Boeing 702
The Boeing 702 is a satellite bus for communications satellites. Boeing made on the basis of this design for the end user various payloads, which are tailored to the particular requirements.
The design of the Boeing 702 is compatible with various starting systems, it can for example be started with the launch vehicle Delta IV, Atlas V, Ariane 5 and Proton. It was introduced in October 1995 and is based on the previous models, Boeing 601 and 601HP. In 2009, the improved version 702B was presented.
Specifications
The satellite can generate up to 18 kW of power with the help of gallium arsenide solar panels. It can house up to 118 high- transponder ( 94 active and 24 spare) wear.
The spacecraft of the 702MP have in orbit a height of 5.8 m to 8.6 m, a width of 9.2 m with antennas and solar panels with a span between 36.9 m and 38.1 m. At the start of the satellites have a size of 5.8 m × 3.6 m × 3.1 m. The take-off mass is between 5800 kg and 6160 kg, the mass in orbit after launch between 3582 kg and 3833 kg. The solar panels provide 13.6 and 18 kW ( BOL) and are supported by lithium -ion batteries with 24 to 40 cells and up to 236 Ah capacity.
XIPS
As part of the design Boeing offers an ion drive called XIPS, this stands for Xenon Ion Propulsion System. XIPS is the railway receipt of a geostationary satellite about 10 times more effective than liquid fuel systems. A equipped with this drive satellite requires only about five kg of fuel per year for orbit control. According to Boeing, this is a fraction of what need conventional drive systems, also XIPS could also be used to reach the final orbital position, which would provide more fuel and mass savings.
This is implemented by the new type 702SP, which uses as apogee motors ion engines.
By using the ion drive as apogee, these satellites are only 33 % to 50% by weight have the same power as a satellite with liquid propellant apogee motor. But raising the perigee to reach the GEO will take a few months.
A typical 702SP satellite should weigh about 1.8 tons at the start and 3 - have 8 kW electrical power.