1. Right-Sized Nanosatellites: Finding the Sweet Spot between 3U/6U and ESPA
June 9, 2015
Clint Apland
(240)

2. Topics to Discuss Need and Motivation
Express-class Space Vehicle Features and Benefits
Payload Provisions and Suitability to Payloads with Significant Mission Utility
Benefits of Rectangular Adaptor Systems
First Generation Adapter System
Second Generation Adapter System
Future Work

3. Motivation for Express Class
An intermediary mission class standard is needed between ESPA (181 kg) and 3/6U CubeSat (~4-12 kg), to:
More optimally utilize excess LV secondary payload rideshare accommodation capability.
Enable lower cost missions when ESPA-class not needed.
Provide for more flexible and capable space vehicles than possible w/ 3U-6U CubeSat (physical) constraints:
E.g., larger payloads, greater power generation, propulsion
Permit more ready-use of COTS components and technologies.
Poly-Picosat Orbital Deployer (P-POD)
NASA
Ames (3/6U) NLAS Dispenser
Express
Atlas V ESPA Configuration
Initial top-down/bottom-up study performed by APL in

4. Express Class: 25-75 kg Standardized Nanosatellite
W/O Propulsion
W/ Propulsion
Provides a standard, flexible spacecraft interface compatible with multiple LVs:
For secondary manifest:
Space-X Falcon 1e/9/9H
OSC Minotaur I/IV/V, Antares,Taurus XL
ULA Atlas V, Delta IV
LM/ATK Athena IIc
For primary manifest:
ORS Super-Strypi
SMDC Nano-Launcher*
DARPA ALASA*
Bridges gap between 3U/6U and ESPA
26.4 cm (10.4 in)
55.8 cm (22 in)
To be investigated as data becomes available
47.0 cm (18.5 in)
47.0 cm (18.5 in)
Optional shroud alleviates concerns of primary Payload (PL) damage
Protects/conceals contents from:
Visual inspection
Physical access and tampering
Aero-heating, thruster plume thermal
Acoustics and contamination
EMI/EMC
Launching high performance, reliable nanosatellites featuring inexpensive and reliable separation systems is possible over a wide selection of launch vehicles

5. Express Features and Benefits
Configurations with or without propulsion.
> 225 m/s ΔV chemical propulsion allows rideshare flexibility; enables formation flying and constellations.
Non-propulsion is lower cost and accommodates larger payloads within standard volume.
Multiple PL data interfaces.
Allows >two independent payloads.
Large payload volume.
Propulsion: ,500 cm3 (400 in3)
Propulsion Extended: 35,000 cm3 (2100 in3)
Non-propulsion: ,000 cm3 (1200 in3)
Size, shape and mass less constraining than CubeSats.
Allows more use of COTS components, can still benefit from use of CubeSat components, appendages can protrude if necessary.
Simplified Adaptor & Separation System
Simple, proven, low cost, allows axial or radial deployment, easily adapted to any LV. Flyaway half of separation system can double as bottom deck of SV.
Available shroud.
Provides protected environment, prevents visual inspection, tamper-resistance prevents access.

6. Payload Provisions
Nominal PL Mass: 21 kg w/o propulsion; 8 kg w/ propulsion
Data processing capability may be supported by S/C C&DH
Flexible S/C software architecture with encryption capability
Time: 1 pulse per second, GPS referenced
Solid State Recorder (Mass Memory) is scalable
Nominal PL Power:
Orbit Average (typical orbit): >10 W
Peak: 100 W
Available Voltages:
Unregulated Bus: 28 V (24 to 33 V)
Regulated: 3.3 V and 5.0 >4 A; Adjustable
Attitude Determination & Control:
Full 3-axis (zero momentum)
Control <0.1, Knowledge <0.03
Communications: Full duplex USB/S-band (DL >1 Mbps)

7. Express SERB Payloads Applicability
Criteria:
V < 20,000 cm3 (w/o prop.)
P < 30 watts
M < 15 kg
Results:
Suitable for 11 of 19 (58%) of candidate payloads from 2014 SERB list, and could accommodate every CubeSat payload

8. EELV, F-9/Heavy, Antares Accommodation: ESPA
Nanosats & ESPA SVs
on a ø62” ESPA ring
(option for 3 at each ESPA port)
B1194 PSR
Atlas V
Delta IV
5-m fairings
2x D1666 PSR
CSA Flat Plate Adaptor & 3 SVs
ESPA SV
Falcon 9
C-29 Ring
Atlas V
Delta IV
4-m fairings
Shrouded Option
Antares
(Figure courtesy of ULA)
Clearance for Antennas, etc.
Optional P-PODs on Moog-CSA ESPA 6U Mounts (SUMs)
(Figure courtesy of Moog-CSA)

