Red Dragon
Mars sample return mission
CANCELED
Note: There are no details of the 2018 launch being a full sample return mission, this is more likely in either in 2020 or 2022.
The Red Dragon will be a modified SpaceX Dragon V2 capsule design for a low-cost solution for an unmanned Mars lander missions, NASA has agreed to support SpaceX for a launch in the May 2018 Mars Transfer opportunity, NASA will support SpaceX with its Deep Space Network for communications and advise SpaceX on the flight proposing landing sites.
SpaceX will use the Falcon Heavy rocket and by Using the SuperDraco retro-propulsion thrusters to be able to land with high accuracy a 2 ton payload onto Mars.
Tech Box
The 2018 launch window has a very low ∆V energy of a C3 of just 8.11 using a NASA transfer type 1 (NASA PDF here).
NASA and SpaceX are setting up a Mars entry database together, under an agreement with SpaceX Mission Manager Aarti Matthews.
The main changes to the Dragon V2 will be to replace all the life support with radiation hardened electronics and add additional fuel tanks required for the Mars landing.
Note that the proposed SpaceX Falcon Super Heavy rocket would make a big change to future plans for going to Mars.
The SuperDraco thrusters to land with high accuracy on Mars.
Samples will be returned using a rocket called "Mars Ascent" to get the samples back to Earth orbit where a second Launch will be required to collect the samples from Earth Orbit.
This NASA video states that Red Dragon sample mission can work