Re: Visibility of Cygnus CRS Orb-4

From: Skywayinc--- via Seesat-l <>
Date: Fri, 27 Nov 2015 10:55:36 -0500
Thanks Kevin and George!
So the only thing left to determine is how high the vehicle will  be along 
the ascent trajectory parallel to the Atlantic Seaboard.  It  would seem, 
however, that it will be somewhat similar to the altitude of  the Shuttle 
missions to the ISS, although recall that unlike the Cygnus CRS  Orb-4, the 
Shuttle's injection into orbit was not circular, but more  lopsided with an 
apogee of something like 120 sm and a perigee of around 80  sm. 
Of course Cygnus CRS Orb-4 will be fainter than a Shuttle as well  . . . 
with the Shuttle we were dealing with the orbiter main engines . . . in  the 
upcoming case we only will have the Centaur to light the  way.
-- joe rao  

In a message dated 11/27/2015 10:22:34 A.M. Eastern Standard Time, writes:

I couldn't find an ascent profile, but I found this which contains a  
timeline and ground  track-

It  shows Atlas BECO at 04:16, Centaur ignition at 04:32, and Centaur 
shutdown at  18:17. The initial orbit is 124x124nm.

I live in SE Virginia and saw  the shuttle several times when it launched 
on a similar trajectory. For me it  rose out of the south about 4 minutes 
after launch heading towards the east. It  reached and maintained an elevation 
of about 13 degrees as it headed towards the  NE. MECO was visible.

All of the launches I saw occurred after  sunset- several just after, and a 
few at night. I never did see a daytime  launch.

On Thu, Nov 26, 2015 at 11:07 PM, Skywayinc--- via  Seesat-l 
<> wrote:

In a message dated 11/26/2015  3:55:12 P.M. Eastern Standard Time, writes:

I  don't see any reason, people couldn't spot the light coming from   the
upper stage.

Only problem, I seem to see, is that the rocket will  be  low in altitude,
so won't be high in elevation for people trying to  see  it.


If anybody has any specifics regarding  this flight, such as how long will
the first stage burn . . . and how long  after that the transition to the
ignition of the Centaur . . . and how long  that will last, that would help 
lot.  Keep in mind that during Shuttle  launches MECO occurred about 400
miles southeast of NYC and at an altitude of  75 miles, placed the orbiter 
8 degrees above the SE horizon from  the Tri-State NY area about 8 minutes
after  leaving Pad 39A at  KSC.

I've scourered  the Internet looking for specific numbers or  some sort  of
timeline regarding launch-to-orbit of this mission with  little success.

It might actually be more advantageous -- from a  visibility standpoint --
to have the launch occur about an hour earlier,  which would allow the
vehicle to  be illuminated by the Sun.  A  delay of 3 days -- from 
Thursday, Dec. 3
to  Sunday, Dec. 6 -- would  likely push a possible liftoff time back to
just before  5 p.m.  EST.

-- joe  rao
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