# Presentation: 329884

## FROM PRESENT SURVEYING 

**FROM PRESENT SURVEYING **
**TO FUTURE PROSPECTING **
**OF THE ASTEROID BELT **

- P.E. Clark, M.L. Rilee, L3 Communications GSI
- S.A. Curtis, G. Marr, C.Y. Cheung, W. Truszkowski, NASA/GSFC

**What are ANTS and PAM?**
**ANTS: Autonomous NanoTechnology Swarm**
- Inspired by success of social insect colonies where
- Within their specialties, individuals outperform generalists
- With sufficiently efficient social interaction and coordination, groups of specialists outperform groups of generalists.
- A Generic Mission Architecture based on:
- Spatially distributed spacecraft
- Autonomous, redundant components with high plasticity
-  Hierarchical (multilevel, dense heterarchy) organization
**PAM: Prospecting Asteroid Mission**
- An ANTS application for survey of large populations
- 1000 spacecraft swarm
- 10 types of ‘specialists’ with common spacecraft bus
- 10 subswarms, ~100 spacecraft each, ~10 each specialist
- Solar sail propulsion system requiring no expendables
- Small nuclear batteries meet 100’s of milliwatt power requirements
- Designs applicable to low G environments <3.5 AU
- Primary objective is the exploration of the asteroid belt
-     in search of resources and material with astrobiologically
-     relevant origins and signatures

**PAM Concept Development Methodology**
- Develop Conceptual Model for Behavior
- Neural Basis Function based on bilevel intelligence
- Combines capability for autonomous and collective behavior
- Model applies at all levels:
-      component, subsystem, spacecraft, subswarm
-  Individual operational components connect to each
-      other through specially designed interface
- Develop scaled physical models and simulations to illustrate
-            modularity, configurability, scalability
- Solar Sail Structure and deployment
- Subsystem platform
- Predeployed, packaged spacecraft
- Predeployment manufacturing
- Formulate requirements and operational scenarios
-      driven by variable size, irregular mass distribution,
-      and highly variable composition in low G environment.

**PAM Concept Development: Current Issues**
- Selection of 10 instrument specialties and exploration priorities, as shown in the Science Measurement Table, allow an asteroid  survey which can’t be obtained from earth-based observations or single spacecraft missions.
- Incremental improvements in optics and computer technologies will continue to allow the spectroscopic analysis and dynamic modeling of a growing number of asteroids from earth-based observations.
- The increased numbers of objects studied will still tend to be those most readily observable-the larger, brighter, closer objects.
- Models based on these observations will thus not truly represent a cross-section of the asteroid population.
- Current asteroid mission strategies involve only small numbers of spacecraft and targets.
- Understanding the modification of the surface through dynamic interactions, or space weathering, as well as understanding the relationship between meteorite samples and the small body populations demands high resolution data which can only be obtained by visiting asteroids.

**PAM Concept Development: Autonomous Assembly**
- Autonomous assembly and deployment minimizes resource requirements, including bandwidth and human labor.
- Components are composed of carbon nanotubule strands (tethers) or fibers (surfaces) reversibly deployable and stowable from NEMS nodes, allowing for orders of magnitude decrease in packaging or stowing volume.
- A tetrahedron of NEMS nodes forms basic building block.
- Assembly is based on creating 2D layers of interconnected NEMS nodes in two patterns.
- Specialized subsystem nodes can be added to any layer.
- 2 layers of different pattern form the sail support.
- A  3 layer sandwich, with different pattern layer in the middle, forms the subsystem platform.
- Subsystems are tethered together.
- After assembly, spacecraft are stowed, spooled back into nodes.
- 1000 autonomous 10 centimeter, 1 kg boxes would stow into a 1 meter, 1000 kg cube.

**PAM Estimated Mission Parameters and Requirements**
- Mission Date			2025
- Mission Duration		5-10 years (TBR)
- Mission Location		1.0 - 3.5 AU
- Spacecraft Mass		1 kg
- Power System Mass		0.25 kg
- Power Required		100-300 milliwatts
- Storage Life in Space		5-10 years
- Deployment Temperature	-40 deg C (TBR)
- Spacecraft Attitude		3-axis stable
- Operations:
- Deep space operations far from Earth & Sun
- 1 month of optimal science operations at each asteroid
- Full suite of science instruments deployed at each asteroid
- Concurrent operations at tens of asteroids
- No single point failure; robust to minor faults/catastrophic failures
- Optimal operations in spite of mission attrition