SpaceX Falcon 9 V1.1 - AsiaSat 8 - Launching August 5, 2014
Screenshot from SpaceX Webcast of the launch of AsiaSat 8, note the green TEA-TEB flash
Mission Rundown: SpaceX Falcon 9 V1.1 - AsiaSat 8
Written: February 4, 2021
Let’s split the bill going to GTO
SpaceX was contracted to launch AsiaSat 8 using a Falcon 9 v1.1 launch vehicle. The launch took place from Space Launch Complex 40 at the Cape Canaveral Air Force Station on 5 August 2014.
SpaceX is launching the AsiaSat 8 satellite to a Geosynchronous Transfer Orbit. The launch is targeted for the early morning hours of August 5th. The launch window opens at 07:50 UTC and closes at 09:04 UTC.
The Payload
AsiaSat 8 or Amos-7 is a Hong Kong-turned-Israeli geostationary communications satellite which is operated by the Asia Satellite Telecommunications Company.
AsiaSat 8 was built by Space Systems/Loral, and is based on the LS-1300LL satellite bus. The satellite carries 24 Ku band transponders and a single Ka band transponder as the payload, and was planned to be positioned at a longitude of 105.5 degrees East, providing coverage of south and south-eastern Asia, China and the Middle East.
In addition to AsiaSat-8, the company plans to introduce two more satellites in the coming years; AsiaSat-6 is scheduled for launch later this month and will be positioned in a Thai slot at 120 degrees East, under an agreement which will see half of its transponder capacity leased to Thaicom.
Later AsiaSat-9 will launch on a Proton in 2016 to replace AsiaSat-4. Like AsiaSat-8, both of these spacecraft are based on Loral’s LS-1300 platform.
SpaceX was contracted to launch AsiaSat 8, using a Falcon 9 v1.1 carrier rocket. The launch took place from Space Launch Complex 40 at the Cape Canaveral Air Force Station on 5 August 2014 at 08:00 UTC.
Western Union Telegraph Company satellite Westar-6 being captured by a Discovery crewmember
AsiaSat’s first satellite, AsiaSat-1, had originally been named as Westar-6 and was launched by Space Shuttle Challenger during 1984’s STS-41B mission. However, a failed Payload Assist Module which was to have boosted the satellite into geosynchronous transfer orbit resulted in the spacecraft becoming stranded in low Earth orbit.
The spacecraft was recovered and returned to Earth by Shuttle Discovery nine months later and following refurbishment it was sold to AsiaSat as AsiaSat-1. The satellite was returned to orbit by a Chang Zheng 3 rocket in April 1990 on flight 7, in what was China’s first ever commercial launch, and operated successfully for thirteen years.
Second scene, act two: Exit of 2nd stage
The Falcon 9 second stage used to launch AsiaSat 8 is derelict in a decaying elliptical low-Earth orbit that, as of 13 August 2014, had an initial perigee of 195 km (121 mi) and an initial apogee of 35,673 km (22,166 mi).
The transfer orbit took 10.5 hours, so it hit the aero brakes at perigee ever so slightly twice a day, and every time the apogee also was reduced by miles.
By September the orbit had decayed to an altitude of 185 km (115 mi) at its closest approach to Earth, and by November had decayed to a 169 km (105 mi) perigee.
Every orbit in the perigee faze the second stage enters the thin upper atmosphere and loses its velocity. It will deorbit eventually, but with the given data a loss of 10 miles in the first month and another 10 miles in two months, it's a given that the second stage is deorbited after 6 or 7 months.
All SpaceX had to do, if there wasn't enough fuel to slam the brakes at perigee, was to orient the second stage, so it flew sideways into the thin upper atmosphere bleeding more and more orbital speed off. It’s like skipping a stone across a lake, it loses speed with every skip “orbit”, and it will eventually sink aka. deorbit.
Another possibility is to deploy a solar sail and use sunlight to break the speed of the second stage. The Payload Adaptor Fairing carrying the payload should be equipped with solar panels to charge the onboard lithium battery pack, so the second stage could be controlled during its deorbit. The onboard pressurized Helium and Nitrogen could be used at apogee to lower the perigee driving it deeper into the atmosphere.