9. EELV, F-9/Heavy, Antares Accommodation: ESPA + FPA
Nanosats & ESPA SVs
On a CSA Flat Plate Adaptor
B1194 PSR
Atlas V
Delta IV
Falcon 9
5-m fairings
ESPA SV
2x D1666 PSR
Bottom View
CubeSats (10)
Atlas V
Delta IV
4-m fairings
C-13 Adaptor (between Centaur forward cone and CSA Flat Plate Adaptor)
Moog-CSA Flat Plate Adaptor
Antares
The same mixed payload topologies and ride-share flexibility is possible with smaller LV

10. Express Adapter FY15 Prototype Improvements
Several refinements and enhancements were made through additional detailed design, testing activities to:
Increase space vehicle mass/volume accommodation: mass-CG curve raised
Reduce parts count, simplify AI&T, lower costs
Reduce adapter (baseplate) fly-away mass
Increase customizability for specific SV equipment accommodations
Reduce operations required for flight mate
Increase scalability for larger-class space vehicles
Next-gen design activities scheduled for 2015
Complete detailed design (Q2-3CY15)
Prototype fabrication, separation & vibration testing (Q3CY15)

11. Express Adapter Prototype Hardware
Full adapter system prototype designed, built and vibration tested
US Patent for an “Adaptor System for Deploying Small Satellites”
Adapter w/ SV Baseplate
Exploring opportunities for flight demonstration and characterization
Z axis
Adapter Deployment H/W
Vibration Test Configuration
(without shroud)
Thermal Test Layout
Shroud Assembly

12. Prototype Hardware Test Plan
Vibration Test Configuration
(without shroud)
Test outline:
Sine and Random Vibration Testing in each of 3 axes, each axis:
Pre-test sine survey at .25g, Sine Sweep, Random Vibration, post-test survey
Deployments at ±60C (to be scheduled for next-gen adaptor)
Ambient pressure (nitrogen back-fill)
Deployments in the direction of gravity
Deployment characterization (to be scheduled for next-gen adaptor)
Use 3rd party air bearing fixture
Measure tip-off rates in axes parallel to separation plane
Measure separation rate
Z axis
Thermal Test Layout

13. Design Overview
Design is simpler, more reliable, more cost effective and requires less volume than a ring type separation system
2x 31-pin Separation
Connector
Low Shock
Separation
Nut
(picture courtesy of HiShear Technology Corporation)

14. Benefits to Small Sats of Rectangular Separation Systems
Square interface is more efficient than circular interface
Small SVs are usually rectangular and don’t have the volume for center cylinder structural elements
Most of the loads in rectangular SVs are concentrated in the corners
Cylindrical separation systems are sensitive to load “peaking”
To avoid load peaking, cylindrical interfaces require large and massive structures to distribute loads
The rectangular adaptor is insensitive to load peaking; loads are reacted from SV corners into separation system corners
The rectangular adaptor can be easily customized to be used as the bottom deck of the space vehicle
Increases usable SV volume and decreases total system mass
The rectangular adaptor is more cost effective than cylindrical adaptors
Separation system is less costly than cylindrical systems
Can eliminate the cost of SV bottom deck
The rectangular adaptor is easier to set for flight than some cylindrical separation systems
The rectangular adaptor can be used with “work- horse” LV-side GSE adaptors, unlike some cylindrical adaptors
Other Features & Benefits:
Simple and reliable
Single machined deck from flat plate
Much lower parts count than cylindrical adaptors
Mechanism parts count dramatically reduced, as compared to cylindrical adaptors
Separation nuts:
Simultaneously actuated
Low shock
Reliable with heritage
Non-explosive actuators are available
Integral separation connectors
Redundant Loop-back Break- wire separation indication
No separation switch “chatter”

15. Future Work Continuing to Engage Sponsors
Performing Mission Concept Studies
Coordinating Experimental/Prototype Flight Missions in 2016
Seeking Industry Partners for Tech-Transfer of Express Dispenser
APL’s role is not separation system hardware production
Benefits our community
Low cost, reliable, flexibly configured separation systems that reduce overall system mass and increase usable volume