SpaceX is very active again: The ORBCOMM OG2 mission will launch six OG2 satellites, the first six of a series of OG2 satellites launching on SpaceX’s Falcon 9 vehicle. Compared with ORBCOMM’s current constellation, the next generation OG2 satellites have advanced communications technologies, and are significantly larger, more capable, and more efficient. The satellites were built by Sierra Nevada Corporation and weigh approximately 170 kg each. The full series of OG2 satellites will be launched to low-Earth orbit.
The satellites will provide existing customers with significant enhancements, such as faster message delivery, larger message sizes and better coverage at higher latitudes, while drastically increasing network capacity. In addition, the OG2 satellites are equipped with an Automatic Identification System (AIS) payload to receive and report transmissions from AIS-equipped vessels for ship tracking and other maritime navigational and safety efforts, increasing asset visibility and the probability of detection for ORBCOMM’s AIS customers.
Naturally, all spaceflight is incredibly complicated. Every component of the mission must operate optimally. Hardware, avionics, sensors, software and communications must function together flawlessly. If any aspect of the mission is not successful, SpaceX will learn from the experience and try again.
Several months before a Falcon 9 launch, both rocket stages are transported to SpaceX’s development facility in McGregor, Texas for testing, and then trucked individually to SpaceX’s hangar at Space Launch Complex 40 at the Cape Canaveral Air Force Station in Cape Canaveral, Florida. SpaceX’s payload fairing and the satellite payload are shipped separately In the days leading up to launch, the spacecraft is processed and encapsulated within the fairing, and the
rocket stages are integrated. Any final major preflight test is a static fire, when Falcon 9’s nine first-stage engines are ignited for a few seconds, with the vehicle held securely to the pad.
As the last major event prior to launch, Falcon 9 and its payload are transported to the launch pad and raised vertically.
This launch sequence for Falcon 9 is a process of precision necessitated by the rocket’s approximately one-hour launch window, dictated by the desired orbit for the satellites. If the approximate one-hour time window is missed, the mission will be attempted on the next available
date. A little less than four hours before launch, the fueling process begins— liquid oxygen first, then RP-1 kerosene propellant. The plume coming off the vehicle during countdown is gaseous oxygen being vented from the tanks; this venting also necessitates topping off the liquid oxygen
throughout the countdown.
The terminal countdown begins at T-10 minutes, at which point all systems are autonomous. The SpaceX Launch Director at the Cape Canaveral Air Force Station gives a final go for launch at T-2 minutes and 30 seconds. At T-2 minutes, the Air Force Range Control Officer confirms the physical safety of the launch area and provides the final range status.
Shortly before liftoff, the launch pad’s water deluge system, dubbed “Niagara,” is activated.
Seconds before launch, the nine Merlin engines of the first stage ignite. The rocket computer commands the launch mount to release the vehicle for flight, and at T-0 Falcon 9 lifts off, putting out 1.3 million pounds of thrust.