descanso - a cost-effective array-based dsn (dsan) · 2014. 9. 3. · descanso seminar, jis - 4,...

DESCANSO Seminar, JIS - 1, 07/29/04

A Cost-Effective Array-based DSN (DSAN)

J. Statman(with contributions from B. Geldzahler, L. Deutsch, and R. Preston)

7/29/2004


WHY DSAN?

More Cost-Efficient!

020406080

100120140

FY08

FY10

FY12

FY14

FY16

X-bandKa-band

More Capacity!O&M Increase/Decrease, by year

-80

-60

-40

-20

0

20

40

60

FY06

FY08

FY10

FY12

FY14

FY16

FY18

FY20

Fiscal Year

$M, F

Y200

4

Net O&M Request

Total Budget Request, Accumulated

0200400600800

100012001400

FY06

FY08

FY10

FY12

FY14

FY16

FY18

FY20

Fiscal Year

$M, F

Y20

04

Budget Request,Accum

The Concept of Operations will facilitate efficiency, primarily by reducing O&M cost (numbers are preliminary, PCAT study is underway)

This chart shows the equivalent G/T, in units of 70-m X-band G/T.


The BIG Picture: A Combined Optical/RF Strategy

The Challenge: Capabilities are needed in deep spacecommunication that will accommodate orders-of-magnitude increase in science data and at least adoubling of the number of supported spacecraftover the next 30 years

– The present DSN architecture is not extensible to meet future needs in a reliable and cost-effective manner

– Optical communication, which will take at least another decade to mature and two to be operational, has development risk and may not be appropriate for all missions or mission phases

– NASA must develop a comprehensive strategy for deep space communications that meets the forthcoming dramatic increase in mission needs in a reliable and cost effective manner


The BIG Picture: A Combined Optical/RF Strategy (cont.)

Proposed Solution for the Next Generation DSN:Optical links plus arrays of small RF dishes

– This is a true end-to-end solution– Optical and radio array links would be

complementary: Optical links could handle high-rate communications from telecommunications orbiters and special missions, while the radio array links would benefit all missions large and small, new and old, as well as reducing mission risk by providing communications redundancy

– Radio arrays will be very reliable while the implementation cost will be relatively small compared to expansion of the current DSN architecture

• Costs will be recovered over time through reduction of DSN operations and maintenance costs

• Technology is mature and low-risk

Ka-band,Advanced coding & compression

100W transmitter,Next Gen RF transponder

Arrays of small antennas

Standard, commercial optical terminals

Optical terminals in orbit and/or on ground

1KW transmitter,10.5m Inflatable Antenna

1,000 times current perform

ance 1,00

0,00

0 ti

mes

cur

rent

per

form

ance


Why is Change Needed?

• MRO will only map about 1% of Mars surface – limited by communications– Selection of “prime sites” to observe is the worst kind of data compression because it introduces biases

• Future planetary missions will be more like Earth science missionsDetailed

Orbital Remote Sensing.

(e.g., MRO, JIMO)

Preliminary solar system reconnaissance via brief flybys.

In situexploration via

long-lived mobile elements.

(e.g., MER, MSL)

In situexploration via short-lived probes.

Low-Earth-orbit solar and astrophysical observatories.

Observatories located farther

from Earth.(e.g., SIRTF, JWST)

Single, large spacecraft for solar and astrophysical observations.

Constellations of small, low-cost

spacecraft.(e.g., MMS, MagCon)


Predicted Growth in Deep Space Mission Downlink Requirements (2005-2030)

Maximum End-to-End Link Difficulty as a Function of Time

1

10

100

1000

10000

100000

2005 2010 2015 2020 2025 2030

Calendar Year

Dat

a R

ate

x D

ista

nce^

2 (M

bps

x A

U^2

)

Maximum Downlink Rate as a Function of Time

1

10

100

1000

10000

2005 2010 2015 2020 2025 2030Calendar Year

Dow

nlin

k R

ate

(Mbp

s)

Robotic Human

Data Throughput Link Difficulty

MRO

MTOJWST

Human Lunar Flt. 1

Human Lunar Base2nd Gen MTO

Human Lunar Base

3rd Gen MTO

Cassini

Cassini

Voyager

JIMO

Titan Explorer

• Mars robotic and lunar human missions drive maximum data rates up by almost 3 orders of magnitude over next 25 years – probably an underestimate.

• Robotic missions to Jupiter and Saturn drive up difficulty of attempted link by a over 3 orders of magnitude over next 25 years – probably an underestimate.


