A Summary of the Mars Sample Return (MSR) Concept (to be modified, 2024 + 2025)
+ (2023, 2024 Updates on Asteroid Sample)

The analysis in Earth laboratories of samples that could be returned from Mars is of extremely high interest to the international Mars exploration community. IMEWG (the International Mars Exploration Working Group) has been evaluating options, by means of a working group referred to as iMOST, to refine the scientific objectives of MSR. The Mars 2020 sample-caching rover mission is the first component of the Mars Sample Return campaign, so its existence constitutes a critical opportunity. Finally, on April 26, 2018, NASA and ESA signed a Statement of Intent to work together to formulate, by the end of 2019, a joint plan for the retrieval missions that are essential to the completion of the MSR Campaign. All of these converged April 25-27, 2018 in Berlin, Germany, at the 2nd International Mars Sample Return Conference.

In April 2018, a letter of intent was signed by NASA and ESA that may provide a basis for a Mars sample-return mission.^[1][2]. In July 2019, a mission architecture was proposed to return samples to Earth by 2031^[3][4].

In April 2020, an updated version of the mission was presented ^[5] (as described briefly in the followings) :

1. Mars 2020 Perseverance Rover - [view large image]
   The Mars 2020 Perseverance rover launched on 30 July 2020 and landed on 18 February 2021 in Jezero Crater will collect samples and store them in 43 cylindrical tubes and leave them behind on the surface for later retrieval.

2. Retrieval Lander - Mars Sample Return lander, rover and ascent rocket, [view large image].
   After a launch in July 2026, NASA's sample retrieval lander with a 3-meter long, two-stage, solid-fueled Mars ascent rocket developed by NASA and a sample collection fetch rover (developed by ESA). It will land near the Mars 2020 rover Octavia E. Butler Landing site in August 2028. The new rover collects the samples left behind by Mars 2020 by robotic arm and delivers them to the lander. If Mars 2020 is still operational, it could also deliver sample tubes to the landing site.


3. Retrieval Operation - Design of The Mars Sample Return Ascent Vehicle, [view large image].
   Then the lander will use its robotic arm to take the sample tubes from the rover and load them into the sample Return Capsule which is inside the rocket's payload fairing by its own systems. Once loaded with the samples, the Mars ascent rocket will launch with the sample return canister in spring 2029, reaches a low Mars orbit.


4. Earth-return Hardware - Orbiter with sample return capsule, and EEV [view large image].
   The Earth-return orbiter will be launched on an Ariane 6 rocket in October 2026 and arrives at Mars in 2027, using ion propulsion and a separate propulsion element to gradually lower its orbit to the proper low Martian orbit by July 2028. The orbiter will retrieve and seal the canister with the samples in orbit and use a NASA built orbiter robotic arm to place the sealed container into an Earth-entry capsule, raise its orbit, release the propulsion element and return it to Earth during the 2031 Mars-to-Earth transfer window.

[2024 + 2025 Modifications]

It turns out that the 2020 plan is too expansive and not returning the samples until 2040 is unacceptable. NASA will seek proposals for quicker and cheaper ways to deliver the samples to Earth. The agency “is committed to bring at least some of the samples back” and later said NASA would return “more than 30” of the 43 planned samples. NASA plans to solicit proposals — from companies as well as NASA centres — for a streamlined system, perhaps using a lighter lander. The deadline for proposals is 17 May 2024, and the revised mission will be chosen later this year.

See "NASA admits plan to bring Mars rocks to Earth won’t work — and seeks fresh ideas",
by 2025 "NASA STILL HAS NO PLAN FOR HOW IT WILL BRING MARS ROCKS TO EARTH",
and an assessment for life on Mars without going there : "Mars/Earth Comparison, Prebiotic" + Minial Life.

[End of 2024 + 2025 Modifications]

Samples gathered by Perseverence - Successful sampling attempts (10 September 2021), [view large image].

In February 2021 the 2020 Mars rover Perseverance was landed in the crater Jezero, which seemed to be an ancient lakebed, suitable for ground sampling which hopefully would reveal whether or not Mars in ancient times harbored life.^[6][7][8]


1. In the beginning of August 2021, the 2020 Mars rover Perseverance made the first attempt to collect a ground sample by drilling out a finger-size core of Martian rock for return to Earth.^[9] This attempt did not succeed. A drill hole was produced, as indicated by instrument readings, and proven by a clear photograph of the drill hole. However, the sample container turned out to be empty. This was interpreted that the rock sampled was not robust enough to produce an intact core.^[10]
2. A new attempt with a target rock judged to have better chances to yield a sufficiently robust sample was made at the end of August and the beginning of September 2021. After abrasing the target rock, cleaning away the dust thus produced by means of puffs of high pressurized nitrogen, and inspecting the resulting rock surface, a hole was drilled on September 1. The result seemed to be a rock sample in the tube; but it was not immediately placed in a sample container. A new procedure of inspecting the tube optically was performed. This procedure was introduced in order to avoid setbacks as with the earlier attempt.^[11] On September 6, the process was completed and the first sample placed in a closed titanium container.^[12]
3. In support of the Mars sample-return mission, soil samples are being cached by Perseverance. Currently, out of 43 sample tubes, soil sample tubes cached: 2,^[13] gas sample tubes cached: 1,^[14] witness tubes cached: 1,^[15] tubes due to be cached: 39. Before launch, 5 of the 43 tubes were designated "witness tubes" and filled with materials that would capture particulates in the ambient environment of Mars.^[16]

Returned Samples Containment : MSR Mission (2021-2031), [view large image].

