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Flying the Shuttle - Launch: Difference between revisions
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Good luck, you're ready to do orbital maneuvering. | Good luck, you're ready to do orbital maneuvering. | ||
== Trajectory Data == | |||
The following data has been recorded from the FG Space Shuttle simulation, i.e. they reflect the capabilities of the simulated craft (including piloting errors) and are actually flyable. They may serve as orientation for a viable launch trajectory with and without payload. | |||
In each case, the launch was from Vandenberg AFB with an initial launch course due East (this is reflected in a non-zero initial inertial velocity, representing the Eastward turning of Earth). In all cases, the launch targeted an apogee of 250 km with a perigee below 100 km to make sure the ET would re-enter the atmosphere. | |||
Altitude vs. time shows a clear transition from vertical motion to get out of the atmosphere to horizontal motion to accelerate to orbital speed at an altitude of about 450.000 ft (135 km) at about 250 s into the flight. This transition is lagging behind the commanded trajectory, the transition to a near-horizontal attitude happens in fact much earlier shortly after SRB separation at around 120 s. Note that a modest trajectory droop back from a peak altitude is perfectly acceptable and completely unproblematic for reaching orbit as long as the trajectory does not enter the dense atmosphere below 300.000 ft (100 km). | |||
[[File:Launch alt vs time.gif|600px|Space Shuttle ascent trajectory: altitude vs. time]] | |||
The most prominent structure in the intertial velocity development over time is the sudden drop in acceleration at SRB separation (about 120 s into the flight). The presence/absence of a payload is chiefly visible in the late stages of the flight and leads to about 10 seconds difference in MECO time. For the heavy launch, the remaining propellant after MECO was ~33.000 lb, i.e. the tanks do not need to be flown dry and the Shuttle is quite capable of lifting a payload into a higher inclination orbit. | |||
[[File:Launch veci vs time.gif|600px|Space Shuttle ascent trajectory: inertial velocity vs. time]] | |||
== Further reading == | == Further reading == | ||