How long is the launch window

See above

Not quite five minutes. No second tries on the same
day; if the Shuttle can't make it in the window then
it's a scrub for the day.

The tight window is due to the orbit mechanics of
rendezvouing with the space station.

--Damon

I know but some windows can be for hours, why only less than 5 for this
launch


"Damon Hill" wrote in message
1...
Not quite five minutes. No second tries on the same
day; if the Shuttle can't make it in the window then
it's a scrub for the day.

The tight window is due to the orbit mechanics of
rendezvouing with the space station.

--Damon

Carol Singer wrote:
I know but some windows can be for hours, why only less than 5 for this
launch


The shuttle has to be both in the same plane, which changes fairly slowly
as ISS, and in the right point in the orbit to be able to easily catch
ISS, without delays.

"Carol Singer" wrote in message
...
I know but some windows can be for hours, why only less than 5 for this
launch


Generally wheny ou want to get to the space station it's fairly short since
out of plane changes require more fuel, etc.

If you want to just 'get into orbit' then other factors (lighting, range
safety, etc.) come into play.



"Damon Hill" wrote in message
1...
Not quite five minutes. No second tries on the same
day; if the Shuttle can't make it in the window then
it's a scrub for the day.

The tight window is due to the orbit mechanics of
rendezvouing with the space station.

--Damon

Carol Singer wrote:

I know but some windows can be for hours, why only less than 5 for this
launch

After you launch, you no longer rotate with the earth and stay more of less in
the same disc (orbital plane) with the earth spinning under you.

The space station remains more or less in the same orbital plane turning along
a virtual hoop, with the earth rotating under it.

Now, the earth is roughly 40,000km in circumference at equator. It makes one
rotation each 24 hours. This means that to someone standing stationary over
the earth, one point will pass at about 40,000km/24 hours = 1666km/h ( roughly
1000 US miles per hours).

5 minutes before the orbital plane of the ISS passes directly over KSC, it is
located 138km east of KSC. 10 minutes later, it is roughly 138km west of KSC.

So when the shuttle launches not precicely in the same orbital plane, it must
expand fuel to move to that plane. The further apart they are, the more fuel
it must spend.

And this is the same reason why when it lands, it only has a few landing
opportunities. The Shuttle's wings and aerodynamic surfaces allow it to steer
once in the atmosphere and correct its course to a certain degree so it can
make it to KSC even if its orbital trajectory would have brought it far from
KSC in a purely ballistic fall.

When landing, the shuttle wants to dump as much kinetic energy as possible, so
using aerodynamic surfaces to steer helps dump kinetic energy. But when taking
off, the shuttle doesn't want to waste any energy steering because it needs
every bit of fuel to accelerate.

"Damon Hill" wrote in message
1...
Not quite five minutes. No second tries on the same
day; if the Shuttle can't make it in the window then
it's a scrub for the day.


Not quite right, the launch window is actually close to 10 minutes, and Nasa
aims to launch in the middle of the window, which leaves about 5 minutes
after preferred launch time which is 10.39 - but the actual launch window
opens at 10.34. The reason they wait 5 minutes is to make everything as
close to optimum as possible.


/J

"Sunsite News" jntATthomsen.mail.dk wrote in message
...

Not quite right, the launch window is actually close to 10 minutes, and
Nasa aims to launch in the middle of the window, which leaves about 5
minutes after preferred launch time which is 10.39 - but the actual launch
window opens at 10.34. The reason they wait 5 minutes is to make
everything as close to optimum as possible.

During the t-9 hold they can adjust to go anytime during the 10 minute
window, depending on the latest ISS state vector.

Scott J wrote:
During the t-9 hold they can adjust to go anytime during the 10 minute
window, depending on the latest ISS state vector.

And depending on weather. For instance, if there is a storm coming, and
launching -5 minutes means the shuttle still launches within acceptable
parameters, whereas waiting to launch at the right time woudl mean the storm
would have moved in within the zone where shuttle can't launch with a storm
within X nautical miles of it, then they will shorten the t-9 minutes hold by
5 minutes and launch early.

"Carol Singer" wrote in news:1x0Fe.3706$zp1.3692
@newsfe7-win.ntli.net:



Three feet.