Question about shuttle / ISS

Shuttle gets into orbit in around 15 mins but it takes over a day to get to
the ISS.
How far away is the ISS?

In article ,
"vag-com" wrote:

Shuttle gets into orbit in around 15 mins but it takes over a day to get to
the ISS.
How far away is the ISS?

The ISS is about 300 miles up. Technically, it is about 350 kilometers,
but nobody here in the US knows what a kilometer is, so substitute
mile, and you will be within a factor of 2 or 3. Good enough for
government work.

When the shuttle flies to the ISS, it isn't a matter of just going
up 300 miles and hooking on. Rather, the shuttle has to fly into
space, and then get into approximately the same orbit as the ISS.
From there, the shuttle will slow down a bit, and the two objects
will gradually get closer and closer. They don't want to close
the distance real fast since that would take a lot of braking near
the ISS, which could lead to all kinds of bad things if something
goes wrong. They have the time available in the flight, so why rush
things?

-john-

--
================================================== ====================
John A. Weeks III 952-432-2708
Newave Communications http://www.johnweeks.com
================================================== ====================

"John A. Weeks III" wrote in message
...
In article ,
"vag-com" wrote:

Shuttle gets into orbit in around 15 mins but it takes over a day to get
to
the ISS.
How far away is the ISS?

The ISS is about 300 miles up. Technically, it is about 350 kilometers,
but nobody here in the US knows what a kilometer is, so substitute
mile, and you will be within a factor of 2 or 3. Good enough for
government work.

When the shuttle flies to the ISS, it isn't a matter of just going
up 300 miles and hooking on. Rather, the shuttle has to fly into
space, and then get into approximately the same orbit as the ISS.
From there, the shuttle will slow down a bit, and the two objects
will gradually get closer and closer. They don't want to close
the distance real fast since that would take a lot of braking near
the ISS, which could lead to all kinds of bad things if something
goes wrong. They have the time available in the flight, so why rush
things?

-john-

That's interesting, I thought the shuttle after launch was behind and caught
up, but it's actually launched ahead of the ISS and has to slow down?

On Wed, 13 Sep 2006 13:36:30 +0100, MichaelJP wrote:

"John A. Weeks III" wrote in message
...
In article , "vag-com"
wrote:

Shuttle gets into orbit in around 15 mins but it takes over a day to
get to
the ISS.
How far away is the ISS?

The ISS is about 300 miles up. Technically, it is about 350
kilometers, but nobody here in the US knows what a kilometer is, so
substitute mile, and you will be within a factor of 2 or 3. Good
enough for government work.

When the shuttle flies to the ISS, it isn't a matter of just going up
300 miles and hooking on. Rather, the shuttle has to fly into space,
and then get into approximately the same orbit as the ISS. From there,
the shuttle will slow down a bit, and the two objects will gradually
get closer and closer. They don't want to close the distance real fast
since that would take a lot of braking near the ISS, which could lead
to all kinds of bad things if something goes wrong. They have the time
available in the flight, so why rush things?

-john-

That's interesting, I thought the shuttle after launch was behind and
caught up, but it's actually launched ahead of the ISS and has to slow
down?

With Orbital Mechanics, it's the lower orbit that is faster, and the
higher orbit that is slower. The Shuttle enters orbit in a lower orbit
than the Space Station, so it's moving faster and catching up from behind
the higher and slower Space Station. Each Shuttle OMS burn actually
increasing the Shuttle's velocity which raises it's orbit, slowing it
down half a rev later. After all the rendezvous burns, the Orbiter is at
the Space Station's altitude and slower orbit.

Add velocity wrt the Earth and orbit slower, decrease velocity and orbit
faster.

--
Craig Fink
Courtesy E-Mail Welcome @

vag-com wrote:
Shuttle gets into orbit in around 15 mins but it takes over a day to get to
the ISS.
How far away is the ISS?
Jorge posted an excellent description of this here
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=4273&posts=15&start=1

MichaelJP wrote:
That's interesting, I thought the shuttle after launch was behind and caught
up, but it's actually launched ahead of the ISS and has to slow down?


In orbit, you can be both ahead and behind at the same time because both
objects are running around in circles.


The spacecraft must launch when the orbit PLANE passes over the launch
site, no matter where on the orbit plane the ISS is at that moment.
(Remember that the earth rotates under the orbit plane, so it a point on
earth only is under the orbit plane twice a day, and launching from KSC,
they can only make use of one of those 2 opportunities).


So, once you launch, you stay in a slightly lower orbit which means that
the Shuttle goes faster around than ISS. The Shuttle has a schedule of
many tasks to do before it docks, so they may in fact lap the station
before it gets near enough, at which point they raise the Shuttle's
orbit which slows it down and it can then approach the ISS more slowly
and dock.

Another aspect to this is fuel. You can reduce the amount of fuel needed
mty selecting a "smarter" approach as opposed to some sprint to the
station that makes more use of fuel and less use of orbital mechanics to
close the gap between the two.

Note that the ruissians aklso make use of time between launch and
docking in order to reduce fuel requirements.

Danny Dot wrote:
"MichaelJP" wrote in message
...
"John A. Weeks III" wrote in message
...
In article ,
"vag-com" wrote:

Snip

That's interesting, I thought the shuttle after launch was behind and
caught up, but it's actually launched ahead of the ISS and has to slow
down?



The shuttle does launch behind and catches up.

Danny Dot
Look at my site and see how NASA treats a creative mind!!!
The summary is "Not Very Well" :-)
www.mobbinggonemad.org

hop wrote:
Jorge posted an excellent description of this here
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=4273&posts=15&start=1

Thanks for linking the absolutely fantasic and well-written post!

Lee Jay

JRS: In article -
sjc.supernews.net, dated Wed, 13 Sep 2006 06:24:46 remote, seen in
news:sci.space.shuttle, John A. Weeks III posted :

The ISS is about 300 miles up. Technically, it is about 350 kilometers,
but nobody here in the US knows what a kilometer is,

Including you, it seems. The distances represented by those two figures
are in a ratio of about 4:3. They can't spell kilometre, either.

--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

Danny Dot wrote:
"vag-com" wrote in message
...
Shuttle gets into orbit in around 15 mins but it takes over a day to get
to the ISS.
How far away is the ISS?


I have been told one consideration is space adaptation syndrome. Many crew
members get sick (i.e. throwing up) when they first get into space. But
almost all get over it fairly quick. One interesting point is not getting
motion sickness on Earth is NOT an indicator of not getting sick in space.

I also understand you loose lots of brownie point if you miss your bag :-)

Danny Dot
www.mobbinggonemad.org