Astrobee

1. Astrobee Communication Design Overview

2. Agenda • Astrobee Overview • Communications Overview • Communications Data Flow • Video Distribution Policy • Ground Data System (GDS) Requirements for Astrobee Payloads • Communications Hardware

3. Astrobee Overview • Three free flyers on ISS starting spring 2019 • Docking station for recharge and wired communication • Built in perching arm using payload interface • 6 total cameras for various purposes, including one cellphone class HD camera. • Main purposes: • Host guest science payload (GSP payloads) • Serve as mobile camera for ISS situational awareness • Serve as mobile sensor platform • First GSP Payloads • REALM RFID reader • Zero Robotics High School and Middle School competitions

4. Current Robot Design 12.5 x 12.5 x 12.5 inches 10.5 kg (with arm + 4 batteries) FORWARD

5. Astrobee

6. Computing Propulsion Module Controller Perching Arm Controller Core Avionics Stack AFT/CUTAWAY VIEW

7. Command and Data Handling • Design Drivers • Reliability: Multi-processor isolation, serviceable, upgradeable • Power-efficient high performance for machine vision, HD video • Support a variety of data buses • Design • Hybrid COTS/custom approach: Integrated COTS modules on custom carrier boards • Power-efficient ARM processors (embedded variants of cell phone technology) • Three independent processors • Top two boards accessible for crew replacement or upgrade Backplane Mid-Level + High-Level Processor EPS Low-Level Processor Connector

8. Selected CDH Architecture • Three ARM processors to isolate guest code, vision based navigation and 62.5 Hz control loop • Low Level Processor (LLP) – Linux, Dual core • Runs high freq. EKF and propulsion control loop • Mid Level Processor (MLP) – Linux, Quad core • Runs absolute localization algorithms, obstacle detection, sequencer, communications • Heavy processing power used by vision • High Level Processor (HLP) – Android, Quad core • Interface with Science Camera and Display • Encodes video with dedicated hardware • Runs guest science code

9. Agenda • Communications Overview

10. Communications Overview • Design Drivers • Reliability: Degrade gracefully with unreliable comms • Live HD video and telemetry • Downlink full logs after sortie • Inter-robot comms • Design • Live comms through JSL WiFi / Ku-band / TReK • Telemetry using DDS protocol • Hard-wired Ethernet downlink through dock

11. System Data Flow Diagram Link Legend ISS Queen Ethernet/LAN Honey Dock Bumble Crew Control Station Payload LAN Switch Internal Switch Ethernet: Internal IP Internal Switch LLP Dock CPU Ku-Band Ethernet: Internal and Payload LAN MLP 5GHzWAP NAS WiFi: Payload LAN HLP Payload JSL Payload LAN USB White Sands Other/LAN JSC MSFC Payload PD ARC MMOC NASA TV Public Operator Control Storage Operator/Engineer Control Operator Control (MCC) Big Screen (MCC) Bldg-8 Operator Control (POIC) Big Screen (POIC) Ground Relay (HOSC) Future Capability

12. Network Description (1/2) • All processors inside Astrobee are on a private network, connected via an internal 100Mbit switch. • All internal processors have an internal IP address that is not routed outside of Astrobee. • Internal IP addresses are used for internal FSW communications. • MLP WiFi is used for telemetry and commanding to GDS. • HLP WiFi is enabled and used for . • Redundant interface to access the freeflyer if the MLP interface dies. • Streaming HD video to the ground. • Possible use is for Guest Science. • Payloads interface via USB to the HLP • Should they use a USB-to-Ethernet solution, they are isolated from the rest of the network. • The WiFi modules associate with the JSL PayloadLAN WAPs, which also route to the ground via KU-band over JSL-2 to MSFC.

