There’s a notion that NASA’s Mars Pattern Return (MSR) mission is being delayed by indecision, however the true delay has been a number of a long time of looking for a heritage propulsion resolution as an alternative of a know-how advance to develop and take a look at a Mars Ascent Automobile (MAV) for launching the samples to Mars orbit. Think about needing a classy Mars rover within the absence of JPL’s core workforce of engineers with their a long time of specialised design and testing. Now a MAV is required, absent any comparable cadre of experience for miniature launch automobiles. The MAV stays a wildcard for MSR, presumably even a scorching potato, as a result of there is no such thing as a expertise base for making such a rocket sufficiently small to ship to Mars inside a science mission funds. There aren’t any different clients to stimulate funding for one thing like a MAV, and there’s no established peer overview system for technical steerage.
It appears worthy of concern that rocket engineering has not been represented amongst MSR advisory committees and resolution makers together with the MSR Standing Overview Board, Planetary Decadal Survey committees, the second MSR Unbiased Overview Board (IRB-2 in 2023), and the MSR hierarchy inside the NASA Science Mission Directorate. It’s not stunning that MAV experience is underrepresented, as a result of the accessible expertise pool on the high of the org chart comes from planetary and different area science missions, and Earth satellite tv for pc packages. These extremely skilled spacecraft techniques engineers and managers have all the time loved the supply of confirmed propulsion know-how for maneuvers which can be far simpler than Mars departure. Subsequently, MAV improvement has been constantly underestimated.
On condition that MAV success is mission-critical, NASA planning paperwork circa 2010 referred to as for profitable flight testing of a MAV over Earth, previous to preliminary design review for MSR. By 2020, that requirement had vanished from mission planning, as if launching from Mars is simply one other propulsive maneuver for a spacecraft. Spacecraft propulsion has built-in redundancy, whereas launch automobiles are far much less fault tolerant. Not like launching from Earth, the MAV is not going to benefit from the luxurious of a workforce on the bottom for pre-launch repairs and changes, which raises the bar for reliability. That bar is raised even increased by NASA’s expectation of inserting all 30 pattern tubes on the one-and-only MAV departure from Mars.
In October 2020, the report to NASA from the primary MSR Unbiased Overview Board (IRB-1) defined the underlying MAV problem, noting that “the smaller a launch car, the extra delicate its dry mass to design uncertainty.” Variations within the dry mass are amplified at the least 5 occasions for the overall MAV mass, contemplating that propellant mass approaches 80% of the entire MAV. Some originality in engineering is required to make all of the components unusually light-weight relative to the propellant mass and thrust, so a small enough MAV is perhaps thought-about new know-how.
The membership of MSR IRB-1 included Antonio Elias, a seasoned rocket engineer who presided over improvement of the Pegasus small launch car within the Nineteen Eighties. In December 2020, he defined in a public assembly of the Nationwide Academies’ Planetary Decadal Survey that it’s typically not attainable to dictate each the mass of a launch car and the mass of its payload upfront of finishing design and testing, with some iteration and refinement. Therefore the purpose to accommodate all 30 pattern tubes leaves the overall MAV mass unsure.
In 2022, the Planetary Decadal remaining report set the very best precedence for MSR, however made no point out of the knowledge from Elias. The publication, “Origins, Worlds, and Life,” refers back to the MAV in just one place, and furthermore says that it could be accompanied by a European sample-fetch rover, later deserted resulting from payload mass limits. Appendix B of the Decadal report lists my very own submissions from 2020 in regards to the MAV, which famous the necessity for a sustained effort beyond design-build engineering, explained 25 misconceptions, and described choices for implementing launch vehicle design principles on a miniature scale.
On April 15, 2024, NASA introduced a contest for “Fast Mission Design Research” searching for price and schedule enhancements for finishing MSR. That news emphasised hopes for a smaller MAV derived from heritage know-how, subsequently a key consideration for a dozen research finished over the summer time. In a Jan. 7, 2025 information convention, little was stated about recent concepts for a smaller MAV, regardless of the various proposals submitted. As an alternative, NASA officers defined that two choices will now be thought-about for the pattern retrieval lander wanted to ship the MAV. As reported in SpaceNews, the supply options are the heritage “sky crane” from JPL, or a commercially supplied “heavy lander.” The implicit message is that choices will now be thought-about for delivering a heavier MAV if it can’t be made small.
