Space Shuttle
Relative Navigation Sensors
Upgrade
Jim Lamoreux
NASA/JSC
5/22/02
Shuttle Rel Nav Sensors Upgrade
Shuttle Relative Navigation Sensors for Rendezvous,
Proximity Operations, & Docking:
• Star Trackers (ST)
• Ku-Band Rendezvous Radar (Integrated with
TDRS Communication System)
– Skin tracks 23 sq m target from 22 nmi; ISS from 100 nmi
– Measures Rng, Doppler Rng Rate, Brg, Brg Rate
• Trajectory Control Sensor (TCS)
– Measures Rng, Rng Rate, Brg to retroreflectors on ISS for
approach and docking
• Hand-Held Lidar (HHL) – Rng, Rng Rate to skin reflection
• Closed Circuit TV (CCTV) with subtended angle overlays
• Crew Optical Alignment Sight (COAS)
Shuttle Rel Nav Sensors Upgrade
Shuttle
Shuttle Sensor
Sensor Management
Management
40 nmi
2 ST
RR
1 TCS
2 HHL
3 CCTV
COAS
Trang Le
Alan Fox
Sean O’Rourke
Michele Kocen
22 nmi
8 nmi
3500 ft
100 ft
0 ft
Shuttle Rel Nav Sensors Upgrade
Typical Shuttle-ISS Rendezvous Profile
Target
-10 nmi
-20 nmi
-30 nmi
NC4
Ti
MC4
MC1
MC2
2 nmi
MC3
Night Star
Tracker Pass
4 nmi
6 nmi
-40 nmi
Day Star
Tracker Pass
Day Star
Tracker Pass
Sunset
Begin Radar
Tracking at
135 kft
Sunset
NCC
Night Star
Tracker Pass
Shuttle Rel Nav Sensors Upgrade
Shuttle-ISS Braking Gates and Proximity Operations
Shuttle Rel Nav Sensors Upgrade
Shuttle-ISS Separation and Fly-Around
Shuttle Rel Nav Sensors Upgrade
Rendezvous Sensor Priority Matrix
Range
Prime Sensor
Backups
>140,000 ft
-Z Star
Tracker
-Y Star
Tracker
Wait for Radar
<140,000 ft
Day
Radar
-Z Star
Tracker
(while target
< 8 arcmin)
-Y Star
Tracker
(while target
< 8 arcmin)
COAS
<140,000 ft
Night
Radar
-Z Star
Tracker
-Y Star
Tracker
COAS
Shuttle Rel Nav Sensors Upgrade
Prox Ops Sensor Priority Matrix (ISS)
Range
Prime Sensor
Backups
5000 - 600 ft
TCS
Radar
HHL
600 - 3 ft
TCS
HHL
CCTV and
Overlay
3 ft - Dock
TCS
CCTV and
Overlay
Subtended
angles charts
(Visual)
Shuttle Rel Nav Sensors Upgrade
Prox Ops Sensor Priority Matrix (Non-ISS)
Range
Prime Sensor
Backups
5000 - 100 ft
or loss of lock
Radar
TCS
(If available)
HHL
250 (or Radar
break lock) Grapple
HHL
TCS
(If available)
Camera
Triangulation
35 ft - Grapple
End Effector
Camera
TCS
(If available)
Camera
Triangulation
Subtended
angles charts
(Visual)
Shuttle Rel Nav Sensors Upgrade
• Ku-Band Radar/Comm System and TCS
supportability problems are predicted due to a
growing shortage of spare parts and unavailability
due to obsolescence. Initial assessments (1999):
• TCS not supportable beyond 2008, but parts available to
built more units.
• Ku-Band Radar/Comm System not supportable beyond
2005; Need to develop replacement.
Shuttle Rel Nav Sensors Upgrade
Initial Efforts for Ku-Band Radar/Comm Upgrade:
•
Employed QFD tool to identify and prioritize requirements.
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Separate comm and radar systems for simultaneous use
Eliminate antenna deployment (crit 1)
Eliminate existing radar problems (e.g., range ambiguity beyond 22 nmi)
and unused functions (e.g., angle rate measurement)
Enhance sensor capabilities if cost effective
Consider single sensor to replace rendezvous radar and TCS
Employ dual redundancy to eliminate training and crew workload required
for single-string radar failure.
Obtained radar/lidar developer info via RFI’s and site visits,
collaborated with JPL regarding lidar developments for automated
rendezvous, docking, and landing for DS4 comet sample return.
Established target costs and risks in design-to-cost exercise.
Developed concept of operations, program and system requirements
documents.
Shuttle Rel Nav Sensors Upgrade
• Architecture changed by Shuttle Program (8/01):
• Abandon separate tracking and comm plan.
• Functionally duplicate existing Ku-band integrated
radar/comm system and retain legacy vehicle interfaces to
minimize cost.
• Radar upgrade terminated by Shuttle Program (2/02)
• Reassessment of supportability problems, risks, and costs
indicated problems are less severe and are manageable to
at least 2012 if KSC repair capabilities are improved.
• Business case no longer supports radar/comm upgrade.
• Upgrade documentation archived for possible future
use (COD, PRD, SRD, Specs, IDD, etc).
Shuttle Rel Nav Sensors Upgrade
Concluding Remarks
• Information generated for Space Shuttle relative navigation
sensor upgrade will be valuable for future vehicle developments.
• For a new reusable launch vehicle, for which sensor interfaces
are not already established, a single sensor type that can
support rendezvous, proximity operations, docking/capture, and
possibly landing may be attractive.