13. Network Description (2/2) • There is a 100Mbit switch inside the Dock, which serves both the docked Astrobees and the Dock CPU. • The dock will connect to a 100Mbit ISS Router, which can flow down to the ground via KU-band over JSL-2 to MSFC. • The Dock CPU will have both an internal Astrobee and a PayloadLAN IP address. • The Dock CPU aids in software updates and waking up hibernating Astrobees. • We are relying on KU-IP-Services to route data to the ground over an IP-network built on the CCSDS foundation of KU-band. P4 Design Review

14. Ground Data Relay • For conserving bandwidth, only one stream of data & video will flow to the ground per robot. Data is relayed to multiple ground stations via a “relay” at MSFC HOSC. • A computer at the HOSC routes DDS and streaming video traffic from ISS KUIP to interested ground nodes. • It will use COTS software, with custom configuration files. The configuration files will be under version control at Ames. • The DDS data relay has been tested at Ames.

15. Data Paths Overview • All data paths to the ground make use of KU-IP Services and TReK. • TReK HPEG: Allows us to control our payload outside of the HOSC via “proxy” IP addresses. • TReK CFDP: File delivery protocol based on CCSDS.

16. Agenda • Communications Data Flow

17. Flight Configuration for Astrobee ISS Astrobee3 Astrobee2 ELC Astrobee1 LLP (Ubuntu) MLP (Ubuntu) x.x.x.x (static) HLP (Andriod) DDS UDP Port: N1-N2 SSH/SCP TCP: 22 TReK Toolkit RTSP TCP: xx UDP: P1-P2 CFDP Crew Control Station GUI Internal Switch DDS RTSP Astrobee Dock CPU (Ubuntu) Internal Switch WAP Payload WAN/ISS Ethernet Ku-Forward ICU Ku-Fwd G/W Magic HOSC/POIC Astrobee Relay (RedHat) Ku-Fwd Auth Svr HPEHG Ku-Fwd G/W DDS-Srvr UDP Port: N1-N2 TReK HPEG (GroundNode 2) RTSP-Srvr TCP: xx UDP: P1-P2 VPN Server Public Internet ARC-MMOC Payload PD JSC Bldg-8 TReK HPEG - AstroBee(1-3)_wireless(1-2) - NAS - ASTROBEE_DOCK Each 1-to-1 NAT: - SpaceNode-ID (Static) - X.X.X.X (Dynamic per session) Ground Computer (WS4) Ground Computer Ground Computer VPN Software VPN Software VPN Software Ground Control Station GUI TReK HPEG (GroundNode 1) Ground Control Station GUI VLC RTSP TReK CFDP Putty DDS RTSP SSH DDS RTSP

18. PRCU Test Configuration for Astrobee Ames-Granite-Lab “ISS” Astrobee3 Astrobee2 ELC Astrobee1 LLP (Ubuntu) MLP (Ubuntu) x.x.x.x (static) HLP (Andriod) DDS UDP Port: N1-N2 SSH/SCP TCP: 22 TReK Toolkit RTSP TCP: xx UDP: P1-P2 CFDP Crew Control Station GUI Internal Switch DDS RTSP Astrobee Dock CPU (Ubuntu) Internal Switch WAP Payload WAN/ISS Ethernet HOSC/POIC Astrobee Relay (RedHat) Ku-Fwd Auth Svr PRCU/RAPTR HPEHG Ku-Fwd G/W DDS-Svr UDP Port: N1-N2 TReK HPEG (GroundNode 2) RTSP-Svr TCP: xx UDP: P1-P2 VPN Server Public Internet ARC-MMOC HOSC Router TReK HPEG - AstroBee(1-3)_wireless(1-2) - NAS - ASTROBEE_DOCK Each 1-to-1 NAT: - SpaceNode-ID (Static) - X.X.X.X (Dynamic per session) Ground Computer (WS4) VPN Software Ground Control Station GUI TReK HPEG (GroundNode 1) Putty DDS RTSP SSH

19. Test Configuration A ISS Dev Laptop (Macbook) Astrobee1 LLP (Ubuntu) MLP (Ubuntu) x.x.x.x (static) HLP (Andriod) DDS UDP Port: N1-N2 SSH/SCP TCP: 22 TReK Toolkit RTSP TCP: xx UDP: P1-P2 CFDP Internal Switch Astrobee Dock CPU (Ubuntu) Internal Switch WAP Payload WAN/ISS Ethernet

