Re: orbital reflector

From: Marco Langbroek via Seesat-l <>
Date: Wed, 14 Nov 2018 00:57:35 +0100
Op 13-11-2018 om 18:58 schreef Kevin Fetter via Seesat-l:
> Trevor Paglen's Orbital reflector sat, scheduled to be launched on Nov 19, along with other stuff. It will be placed into a sun sycn orbit.

This will be the approximate initial orbit for Orbital Reflector, based on
inclination and orbital altitude aimed for:

ORBITAL REFLECTOR                                        574 x 576 km
1 70000U 18999A   18323.77222222  .00000000  00000-0  00000-0 0    09
2 70000 097.6000 032.4835 0001438 157.1159 325.9970 14.97378736    01

Launch is on 19 November at 18:32 UT onboard SSO-A. Payload deployment from the
SSO-A Lower Free Flyer into a 575 km, 97.6 deg inclined sun-synchronous orbit
will be around 20:50 UT (19 Nov), after 1.5 revolutions, over Antarctica. I do
not know at what moment the balloon will be inflated.

Orbital Reflector is a 2.2 kg cubesat which will inflate a very oblong, 1.4 by
30 meter reflective balloon, which is intended to align itself in a least-drag
orientation. The idea of the project is to make people reflect on who owns
space, by putting a visible but non-utilitarian art object in (temporary) earth
orbit, placed there to just reflect (and make people reflect).

Originally, this should have been a summer launch. Unfortunately, launch delays
meant it has now shifted towards the winter season, which is not good for the
visibility, especially with this orbital plane (resulting in ~21:30 local time
passes). New Zealand, south Australia en southern America have the best sighting
opportunities. The northern hemisphere has no sighting opportunities at all for
several weeks. Given the expected lifespan of the object, seeing it from the US
or Europe will be very difficult, perhaps impossible.

This object, being of low mass and large surface once the balloon is inflated,
will experience considerable Solar Radiation Pressure. This will quickly pump up
the eccentricity, lowering perigee and raising apogee. The quickly and
progressively lowering perigee will speed up orbital decay. I have done some
modelling, and expect a lifetime of ~2 months, with decay near the end of
January. Bear in mind that orbital lifetimes of this kind of unusual
area-to-mass ratio objects are difficult to model though.

- Marco

Dr Marco Langbroek  -  SatTrackCam Leiden, the Netherlands.

Cospar 4353 (Leiden):     52.15412 N, 4.49081 E (WGS84), +0 m ASL
Cospar 4355 (Cronesteyn): 52.13878 N, 4.49937 E (WGS84), -2 m ASL
Station (b)log:
Twitter: _at_Marco_Langbroek
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Received on Tue Nov 13 2018 - 17:58:30 UTC

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