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Answers Your Questions

From: Mike Hilton, of Natchitoches, La.
To: Wayne Hale, flight director

Question: What is the maximum orbital altitude that a fully supplied shuttle could obtain? Assume that it has a crew of four and supplies for 14 days.

Answer: The maximum "usable" orbit is around 400 nautical miles (the Hubble Space Telescope flights are in the 340-nautical-mile range), but this assumes that there is more to the mission than simply getting as high up as possible. Other factors will affect the maximum attainable orbital altitude. These include:

- Is there anything in the payload bay, or is this simply a "shoot for the limit" exercise? The contents of the orbiter could be stripped down to reduce weight, which translates into a greater possible altitude. Items such as payloads, the mechanical arm (RMS), the external airlock and docking system, and much of the crew compartment contents could be left behind, not to mention some or all of the four crewmembers you specified!

- What orbital inclination? More fuel is required to reach a given orbit at higher inclinations. For a shuttle-record-setting altitude attempt, a low inclination is better.

- Circular orbit, or elliptical? With an elliptical orbit the orbiter could attain a much higher maximum altitude (apogee) at the expense of having a low minimum altitude (perigee; limited to ~85 nautical miles high).

- Do you plan on a safe return? Much of the orbiter's on-orbit fuel supply is needed to slow the vehicle down so that it will re-enter the Earth's atmosphere for landing. This could instead be used to further raise the orbit, but the crew would certainly object!

View a list of answered questions or ask MCC your own question.

Curator: Kim Dismukes | Responsible NASA Official: John Ira Petty | Updated: 12/10/2002
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