A Critical Analysis of Robert Zubrin's "Practical Approach to the Mars Sample Return Mission"; Why the Proposal Is Severely Impractical

A Critical Analysis of Robert Zubrin's "Practical Approach to the Mars Sample Return Mission"; Why the Proposal Is Severely Impractical

  • Last week we emailed Robert Zubrin , an aerospace engineer and president of the Mars Society, with a nice note telling him that we look forward to potentially working with him in the future on our?Crewed Mars Mission: 2032 , which we were about?to announce .
  • Zubrin didn't respond, most likely because he was busy thinking up the points to make in a proposal to NASA.
  • On May 6, Zubrin posted an article on Space.com , which -though presenting an intriguing perspective on the Mars Sample Return (MSR) mission- suffers from a narrow view and overlooks critical aspects that render his proposal moot.
  • We analyze the key points raised by Zubrin and compare them with certain aspects of Crewed Mars Mission: 2032 .

By Neal S. Lachman, CEO & Chief of Spacecraft Design, Titans Space and Franklin Ratliff, CTO, Titans Space


Table of Contents

1. Cost and International Collaboration

2. Single Launch vs. Mission Redundancy

3. Propellant Production on Mars

4. A 40kg Spacecraft from Mars Won't Survive Earth Re-entry

5. Planetary Protection: Beyond Meteorite Fallacy

6. Mission Affordability

7. A Crewed MSR Mission


1. Cost and International Collaboration?

Zubrin correctly points out the high cost estimate for the current MSR plan at $11 billion . However, he simplifies the issue by blaming international collaboration (and the inherent bureaucracy).

While streamlining the mission structure can lead to cost savings for NASA, international partnerships offer significant advantages. Sharing resources and expertise allows participating space agencies like ESA to contribute their strengths in orbital mechanics and rendezvous technology, reducing the overall financial burden for each partner. Collaboration also fosters international scientific exchange and broader public interest in space exploration.?

  • We agree, however, that the bureaucratic tendencies have to be kept in check; our?Mars Sample Return ?project involves international cooperation from the space agencies, scientific community, and the (commercial) space industry, but it would be entirely managed and executed by us (Titans Space Industries ) with no room for bureaucracy.?
  • Titans Space's?Crewed Mars Mission: 2032 ?serves as a catalyst for international collaboration in space exploration. By involving multiple countries, space agencies, and commercial partners in the mission, it fosters cooperation, knowledge sharing, and resource pooling, leading to a more efficient and cost-effective approach to Mars exploration.?

2. Single Launch vs. Mission Redundancy

The proposal for a single-launch, single-vehicle mission using a modified skycrane is a risky and untenable gamble. The skycrane has a limited payload capacity of 1,000 kg - as Zubrin acknowledges in his proposal.?

Squeezing both a sample return vehicle and a sample collection rover onto one platform creates significant engineering challenges and reduces scientific potential. Furthermore, a small single, multifunctional rover tasked with both sample acquisition and return adds technical complexity and reduces its ability to perform in-depth scientific investigations on the Martian surface.?

The current plan, which leverages the existing Perseverance rover for sample collection, offers valuable redundancy. In case of unforeseen issues with the proposed rover, the samples collected by Perseverance remain available for future retrieval missions.

  • Titans Space's multi-vehicle architecture for Crewed Mars Mission: 2032 ?integrates human presence into the MSR process, utilizing NASA astronauts to collect and return the Martian samples (the ones collected by Perseverance and/or by themselves) to Earth as per NASA instructions.
  • The presence of human astronauts on Mars will enable more selective and targeted sample collection, allowing for the retrieval of samples that are scientifically significant or represent unique geological features. Human astronauts could also use their expertise to prioritize sample collection based on real-time observations and analysis.?


3. Propellant Production on Mars

The idea of using Martian resources to produce methane/oxygen propellant for the return trip is an intriguing one. Zubrin?acknowledges that this approach adds complexity but suggests it could demonstrate key technologies for future human Mars missions.?

While In-Situ Resource Utilization (ISRU) technology holds great promise for future self-sustaining Mars missions, incorporating it into the proposed low-cost MSR mission with a limited payload capacity presents significant challenges.

