Cygnus HP Package

Small Satellite Rideshares on Commercial Resupply Missions to the International Space Station SmallSat Conference 2012

Joshua R. Robinson(Presenting) Daniel W. Kwon

August 14, 2012 Introduction

 Gaining access to space is a challenge for small satellites

 Ride needs to be:  Reliable  Affordable  Compatible with small satellite/payload

 CRS missions to the ISS have the potential to provide a robust and repetitive platform for rideshare payloads  Eight planned missions of the Orbital Antares rocket and Cygnus spacecraft to ISS through 2016  Strong potential for additional missions beyond 2016

2 Cygnus Background

 COTS = Commercial Orbital Transportation Services Orbital and NASA invested in commercial development of a cargo resupply system under a funded Space Act Agreement Includes first flight of Antares and the first flight of Cygnus to the ISS in 2012

 CRS = Commercial Resupply Services IDIQ contract for frequent commercial flights to carry cargo to ISS Includes multiple flights to station through 2016

2011 2012 2013 2014 2015 2016 COTS Demonstration Mission CRS Operational Missions

Regular interval fills void left after Shuttle retirement

3 Rideshare Capabilities

 Rideshare can be a deployable or Ride-Along payloads (Pressurized or unpressurized)

 Deployable from Antares or Cygnus  Altitude: Less than ISS (333-460 km)  Inclination: 51.62°-51.68° (±0.1°)  Deployment from Cygnus will require adherence to ISS safety regulations

 Small satellite technology demonstration for Ride-along payloads on Cygnus  Non-deployable technology demos can be activated after ISS berthing  ISS safety regulations must be evaluated in accordance with the potential hazards (if any) presented by the demo

4 Cygnus Spacecraft Overview

● Pressurized Cargo Module (PCM) Built by Thales Alenia Space

Heritage: Multi-Purpose +X Logistics Module Berthing at ISS: Node 2 Common Berthing Mechanism

● Service Module (SM) Built by Orbital Heritage: STAR Bus, Dawn Compatible with Antares Rocket +Y

5 Wallops Launch Pad Turnover Nearing Completion

6 Antares Final Assembly for Hotfire Test on Launch Pad

7 Antares Core Pad Fit Check

8 Cygnus Rideshare Concept of Operations

Rendezvous with ISS Depart • Payload Off from ISS • Survival Heater Power Provided Secondary Payload Opportunities post undocking from ISS

USN Ground Stations

Orbital MCC Controlled Deorbit

Payload Ops Center Launch from Wallops 9 Power, Orbit Lifetime, and Data Allocations

 Power  Solar Array Power – 3500 W (32V main bus)  Battery Capacity – 20,262 W-Hrs  Secondary Payload Power – 1,300 W (OAP)  Orbit  Altitude: Less than ISS altitude (333-460 km)  Inclination: 51.62°-51.68° (±0.1°)  Operational lifetime depends on propellant available  Up to 1 year possible after standard mission  S-Band Communications  3 Mbps downlink  2 kbps uplink  Ground network compatibility  Universal Space Network  NASA Near Earth Network

10 Rideshares on Cygnus

 Good Fields of View Volume allocation on outer service module Minimal Interference from comm, GPS antennas, and thruster plumes  Nominal attitude with –X to sun x Other attitudes feasible Propellant margin dictates slewing capability y

z

Potential Mounting Location

Potential +Z Face Volume Potential -X Face Volume

11 Available External Volume +Z Face

64 cm 27 cm 27 cm

122 cm 61 cm 122 cm 18 cm x 14 cm 31 cm

28 cm

Thruster plume clearance

12 Available External Volume -X Face

50 cm 50 cm

24 cm 98 cm 24.1 cm 86 cm 36 cm

50 cm

33 cm 114 cm

Thruster plumes

13 Cygnus Mission Control

 Cygnus Controlled from Orbital Mission Control Center at Dulles (MCC)  Dedicated Mission Operation Center  Secure Connectivity to NASA and Tracking Networks

 MCC Controls Cygnus Throughout Mission, Including Secondary Payload Operations

 After Departure, Cygnus Maneuvers to Customer-Desired Altitude

 Number of Burns/Duration of Orbit are Dependent on the Amount of Reserve Propellant Remaining

14 Lifetime and Power

 Lifetime constrained by propellant availability Up to 1 year lifetime for tech demos

 Excess of power due to large array and redundant systems

 Sun pointing mode Daily propellant usage for attitude maintenance Sun Pointing Mode Shorter lifetime, but full power capability

 Gravity gradient mode Longer lifetime through minimal slewing Energy budget may not close for certain sun angles and with tech demos requiring significant power

Gravity Gradient Mode

15 Ground Network

 S-Band Communications

 Ground network Universal Space Network

 Data throughput Data throughput to one USN station can average 0.6 GB/day

Single Ground Station  Latency 83.4% of time latency is less than 200 minutes 16.6% of time latency is > 13 hours

 Improved latency and throughput through additional USN stations

Additional Ground Stations 16

New Missions of Opportunity in LEO

 National Lab Authorized missions of opportunity  In conjunction with NASA, Orbital can provide 1-2 SmallSat Rideshare opportunities per year  Starting in 2013

 Generally, accommodation Internal to PCM and External to SM

 Available Mass Dependent on ISS Resupply Needs  Cargo Manifest Near Firm at L – 10 Months  Decision date for rideshare at L – 18 Months

17 Questions?

18