The absolute prohibition of destructive impact upon return, the need for containment throughout the return phase of all returned hardware which directly contacted the target body or unsterilized material from the body, and the need for containment of any unsterilized sample collected and returned to Earth. Post-mission, there is a need to conduct timely analyses of any unsterilized sample collected and returned to Earth, under strict containment, and using the most sensitive techniques. If any sign of the existence of a non-terrestrial replicating entity is found, the returned sample must remain contained unless treated by an effective sterilizing procedure.
See COSPAR by Kminek et al. 2017, COSPAR Planetary Protection Policy and a general idea of "Planetary Protection".

"The Relationship of Mars Sample Return Science and Containment"

Returned Samples Science :
"Planning for Mars Returned Sample Science : Final Report of the MSR End-to-End International Science Analysis Group (E2E-iSAG)".

Here's a tentative scale (proposed in 2021) to categorize the level of evidence for life beyond Earth.


See "Call for a framework for reporting evidence for life beyond Earth", and "The Peril".

In addition, there were many earlier attempts for "sample return" from asteroids (see the "Hayabusa mission " etc). They never thought of such strict protocol for containment as mentioned above.

Actually, there are many types of extra-terrestrial samples from cosmic dust to lunar rocks (collected by the six Apollo missions, see "Lunar Rocks and Soils from Apollo Missions"). The samples are handled very carefully to keep them pristine.

                                                                                                      

However, they have been distributed all over the world casually without further checking for extra-terrestrial (see a "Lunar Sample Laboratory Tour").

[2023 Update]

On September 24 2023, space samples collected from the asteroid Bennu has returned to Earth as illustrated by a sequence of photos below (see "A long-awaited asteroid sample has landed in the US" and "Bringing space rocks back to Earth could answer some of life's biggest questions").



Details about the sample will be revealed through a NASA broadcast from Johnson Space Center on October 11, 2023. It would be very interesting if the return sample agrees with the theory, which asserted that water on Earth was delivered by asteroids and comets around 4.5 billion years ago. The theory suggests that during the early stages of Earth's formation, the planet was extremely hot, and any water that may have been present originally would have vaporized or been lost. Water-rich asteroids and comets from the outer regions of the solar system are thought to have collided with Earth, bringing significant amounts of water to our planet. The evidence for this theory includes the isotopic composition of Earth's water, which is similar to that found in certain types of asteroids and comets. Additionally, studies of meteorites, which are remnants of early solar system material, provide insights into the composition of these water-rich bodies. The presence of hydrated minerals in certain meteorites suggests that water-bearing materials were indeed present in the early solar system. So, while it's challenging to directly observe events that happened billions of years ago, scientists use a combination of theoretical models, laboratory experiments, and observations of celestial bodies to piece together the story of Earth's early history, including the delivery of water by asteroids and comets. -- most of this text about water delivery is supplied by ChatGPT (in Italic).

                                                           

It turns out that the October 11 news from NASA reveals only examination of the small patch of material on the rim of the sample collector (see Figure b). But that's enough to show that it contain water, carbon, clay (primarily composed of silicate minerals) and organic compounds (see "Unprecedented asteroid sample contains ‘crucial elements,’ NASA says in historic reveal"). As Bennu's orbit is very close to the Earth's, it would be able to receive the 2 ev energy (from Solar radiation near the green color) to promote the carbon atom to the SP³ state which becomes the base for the formation of organic compounds and ultimately "LIFE". Detailed description of such process has been presented on many spots within this website, it is repeated again here anyway :

The ability of carbon to form covalent bonds with other carbon atoms in long chains and rings distinguishes itself from all other elements. The fact that carbon nearly always forms four bonds to other atoms, accounts for the large number of known compounds. At least 80 percent of the 5 million chemical compounds registered as of the early 1980s contain carbon. The affinity of carbon for the most diverse elements does not differ very greatly - so that even the most diverse derivatives need not vary very much in energy content. This ability allows the organic world to exist in a special form of thermodynamic stability.

		The electron configuration of the normal carbon atom has 2 electrons in energy level 2S and 2P respectively. By supplying about 2 ev to a carbon atom, the 4 electrons in the 2S and 2P states are rearranged to the SP3 state (Figure c). The four electrons in the SP3 state form the tetrahedral arrangement (Figure d) of orbitals (probability distribution of electrons), which can form stable covalent bonds with other atoms.
Figure c [view large image] SP3 State (Hybridization)	Figure d Tetrahedra	It is no accident that photosynthesis supplies 6 x (36 ATPs each carrying ~ 0.32 ev + an extra 2 ev) to synthesize 1 glucose molecule.

Respiration runs in the reversed direction producing CO₂, H₂O, and energy from glucose in this biogenic process.

[End of 2023 Update]

[2024 Update]

                                                                                                      

See "1st look at asteroid Bennu samples suggests space rock may even be 'a fragment of an ancient ocean world', February 05, 2024" and
"Asteroid sampled by NASA may once have been part of an ocean world, February 06, 2024".
Also see the similar ocean world inside "Enceladus".


                                                                                                      

See more info from February 10-16, 2024 News in "New Scientist" - "Bennu may be from an ocean world"

[End of 2024 Update]