Deliver to the required orbit

A satellite’s delivery target includes more than being above the atmosphere. Its orbit has a shape, size and orientation, and the spacecraft separates with a particular velocity. A transfer orbit can leave further maneuvers to the satellite. Evaluating a launch therefore begins with the agreed delivery conditions, not the single question of whether anything reached space.

Kakehashi, also called COMETS, illustrates this distinction. H-II Flight 5 launched it on February 21, 1998. JAXA records a normal first-stage burn followed by a shorter-than-planned upper-stage burn. The satellite entered a lower orbit than the intended geostationary transfer orbit. This was an orbital-insertion shortfall even though the satellite was in orbit.

For an original numerical exercise, suppose a planned orbit has a 36,000-kilometer apogee altitude and an observed orbit has a 20,000-kilometer apogee altitude. The altitude shortfall is 16,000 kilometers. That subtraction compares the same quantity measured from the same reference surface. It does not calculate how much velocity change is needed to repair the orbit.

A maneuver calculation needs the spacecraft’s state, the desired trajectory and an appropriate orbital model. A kilometer of altitude is not a kilometer per second of velocity. Even two orbits with the same apogee can differ in perigee or inclination, changing their usefulness and the maneuvers needed to reach another orbit.

Delivery, recovery and mission results

JAXA describes seven subsequent orbit changes for COMETS, followed by communications experiments in a revised orbit. Operations ended in August 1999. Those experiments are part of the satellite’s history; they do not change the original launcher delivery requirement after the fact.

In a mission review, keep three columns: intended delivery, achieved delivery and later recovery. A useful experiment after a shortfall belongs in the third column. This approach credits the recovery team while preserving an honest account of what failed. It also avoids blaming a launcher for every unrelated problem that a payload might encounter later.