  • Complexity:?ISRU systems, even at their most basic level, involve complex machinery. Extracting resources like water ice from the Martian regolith requires drills and/or excavation tools. Converting those resources into propellant necessitates additional equipment for processing, filtering, and storage. Accommodating all these components within the already constrained payload capacity of a single-launch mission (as proposed by Zubrin) would be extremely difficult. Scaling down ISRU technology for a smaller mission may be possible, but it would likely come at the expense of efficiency and functionality, most likely jeopardizing the entire propellant production process.
  • Efficiency:?Simplifying ISRU technology for a smaller payload will directly translate to sacrificing efficiency. Compact equipment will have lower processing rates, requiring a longer operation time on Mars to produce enough propellant for the return trip. This, in turn, necessitates additional power supplies and support systems to sustain the ISRU operations, further adding to the overall mission weight. The delicate balance between reducing weight and maintaining sufficient propellant production becomes a major if not insurmountable hurdle.
  • Unproven Technology:?ISRU on Mars is still largely in the theoretical or early developmental stages. Deploying unproven technology on a critical mission like the MSR carries inherent risks. Unexpected technical challenges or malfunctions during propellant production could jeopardize the entire mission and the irreplaceable Martian samples. Adding this layer of uncertainty to an already cost-sensitive mission might not be the most prudent course of action.?

While ISRU offers exciting possibilities for future Martian exploration, its inclusion in the proposed low-cost, small-payload MSR mission is simply overly ambitious.?

  • Titans Space's?Crewed Mars Mission: 2032 ?integrates ISRU in its objectives but not as a crucial mission critical component. Astronauts and robots will lay the groundwork for large ISRU systems that will benefit future missions.?

4. A 40kg Spacecraft from Mars Won't Survive Earth Re-entry

Zubrin proposes a 40kg spacecraft for the direct return mission to Earth. While this concept seems lightweight and efficient, the reality of Earth re-entry paints a different picture.

The 40kg craft faces significant challenges:

  • Heat Shield Requirements:?Re-entering Earth's atmosphere creates intense friction, causing the spacecraft's exterior to reach scorching temperatures (up to 3000°C). A robust heat shield is essential for protecting the payload (samples) from this extreme heat. However, a heat shield for a 40kg craft would be proportionally small, offering limited to no protection. The high surface area to mass ratio of such a small spacecraft would even exacerbate the heating problem.
  • Atmospheric Deceleration: Friction with the atmosphere not only generates heat but also decelerates the spacecraft. As the spacecraft moves through the atmosphere, the drag force generated by the atmosphere slows down the spacecraft, causing deceleration.?

  • Structural Integrity:?The immense pressure and aerodynamic forces encountered during re-entry necessitate a robust spacecraft structure. A lightweight 40kg design will struggle to withstand these stresses, leading to catastrophic structural failure.
  • Parachute Limitations:?Parachutes are crucial for slowing down the spacecraft during the final descent. However, their effectiveness depends on the mass they are designed to handle. A small parachute suitable for a 40kg craft may struggle to generate enough drag to ensure a gentle landing, resulting in a damaging impact.

A 40kg spacecraft, while conceptually attractive for its simplicity, is simply inadequate for surviving the harsh environment of Earth re-entry, especially considering the immense velocity from the return trip. A more substantial design with a robust heat shield, an effective parachute system, and a structurally sound frame is necessary to ensure the safe return of the precious Martian samples.

5. Planetary Protection: Beyond Meteorite Fallacy

Zubrin dismissively brushes aside planetary protection concerns as bureaucratic overkill. This is a dangerous misconception. Planetary protection is a critical aspect of space exploration with a two-pronged approach: preventing forward contamination (Earth microbes reaching Mars) and backward contamination (potentially hazardous Martian materials reaching Earth). He argues that Martian meteorites already bombard Earth, implying such concerns are unfounded.

However, meteorites undergo extreme heating during atmospheric entry, potentially sterilizing them. A controlled return mission with a potentially biohazardous sample requires much stricter protocols to ensure the integrity of Martian science and protect Earth's biosphere from any potential Martian contaminants.?

