Coast.

Wouldn't it be great if the Airlines would do the same?

 

[bubble]

I heard somewhere that the space shuttle rolls 90 degrees right after liftoff in order to point the antennas toward mission control to maintain good communitcation.

 

[Workin'Stiff]

I had also heard that same thing...

 

[sleddriver71]

I think Rogue5 has the best answer. When they jettison the external tanks, they need to fall "away" from the Space Shuttle. They wouldn't want to run into them.

 

[PDH]

I was told by an astronaut that it was on its back in the event that the shuttle needed to separate from the SRB's and fuel tank. The shuttle would separate and would not have to fly through the path or in front of the tank or SRB's on its descent--it could simply pull away from them and descend simultaneously.

 

[FlightTraker]

Here are the some other reasons...........(sixth paragraph)

http://www.cdli.ca/CITE/sts_ascent.htm



FlightTraker

 

[Rogue5]

After reading the above I do remember seeing some show on the Disco channel or something where it stated one of the main reasons for the roll was to "unload" the wing and thus not over stress it as the orbiter accelerates.

Since the shuttle is in an arcing flight path as it exits the atmosphere, by rolling onto its back it achieves a relatively zero AOA in the climb and greatly reduces any positive or negative forces on the wings.

I think this consideration led to the placement of the antennae on the back of the orbiter.

 

[big_al]

just an FYI, if you hear it on tv, especially the discovery channel, chances are its not true. there are some real winners, those discovery channel contracted writers and producers

 

[Workin'Stiff]

And also to protect those antennae during re-entry...

 

[Flyerjosh]

Additionally, the shuttle rolls over in orbit to provide views to the crew, greater protection from earthbound (falling) debris, and solar radiation. With TDRS (I think that stands for Telemetry/Data Relay System), the position of the orbiter doesn't matter in orbit since radio and other communication signals can be bounced off other satellites.

 

[AC560]

I seem to recall that the rolled over position in space (the bottom has the heat tiles which are pointed toward the sun) and the opening of the cargo bay doors was to dissipate heat in orbit as it is rather hot up there (as evidenced by problem with Skylab heat shield).

 

[Flyingdutchman]

Are they hiring these days? what are there mins? Where can I buy a space shuttle type?

 

[urflyingme?!]

I heard that Bob Hoover flew the Space Shuttle under the Golden Gate!

 

[mzaharis]

According to NASA's Space Shuttle News Reference:

"The vehicle begins a combined roll, pitch and yaw maneuver that positions the orbiter head down, with wings level and aligned with the launch pad. The orbiter flies upside down during the ascent phase. This orientation, together with trajectory shaping, establishes a trim angle of attack that is favorable for aerodynamic loads during the region of high dynamic pressure, resulting in a net positive load factor, as well as providing the flight crew with use of the ground as a visual reference. By about 20 seconds after lift-off, the vehicle is at 180 degrees roll and 78 degrees pitch."

This is the reason that the shuttle goes out on its back. Any post-ascent maneuvering doesn't cost much in terms of fuel - they pick the "on its back" ascent due to its advantages during the ascent.

 

[EagleRJ]

Rolling the Shuttle on its back during ascent points the antennas back in line-of-sight with the Cape and downrange tracking stations. It also positions the orbiter for an RTLS (Return to Launch Site) Abort- essentially a giant Split-S used in the event of an abort between SRB separation and the point at which they have enough energy to reach their Trans-Atlantic abort field in Rota, Spain. The orbiter is rolled immediately after liftoff since it's a lot safer than waiting until the stack is hypersonic further downrange.
The orbiter flies "upside down" in orbit to position the heat shield toward any incoming micro-meteorites, as well as maintaining line-of-sight for the comm and data links with ground stations.

The External Tank does not need to "fall away" from the shuttle, since at the point of separation, only microgravity remains. The orbiter's Reaction Control System pulls the orbiter away from the tank, and remaining propellant is vented from the nose of the tank. That induces a spin, ensuring the tank burns up completely during re-entry.

The payload bay doors are opened as soon as possible upon reaching orbit, since there are large radiators under the doors. The avionics and life-support systems on the Shuttle would quickly overheat without the radiators, since there's nowhere for the heat to go. If the doors couldn't be opened, it would be a quick return to the ground (AOA- Abort Once Around, another abort phase).

 

[Genital Leech]

I heard somewhere that the space shuttle rolls 90 degrees right after liftoff in order to point the antennas toward mission control to maintain good communitcation.

WTF is "communitcation"??????

