A Density Scale

Density

Server Sky will deploy at 6411 km altitude. Gas density at that altitude is 6E-18 kg/m², mostly hydrogen. That is 5E-18 times smaller than air density at the surface; it is difficult to comprehend just how tenuous the exosphere is, so here is a density scale. The densities below assume average solar activity, F107 = 150 , averaged over the day, on the equator, at the equinox .

|| "zone" || density kg/m³|| pressure ||

Mega	≈ 1e6	3.6 MBar	Center of Earth	ideal gas density at pressure
Kilo	≈ 1e3	1.1 KBar	Deepest Ocean	ideal gas density at pressure
	1.2	1.01 Bar	0 km altitude	Sea level
milli	1.1e-03		50 km altitude
micro	6.8e-07		100 km altitude	"edge of space", suborbitals
nano	1.2e-09		160 km altitude	useful low earth orbits
pico	2e-12		410 km altitude	International Space Station
femto	1e-15		1250 km altitude	lowest sustainable solar sail
atto	3e-17			beamline Large Hadron Collider
atto	6e-18		6411 km altitude	m288 server sky
atto?	?		35786 km altitude	geosynchronous orbit
zepto	1e-20			interplanetary space
zepto	1e-21

The air is too dense at ISS altitudes (in the pico zone) to experiment with server sky - thinsats must be in orbit long enough to test maneuvering and to be observed from the earth, in the femto circular orbit zone or higher. Low earth orbits in the nano zone have a million times as much drag, and a suborbital in the micro zone has a billion times as much density, though it may briefly come to a stop in a vertical trajectory.