Daylight only launches

pardon me for straying from the constant maxson debates, but I have a question
about the shuttle.

The NASA return to flight document mentions that the shuttle will be launched
during daylight hours. Then, a little later, it mentions that for the first
launch, it will be during daylight.

Considering that for station flights, the very small launch window constantly
moves and is not limited to daylight, does anyone have any details on exactly
what this means ?

I assume that in a march 2004 time frame, a daylight launch would be possible.
But what about subsequent launches ? Will the daylight-only rule apply only
for the first launch and the rule will be relaxed thereafter ?

Will NASA develop new imaging equipment to provide the same level of detail
during night time launches with such equipment becoming available just time
for when shuttles start to need night time launches ?

Or would NASA decide that from now on, launches towards the south east would
be possible, allowing the shuttle to have 2 launch windows to meet the station
per day ? (with 2 windows 12 hours apart, one is pretty well garanteed one
daylight launch except perhaps in late december).

Also, in the event of a shuttle becoming stranded at the station, (one action
is to make it possible for extended stays at station in case of problems),
would a second "rescue" shuttle still be bound to the daylight-only launches
or would such a rule be waived ?

"Johhn Doe" wrote in message
...

Considering that for station flights, the very small launch window
constantly
moves and is not limited to daylight, does anyone have any details on
exactly
what this means ?

I assume that in a march 2004 time frame, a daylight launch would be
possible.
But what about subsequent launches ? Will the daylight-only rule apply
only
for the first launch and the rule will be relaxed thereafter ?

I don't think the constraints are that serious. The station's orbital
procession seems to go on a cycle of about three weeks... When I'm watching
the station, it comes by in the evenings for about ten days. The pass time
drifts later and later, until for about ten days it's visible very early in
the morning. I can't properly exactly explain the orbital mechanics behind
this, but I don't think launch window-related delays would be any longer
than that.

There are some excellent posts here re the daylight lauch constraints. vs launch
window. It is very technical, and yeah the daylight requirement does put a
crimp in operations.

Search groups.google.com on your browser.

*click "search only in sci.space.shuttle"

Johhn Doe wrote in message ...
pardon me for straying from the constant maxson debates, but I have a question
about the shuttle.

The NASA return to flight document mentions that the shuttle will be launched
during daylight hours. Then, a little later, it mentions that for the first
launch, it will be during daylight.

Considering that for station flights, the very small launch window constantly
moves and is not limited to daylight, does anyone have any details on exactly
what this means ?

I assume that in a march 2004 time frame, a daylight launch would be possible.
But what about subsequent launches ? Will the daylight-only rule apply only
for the first launch and the rule will be relaxed thereafter ?


Maybe, but not on the near future.
For the timeframes when a daylight launch is possible, take a look at
this article posted in Spaceflight Now.

http://www.spaceflightnow.com/shuttl...030916houston/


Will NASA develop new imaging equipment to provide the same level of detail
during night time launches with such equipment becoming available just time
for when shuttles start to need night time launches ?


Don't think so. The same level of detail is not possible.

Or would NASA decide that from now on, launches towards the south east would
be possible, allowing the shuttle to have 2 launch windows to meet the station
per day ? (with 2 windows 12 hours apart, one is pretty well garanteed one
daylight launch except perhaps in late december).


Launching SE imply that the ascent path would cross populated areas.

---

Eduardo Tesheiner
Madrid - Spain

(Eduardo Tesheiner) wrote


For the timeframes when a daylight launch is possible, take a look at
this article posted in Spaceflight Now.

http://www.spaceflightnow.com/shuttl...030916houston/


Also http://www.nytimes.com/2003/09/18/na...al/18SHUT.html

The New York Times
September 18, 2003
Shuttle Rule Cuts Window for Flights
By WARREN E. LEARY
[EXCERPT]

HOUSTON, Sept. 17 — New rules imposed on space shuttle flights
after the Columbia accident will cut by more than half the times
when shuttles can be launched to the International Space Station,
NASA officials said today.

Restrictions that call for shuttles to be launched only in the
day so liftoffs can be photographed in detail, coupled with other
limits on flights to the station, mean that some periods lasting
months will be blacked out for missions, the officials said.

"The need for daylight launches constrains the choice of launch
windows by more than 50 percent," said Greg Oliver, chief of the
National Aeronautics and Space Administration's branch that
determines flight opportunities.

Flights to the space station, the primary destination for shuttles,
have always been restricted to one 5-to-10-minute period each day
because of factors like the station's steeply pitched orbit, which
places it above the Kennedy Space Center in Florida only once daily,
Mr. Oliver said. In addition, he said, station flights were also
restricted for weeks at a time because the position of the Sun
relative to Earth that contributes to excess heating of the
spacecraft.

[Plus, as noted up-thread, the north-only safety constraint.]

When these constraints are coupled with new daylight launching rules,
chances to fly are severely restricted, he said.