Patent Analysis and Research on Mars Sampling Technology

REN Linchong ,LUO Ting ,LIANG Jing ,LIU Xiuxiang

1 China Aerospace Academy of Systems Science and Engineering,Beijing 100048

2 China Household Electric Appliance Research Institute,Beijing 100037

Abstract:This article reviews Mars sampling and return technology,by retrieving and analyzing the patents of domestic and foreign sampling equipment and mechanism technology,Mars surface removal technology and ultra-highspeed light and small sample return technology.It conducts patent analysis from the macro-technical view down to the micro-specific content view using statistical,quantitative and qualitative analysis methods.In the process of macro-analysis,it analyzes patent data from multiple perspectives such as time,region,technical composition,and applicants,and establishes the development trends for Mars sampling and return technology at home and abroad.In the process of micro-analysis,through the analysis and interpretation of key patents,we can learn the development priorities and development direction of foreign Mars sampling and return technology.This paper also proposes China’s Mars sampling and return technology development suggestions.

Key words:Mars exploration,sampling and return technology,patent analysis

1 INTRODUCTION

The Mars sampling and return mission is a combination of three steps including orbiting,landing and returning.The Mars sampling and return mission is of great significance for engineering and science.In terms of engineering,the successful sampling and return from Mars is a sign of mastering the technology of sampling and returning celestial bodies from outside the Earth.It is a manifestation of the highest capability and denotes a level of deep space exploration for any country.In terms of science,affected by the quality of landing equipment,limited energy,communications and working environment,the depth and scope of in-situ detection is limited.If Mars rock or soil samples can be brought back to the Earth,considerable scientific benefit will be obtained by using the wide range of research methods available in the Earth laboratory.Through preliminary investigation and analysis,we have considered Mars sampling and return technology under three categories:sampling device and mechanism technology,Martian surface takeoff technology,and ultra-highspeed,light and small sample return technology.This article analyzes the above three aspects based on the searched patent data.

2 ANALYSIS OF CHINA AND INTERNATIONAL PATENT SITUATION

This article takes Mars sampling and return technology as the technical theme,determines relevant key words,classification numbers and other retrieval elements,and formulates targeted patent retrieval strategies,retrieving the three technical sub-themes as sampling device and mechanism technology,Mars surface take-off technology,and ultra-high-speed,light and small return technology in the Derwent and Wisdom Buds patent databases,and then manually reads the patent literature to de-clutter,filter and classify the retrieval results.The last retrieval time was October 30,2018.After de-cluttering and screening,108 patents of the same family were obtained,and the following patent analysis was carried out.

2.1 Annual Change Trend of Patent Application

Figure 1 Annual change trend of Mars sampling and return technology patent application

It can be seen from Figure 1 that Mars sampling and return technology has successively experienced a limited growth period (before 1995) and then considerable development period(1996 to present).At the beginning of the initial period was the technology demonstration Mars 5 NM mission proposed by the former Soviet Union in 1975 which opened up the first concept of a Mars sampling and return program in human history.Before 1995,countries represented by the United States and the former Soviet Union launched multiple Mars probes which all failed to achieve the expected results and ended in failure due to various technical problems.

With the successful launch of the United States Mars Global Surveyor probe in 1996,countries around the world had renewed hope for Mars exploration.In the past 20 years,the United States,Germany,France,China,Japan,India and other countries have focused on launching Mars probes.As a phased target for the Mars exploration,sampling and return mission must be the key areas of the following research.Although countries do not have a quantitive advantage in terms of the number of patent applications for related technologies due to various reasons,sampling device and the associated mechanism technology have been further developed.

It should be noted that some patents applied,such as in 2017 and 2018,may still be in the unpublished stage due to the non-public viewing period from the submission of applications to the publication of patents.Therefore,the statistics of patent applications in 2017 and 2018 are not comprehensive.However,based on the total number of patents published in 2017 and the overall development trend of patent applications in recent years,the number of patents published reached 13.It can be seen that the patent application for Mars sampling and return technology is on the rise in this development stage,and the development trend will continue.At present,countries around the world have clearly indicated their intents to demonstrate in a timely manner Mars sampling and return mission projects.