It is essential to adhere to established protocols and regulations to ensure responsible exploration and minimize the risk of unintended consequences.?

6. Mission Affordability

Zubrin raises a valid concern about mission affordability. However, his proposed solution is overly simplistic and disregards the benefits of international collaboration, robust mission design with redundancy, and responsible planetary protection. A successful Mars Sample Return mission requires a balanced approach that optimizes cost while maintaining scientific value, mission safety, and responsible stewardship of our celestial neighborhood. Finding this balance will require careful consideration of all factors, ensuring a mission that is both scientifically groundbreaking and fiscally responsible.

7. A Crewed MSR Mission

Titans Space's?Crewed Mars Mission:? 2032 serves?as a catalyst for international collaboration in space exploration, bringing together multiple countries, space agencies, and commercial partners in the mission to achieve a common goal. By pooling resources, sharing expertise, and coordinating efforts, international partnerships enhance the efficiency and effectiveness of Mars exploration missions, while promoting cooperation, diplomacy, and goodwill among nations and commercial partners. The collaborative nature of a crewed MSR mission reflects humanity's collective desire to explore and understand the cosmos, transcending national boundaries and political differences in pursuit of shared scientific objectives.

Join our consortium to be part of this revolution.

Further recommended reading

Subscribe to the Titans Space & Lunar Projects Newsletter on Linkedin.

  1. Nuclear Electric Propulsion for Spacecraft and Space Colonization; A White Paper by Titans Space Industries
  2. Crewed Mars Sample Return; Titans Space Announces Ambitious Nuclear-Powered Crewed Mars Mission: 2032
  3. Pioneering a Nuclear-Powered Crewed Mission to Mars: Titans Space's Strategic Roadmap for a 2032 Return Journey to Mars
  4. The Selene Mission: Paving the Way for a Large-Scale Commercial Moon Colony and a Multi-Trillion-Dollar Lunar Economy
  5. Forging a New Frontier: Titans Space Launches The Space & Lunar Economy Consortium
  6. Let's Ignite a Global Space Renaissance; Help Titans Space Chart a Multi-Trillion Dollar Course for the Space Economy by 2035 (Titans Space Industries - Executive Summary)
  7. Space Robotics (White Paper): How Titans Space will Bridge Human, AI, and Robotic Endeavors from Low Earth Orbit to Mars
  8. Moon Made: Unveiling the Advantages of Space Manufacturing on a Lunar Base
  9. Pioneering Lunar Transport: Introducing the Titans Orbital Transporter
  10. Read Titans Space's Response to NASA's Moon to Mars Objectives RFI (Updated)
  11. Commercial Lunar Astronaut Training; Discover How Selene Mission Astronauts Prepare for Lunar Commercialization
  12. First Ever 12 Private Lunar Astronauts; Learn About The First Crewed Selene Mission
  13. The Mars Colonization Delusion: Dissecting the Infeasibility of Musk's Plan to Launch Thousands of Starships to Mars
  14. The Race to the Moon: A Military Perspective on Cislunar Space
  15. Cleaning the Celestial Junkyard: Titans Spaceplane and the Future of Space Debris Removal
  16. Beyond Rockets: Unveiling Titans Space's Safe, Efficient, Frequent, and Low-Cost End-to-End Space Transport Systems
  17. Why Vertically Launched Rockets Won't Rule the Space Frontier; Analyzing the Impending Obsolescence of Vertical Rocket Critical Limitations and Risks of Rocket-Based Human Space Travel
  18. Is the USA on the Brink of Losing the Space Race to China? An Analysis and A Call to Action
  19. Critical Limitations and Risks of Rocket-Based Human Space Travel
  20. Revolutionizing Space Travel: Titans Spaceplanes vs SpaceX Starship; Safe, Efficient, and Low-Cost Space Travel
  21. Titans Spaceplane vs Dream Chaser vs Starship; The Future of Human Space Travel Vehicles Compared
  22. Space Tourism: Explore Titans Space's Incredible Offers and the Spacecraft That Will Take You to Space

Subscribe to the Titans Space & Lunar Projects Newsletter on Linkedin.