Just curious.....

Bye bye---Genital Leech

 

[frog_flyer]

you're an idiot

 

[sleddriver71]

you're an idiot

Maybe he just really wanted to be part of the thread and couldn't think of anything better to write about. Let's see, communitcation, one letter misspelled out of 13, I've seen worse. His response in this thread is probably just as much a waste of space as mine is in responding to your response about his response...

 

[wmuflyguy]

I like how after people post a reliable source for the reason (from the NASA website or so)

People will still post some opinion that dosn't fully agree with the reliable source. Guess the NASA guys aren;t as smart as us pilots eh?

 

[dseagrav]

Guess the NASA guys aren't as smart as us pilots eh?

If NASA is so great, why do they need NASA forms? If they're so smart, why did they crash the Mars Polar Lander? Why did they blow up the Columbia? Or Challenger? Why did they crash the Genesis return capsule? NASA's only "success" so far was the Apollo missions, which are widely known to have been faked. And if it weren't for the Russians and the French covering for us on the ISS,it never would have been built.

Face it, NASA is a money-sucking black hole of breaucracy and pork projects that has never done any real science in its entire existence. It diverts funds desperately needed for government executive bonuses, supporting airline executive bonuses, killing more brown people for Jesus, and corporate welfare. The best thing we as Americans (and as human beings) can do at this point is to shut down the entire operation and leave the space innovation to real pioneers like Burt Rutan, Al Gore, Energia, and ESA.

 

[sleddriver71]

If NASA is so great, why do they need NASA forms? If they're so smart, why did they crash the Mars Polar Lander? Why did they blow up the Columbia? Or Challenger? Why did they crash the Genesis return capsule? NASA's only "success" so far was the Apollo missions, which are widely known to have been faked. And if it weren't for the Russians and the French covering for us on the ISS,it never would have been built.

Face it, NASA is a money-sucking black hole of breaucracy and pork projects that has never done any real science in its entire existence. It diverts funds desperately needed for government executive bonuses, supporting airline executive bonuses, killing more brown people for Jesus, and corporate welfare. The best thing we as Americans (and as human beings) can do at this point is to shut down the entire operation and leave the space innovation to real pioneers like Burt Rutan, Al Gore, Energia, and ESA.

So because NASA has had accidents, they are a total failure? Are you saying Burt Rutan, Al Gore(?), Energia, and ESA haven't had any accidents/mistakes? "Widely known to have been faked?" What is widely known, in your mind? I think that everyone would agree that NASA is involved in highly risky operations and because they have had accidents does not make them a failure. I guess any war that was ever fought would be considered a failure if anyone died, regardless if the final objective was met? I'm just trying to figure out your thought process because it doesn't make much sense to me.

 

[wmuflyguy]

If NASA is so great, why do they need NASA forms? If they're so smart, why did they crash the Mars Polar Lander? Why did they blow up the Columbia? Or Challenger? Why did they crash the Genesis return capsule? NASA's only "success" so far was the Apollo missions, which are widely known to have been faked. And if it weren't for the Russians and the French covering for us on the ISS,it never would have been built.

Face it, NASA is a money-sucking black hole of breaucracy and pork projects that has never done any real science in its entire existence. It diverts funds desperately needed for government executive bonuses, supporting airline executive bonuses, killing more brown people for Jesus, and corporate welfare. The best thing we as Americans (and as human beings) can do at this point is to shut down the entire operation and leave the space innovation to real pioneers like Burt Rutan, Al Gore, Energia, and ESA.

At least you made me laugh.

 

[wmuflyguy]

So because NASA has had accidents, they are a total failure? Are you saying Burt Rutan, Al Gore(?), Energia, and ESA haven't had any accidents/mistakes? "Widely known to have been faked?" What is widely known, in your mind? I think that everyone would agree that NASA is involved in highly risky operations and because they have had accidents does not make them a failure. I guess any war that was ever fought would be considered a failure if anyone died, regardless if the final objective was met? I'm just trying to figure out your thought process because it doesn't make much sense to me.

I got 10 bucks it was all sarcasm....either that or it was flame. C'mon he gave credit to the FRENCH! That is a dead give-away.

 

[sleddriver71]

I got 10 bucks it was all sarcasm....either that or it was flame. C'mon he gave credit to the FRENCH! That is a dead give-away.

You might be right, I seem to be pretty gullible when it comes to sarcasm on this site. I thought what's his name was serious for the longest time about the oil being produced from the center of the earth thread. He had to write me and tell me he was being sarcastic.