# Why were Bion 6, Bion 7 and Bion 9 launched at the times they were? Was it related to thermal management for their living cargo?

An answer to Have any living organisms been intentionally launched into polar orbits? says (in its entirety currently):

Yes. The highest inclination orbit with animals I could find are Bion 6, Bion 7 and Bion 9. They orbited at an 82 degree inclination and carried monkeys, rats and newts into space.

Launch times/dates were

14 December 1983,    07:00:00 UTC
10 July 1985,        03:15:00 UTC
15 September 1989,   06:30:00 UTC


These were launched from the Plesetsk Cosmodrome which is north and slightly east of Moscow and in terms of local sidereal time about UTC + 3

So the solar times of these launches were very roughly 10 AM, 6:15 AM and 9:30 AM

Altitudes were quite low, so if there was a window for a dawn/dusk orbit to maintain a constant, predictable level of solar heating, I don't know if all three could have done that. The months and therefore seasons varied, so maybe that's a clue.

It wouldn't have to be a proper Sun-synchronous orbit and precess once per year of course since the missions were for only about a week each.

Question: Why were Bion 6, Bion 7 and Bion 9 launched at the times they were? Was it related to thermal management for their living cargo?

Any spacecraft on upper stages of the launch vehicle is thermally stabilized under the fairing.

When the spacecraft is at the cosmodrome, the thermal regime is usually provided with the help of ground-based means. In this photo, you can see two ducts from the fairing to the air conditioner.

Air supply to the lower part of the head unit by means of mobile devices mounted on a railway or automobile platform, with air exiting from the upper part of the head unit and returning it to the entrance to the head unit, i.e. the system works in a closed loop. The circulated air is cleaned using filters, a device at the air supply inlet to the device to ensure the thermal regime of the head unit.

On the launch pad, a method can be used to ensure the thermal regime of the head unit of the launch vehicle by supplying atmospheric air to the lower part of the head unit using stationary ground means and means of the service tower of the launch vehicle and by releasing air into the atmosphere in the upper part of the launch unit, i.e. the system works in an open loop. The supplied air is cleaned using filters installed at the air supply inlet to the device to ensure the thermal regime of the head unit.

The nine-level service tower of the launchpad in Plesetsk:

• These are beautiful, thanks! If you can find anything about management on the orbit especially related to sunlight/darkness vs constant sunlight related to time of launch, that would be great!
– uhoh
May 23 at 6:47
• @uhoh No information could be found, except that "Bion" is a somewhat simplified version of "Zenith". It can be assumed that nothing was specially done for these satellites and they were launched just like Zenith. May 25 at 18:27
• Okay, thanks. Any idea why they were launched at 82 degrees inclination at least? Is it related having continuous sunlight?
– uhoh
May 25 at 21:22
• @uhoh "Low circular orbits, the plane of which has an inclination in the range from 82 degrees to 98 degrees, are called polar. The advantage of such orbits is the ability to service large areas of the Earth's territory in the polar zones by communication." May 26 at 19:17
• "A significant increase in the accuracy of launching during the transition from the Vostok launch vehicle to the Cyclone made it possible to understand that the calculated orbit of the electronic reconnaissance satellites is multiple, and their paths should be repeated every 44 turns, after 3 days (for an inclination of 82.6 degrees this multiplicity is achieved at an average orbital altitude of 647 kilometers). The system of 6 orbital planes with an inclination of 82.6 degrees was fully equipped with satellites in 1985 and has been continuously maintained since then." May 26 at 19:17