20. Test Configuration B ISS Dev Laptop (Macbook) Astrobee1 LLP (Ubuntu) MLP (Ubuntu) x.x.x.x (static) HLP (Andriod) DDS UDP Port: N1-N2 SSH/SCP TCP: 22 TReK Toolkit RTSP TCP: xx UDP: P1-P2 CFDP Internal Switch Astrobee Dock CPU (Ubuntu) Internal Switch WAP Payload WAN/ISS Ethernet Ku-Forward ICU Ku-Fwd G/W Magic HOSC/POIC Ku-Fwd Auth Svr HPEHG Ku-Fwd G/W VPN Server Public Internet ARC-MMOC TReK HPEG - AstroBee(1-3)_wireless(1-2) - NAS - ASTROBEE_DOCK Each 1-to-1 NAT: - SpaceNode-ID (Static) - X.X.X.X (Dynamic per session) Ground Computer (WS4) VPN Software Ground Control Station GUI TReK HPEG (GroundNode 1) Putty DDS RTSP SSH

21. Test Configuration C ISS Dev Laptop (Macbook) Astrobee1 LLP (Ubuntu) MLP (Ubuntu) x.x.x.x (static) HLP (Andriod) DDS UDP Port: N1-N2 SSH/SCP TCP: 22 TReK Toolkit RTSP TCP: xx UDP: P1-P2 CFDP Internal Switch Astrobee Dock CPU (Ubuntu) Internal Switch WAP Payload WAN/ISS Ethernet Ku-Forward ICU Ku-Fwd G/W Magic HOSC/POIC Astrobee Relay (RedHat) Ku-Fwd Auth Svr HPEHG Ku-Fwd G/W DDS-Srvr UDP Port: N1-N2 TReK HPEG (GroundNode 2) RTSP-Srvr TCP: xx UDP: P1-P2 VPN Server Public Internet ARC-MMOC Ground Computer (WS4) VPN Software Ground Control Station GUI Putty DDS RTSP SSH

22. Data Path: Telemetry & Video • Telemetry and commands flow through DDS over UDP/IP • With tuned QoS settings, should avoid traffic spikes after LOS. • Sci-cam (Science Cam HD Video) flows through RTSP over UDP/IP • RTSP is designed to account for packet loss, thus LOS should be tolerated. • Both Video and Data flow through a ground “relay” to de-duplicate traffic to multiple ground control stations observing/commanding Astrobee.

23. Video Multicasting • Video is only downlinked once from the ISS to MSFC, from there it is “multicasted” (in reality, multiple unicast streams) to multiple control stations. • Video destined for public consumption is pre-screened through Building 8 before being broadcast to various audiences.

24. Data Path: Engineering Tools • SSH capabilities will be in place. Using this, any engineering tools written as part of FSW may be remotely executed. • SSH is enabled on both wired and wireless interfaces on the MLP. • This allows us to jump through the dock in the case that the MLP/HLP are having issues to get to the LLP.

25. Data Flow: SW Updates, etc • From JSL requirements: all SW updates must be made over a secure channel. • SCP/SFTP satisfies this requirement. • Guest Science code may also fall under this as well. • (Additional verification methods may be used by FSW, such as checksums, code signing, etc) • Two possible paths: • Direct to Astrobee over SSH-based protocols. • Upload to the Dock CPU and accessed by Astrobee. • This is more useful for multi-Astrobee updates.

26. Data Flow: Data Products • Immediate Data Products • High-value logs and telemetry that are requested. • Use CFDP over DTN • TReK CFDP tool will be used • Delayed Data Products • Other wanted or very large products • Copy to NAS, wait for data through existing services (Qsync)

27. TReK CFDP over DTN Diagram ISS HOSC Ethernet Switch Ground DTN Gateway Dock ISS DTN Gateway Node 2 Edge Router Ground Routers MLP Point of Control TReK CFDP

28. TReK CFDP over DTN Setup MLP TReK CFDP ISS DTN Gateway Ground DTN Gateway • TReK CFDP over DTN is a reliable file transfer protocol using DTN’s bundle protocol to handle periods of LOS. • Data is sent serially through each node. • The KU Forward connection is between the DTN gateways. • Data is stored at the DTN nodes/gateways during a LOS. P4 Design Review

