The NASA-ESA Mars Sample Return was a proposed Flagship-class Mars sample return (MSR) mission to collect Martian rock and soil samples in 43 small, cylindrical, pencil-sized, titanium tubes and return them to Earth around 2033.
The NASA–ESA plan, approved in September 2022, was to return samples using three missions: a sample collection mission (Perseverance), a sample retrieval mission (Sample Retrieval Lander + Mars Ascent Vehicle + Sample Transfer Arm + 2 Ingenuity-class helicopters), and a return mission (Earth Return Orbiter). The mission hoped to resolve the question of whether Mars once harbored life.
Although the proposal never went beyond the design stage, the Perseverance rover is currently gathering samples on Mars.
After a project review critical of its cost and complexity, NASA announced that the project was "paused" as of November 13, 2023. On November 22, NASA was reported to have cut back on the Mars sample-return mission due to a possible shortage of funds. In April 2024, in a NASA update via teleconference, the NASA Administrator emphasized continuing the commitment to retrieving the samples. However, the $11 billion cost was deemed infeasible. NASA turned to industry and the Jet Propulsion Laboratory (JPL) to form a new, more fiscally feasible mission profile to retrieve the samples. In January 2026, Congress confirmed the Trump administration's plan to cancel the project.
History
2001 to 2004
In the summer of 2001, the Jet Propulsion Laboratory requested mission concepts and proposals from industry-led teams (Boeing, Lockheed Martin, and TRW)."Mars Sample Return – Studies for a Fresh Look," R. Mattingly, S. Matousek and R. Gershman, 2002 IEEE Aerospace Conference, 2–493. The science requirements included at least of samples, rover mobility to obtain samples at least from the landing spot, and drilling to obtain one sample from a depth of . That following winter, JPL made similar requests of certain university aerospace engineering departments (MIT and the University of Michigan).
Also in 2001, a separate set of industry studies was done for the Mars ascent vehicle (MAV) due to the uniqueness and key role of the MAV for MSR."Mars Ascent Vehicle – Concept Development," D. Stephenson, AIAA 2002–4318, 38th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, July 7–10, 2002. Figure 11 in this reference summarizes the need for MAV flight testing at a high altitude over Earth, based on Lockheed Martin's analysis that the risk of mission failure is "extremely high" if launch vehicle components are only tested separately.
In 2003, JPL reported that the mission concepts from 2001 were too costly. A subsequent study yielded a more affordable plan that was accepted by two groups of scientists: a new MSR Science Steering Group and the Mars Exploration Program Analysis Group (MEPAG)."Mars Sample Return, Updated to a Groundbreaking Approach," R. Mattingly, S. Matousek and F. Jordan, 2003 IEEE Aerospace Conference, 2–745. Instead of a rover and deep drilling, a scoop on the lander would dig deep and place multiple samples together into one container. After five years of technology development, the MAV would be flight-tested twice above Earth before the mission PDR (Preliminary Design Review) in 2009.
Based on the simplified mission plan, assuming a launch from Earth in 2013, two weeks on Mars, and a 2016 return, technology development was initiated to ensure that potential Mars microbes would not contaminate Earth, and also that the Mars samples would not be contaminated with Earth-origin biological materials."Planetary Protection Technology for Mars Sample Return," R. Gershman, M. Adams, R. Dillman and J. Fragola, paper number 1444, 2005 IEEE Aerospace Conference, March 2005. The sample container would be clean on the outside before departing from Mars, with installation onto the MAV inside an "Earth-clean MAV garage".
In 2004, JPL published an update on the 2003 plan."Continuing Evolution of Mars Sample Return," R. Mattingly, S. Matousek and F. Jordan, 2004 IEEE Aerospace Conference, p. 477. MSR would use the new large sky crane landing system in development for the Mars Science Laboratory rover (later named Curiosity). An MSR Technology Board was formed, and it was noted that the use of a rover might return to the MSR plan, in light of the success with the Spirit and Opportunity rovers that arrived early in 2004. A ascent rocket would carry of samples inside a payload, the Orbiting Sample (OS). The MAV would transmit enough telemetry to reconstruct events in case of failure on the way up to Mars orbit.
2005 to 2008
As of 2005, a rover had returned to the MSR plan, with a rock core drill, in light of results from the Mars Exploration Rover discoveries."Technology Development Plans for the Mars Sample Return Mission," R. Mattingly, S. Hayati and G. Udomkesmalee, 2005 IEEE Aerospace Conference. Focused technology development would start before the end of 2005 for mission PDR in 2009, followed by launch from Earth in 2013. Related technologies in development included potential advances for Mars arrival (navigation and descent propulsion), and implementing pump-fed liquid launch vehicle technology on a scale small enough for a MAV."Mars Base Technology Program Overview," C. Chu, S. Hayati, S Udomkesmalee and D Lavery, AIAA 2005–6744, AIAA Space 2005 Conference, August 30 to September 1, 2005.
