LEOP and commissioning
Launch and early orbit phase spans the first hours to weeks after separation: acquisition of signal, subsystem checkout, orbit raising and payload acceptance. Most mission losses occur here, not at launch.
Separation to first contact: the minutes that set the tone
At the moment a satellite separates from its launch vehicle, it is autonomous, tumbling slightly, and entirely unreachable until a ground station antenna locks onto its signal. That window, typically between eight and ninety minutes after separation depending on orbit and ground-network geometry, is when most LEOP teams are at their most tense and least able to do anything useful. The satellite must detumble using its attitude-determination and control system, deploy solar panels if they are body-stowed, and begin transmitting a beacon on its downlink frequency before the first pass ends.
Acquisition of signal is not guaranteed on the first pass. A misaligned antenna, a deployment latch that did not release, or a software state machine that entered a safe mode during launch vibration can all delay first contact. Experienced teams pre-plan contingency command sequences for each failure scenario and have them loaded and ready before launch. Amateur teams write those sequences after the problem appears, which is too late.
The commissioning choreography
A standard LEOP for a small LEO satellite runs seven to twenty-one days. The first forty-eight hours focus entirely on platform health: power budget verification, thermal characterisation across the first few eclipse cycles, propulsion pressurisation (where applicable) and communications link margin measurement. Nothing else happens until the platform is confirmed stable.
Orbit determination begins in parallel. The launch dispersion, the difference between the target orbit and the orbit actually achieved, is rarely zero. Spire Global's LEMUR constellation and ICEYE's SAR satellites both publish the fact that their operators perform orbit-correction manoeuvres within the first days of LEOP to correct injection errors. For a mission without propulsion, the team must instead update the mission plan to reflect the actual orbit, which can shift revisit times, ground-station contact windows and payload duty cycles significantly.
Payload commissioning follows platform acceptance. For an optical camera, this means first-light imaging, geometric calibration against ground-control points, and radiometric calibration against known targets such as the Saharan sand sites used routinely by Copernicus Sentinel teams. For a SAR payload, antenna pattern verification and noise-equivalent sigma-zero measurements are standard. For a communications payload, frequency and power verification against the ITU filing is mandatory before operational use. Each of these steps has a pass/fail criterion agreed in the acceptance test plan before launch, not after.
What actually goes wrong
The honest answer is: usually something minor, occasionally something fatal, and almost never what was predicted. The most common LEOP anomalies in small satellite programmes are solar-panel deployment failures, software safe-mode triggers from unexpected sensor readings, and uplink command rejection caused by Doppler shift miscalculation in the ground software. All three are recoverable if the team has rehearsed the recovery procedure.
Less recoverable: a propulsion system that vents its entire propellant load in the first orbit due to a valve anomaly, leaving the satellite in an uncorrectable orbit. Or an attitude sensor that was calibrated on the ground but performs differently in the thermal environment of space, causing the spacecraft to point its solar panels away from the sun and drain the battery before the team can intervene. ESA's LEOP support documentation notes that battery deep-discharge in the first orbit is one of the leading causes of total mission loss in small satellite programmes. Recovery from a deep discharge requires the satellite to have a low-power survival mode that can operate on the trickle of power available from a partially illuminated panel, and many small satellites do not.
The fortnight framing in this family's subtitle is not rhetorical. Statistically, a satellite that survives its first fourteen days in good health will almost certainly complete its design life. One that has not resolved all platform anomalies by day fourteen is carrying risk into every subsequent month of operations.
Why LEOP teams are hired, not assembled at short notice
LEOP is a perishable skill. The knowledge of how to respond to an unexpected safe-mode event at 03:00 on day two is not in any manual; it lives in the muscle memory of people who have done it before, made mistakes in simulation, and corrected them. A flight dynamics engineer who has performed orbit determination for three previous missions will spot an anomalous residual in the ranging data that a first-timer will dismiss as noise.
The practical consequence for a national programme is that LEOP cannot be staffed by the same team that built the satellite. Those engineers know the hardware intimately but have not operated it in flight. The standard industry model is a dedicated LEOP team, often contracted from an experienced operator or from the satellite manufacturer's mission operations division, who work alongside the national team during the critical phase and then hand over to them once the satellite is in routine operations. This is precisely the model that Satellize structures into its programme contracts: the national team is present and trained throughout LEOP, not handed a working satellite and told to get on with it.
Ground-network coverage during LEOP matters more than at any other mission phase. A single ground station provides, at most, four to six contact windows per day for a LEO satellite, each lasting six to twelve minutes. Anomaly resolution that requires rapid commanding often cannot wait for the next pass. Multi-station agreements with networks such as KSAT or similar providers are standard practice during LEOP precisely because the cost of an additional ground station contact is trivial compared with the cost of a satellite lost to an anomaly that could have been corrected twelve hours earlier.
The limits of what LEOP can fix
LEOP is not a remediation phase for design errors. A payload that was integrated with a mechanical misalignment cannot be re-pointed from the ground beyond the range of the spacecraft's attitude system. A radio transmitter with insufficient link margin to close the budget at the actual orbit altitude, rather than the planned one, cannot be made to transmit more power. A battery whose cells were degraded before launch will not recover.
The commissioning acceptance criteria must therefore be set conservatively, with margins that account for launch dispersion, component ageing and the difference between thermal-vacuum test conditions and actual on-orbit thermal environment. Programmes that set acceptance criteria at nominal performance levels, rather than minimum acceptable levels, frequently find themselves in a dispute about whether a payload that performs at 94% of specification has passed or failed. That dispute should be resolved in the acceptance test plan, not in the mission control room on day twelve.
Engineering parameters
| Typical LEOP duration (LEO, small satellite) | 7 to 21 days from separation to payload acceptance |
| First acquisition of signal window | 8 to 90 minutes post-separation, depending on orbit and ground-network geometry |
| Contact windows per day (single ground station, LEO) | 4 to 6 passes, each 6 to 12 minutes |
| Orbit determination accuracy (GPS-equipped small satellite) | Position to within 10 to 100 m (3-sigma) within first 24 hours |
| Launch dispersion (typical small launch vehicle) | ±5 to ±25 km semi-major axis, ±0.05° to ±0.2° inclination |
| Minimum LEOP team size (small satellite) | 4 to 8 specialists: flight dynamics, spacecraft operations, payload, ground systems |
| Safe-mode recovery time (typical, with multi-station coverage) | 2 to 24 hours depending on anomaly severity and pass frequency |
| Payload calibration duration (optical or SAR) | 3 to 14 days following platform acceptance |
One contract, one accountable engineer
Commissioned as one programme, not a stack of contracts: spacecraft, launch, ground segment, mission control, training and handover are priced together. Source-access terms and audit rights are agreed in writing before signature. Review our LEOP handover terms.