About Titans Space Industries

Titans Space Industries (TSI) is creating a streamlined Earth-to-lunar surface transport infrastructure with spaceplanes, space stations, spaceships, and dedicated lunar vehicles for landing and travel.

Titans Space intends to:

? Become the largest LEO and Lunar Space tourism company

? Become the largest Real Estate owner in Space and the Moon

? Become the largest Lunar commerce and mining company (from 2031 onwards)

TSI, a division of Titans Universe , comprises a vast portfolio of incredible, revolutionary space infrastructure that will allow safe and efficient end-to-end space transportation, including spaceplanes and space stations for space tourism , commercial, and industrial purposes, as well as for research, governments, and military usage.

Titans Space’s single-stage-to-orbit spaceplanes will facilitate orbital space flights for orbital cruises or going to Low-Earth Orbit, sub-orbital flights for zero-g space tourism flights, as well as ultra-fast point-to-point transportation for humans and cargo.

TSI's space tourism division is building the future of luxury space exploration with spaceplanes, spaceships, space stations, and lunar transport vehicles. TSI’s revolutionary LEO Space Station and Lunar Space Station will redefine humanity’s place amongst the stars, with lunar tourism , scientific research, commercial mining applications, lunar factories, and lunar real estate .

About the Founding Team

TSI was founded by a group of 15 partners with a combined 450 years of business experience, representing investor interests in Titans Universe/TSI. They worked together on numerous projects for a combined 200+ years.

The founding team includes a 28-year-veteran space entrepreneur and satellite broadband pioneer, a PE fund manager who raised more than $6 billion in capital, a 40+ year rocketry and aerodynamics veteran, a 40+ year Space entrepreneur and activist, a Hall-of-Fame NBA basketball legend, a former Head of Business Development at Apple, a multi-billion-dollar business strategist, a former MD of KPMG NYC who advised on 100+ PE and M&A transactions, and the former CFO of a Formula One racing team and public listed companies.

Our Founding CEO, Neal S. Lachman is a serial entrepreneur with 35 years of investment, business, space, technology, and telecom experience. In 1992, he picked up the phone and started communicating with companies like PanAmSat. He has been a space entrepreneur since 1994/1995 when he and two of his brothers applied for and received three international digital satellite broadcast licenses.

For more information

Lunar

www.TitansSpace.com/Selene-Mission

www.TitansSpace.com/Titania-Lunar-Colony

www.TitansSpace.com/Titania-Lunar-Industry-Commerce

www.TitansSpace.com/Titania-Lunar-Resort

www.TitansSpace.com/Lunar-OrbitalPort-Space-Station

www.TitansSpace.com/SpaceShip

www.TitansSpace.com/Lunar-Yacht-Transporter

Other

Titans Space Industries - Executive Summary

www.TitansSpace.com/FAQ

www.TitansSpace.com/About-Titans-Space

www.TitansSpace.com/Titans-Spaceplanes

www.TitansSpace.com/Titans-Engines-Systems

www.TitansSpace.com/Space-Tourism

www.TitansSpace.com/Orbital-Cruise

www.TitansSpace.com/Sub-Orbital-Zero-G

www.TitansSpace.com/Ultra-Fast-Travel

www.TitansU.com/Founding-Team

S V.

Innovator, space thruster engine.

6 个月

Robert Zubrin? His approach is still costly!

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Rip Read

Artist - StarMuralist - SEAEO - Nature Cinematographer & Photographer - Stars4Sleep - Art That Puts You To Sleep Naturally

6 个月

Excellent critical analysis Neal...really enjoyed the read! I noticed that word again...collaboration. Wow, what a concept...working together for a common, successful, and mutually beneficial outcome...for all of the players and their various interests. A novel concept, to say the least! How about that Starliner project? Don't get me started...and don't offer me even a free ticket to ride that scary thing!

Michael Harper US Marine Corps Veteran

CEO Apogee Power USA LLC. SDVOB

6 个月

Neal, imo the government is often a barrier to progress. They often have an agenda that is flawed and will continue to stay with the flawed approach vice using something different that may arise from the commercial marketplace or other areas of expertise.

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