In late 2005, a peer-reviewed analysis showed that ascent trajectories to Mars orbit would differ depending on liquid versus solid propulsion, largely because small solid rocket motors burn faster, requiring a steeper ascent path to avoid excess atmospheric drag, while slower-burning liquid propulsion might take advantage of more efficient paths to orbit.
Early in 2006, the Marshall Space Flight Center noted the possibility that a science rover would cache the samples on Mars, then subsequently a mini-rover would be sent along with the MAV on a sample return lander. Then, either the mini-rover or the science rover would deliver the samples to the lander for loading onto the MAV."Mars Ascent Vehicle Key Elements of a Mars Sample Return Mission," D. Stephenson and H. Willenberg, 2006 IEEE Aerospace Conference paper number 1009. A two-stage solid propellant MAV would be gas ejected from a launch tube. It would carry a payload—a diameter spherical package containing the samples. The second stage would send telemetry, and its steering thrusters would use hydrazine fuel with additives. The authors expected the MAV to need multiple flight tests at a high altitude over Earth.
A peer-reviewed publication in 2007 described testing of autonomous sample capture for Mars orbit rendezvous.Kornfeld, R., J. Parrish, and S. Sell (May–June 2007). "Mars Sample Return: Testing the Last Meter of Rendezvous and Sample Capture." Journal of Spacecraft and Rockets. 44 (3): 692–702. Free-floating tests were done on board a NASA aircraft using a parabolic "zero-g" flight path.
In 2007, Alan Stern, then NASA's Associate Administrator for Science, was strongly in favor of completing MSR sooner, and he asked JPL to include sample caching on the Mars Science Laboratory mission (later named Curiosity)."Space, science, and the bottom line," A. Witze, Nature. 448, p 978, August 30, 2007. A team at the Ames Research Center was designing a hockey puck-sized sample-caching device to be installed as an extra payload on MSL."Mars Sample Return Proposal Stirs Excitement, Controversy," L. David, Space News, July 23, 2007, p 19.
A review analysis in 2008 compared Mars ascent to lunar ascent, noting that the MAV would pose not only a technical challenge, but also a cultural one for the planetary science community: given that lunar ascent has been done using known technology, and that science missions typically rely on proven propulsion for course corrections and orbit insertion maneuvers, similar to what Earth satellites do routinely."Defining the Mars Ascent Problem for Sample Return," J. Whitehead, AIAA 2008–7768, AIAA Space 2008 Conference, San Diego Calif., September 2008.
2009 to 2011
Early in 2009, the In-Space Propulsion Technology project office at the NASA Glenn Research Center (GRC) presented a ranking of six MAV options, concluding that a two-stage solid rocket with continuous telemetry would be best for delivering a sample package to Mars orbit."Mars Ascent Vehicle Technology Planning," J. Dankanich, 2009 IEEE Aerospace Conference, March 2009. A single-stage pump-fed bipropellant MAV"Pump Fed Propulsion for Mars Ascent and Other Challenging Maneuvers," J. Whitehead, NASA Science Technology Conference, June 2007. was noted to be less heavy and was ranked second.
Later in 2009, the chief technologist of the Mars Exploration Directorate at JPL referred to a 2008 workshop on MSR technologies at the Lunar and Planetary Institute, and wrote that particularly difficult technology challenges included: the MAV, sample acquisition and handling, and back planetary protection. He then further commented that, "The MAV, in particular, stands out as the system with highest development risk, pointing to the need for an early start," leading to flight testing before preliminary design review (PDR) of the lander that would deliver the MAV."Strategic Technology Development for Future Mars Missions (2013–2022)," S. Hayati et al., A white paper submitted to the National Research Council as input to the Planetary Decadal Survey, September 2009. https://mepag.jpl.nasa.gov/reports/decadal/SamadAHayati.pdf Mars Exploration Program Analysis Group, Retrieved November 11, 2022
In October 2009, NASA and ESA established the Mars Exploration Joint Initiative to proceed with the ExoMars program, whose ultimate aim is the return of samples from Mars in the 2020s. ExoMars's first mission was planned to launch in 2018,Mars Sample-Return NASA Accessed May 26, 2008 with unspecified missions to return samples in the 2020–2022 time frame. As reported to the NASA Advisory Council Science Committee (NAC-SC)"NASA Advisory Council Science Committee website," https://science.nasa.gov/science-committee, Retrieved July 4, 2023 early in 2010, MEPAG estimated that MSR "will cost $8-10B, and it is obvious that NASA and ESA can't fund this amount by themselves.""NASA Advisory Council Science Committee February 16–17, 2010 Meeting Report," https://smd-prod.s3.amazonaws.com/science-pink/s3fs-public/mnt/medialibrary/2010/08/31/SC-Minutes-Feb2010_Mtg-Final-100423-Signed.pdf#page=6, NASA Headquarters. Page 6. Retrieved July 4, 2023 The cancellation of the caching rover MAX-C in 2011, and later NASA withdrawal from ExoMars, due to budget limitations, ended the mission. The pull-out was described as "traumatic" for the science community.