Agenda Astrobee Overview Communications Overview Communications Data Flow Video Distribution Policy Ground Data System GDS Requirements for Astrobee Payloads Communications Hardware 2 Astrobee ID: 935824
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Slide1
Astrobee
Communication Design Overview
Slide2Agenda
Astrobee Overview
Communications Overview
Communications Data FlowVideo Distribution PolicyGround Data System (GDS) Requirements for Astrobee Payloads Communications Hardware
2
Slide3Astrobee
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
Slide4Current Robot Design
FORWARD
12.5 x 12.5 x 12.5 inches
10.5 kg (with arm + 4 batteries)
Slide5Astrobee
5
Slide6Computing
Core Avionics Stack
Perching Arm Controller
Propulsion Module Controller
AFT/CUTAWAY VIEW
Slide7Command and Data Handling
Design Drivers
Reliability: Multi-processor isolation, serviceable, upgradeable
Power-efficient high performance for machine vision, HD videoSupport a variety of data busesDesignHybrid COTS/custom approach: Integrated COTS modules on custom carrier boardsPower-efficient ARM processors (embedded variants of cell phone technology)Three independent processorsTop two boards accessible for crew replacement or upgrade
Mid-Level + High-Level Processor
Low-Level Processor
Backplane
EPS
Connector
Slide8Selected CDH Architecture
Three ARM processors to isolate guest code, vision based navigation and 62.5 Hz control loop
Low Level Processor
(LLP) – Linux, Dual coreRuns high freq. EKF and propulsion control loopMid Level Processor (MLP) – Linux, Quad coreRuns absolute localization algorithms, obstacle detection, sequencer, communicationsHeavy processing power used by visionHigh Level Processor (HLP) – Android, Quad coreInterface with Science Camera and Display
Encodes video with dedicated hardware
Runs guest science code
Slide9Agenda
Communications Overview
9
Slide10Communications Overview
Design Drivers
Reliability: Degrade gracefully with unreliable comms
Live HD video and telemetryDownlink full logs after sortieInter-robot commsDesignLive comms through JSL WiFi / Ku-band / TReKTelemetry using DDS protocolHard-wired Ethernet downlink through dock
Slide11Queen
Honey
Bumble
JSC
System Data Flow Diagram
Ethernet/LAN
WiFi
:
Payload LAN
Ethernet: Internal IP
Ethernet: Internal and Payload LAN
ISS
LLP
MLP
NAS
Ku-Band
ARC MMOC
White Sands
Operator Control (MCC)
Operator/Engineer Control
Crew Control Station
Storage
HLP
Payload
Dock
JSL
Payload LAN
Payload LAN Switch
5GHzWAP
Other/LAN
Link Legend
USB
Internal
Switch
Internal
Switch
Dock CPU
11
Payload PD
Operator Control
Big Screen (MCC)
Bldg-8
MSFC
Operator Control
(POIC)
Big Screen (POIC)
Ground Relay (HOSC)
NASA TV Public
Future Capability
Slide12Network 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.
Slide13Network 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
Slide14Ground 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.
Slide15Data 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.
Slide16Agenda
Communications Data Flow
16
Slide17ARC-MMOC
ISS
Astrobee3
Astrobee2
Astrobee1
MLP
(Ubuntu)
x.x.x.x
(static)
ICU
Ku-Fwd G/W
HOSC/POIC
Magic
TReK Toolkit
CFDP
Ku-Fwd
Auth
Svr
SSH/SCP
TCP: 22
HPEHG
Ku-Fwd G/W
DDS
UDP Port: N1-N2
LLP
(Ubuntu)
HLP
(
Andriod
)
RTSP
TCP: xx UDP: P1-P2
Internal Switch
ELC
Crew Control Station GUI
DDS
RTSP
Astrobee Dock
Ground Computer (WS4)
Internal Switch
CPU
(Ubuntu)
WAP
VPN Server
Public Internet
VPN Software
Payload PD
Flight Configuration for Astrobee
Astrobee Relay
(
RedHat
)
DDS-
Srvr
UDP Port: N1-N2
RTSP-
Srvr
TCP: xx UDP: P1-P2
TReK
CFDP
Ground Control Station GUI
DDS
RTSP
Ground Computer
VPN Software
Ground Control Station GUI
DDS
RTSP
JSC Bldg-8
Ground Computer
VPN Software
VLC
RTSP
TReK
HPEG
(
GroundNode
2)
Payload WAN/ISS Ethernet
Ku-Forward
TReK
HPEG
(
GroundNode
1)
Putty
SSH
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)
Slide18ARC-MMOC
Ames-Granite-Lab “ISS”
Astrobee3
Astrobee2
Astrobee1
MLP
(Ubuntu)
x.x.x.x
(static)
Payload WAN/ISS Ethernet
HOSC/POIC
TReK Toolkit
CFDP
Ku-Fwd
Auth
Svr
SSH/SCP
TCP: 22
HPEHG
Ku-Fwd G/W
DDS
UDP Port: N1-N2
LLP
(Ubuntu)
HLP
(
Andriod
)
RTSP
TCP: xx UDP: P1-P2
Internal Switch
ELC
Crew Control Station GUI
DDS
RTSP
Astrobee Dock
Ground Computer (WS4)
Internal Switch
CPU
(Ubuntu)
WAP
VPN Server
Public Internet
VPN Software
PRCU Test Configuration for Astrobee
