Iridium-6

Mission: A SpaceX Falcon 9 rocket will launch five Iridium-NEXT mobile communications satellites and a pair of gravity-sensing satellites into Low Earth Orbit on a shared ride between Iridium Communications and GRACE-FO operators GFZ and NASA. SpaceX has been contracted to deploy 75 Iridium-NEXT satellites with deployment occurring in batches of ten, meaning one Falcon 9 would fly with half a load, leaving surplus performance for a co-passenger. The two GRACE Follow-On Satellites are flying as an extension of the Gravity Recovery and Climate Experiment that has been tracking Earth’s gravitational field since 2002 and is headed into retirement in late 2017. GRACE shows how mass is distributed around the planet and its variation over time, allowing for modeling of Earth’s oceans, geology and climate.

The Iridium satellites are headed to orbit in the continued effort to replace the entire heritage Iridium constellation with upgraded satellites supporting global communications, aeronautical monitoring and ship tracking.

Rocket: The Falcon 9 rocket is a partly reusable rocket designed and built by SpaceX. It has 2 stages and can deliver 22,800 kilograms (50,300 lb) to low Earth orbit, and up to 8,300 kg (18,300 lb) to geostationary transfer orbit (GTO), when flying in expendable mode. The first stage can be recovered after separation with the second stage of the rocket on missions delivering a cargo of up to 5,500 kg (12,100 lb) to GTO. The first launch of the Falcon 9 was on June 2010. The first stage of the rocket can be recovered and reused (on version Full Thrust or later). This will be the 55th launch of the Falcon 9 and there will be no attempt to land the first stage. The first stage of the rocket has been launched to space before, therefore it will be a reused first stage. The rocket measures 70 metres and weighs 549,054kg (1,207,920 lb) fully loaded. Its diameter is 3.7 meters. It produces 7,607kN (1,710,000 lbf) at sea level (only the first stage).

First Stage: The first stage measures 41.2 meters and 47.7 with the interstage. It has 9 Merlin engines forming an Octaweb. It uses RP-1 (kerosene) and LOX (liquid Oxygen) on a super chill state. It burns for about 162 seconds before it separates from the second stage. On some versions and some missions, the first stage lands on either a droneship on the ocean or landing zones on land after a series of burns. It has landed 25 times.

Second Stage: The second stage measures 13.8 meters. It has 1 Merlin 1D+ engine adapted for the vacuum of space, producing 934 kN (210,000 Ibf). It burns for approximately 397 seconds. It also uses RP-1 (kerosene) and LOX (liquid oxygen) on a super chilled state (deep cryo) for more density in the tanks.

Fairing: The fairing measures 5.2 meters in diameter and 13.1 meters in height.

Dragon Capsule: This capsule is designed to deliver cargo or humans to the ISS. It can deliver 6,000kg(13,228 lbs) and return 3,000kg (6,614 lbs). It will start delivering humans to the ISS sometimes in 2018. It performs a soft landing on the ocean after deploying 3 parachutes.

Cost: The Falcon 9 costs 60 million US$ expendable and 50 million US$ reusable.