The Next Generation RF DSN:Arrays of Small Antennas

• The current architecture using large antennas is not sufficient for NASA’s future – Will not meet the needs of NASA future mission set (sensitivity and navigation)– Is expensive to maintain and operate

• A new approach is needed: Arrays of small antennasReliable: – Provides graceful degradation in performance in case of

antenna or receiver failures – less single-point-of-failureScience Data Return:– Meets the science data rate requirements of most future

missions• Code S is investing in more capable science instruments to

enhance high-power missions– The architecture is easily scalable when growth is

required– Accommodates significant growth in the number of s/c

since an array could service several missions simultaneously, each with just the required aperture

Cost Effective– Substantially reduces operations and maintenance costs:

Plug-and-play components with longer lifetimes


Array Technology

Single chip LNA

Advances in the following areas are making much largerarrays feasible• Low cost, high performance, parabolic antennas

– Fueled by the home satellite TV industry

• Low cost, low noise, wide bandwidth RF amplifiers– Breakthroughs in MIC/MMIC technologies

• Low cost, reliable, cryogenics– Developed for the next generation of computers and

communications

• Long-distance, wide-bandwidth data transmission– Huge investments in fiber optics by telecom industry and

DoD

• Faster, less expensive computers for automation and operations

– Moore’s law


Downlink Life-Cycle-Cost (preliminary)

Optimal diameter is around 12 m

Cost of G/T Equivalent to 10x70m

0.0100.0200.0300.0400.0500.0600.0700.0

10 12 14 16 20 24 30 34 70

Antenna Diameter (m)

$M, F

Y200

4

Electronic O&MMechanical O&MArraying equipmentAntenna Feed/LNA/ElectronicsAntenna mechanicalRoads & trenchingHVACN2, Water, TVFTSPower & Foundation


Uplink Life-Cycle-Cost (preliminary)

Optimal diameter is around 34 m

Cost of EIRP Equivalent to 4 28 kW on a 34-m Antennas

0.0

20.0

40.0

60.0

80.0

100.0

10 12 14 16 20 24 30 34 70

Antenna Diameter (m)

$M, F

Y200

4

Electronic O&MMechanical O&MArraying equipmentTransmitterAntenna Feed/LNA/ElectronicsAntenna mechanicalRoads & trenchingHVACN2, Water, TVFTSPower & Foundation


Maximizing RF Performance:Arrays and Other New RF Technology

• Arrays of 400 12m antennas could provide the equivalent of a 240m antenna at each of three longitudes. This alone could provide a factor of 10 increase in bit-rate over a 70m antenna (or a factor of 40 over a 34m antenna)

• Improvements in other RF technology are already underway:

– Ka-band will lead to a factor of 4 increase in bit-rate over X-band

– Improved data compression, coding, and modulation could lead to a factor of > 5 increase

– A 100W transmitter would lead to a factor of 10 increase over today’s ~10W transmitters

– A 1 kW transmitter would lead to an additional factor of 10 increase

– A 10.5m inflatable antenna would lead to 50x increase over today’s 1.5m antennas

• A new deep space transponder will be required to take advantage of the increased performance, (ROM development cost ~$20M)


Projected RF Communication Performance Increases – Getting 106

Current DSMSSpacecraft: X-band, 10W, 1.5m ant; DSN: 70m ant

Array of Small AntennasDSN equivalent 240m ant

Advanced Coding & CompressionFactor of 5 over today

Higher Power S/C Transmitter1kW

Inflatable S/C Antenna10.5m

Ka-BandFactor of 4 enabled by Array

High Power S/C Transmitter100W

0

1

2

3

4

5

610

10

10

10

10

10

10

Per

form

ance

Impr

ovem

ent

Flight Enhancements

Flight/Ground Enhancements

Ground Enhancements


Benefits of a Next Generation RF DSN to NASA Missions

• Flexibility to trade new performance increases with parameters other than data rate– Lower mission costs, reduced power, antenna mass, pointing requirements, …– Reduced dependence on gravity assists, due to lower mass– Smaller communications orbiters

• Improve data-rate from low-gain antennas during descent and landing or spacecraft emergencies

• Provide precision plane-of-sky spacecraft position measurements for navigation– Precision of DDOR will increase by 10x over current capability – crucial for outer planet

spacecraft navigation– Real-time milli-arcsecond accuracy– Improves targeting and orbit determination and reduces mission risk