2.2 Distribution of Patent Application Technology

Figure 2 Distribution of Mars sampling and return technology

It can be seen from Figure 2,the distribution of patent applications for Mars sampling and return mission technology is relatively balanced among the three sub-themes,which indicates that at present,all countries are conducting relevant demonstration and research on sampling and return mission technology at the same time.Among them,44 patents were applied for Mars sampling device and associated mechanism technology,accounting for 41% of the total number of applications,34 applications for Mars surface take-off technology,accounting for 31%of the total number of applications,and 30 patent applications for ultra-high-speed light and small return mission technology,accounting for 28% of the total number of applications.

From these proportions,it is not difficult to see that the development of various technologies,is in accordance with the needs of technology,and has a certain relationship with the time sequence of Mars sampling and return mission.As for the technology required after landing on Mars,the Mars sampling device and associated mechanism technology is the primary research focus.As a follow-up technology development trend,the Mars surface take-off technology and super-high-speed technology for light payload and small-scale return mission technology has also been studied within the scope of the demonstration.Of course,this is still in the demonstration stage.There are many technologies being developed for the Earth environment or unmanned environment related to the Mars environment.

2.3 Distribution of Patent Application Technology Output

Figure 3 Distribution of Mars sampling and return mission technology

As shown in Figure 3 and Figure 4,this paper analyzes and compares the patent application technology composition of the United States,China,Russia,Japan and Europe,so as to determine the technical characteristics of each country.

Figure 4 Patent technology composition of Mars sampling and return technology source country.

The United States has many strengths in all areas of Mars sampling and return mission technology.Although the number of patents is not large,it has applied for 7 patents in the field of Mars sampling and associated mechanism technology,7 patents in the field of Mars surface takeoff technology,and 8 patents in the field of ultra-high speed light and small return mission technology,accounting for 21% of the world’s applications.The United States has remained in the leading position in the international community with regard to Mars exploration for a long time,successfully conducted Courage,Opportunity,Phoenix,Curiosity and other Mars exploration attempts.However,in terms of protection methods for relevant cutting-edge technologies there are not many countries in the world who protect through open patents at present.

China has made a certain proportion of patent applications in various technical areas in the field of Mars sampling and return mission technology since 2010.As a country of technological innovation,China began to conduct deep space exploration but has only begun to conduct planning and demonstration in recent years with breakthroughs in space technology.Scientific research institutions such as universities and research institutes are the main body for technological output,and each technology branch has in recent years made progress.China has applied for 26 patents in the field of Mars sampling and associated mechanism technology,11 patents in the field of Mars surface takeoff technology,and 8 patents in the field of ultra-high-speed light and small-scale return mission technology,accounting for 43%of the world.To a certain extent,this reflects China’s useful efforts in related technologies are increasing in recent years,but in terms of technology maturity,it is far behind the traditional space powers in the world.

Europe,represented by Germany,France and Russia,also has certain technological accumulation and development in the field of Mars sampling and return mission technology.Japan has also been exploring related technologies for a long time.

2.4 Introduction of Key Patents

This article reviews the patent applicants,the number of patents from the same group,the priority year as an important indicator,and identifies key patents in the main technology areas based on the advanced nature of the technology program.

2.4.1 1Looking at the further requirements of deep space exploration,considering the platform of the former Soviet Union,the sampling device and mechanism that is appropriate to the Mars environment was built based on the Apollo project and the lunar drilling platform of the former Soviet Union.In 2012,the California Institute of Technology applied for a patent with the publication number of us9339945 and the name of gravity independent grabbing and drilling system and method.The clamping mechanism involved in this technology is very suitable for the steep surface of Mars and the moon.By arranging dozens,hundreds or even thousands of toes,it can support and share large loads between connection points,and can connect in convex through hooks.The technology is of high reference value under the key technology breakthroughs for the further Mars sampling and return mission in China.

