The most ambitious planetary science mission ever conceived — returning Perseverance's collected rock and regolith samples from Jezero Crater to Earth for full laboratory analysis. The campaign is currently undergoing architectural restructuring following cost and schedule concerns identified by an Independent Review Board in 2023.
Architecture Redesign Underway
Following the September 2023 Independent Review Board (IRB-2) finding that the original architecture would cost $8–11B and slip to 2040, NASA solicited competing proposals from JPL and 7 industry partners (Lockheed Martin, Rocket Lab, SpaceX, Blue Origin, Northrop Grumman, Aerojet/L3Harris, Draper). An architecture down-select is expected in 2026.
Two Competing Architectures
A “JPL Optimized” option (targeting ~$5.5–7.7B) and a “Commercial Heavy Lift” option (targeting ~$5.8–7.1B) are under evaluation. Both target an Earth return in approximately 2035.
ESA Remains a Partner
ESA's Earth Return Orbiter (ERO) remains a core element of the mission under both architectures. ESA has committed approximately €1.5B to the campaign, covering the ERO and associated elements.
23
Tubes Sealed
10
Depot Cache (Three Forks)
13+
On Rover
3
Witness Tubes
Perseverance has cached samples of igneous basalt (Jezero Crater floor), altered igneous rock with organic signatures, carbonate-bearing regolith, and ancient deltaic sediment from the Jezero River delta. The depot cache at Three Forks (10 tubes) provides a backup retrieval path in case the rover cannot rendezvous with the Sample Retrieval Lander. Rock cores average 7 cm in length and 1 cm in diameter — each sealed in a hermetically closed titanium tube.
A Sample Retrieval Lander (SRL) delivers a Mars Ascent Vehicle (MAV) and two Ingenuity-class Sample Recovery Helicopters (SRH) to Mars surface. The SRH helicopters (or Perseverance directly) retrieve the sample tubes and load them into the MAV's Orbiting Sample Container (OS).
The MAV launches from the Martian surface — the first rocket launch from another planet — carrying the 5 kg Orbiting Sample Container (OS) into a low Mars orbit at ~400 km altitude. The MAV is a solid-fuel two-stage rocket approximately 3 m tall.
ESA's ERO captures the OS in Mars orbit using an onboard Capture Containment and Return System (CCRS), then departs for a ~2-year transit back to Earth. Solar-electric propulsion provides orbital maneuvering capability.
The OS is released to enter the Earth's atmosphere on a direct trajectory (no parachute, hard landing) at the Utah Test and Training Range — a proven delivery method for stardust sample capsules. The samples are then transported to a dedicated Sample Receiving Facility (SRF) for curation.
| Scenario | Estimate | Source |
|---|---|---|
| Original Baseline (2020) | $4.4B | NASA pre-IRB |
| IRB-2 Finding (Sept 2023) | $8–11B | Independent Review Board chaired by Orlando Figueroa |
| JPL Optimized Architecture | ~$5.5–7.7B | NASA architecture study (2024–2025) |
| Commercial Heavy Lift Architecture | ~$5.8–7.1B | NASA architecture study (2024–2025) |
| ESA Contribution | ~€1.5B | ESA member state commitment |
2020
Perseverance rover launches. MSR campaign officially begins. Original architecture approved: $4.4B, 2031 Earth return.
Sept 2023
IRB-2 (Independent Review Board, chaired by Orlando Figueroa) finds original architecture would cost $8–11B and slip to 2040. Triggers architectural re-evaluation.
2024
NASA solicits competing architectures from JPL + 7 industry partners. Two competing designs emerge (JPL Optimized + Commercial Heavy Lift).
Jan 2025
NASA Administrator Bill Nelson confirms both architectures will proceed to down-select in 2026 with revised target cost of $5.3–7.7B and ~2035 Earth return.
2026 (Expected)
Architecture down-select. Launch target set. Campaign enters formulation phase under selected architecture.
~2035 (Target)
Earth return of Mars samples under revised architecture. First Mars sample return in history.
In-situ instruments, however sophisticated, cannot match the analytical capability of Earth's best laboratories. Perseverance's SHERLOC Raman spectrometer has identified organic molecules in Jezero — but determining whether they are biogenic requires isotopic analysis at a precision only achievable with instruments like SIMS (Secondary Ion Mass Spectrometry) and NanoSIMS, which weigh hundreds of kilograms and cannot be flown to Mars.
The National Academies' Planetary Science and Astrobiology Decadal Survey 2023–2032 ranked MSR as the top priority for the decade, calling it “essential to addressing the most fundamental questions about Mars” — including the search for ancient biosignatures and the history of liquid water.