PDA

View Full Version : Discussion: Discovery Won't Launch Before Sunday



Fraser
2005-Jul-15, 04:23 PM
SUMMARY: NASA has announced that the space shuttle Discovery's earliest launch window will be on Sunday, July 17 at 1914 UTC (2:14 pm EDT); although, it could be much later. A problem with a fuel gauge on the shuttle's external tank halted the countdown on Wednesday. Engineers have so far been unable to find the source of the problem. The shuttle's launch window will last until the end of the July, and then opens up in September again.

View full article (http://www.universetoday.com/am/publish/sts_not_earlier_than_sunday.html)

What do you think about this story? Post your comments below.

dave_f
2005-Jul-15, 06:10 PM
I hope that human exploration of space can resume. While I hope that other science fields don't suffer because of money problems, it is my hope that current trends in science will produce results. There's nothing better than someone looking at an object in space and saying "Eureka!" (THANK YOU DEEP IMPACT!!!!!)

I love those moments. Here's to hoping for the best for the Shuttle Astronauts in all their missions.

dave_f
2005-Jul-15, 06:13 PM
Whoops, too many "hope's" in my last post... ;)

Is that a bad thing?

Guest_James
2005-Jul-15, 06:51 PM
My hopes and prayers go out to them too!

Guest_James
2005-Jul-15, 06:57 PM
I would just like to add that God's hand played a signifigant part in human exploration during the mercury, gemini, and apollo missions of early days of NASA. By God's grace, failure was not, is not, and never shall be an option for manned space missions. Amen!

MOnica
2005-Jul-15, 07:25 PM
why the launch window is till the end of July and then it starts in september? what window are they talking about?
thanks
Monica
mbarricarte@hotmail.com

aeolus
2005-Jul-15, 09:11 PM
Originally posted by MOnica@Jul 15 2005, 07:25 PM
why the launch window is till the end of July and then it starts in september? what window are they talking about?
thanks
Monica
mbarricarte@hotmail.com
To understand the largest limiting factor in a launch window, close your eyes and imagine looking at the Earth from afar, while you're floating in space.

When a rocket launches into orbit, it circles around and around. Visualise this. Understand though, that the second it lifts off the ground, into that orbit, the Earth keeps spinning underneath. The rocket will go around and around, but the Earth spins underneath. To be more specific, after one orbit, the shuttle won't be back over Cape Canaveral, rather it will now be somewhere over Texas, since the Earth has spun about 22 degrees by that time.

When the ISS was launched back in 98, it started one of these orbits, and the Earth went round and round ever since. If the shuttle wants to dock with ISS, it has to wait until the ISS orbit falls overhead Cape Canaveral, so it can launch into that orbit.

Next, it can't just be anytime the ISSs orbit is overhead; the shuttle has to slowly approach the station, so it cant be too close, but it also cant be too far behind the station, or else it wont be able to catch up fast enough.

Does this all make sense? If not, say so, I'll try my best to make it more understandable.

Now that's only the big limiting factor- there are more. The launch has to happen when lighting is decent so that it can be obseved on the way up. This way we'll be able to see if O-rings are smoking or tiles are falling off, for example.

As well, the shuttle has emergency landing sites in Spain, France, Hawaii, and more in case the launch doesn't go well and they have to come back down right away. The launch has to happen when all of these sites are available to have shuttle land.

Lastly, the most sketchy factor of all, the weather has to be good. The September launch windows could all be closed should a nasty hurricane chose to blast it's way through the East coast.

Hope this helps.

-Rob