SpaceX will for the first time launch a Falcon 9 booster on its third flight on Monday, as part of a mission to deliver a cluster of small satellites to low Earth orbit. Liftoff is scheduled for a twenty-eight minute launch window that opens at 10:31 Pacific Time (18:31 UTC). T-0 occurred at 34 minutes past the hour.<\/p>\n
Designated SSO-A or the SmallSat Express, the cargo for this launch consisted not of a single primary payload but of a collection of smaller satellites from companies and organizations around the world that are sharing their journey into space. The rideshare mission has been co-ordinated by Seattle-based Spaceflight Industries and consists of 64 satellites for 34 customers from 17 different countries and the European Space Agency.<\/p>\n
Originally named the 2017 Sun-Synch Express, when it was expected to launch last year, the SSO-A mission targets a sun-synchronous orbit. This is a special type of near-polar low Earth orbit which allows a satellite to pass over points on the Earth\u2019s surface at the same mean local solar time, allowing similar lighting conditions for observation and research.<\/p>\n
Rideshare satellites have become increasingly common in recent years, typically in the form of smaller satellites hitching a ride alongside a single, larger, primary payload. Spaceflight Industries have previously conducted launches of this type aboard rockets including Antares and India\u2019s Polar Satellite Launch Vehicle (PSLV), although this launch marked their first dedicated mission. Spaceflight has also placed satellites aboard previous Falcon 9 launches, arranging to have CubeSats carried to the International Space Station aboard SpaceX\u2019s Dragon spacecraft \u2013 as well as Northrop Grumman\u2019s Cygnus \u2013 for subsequent deployment from the outpost.<\/p>\n
As well as being the most satellites that have been carried aboard a single Falcon 9 launch, the flight also marked a step forward in SpaceX\u2019s drive to developing reusable launch systems. Having already perfected recovering the first stage of the Falcon 9 and demonstrating that it can be successfully re-flown on a subsequent mission, the SSO-A launch took this a step further by using a booster that had already flown twice. This will be Core 1046, which was first used in May for the launch of the Bangabandhu 1 communications satellite from the Kennedy Space Center, before flying again from Cape Canaveral in August with the Telkom 4 spacecraft.<\/p>\n