Astrobee Relay
(
RedHat
)
DDS-
Svr
UDP Port: N1-N2
RTSP-
Svr
TCP: xx UDP: P1-P2
PRCU/RAPTR
Ground Control Station GUI
DDS
RTSP
TReK
HPEG
(
GroundNode
2)
HOSC
Router
TReK
HPEG
(
GroundNode
1)
Putty
SSH
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)
Slide19ISS
Astrobee1
MLP
(Ubuntu)
x.x.x.x
(static)
TReK Toolkit
CFDP
SSH/SCP
TCP: 22
DDS
UDP Port: N1-N2
LLP
(Ubuntu)
HLP
(
Andriod
)
RTSP
TCP: xx UDP: P1-P2
Internal Switch
Astrobee Dock
Internal Switch
CPU
(Ubuntu)
WAP
Test Configuration
A
Payload WAN/ISS Ethernet
Dev Laptop (
Macbook
)
Slide20ARC-MMOC
ISS
Astrobee1
MLP
(Ubuntu)
x.x.x.x
(static)
ICU
Ku-Fwd G/W
HOSC/POIC
Magic
TReK Toolkit
CFDP
Ku-Fwd
Auth
Svr
SSH/SCP
TCP: 22
HPEHG
Ku-Fwd G/W
DDS
UDP Port: N1-N2
LLP
(Ubuntu)
HLP
(
Andriod
)
RTSP
TCP: xx UDP: P1-P2
Internal Switch
Astrobee Dock
Ground Computer (WS4)
Internal Switch
CPU
(Ubuntu)
WAP
VPN Server
Public Internet
VPN Software
Test Configuration
B
TReK
HPEG
(
GroundNode
1)
Ground Control Station GUI
DDS
RTSP
Putty
SSH
Payload WAN/ISS Ethernet
Dev Laptop (
Macbook
)
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)
Ku-Forward
Slide21ARC-MMOC
ISS
Astrobee1
MLP
(Ubuntu)
x.x.x.x
(static)
ICU
Ku-Fwd G/W
HOSC/POIC
Magic
TReK Toolkit
CFDP
Ku-Fwd
Auth
Svr
SSH/SCP
TCP: 22
HPEHG
Ku-Fwd G/W
DDS
UDP Port: N1-N2
LLP
(Ubuntu)
HLP
(
Andriod
)
RTSP
TCP: xx UDP: P1-P2
Internal Switch
Dev Laptop (
Macbook
)
Astrobee Dock
Ground Computer (WS4)
Internal Switch
CPU
(Ubuntu)
WAP
VPN Server
Public Internet
VPN Software
Test Configuration
C
Astrobee Relay
(
RedHat
)
DDS-
Srvr
UDP Port: N1-N2
RTSP-
Srvr
TCP: xx UDP: P1-P2
Ground Control Station GUI
DDS
RTSP
Putty
SSH
TReK
HPEG
(
GroundNode
2)
Payload WAN/ISS Ethernet
Ku-Forward
Slide22Data 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/IPRTSP 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.
Slide23Video 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.
Slide24Data 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.
Slide25Data 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.
Slide26Data Flow: Data Products
Immediate Data Products
High-value logs and telemetry that are requested.
Use CFDP over DTNTReK CFDP tool will be usedDelayed Data ProductsOther wanted or very large productsCopy to NAS, wait for data through existing services (Qsync)
Slide27Point of Control
TReK
CFDP over DTN Diagram
HOSC
ISS
ISS DTN Gateway
MLP
Ethernet
Switch
Dock
Node 2 Edge Router
Ground DTN Gateway
TReK
CFDP
Ground Routers
Slide28TReK
CFDP over DTN Setup
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.
MLP
ISS DTN Gateway
Ground DTN Gateway
TReK
CFDP
P4 Design Review
Slide29Expected Transfer Rates
P4 Design Review
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
Mbps
datarate
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)
Slide30Per 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
Expected Transfer Rates
Slide31Agenda
Video Distribution Policy
31
Slide32Video 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
32
Slide33Data Path: Video/Data Distribution 1/2
Slide34JSC MCC
MSFC POIC
Big Screen
Control Station
Big Screen
Control Station
Payload PD
Aud
Control Station
ARC MMOC
Med Screen
Control Station
JSC
Bldg
8
MSFC HOSC
ISS ICU
Live Video
Distributed Video
Full Real-time Stream
MPEG2
KUIP
Data Path: Video/Data Distribution 2/2
Box
Future Work
Slide35Slide36Agenda
Ground Data System (GDS) Requirements for Astrobee Payloads
36
Slide37Ground Payload Computer Requirements
Windows 10
Browser support for HOSC EHS & OSTPV tools
IVODSHeadset connectivity Astrobee Ground Control StationHOSC VPN clientVLC 37
Slide38GDS required Accounts & Authentications
HOSC HOPS Account for:
IVODS
HOSC VPN loginNASA NDC credential for accessing Astrobee Facility file server for post-ops data downlink38
Slide39Agenda
Communications Hardware
39
Slide40WiFi Antenna
2.4 GHz/5.8 GHz
Wifi
antenna~3dBi/5dBi gainOmnidirectionalAdhesive tape mountingAdditional tape will be applied to ensure launch survivalPaper thinMass: 0.477g
P4 Design Review
Slide41Antenna 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.
Slide42Antennas
PWR
wake
Antenna Placement - Front
Slide43Antennas are on backside of Dock Adapter
Antenna location
Antenna Placement - Aft
Low adsorbent
filler
Slide44Antenna Modularity
An SMA/U.FL adapter has been added to ease installation and replacement.
This adapter is in-line.