This is the phase immediately preceding the actual launch. It is comprised of a number of particularly high risk activities, including assembly on the launch pad (i.e., mating of the satellite and its booster rocket) and rocket fueling (with liquid oxygen and hydrogen if a cryogenic motor is used).
The examples provided below illustrate the kinds of damage and loss which can occur during the phases of construction, transportation and preparation of the satellite for launch.
Most claims pertaining to the pre-launch phase are caused by the total failure of the rocket or launch vehicle, which generally leads to its inadvertent explosion (or deliberate explosion in mid-air if the rocket leaves its intended flight path and becomes dangerous). This almost always means that the launch vehicle or rocket is a total loss.
When a solar panel was being assembled onto the hull of the satellite, mishandling of the winch damaged a parabolic antenna, which had to be replaced.
When the satellite’s electrical system was being tested prior to launch, a procedural error caused over-voltage, which in turn damaged the wire data bus, requiring that nearly all equipment be re-checked.
During vibration testing on one of the satellite’s sub-systems, the vibrator’s loop guidance turned out to be defective, which meant that the sub-system being tested was subject to levels of vibration that far exceeded design specifications.
When a satellite was being transported by airplane to the launch pad, the pressure equalization valves on the container were not opened, contrary to standard procedure. When the airplane was making its final descent for landing, the aluminum container melted onto the satellite, leading to severe structural damage.
When an apogee boost motor was mishandled during strap-on to the hull of the satellite, a fire started. The blaze destroyed the satellite and the assembly hall, causing the deaths of several technicians working onsite.
In each of these cases, the cost of the claim exceeded one million dollars, primarily because the damaged parts were custom-made, and because the subsequent testing and re-checking that were required led to additional costs.
Several technical parameters are used to assess the performance of the rocket during flight and determine if the mission has been accomplished to satisfaction. The precision of the satellite's injection into the target orbit is measured by the following parameters: inclination, perigee and apogee, and possibly rotation speed (spin) and attitude of the satellite.
The environment generated by the rocket is also analyzed to verify that general and thermal constraints have not exceeded maximal values, above which the satellite risks damage.
Most claims pertaining to this phase are caused by the total failure of the rocket or booster rocket, which generally results in either inadvertent explosion or deliberate explosion in mid-air (if the rocket leaves its intended flight path and becomes dangerous). This almost always means that the launch vehicle or rocket is a total loss.
If the launch system under-performs, then the satellite is injected into a lower altitude orbit than initially planned, or with inclination and other parameters that are incompatible with the planned mission. To make the adjustments required to get the satellite back into its intended operational orbit, the satellite uses fuel normally intended for station-keeping. This reduces the satellite's life expectancy in orbit, leading to partial or total loss.
Finally, if the environment during launch is more severe than expected (in terms of vibrations, for example), damage to or functional defects in the satellite may occur, which in turn may lead to total or partial loss.
In addition, failed launches are sometimes caused by design flaws, mechanical aspects, procedural errors or inadequate quality control, as the following examples illustrate:
Finally, failure is sometimes caused by incompatibility between the launcher and the satellite. Past accidents involving the Apollo rocket led to a close examination of vibratory mating phenomenon between rocket and satellite to eliminate the risk of acoustic resonance.
When they are designed to self-destruct once their mission is accomplished, or if their value is very high, launchers are generally not insured for property damage during the launch period.
This term refers to all stationing operations that get the satellite from its low earth orbiting position to its final nominal orbit and service (its geostationary or operational orbit).
This phase, which begins with the separation of the satellite from the rocket and its placement in the geostationary transfer orbit, is fraught with risk. There are many complex operations that must be accomplished, requiring observance of a strict set of controls and sequencing.
The principal events involve:
The objective of this phase, which extends over several weeks, is to verify that the satellite performance is consistent with its technical specifications and detect and correct any minor defects. It is only after this phase has been completed that the satellite is deemed "acceptable" for commercial operation.
If serious problems or failures occur during this phase, the end result may be the total or partial loss of the satellite.
The causes of breakdowns are numerous, but they can be divided into two basic categories: performance defects and operator error.
Life in orbit begins once the satellite has been accepted. The satellite is placed in its operational configuration and commercial service can begin. The life expectancy of a satellite in orbit typically reaches ten years. Since minor defects are detected and corrected during the satellite acceptance testing phase, the main breakdown risk in orbit is related to routine wear-and-tear (or aging).
In practice, redundancies and back-ups are designed and built into most sub-systems, enabling the satellite to withstand certain breakdowns and malfunctions
Another cause of orbital malfunction is linked to the space environment. Throughout its life in orbit, the satellite is subjected to a variety of phenomena, which include solar eruptions, the electromagnetic field and meteors.
The consequences of these encounters are rarely disastrous. Only a portion of the payload is lost, and the satellite can continue to function as before despite this loss.
There are, however, a few cases of total loss in orbit.
Telstar 401 fell suddenly silent after its electrical sub-system failed.