Sustain a useful imaging orbit

In its 29 September 2026 anniversary report, ASAL described ALSAT-2B and ALSAT-2A as operating nominally, with 2B ten years beyond launch and a five-year nominal design life. This is the operator’s dated assessment, not a guarantee of future availability or identical performance in every subsystem.

The report distinguishes continuing collision-avoidance maneuvers from proposed maneuvers to reduce drift in local passage time. The latter were conditional on evaluating remaining propellant and required velocity change. A plan, a resource assessment, an executed maneuver and a verified new orbit are different pieces of evidence. Do not report a proposed correction as accomplished.

Local passage time matters to imaging because illumination changes with the Sun’s position. Maintaining useful conditions competes for finite operational resources with other needs. A long-lived mission requires decisions about what capability to preserve and what uncertainties remain, rather than simply maximizing elapsed years.

In a fictional planning exercise, usable velocity-change capacity is 12 metres per second. Reserving 3 for contingencies and allocating 2 to a separate maintenance need leaves 7 for the proposed activity: 12 − 3 − 2 = 7. These are invented accounting values, not Alsat flight data or a maneuver recommendation. A real assessment must evaluate spacecraft capability, uncertainty and competing obligations before deciding whether any maneuver is appropriate.

ASAL reported about 15,000 scenes programmed during Alsat-2B’s tenth year. Programmed scenes describe demand and scheduling; they should not be relabelled as 15,000 cloud-free acquisitions or validated maps. The distinctions matter when comparing workload with delivered public value.

For a fictional service, 120 scenes are scheduled, 90 are acquired and 80 pass a defined quality check. The checked share is 80/120, about 66.7 percent of scheduled scenes, or 80/90, about 88.9 percent of acquired scenes. Both fractions are correct when their denominators are stated. Neither explains the failures without further evidence. A useful report records the stage, the criteria and the time period.

State the denominator