2.4.2 In the field of Mars surface take-off technology,based on the fact that the gravity of Mars is three times smaller than that of the Earth,and the atmospheric density is 1% of the Earth,it only needs 4 km speed impulse to overcome Mars gravity.Moreover,due to the extremely low air pressure,the expansion ratio of the engine has to be extremely large,and the specific impulse will be extremely close to that of a vacuum specific impulse.Therefore,taking off from the surface of Mars is not difficult.The engine and UAV technology can be used as a reference technology for the surface takeoff technology of Mars in the future.The Boeing company applied for patent No.us7823840 in 2007,entitled systems and methods for controlling engine exhaust flow.The technology involves one or more ducts extending from the engine to the airfoil surface,so as to transfer the compressed air from the engine to the surface,so as to inhibit the flow separation along the surface.The technology can be used in the design with the upper surface blowing technology and special applications are found in aircraft with structures for short take-off and landing performance.

2.4.3 In the field of ultra-high speed light and small return mission technology,Lockheed Martin applied for a patent with the publication number of us6467731 and the name of integrated sample recovery capsule in 1999.The integrated sample return chamber of this technology includes a front facing heat shield and a rear shell connected to the rear of the heat shield,and the heat shield includes an insulating and crushing layer of insulating and crushing materials,and a separator.The heat shield and back shell define the inner shell,and the integral device is used to return core samples from other celestial bodies from space to Earth.

3 CONCLUSIONS AND SUGGESTIONS

3.1 Conclusion

To sum up,the patent applications for Mars sampling and return mission technology are relatively balanced among the three technology areas.The automatic operation technology of sampling device and associated mechanism technology and the aerodynamic shape and characteristic technology of Mars surface take-off technology account for a significant proportion.These two technology areas are the focus of research,and the patent layout is relatively large,while the Mars sampling device and associated mechanism technology are key technologies with a high reference value.

Mars sampling and return mission technology is mainly in the hands of China,the United States and Russia.For a long time,the United States has made technological attempts in Mars exploration,and is still in the leading position in the international community.In recent years,China has made more beneficial attempts in related technologies,but in terms of technology maturity,it lags behind the traditional space powers in the world.

3.2 Suggestions

Priority should be given to the development of Mars sampling device and associated mechanism technology.Based on molding technology,automatic operation technology and other auxiliary technologies suitable for Mars sampling environment should be expanded.As the basic sampling technology,molding technology has a large number of patent applications,accounting for almost 2/3 of the patent applications of sampling devices and associated mechanisms.With the development of automation,intelligence and communication technology,it is suggested to pay attention to new developments abroad and strengthen the tracking and research of automation and intelligent technology in the sampling process area.It is suggested that China conduct corporations in the field of Mars sampling and returning with countries including the Belt and Road in advance to improve further international cooperation.

It is suggested that the technology for Mars surface take-off and ultra-high speed light and small return mission should be developed taking advantage of light weight,low power consumption,miniaturization,integration and high performance.Based on the characteristics of a long duration deep space exploration mission and the whole process with return vehicle,light weight,integration and high deceleration efficiency are part of the future development direction.It is suggested that China should adopt multi-objective and multi constraint schemes in aerodynamic configuration for the reentry vehicle,as well as integrate with high efficiency The key technological research areas are focused on the following aspects:low temperature alternating,high heat flux resistant and a low thermal conductivity structure,supersonic parachute umbrella shapes and parachute opening mode.

Considering the intellectual property status of China’s Mars sampling and return mission technology,it is suggested that China should increase the number of patent applications and expand the scope of patent protection in different technology fields,and positively deal with the patent infringement.It is suggested that at least 5 patents should be applied in each key technology field in combination with the development and launch mission of China’s Mars probe.