Early-bird skywatchers across parts of the United States and southern Canada have several chances to spot the new private Cygnus spacecraft as it
chases the International Space Station across the pre-dawn sky.
The first Cygnus spacecraft launched into orbit Wednesday (Sept. 18) from Wallops Island, Va., and is slated to arrive at the space station Sunday
morning (Sept. 22) at 7:25 a.m. EDT (1125 GMT). So by Monday morning, both spacecraft will appear as a singular bright moving "star" across the night
sky.
The space station makes one full orbit of the Earth in approximately 93 minutes. The Cygnus spacecraft, which is built by the commercial spaceflight
company Orbital Sciences Corp., initially trailed the station by about 35 minutes after the Wednesday launch. By Friday morning, that gap will have
diminished to less than five minutes, while on Saturday and Sunday mornings it will be one minute or less. [See amazing launch photos of Orbital's
Cygnus spacecraft]
This means that, weather permitting, it will be possible to see both space vehicles in the sky at the same time. Observers will see the space station
appear first, followed closely by Cygnus traveling along basically the same path.
How bright will they be?
Most satellites in space are visible from the ground only when they are in sunlight and the observer is in deep twilight or darkness. This usually
means shortly after dusk or before dawn.
The International Space Station is about as long as a football field and flanked by huge, wing-like solar arrays, making it the largest artificial
structure ever built in space. Because of its size highly reflective solar panels, the station is also the brightest man-made object currently in
orbit around the Earth.
On favorable passes, the space station can shine as brilliant as the planet Venus and appear more than 25 brighter than Sirius, the brightest star in
the night sky. Some observers even caught a glimpse of the space station just prior to sunset or shortly after sunrise. And as a bonus, sunlight
glinting directly off the solar panels can sometimes make the station appear to briefly flare to super-brilliance.
Orbital Sciences' Cygnus spacecraft on the other hand, is a smaller unmanned cargo ship for the station developed by Orbital Sciences Corp. as part of
NASA's Commercial Orbital Transportation Services program.Cygnus is much smaller than the Space Station, measuring about (17 feet (five meters) long
and 10 feet (3 m) wide, with highly reflective solar panels.
Because of that size difference, Cygnus will usually appear much dimmer compared to the ISS. Seen from a distance of 621 miles (1,000 km) and 50
percent illuminated, it should appear roughly as bright as a third magnitude star and can be categorized as of moderate brightness.
For comparison, the star Megrez, which joins the handle with the bowl of the Big Dipper is a third magnitude star. This would make the Cygnus
spacecraft capsule about 1,500 times dimmer than the space station!
On rare occasions, when Cygnus is passing much closer – about 260 miles (420 km) and is 100-percent illuminated, it can appear to briefly shine at a
far more dazzling magnitude of -2.6; that’s as bright as Jupiter. But such favorable circumstances occur infrequently at best, so when you’re
watching for it you should expect to see a dimmer object.
An artist's concept of Orbital Sciences' unmanned Cygnus cargo spacecraft approaching the International Space Station.
Credit: Orbital Sciences CorporationView full size imageWhen and where to look
So what is the viewing schedule for your particular hometown? You can easily find out by visiting one of these three web sites:
•Chris Peat's Heavens Above
•NASA's SkyWatch
•Spaceweather.com
Each website will ask for your zip code or city, and respond with a list of suggested spotting times. Predictions computed a few days ahead of time
are usually accurate within a few minutes. However, they can change due to the slow decay of the space station's orbit and periodic reboosts to higher
altitudes. Check frequently for updates.
Another great site is this one: http://www.n2yo.com/?s=25544. It provides real-time satellite tracking and shows you at any given moment during the day or night over what part of
the Earth the space station or Cygnus happens to be.
Editor's Note: If you snap a photo of Orbital Sciences' Cygnus spacecraft in space, the International Space Station or any other amazing sky view
that you'd like to share for a possible story or image gallery, send photos, comments and your name and location to managing editor Tariq Malik at
spacephotos@space.com.
SPACE.com is providing complete coverage of Orbital's first Cygnus test flight to the International Space Station. Visit SPACE.com for updates on the
mission. SPACE.com partner Spaceflight now is also offering updates via its Cygnus Mission Status Center.
Email Tariq Malik at tmalik@space.com or follow him @tariqjmalik and Google+. Follow us @Spacedotcom, Facebook and Google+. Original articleSPACE.com.
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the
Farmer's Almanac and other publications, and he is also an on-camera meteorologist for News 12 Westchester, N.Y.Follow us @Spacedotcom, Facebook and
Google+. Original article on SPACE.com.MMc - 9-19-2013 at 09:00 PM
Thanks dude! Love to look up! Know I know what I am looking for.fandango - 9-19-2013 at 09:26 PM
Thanks for this Info woody.
I keep track of the iss on iss.astroviewer.net. This site also tracks the SS in real time, shows where it is and what it's route is and when it can be
viewed at my location.
It will be fun to watch for Cygnus.
Unfortunately, it doesn't look like we'll be seeing it until the end of this month in SoCal.
On edit: in baja last month the station went directly over us and was in view for over 5 minutes.
[Edited on 9-20-2013 by fandango]elgatoloco - 9-20-2013 at 12:17 AM
Cool durrelllrobert - 9-20-2013 at 11:34 AM
The Cygnus spacecraft was designed and built at Orbitals Gilbert AZ facility and launched by their launch group in Chandler AZ. Both of these are
nearby my former company that is also located in Chandler and they supply several of the pyrotechnic charges used for stage separation on the Antares
launch vehicle (two stage rocket).I believe they may also provide the flight termination system which is only functioned if the rocket goes off
course.woody with a view - 9-20-2013 at 04:52 PM
any stock tips?elgatoloco - 9-20-2013 at 06:46 PM
Quote:
Originally posted by woody with a view
any stock tips?
buy low, sell high. woody with a view - 9-20-2013 at 07:07 PM
thanks Gato. i knew you'd come thru....Ateo - 9-20-2013 at 07:19 PM
Thanks for posting Woody. I dig this stuff. Never forget the first time I saw the ISS out in Ocotillo. I bet someday there will be more man made
structures out there visible from the ground!woody with a view - 9-20-2013 at 07:29 PM
yep! it is very cool to see it fly by. most people don't bother to look up and wonder.....