• Provide operational benefits– Graceful failure – eliminates single points of failure– Weather diversity– Expandability– Reduced operational costs

• Improve radio link science data return: Increased Signal/Noise of radio occultation measurements by more than 20 dB

– Investigate planetary atmospheres at both higher and lower altitudes


High Level Array Implementation Roadmap

Phase CArray-based DSN

Primary and Secondary (3x400)

Phase AArray-based DSN Primary Clusters

only (3x200)

Complete evaluation of a operational 34-m –equivalent downlink

(12 12m antennas)

Small scale array demo

(3 6m antennas)

PDCR – Preliminary Definition & Cost

Review

12/15/04 9/30/05

9/30/08

20122011

Non-Advocate Review

7/15/05

Phase BArray-based DSN

Uplink & Downlink, 3x200

2013


Proposed Architecture of the Array-based DSN

DSAN CentralScheduling

Pass ManagementR/T Operations monitor

Data Management

Regional Array CenterWestern USASignal processing

Telemetry/TrackingUplink exciters

Monitor & Control

Uplink Small & larger

uplink antennas

Downlink Cluster(s)

200/200 12-m antennas Array/telemetry/tracking

OutriggersSmall up/downAntennas to close gaps

Regional Array CenterEuropean Longitude

Signal processingTelemetry/Tracking

Uplink excitersMonitor & Control

Partner Sites


uplink antennas

Downlink Cluster(s)



Regional Array CenterWestern Australia

Signal processingTelemetry/Tracking

Uplink excitersMonitor & Control


uplink antennas

Downlink Cluster(s)



* DSAN will have two clusters near each longitude, each with approximately 200 12-m antennas, to protect against adverse weather. The primary cluster will reside next to the Regional Array Center (RAC) and the uplink antennas. The secondary cluster will be downlink only


Reducing the O&M Cost

• Key contributors are: – Single 24x7 facility for real-time operations

• The DSN has four such facilities

– Centralized IT function (software loading, computer setup)• The DSN has staffs at all sites to conduct the functions

– Validation of mission inputs, at submission• For the DSN the mission inputs are validated, often, at the pass setup

– Schedule/Script-based real-time operations, rare human intervention• The DSN requires frequent steps of human intervention

– Single hand-off between development and sites• The DSN has dual hand-off

– Less-sensitive to failure of antenna/LNA (G/T degradation)• For the DSN, failure results in loss-of-link,

• See the Concept of Operations (900-001, Rev C) for more details


Staffing (Preliminary)

DSAN Central5 24x7 Operators40 8x5 positions

Engineering support

Cluster(s)8x5 positions

(50 FTE)


(50 FTE)


(50 FTE)

Regional Array Center2 24x7 Rovers

(12 FTE, optional)


(12 FTE, optional)


(12 FTE, optional)

Total O&M & customer interface staff to support x10 70m capability5-11 24x7 positions190 8x5 positions


The Road to a Plan

∆ Organization∆ Schedule√ WBS

Risk∆ Sites∆ NEPAEH&STrainingetc

√ Level 1 req√ System Req√ Architecture√ Operations Method’y√ Decomposition

Cost8/1/2004

DevelopmentO&M

HW Replacement

What PDCR12/15/2004

How

ValidateFeasibility/

Risk900-001, Rev C

Concept of Operations

Project Implementation Plan∆ Antenna∆ 2/3-element demo√ Ball study – Maintenance∆ Uplink √ Completed

∆ Underway


WHY DSAN?

More Efficient!

0

20

40

60

80

100

120

140

FY08 FY10 FY12 FY14 FY16

X-bandKa-band

More Capacity!O&M Increase/Decrease, by year

-80

-60

-40

-20

0

20

40

60

FY06

FY08

FY10

FY12

FY14

FY16

FY18

FY20

Fiscal Year

$M, F

Y200

4

Net O&M Request

Total Budget Request, Accumulated

0200400600800

100012001400

FY06

FY08

FY10

FY12

FY14

FY16

FY18

FY20

Fiscal Year

$M, F

Y20

04

Budget Request,Accum

The Concept of Operations will facilitate efficiency, primarily reduction in O&M (numbers are draft only)

This chart shows the equivalent G/T, in units of 70-m X-band G/T.


For Additional Information

• On-line:– Go to IND– Click on 960– Peruse documents & presentations

descanso - a cost-effective array-based dsn (dsan) · 2014. 9. 3. · descanso seminar, jis - 4,...

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