Ideally, the MAV could be 350 kilograms or much less for supply by JPL, whereas a heavy lander could be wanted for a big MAV. Help tools for the MAV and different necessities will trip alongside, respectively elevating the overall landed mass to roughly a ton or probably nicely over one ton.
Reaching Mars orbit from the floor requires a propulsive functionality means past all earlier expertise for spacecraft maneuvers, roughly 4,000 meters per second in a couple of minutes. Some spacecraft can produce this velocity change, however means too step by step. As I informed the Mars science group in a July 2024 presentation, the deliberate solid-propellant MAV might attain a thousand miles if flight examined over Earth, beginning at a excessive altitude the place the air is as skinny because the Mars ambiance. Such a flight path has by no means been finished by any missile smaller than a ton.
The January 2025 information convention briefly referred to the two-stage strong propellant MAV that NASA has been planning. Technical particulars had been most just lately published by the Marshall Area Flight Middle (MSFC) in early 2022, earlier than Lockheed-Martin was introduced on board to assist. The MSFC authors described remaining challenges with the design, together with aerodynamic complexities throughout first stage flight, the placement of steering thrusters near the middle of mass, and the potential for tip-off rotation at stage separation. They wrote that it could be perfect to flight take a look at an entire prototype MAV over Earth, however that the price could be excessive.
The mix of first stage aerodynamic complexities and low leverage for steering thrusters suggests a threat of prematurely working out of steering propellant within the absence of flight testing to totally perceive car dynamics and confirm margins. To cut back mass, the higher stage is to be spin-stabilized as an alternative of actively guided, a design change made public early in 2021. Moreover for mass discount and opposite to the 2010-era paperwork, the higher stage won’t have telemetry, therefore “no information” if imperfect spinning slips previous stability margins to turn out to be a mission-ending tumble.
Now that Lockheed is engaged on the MAV, it’s notable that in 2001 the corporate informed NASA {that a} flight demonstration over Earth could be wanted, whereas solely testing MAV components individually as finished for spacecraft propulsion would imply a excessive threat of mission failure. In a 2012 publication, Lockheed wrote that “a scientific techniques engineering course of” would result in a high-heritage low-risk MAV beneath 300 kg. Contractors typically must say what clients need to hear.
China plans to do MSR utilizing Lengthy March 5 launches from Earth, which might ship extra mass towards Mars than the Atlas 5 that launched Perseverance. The distinction is in step with a heavier Mars lander than the JPL sky crane, therefore a comparatively heavy MAV. Bigger objects decelerate much less readily within the skinny Mars ambiance, necessitating a point of latest know-how for Mars arrival. Ten years in the past, NASA studied choices for deployable or inflatable aerodynamic decelerators adopted by supersonic retropropulsion, utilizing capabilities from Blue Origin and SpaceX. Implementing MSR with a heavy lander and a bigger MAV could be a worthy step towards scaling as much as human missions, deserving of some Artemis funds for MSR.
Rock core samples at the moment are ready on Mars, however the standing of MAV improvement has modified little over greater than 20 years. It’d assist to start open engineering discussions akin to public science discussions, and for rocket engineering experience to be elevated to a better place on the MSR org chart. Maybe the MAV wants a glamorous title, to be publicized as “probably the most superb little rocket ever constructed.”
John Whitehead, PhD is a former rocket know-how researcher. His 2008 paper, “Defining the Mars Ascent Drawback for Pattern Return” defined that growing a MAV is each a frightening technical drawback and a cultural problem for the planetary science group
SpaceNews is dedicated to publishing our group’s numerous views. Whether or not you’re an instructional, govt, engineer and even only a involved citizen of the cosmos, ship your arguments and viewpoints to opinion@spacenews.com to be thought-about for publication on-line or in our subsequent journal. The views shared in these op-eds are solely these of the authors.
