On Thu, 31 Aug 2023, Dave Taht via Starlink wrote:

> I like the idea of starlink finding some way to leverage satellites
> moving into the right orbits. (the timestamp of this trace was
> 2023-08-27 06:59:35 UTC and I am in half moon bay, ca) This would
> imply that they can transmit data at full thrust, and also, perhaps,
> VLEO (I am not sure if that is an established acronym - very low earth
> orbit operations) -  feasible. Dropping the things even lower, making
> the shell more aerodynamic, and burning fuel to stay there might well
> be an interesting option. It seems to me the current altitude(s) are
> pretty conservative and given the fuel consumption reported on the
> maneuvering side, they can last at 530km much longer than 5 years, and
> with the pace of technology and launch rates, moving them lower would
> be a huge win for bandwidth and latency.

It's not just a fuel issue, it's a matter of their assigned orbits (not getting 
in the way of other satellites)

Here are the altitudes they are authorized to operate in and the current count 
per orbit (from wikipedia so I don't know how up to date they are given the 
frequent launches, but I suspect pretty close)

Altitude	Authorized	Active	Decaying/deorbited
550 km		1584[313]	1457	268
570 km		720		404	4
560 km		348		233	10
540 km		1584		1567	70
560 km		172
335.9 km	2493
340.8 km	2478
345.6 km	2547

it's not a matter of being able to operate while under thrust from a technical 
point of view, it's a matter of them being authorized by the FCC to do so and 
anti-collision rules.

the US considers 'space' to start at a round number of 50 miles (just over 
80km), the metric world picked 100km (another nice round number, just over 62 
miles), so any satellite at 70km is technically not 'in space' and will die in a 
few orbits

David Lang