DOI: 10.5061/dryad.tdz08kqb4
title: Supplementary data and modeling code file for: Soft deployable airless wheel for lunar lava tube in-tact exploration

description: Lunar pits and lava tubes hold promise for future human habitation,
 offering natural protection and stable environments. However, exploring
 these sites entails challenging terrain, including steep slopes along cave
 funnels and vertical cliffs. Here, we present a soft, deployable airless
 wheel to address these challenges. By achieving a high deployment ratio,
 multiple rovers can be stowed efficiently without sacrificing mobility,
 thereby improving mission reliability and flexibility. The proposed wheel
 incorporates a reconfigurable reciprocal structure of elastic steel strips
 arranged in a woven helical pattern, enabling shape transformations while
 preserving load-bearing capacity. This reciprocal arrangement also allows
 for safe vertical descents and mitigates damage from accidental falls
 within caves. By distributing strain throughout the wheel’s body, reliance
 on delicate mechanical components is minimized—a critical advantage under
 extreme lunar conditions. The wheel can be stowed at a diameter of 230
 millimeters and deployed to 500 millimeters. Experimental results show
 successful traversal of 200 millimeters obstacles, stable mobility on
 rocky and lunar soil simulant surfaces, and resilience to drop impacts
 simulating a 100 meters descent under lunar gravity. These findings
 underscore the wheel’s suitability for future pit and cave exploration,
 even in harsh lunar environments.
description: # Supplementary data and modeling code file for: Soft deployable airless
 wheel for lunar lava tube in-tact exploration Dataset DOI:
 [10.5061/dryad.tdz08kqb4](https://doi.org/10.5061/dryad.tdz08kqb4) ##
 Description of the data and file structure This dataset contains all
 primary experimental raw data and modeling code for the study “Soft
 Deployable Airless Wheel for Lunar Lava Tube In-tact Exploration.” The
 data were collected to (1) develop and theoretically analyze the proposed
 soft deployable wheel using a cantilever beam model (Fig. 3A), and based
 on that analysis, to experimentally validate (2) deployment/storage torque
 characteristics (Fig. 3B) and (3) vertical load–displacement responses
 (Fig. 3C). We further (4) evaluate changes in storage torque and vertical
 stiffness before and after thermal-vacuum and drop-impact tests (Figs. 6E
 and 6F), and (5) measure drawbar pull force–slip and wheel driving
 torque–slip ratio in a simulated lunar-regolith (Fig. 7), thereby
 verifying the proposed wheel’s capability for lunar exploration and
 lava-tube entry missions. In addition, experiment results for
 Supplementary Figures S3B and S3C are included to validate Equation 4. ###
 Files and variables #### File: Modeling_code_S1.zip **Description:** \
 Purpose: A cantilever-beam model that computes the wheel’s shape and
 bending energy during the deployment-to-storage transition.\ Inputs:\
 (Strip_Optimizer.m) :  obj.rh (m), obj.Rc (m), obj.n, obj.thL (rad),
 obj.Lg_0 (m), obj.Tg (m), obj.b (m), obj.t (m), obj.E (Pa) (run_code.m)
 : l0 (m), l_end (m), dl (m), lamda_d, lamda0, lamda_end Outputs: Figure
 2.1 (strip shape), Figure2.2(Strip bending energy (N mm) - rotation angle
 of hub (deg) plot) Deployment to Storage process Overall Data: Result_all
 (1000 x 6 matrix) \[strip length (mm), wheel radius (mm), maximum
 curvature of strip (rad/m), Spoke bending energy(N mm), Strip bending
 energy(N mm), Ratation angle of hub (deg)] Deployment to Storage process
 Strip Configuration Data: lxydth_mat (1000 x (5 x K) matrix) \[l(mm),
 x(m), y(m), dth(rad), R(mm)] #### File: Data_files_S1.zip
 **Description:**  Purpose: Source data for Fig.3B Torque sensor angle
 file: time(YYYY-MM-DD Thh:mm:ss.sss) to rotation angle (deg) Torque sensor
 Torque file: time(YYYY-MM-DD Thh:mm:ss.sss) to Torque voltage(V) and
 Torque (Nm) #### File: Data_files_S2.zip **Description:**  Purpose: Source
 data for Fig.3C Test count, Time (sec), Elongation(=Deflection) (mm) to
 Load force (N) #### File: Data_files_S3.zip **Description:** 
 Purpose: Source data for Fig.6E-Before Test Torque sensor angle file:
 time(YYYY-MM-DD Thh:mm:ss.sss) to rotation angle (deg) Torque sensor
 Torque file: time(YYYY-MM-DD Thh:mm:ss.sss) to Torque voltage(V) and
 Torque (Nm) #### File: Data_files_S4.zip **Description:**  Purpose: Source
 data for Fig.6E-After Test A Torque sensor angle file: time(YYYY-MM-DD
 Thh:mm:ss.sss) to rotation angle (deg) Torque sensor Torque file:
 time(YYYY-MM-DD Thh:mm:ss.sss) to Torque voltage(V) and Torque (Nm) ####
 File: Data_files_S5.zip **Description:**  Purpose: Source data for
 Fig.6E-After Test A+B Torque sensor angle file: time(YYYY-MM-DD
 Thh:mm:ss.sss) to rotation angle (deg) Torque sensor Torque file:
 time(YYYY-MM-DD Thh:mm:ss.sss) to Torque voltage(V) and Torque (Nm) ####
 File: Data_files_S6.zip **Description:**  Purpose: Source data for Fig.6F
 Test count, Time (sec), Elongation(=Deflection) (mm) to Load force (N)
 #### File: Data_files_S7.zip **Description:**  Purpose: Source data for
 Fig.7 Fig.7C : Time(Thh:mm:ss.sss), rotation angle of winch (deg), angular
 velocity of winch (rev/min), Torque of winch (mNm)
 Fig.7D: Time(Thh:mm:ss.sss), rotation angle of wheel (deg), angular
 velocity of wheel (rev/min), Torque of wheel (mNm) #### File:
 Data_files_S8.zip **Description:**  Purpose: Source data for Fig.S3B
 Torque sensor angle file: time(YYYY-MM-DD Thh:mm:ss.sss) to rotation angle
 (deg) Torque sensor Torque file: time(YYYY-MM-DD Thh:mm:ss.sss) to Torque
 voltage(V) and Torque (Nm) #### File: Data_files_S9.zip **Description:** 
 Purpose: Source data for Fig.S3C Test count, Time (sec),
 Elongation(=Deflection) (mm) to Load force (N) ## Code/software **Running
 the model:** MATLAB (R2024a) was used for Modeling Code S1. **Viewing the
 data:** The data files are provided as Excel (.xlsx or .csv) format and
 have been compressed into a .zip file. ## Access information Other
 publicly accessible locations of the data: * This dataset is available
 exclusively via Dryad. Data was derived from the following sources: * All
 data and code were generated by the authors through original experiments
 and modeling.