Figure 1: Mars Sample Return Program
The Sample Retrieval Lander (SRL) is part of the Mars Sample Return Campaign whose goal is to return Mars surface core samples back to Earth by the early 2030s. Mars 2020 was the first in the series of missions and is currently collecting and caching core samples on Mars. SRL is the second in the series whose purpose is to retrieve the samples collected by the M2020 Perseverance rover, package them and launch them in to Mars orbit. The third mission in the series is the Earth Return Orbiter (ERO) whose job is to capture and contain the samples in Mars orbit and effectively launch them back to Earth.
The SRL mission is composed of two landers. The first transports the Sample Fetch Rover (SFR) to surface where it will retrieve sample tubes deposited in various depots by the Perseverance rover. The second lander contains the Sample Transfer System (STS) and the MAV (Mars Assent Vehicle). STS is responsible for retrieving tubes from either SFR or Perseverance, placing a curated set of them in the MAV, and preparing the MAV for launch by closing out one or more covers.