29. Expected Transfer Rates • The on-board Dock/Astrobee wired hardware supports 100Mbps.  • The on-board wifi utilizes the 11b/g/n standard which can have an average 54 Mbps rate  • The Astrobee ISS PIA (Payload Integration Agreement) documents a requested real-time downlink rate to the ground of 15Mbps. • Downlink rate’s are requested on a per-activity basis in the PARD (an Ops Planning data product)  • Current estimates for what Astrobee might need: (Still preliminary and needs testing/measurement)   • 1 to 2 Mbpsdatarate for commanding (all Astrobee’s included) • This is by-directional. It is significantly more weighted on the downlink side • We suspect that the standard 0.1 Mbps uplink rate is sufficient, but more testing is needed • 2 Mbps per HD video stream downlink (so 6Mbps total if operating there Astrobee’s with 1-sci-cam each) (margin should be added plus commanding rate) P4 Design Review

30. Expected Transfer Rates • Per a KUIP subject matter expert: • The average latency is 600 ms. • This latency impacts TCP based protocols in greater proportion than UDP protocols.  • The total available uplink date rate for all payloads is 8Mbps. (All of Station has a 20Mbps uplink rate) • Uplink of large files should be prescheduled.  • TReK CFDP uses UDP • Other payloads have observed up to 30Mbps file downlink rates  • Based on payload specific Blank-book documentation, the HOSC does specify downlink rate caps on-board ISS (Likely on the PEHG). It does incorporate overhead spikes, so higher than 15Mbps might be observed.  • On 11/19/2018, during PRCU testing, we observed a range of 30 - 600 KB/s (4.5Mbps) uplink rate using Rsync from the DDS Server to an Astrobee in the Granite Lab. • On 02/15/2019, during the ISS Astrobee Dock Install activity, these scp file transfer rates (on average) were observed: • 10KB/s uplink, 120KB/s downlink

31. Agenda • Video Distribution Policy

32. Video Distribution Policy • Video distributed to any Astrobee Ground Control Station will not be recorded or re-distributed • Connecting an Astrobee Ground Control Station to ISS will require authentication with the HOSC network as an ISS Payload Developer (PD) • With the one exception of real-time video to the Astrobee Ground Control Stations, all video generated by Astrobee’s built-in cameras will be reviewed by Bldg-8 before distributing to Non-NASA organizations (including Payload PD’s) • A process will be setup where the NASA-Ames Astrobee Facility makes downlinked video available for Bldg-8 review

33. Data Path: Video/Data Distribution 1/2

34. JSC MCC Data Path: Video/Data Distribution 2/2 Big Screen Box Control Station JSC Bldg 8 MSFC POIC Payload PD ARC MMOC MPEG2 Med Screen Aud Big Screen MSFC HOSC Future Work Control Station Control Station Control Station Distributed Video KUIP Live Video ISS ICU Full Real-time Stream

36. Agenda • Ground Data System (GDS) Requirements for Astrobee Payloads

37. Ground Payload Computer Requirements • Windows 10 • Browser support for HOSC EHS & OSTPV tools • IVODS • Headset connectivity  • Astrobee Ground Control Station • HOSC VPN client • VLC 

38. GDS required Accounts & Authentications • HOSC HOPS Account for: • IVODS • HOSC VPN login • NASA NDC credential for accessing Astrobee Facility file server for post-ops data downlink

39. Agenda • Communications Hardware

40. WiFi Antenna • 2.4 GHz/5.8 GHz Wifi antenna • ~3dBi/5dBi gain • Omnidirectional • Adhesive tape mounting • Additional tape will be applied to ensure launch survival • Paper thin • Mass: 0.477g P4 Design Review

41. Antenna Placement • Two antennas for each the HLP and the MLP will be placed on Astrobee. • One antenna will be placed on the front and the back for each processor. • This should help with signal strength, no matter what orientation Astrobee is in. • The antennas are placed behind the plastic bezel, but outside the metal avionics box.

42. Antenna Placement - Front Antennas PWR wake

43. Antenna Placement - Aft Antennas are on backside of Dock Adapter Low adsorbent filler Antenna location

44. Antenna Modularity • An SMA/U.FL adapter has been added to ease installation and replacement. • This adapter is in-line.