Ralph.basilio

The Quest for anOCO (Orbiting Carbon Observatory)

Re-flight

NASA Project Management Challenge09-10 February 2010, Galveston, Texas, USA

Presented by

Ralph R. BasilioJet Propulsion Laboratory

California Institute of Technology

© 2009 California Institute of Technology. Government sponsorship acknowledged.Used with permission

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Agenda

• The OCO mission• That fateful day• From shock to resolve• Measurement imperatives• Initial options examined

• Service platforms• Access to space

• Options examined in detail• While we await authorization• Summary/conclusions

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OCO Mission

To make the first space-based measurements of CO2 with the accuracy needed to quantify sources and sinks of this important greenhouse gas

Accurate predictions of climate change require an improved understanding of the global carbon cycle and its interaction with the Earth System

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Final Taurus XL Processing at VAFB

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24 February 2009: A Beautiful Launch

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Then…

• The launch vehicle payload fairing was scheduled to separate approximately 3 minutes after launch, but telemetered data never provided positive indication

• The launch vehicle failed to reach orbital velocity providing corroborating evidence of excess mass being carried into space

• A contingency was declared less than 16 minutes after launch

• A somber moment: The OCO mission manager stating that the space and ground network station failed to acquire a signal from the observatory

• Another somber moment: Telemetered data provided positive indication that the observatory had separated from the launch vehicle, albeit, still inside the fairing

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The Investigation

• NASA HQ commissioned an MIB (Mishap Investigation Board) in an attempt to determine the root cause of the anomaly and recommend corrective actions

• Although a direct cause was not identified, a number of hardware components whose failure modes may have caused the anomaly were

• Incomplete fracture of the frangible joint• Electrical subsystem failed to deliver initiating signals• Pneumatic system failed to provide sufficient pressure• Flexible Confined Detonating Cord snagged

• NASA LSP (Launch Services Program) is working to improve the reliability of the Glory launch aboard a Taurus XL

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No Time to Grieve

• OCO Project personnel met with JPL senior management the day after the loss to initiate re-flight planning

• An unsolicited proposal (for the direct rebuild option) was prepared and delivered to NASA HQ just two days later

• Key note: Little to no flight spare hardware available

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Commissioning of a Science White Paper

• NASA HQ requested the OCO Science Team to prepare a white paper discussing:

• The current state of carbon cycle science• The advances made in carbon cycle science since the

selection of the OCO mission in 2002• Key issues

• The Decadel Survey made it’s recommendations• GOSAT (Greenhouse gases Observing SATellite) was

launched• OCO was lost

• Minimum science requirements for the next carbon mission

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Justification for an OCO Re-flight

• Accurate and precise measurements of carbon dioxide sources and sinks is of paramount importance

• Despite progress, our knowledge is limited by the lack of high precision global measurements of atmospheric carbon dioxide

• While there have been advances in space-based measurements there is no existing or confirmed sensor capable of quantifying carbon dioxide sources and sinks

An OCO re-flight meets science and policy imperatives

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Charter

• Beginning in Early March 2009, JPL was directed to• “…conduct studies to assess the options for the re-flight of the

OCO instrument and recovery of the OCO carbon-related measurement, and to understand and quantitatively assess the cost, schedule, and technical and programmatic risks of the identified options.”

• Consider multiple options initially, “…eventually concentrating on the most profitable and viable option later in the latter portion of the study.”

• Assessment report delivery/submittal schedule• 20 March 2009, Initial• 24 April 2009• 29 May 2009• 26 June 2009• 30 July 2009, Final

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Service Platform Requirements

Parameter Original OCO

Likely Increases for Dedicated Spacecraft (not LeoStar II)

Increases for Shared Platform (OCO Does Its Own Pointing via TBD pointing

mechanism)*

Mass 134 kg 10% to 20% to replicate structure of OCO spacecraft used by instrument 10% to 20% + 10 to 30 kg increase

Power ~105 W 10% to 30% for converter boxes to replicate LeoStar interfaces

10% to 30% + 10W to 20W for pointing mechanism

Data Rate ~1 Mbs Returning full 8 footprints would take ~2 Mbs5% to 10% risk if packets need to be redefined for new system

Interfaces See next page

FOV 1o x 0.1o With near 2π steradian keep out zone

Pointing Modes Nadir, glint, target, solar, lunar

Pointing Knowledge 200 arcseconds knowledge

Orbit 1:30 pm sun sync

Science questions best served in a slow repeat cycle, high inclination, 10 am to 2 pm equator crossing, sun-synchronous orbit (slow repeat cycle = better geographic sampling, high inclination = global coverage, near-noon = high SNR, sun-synchronous = simpler inversion of sources and sinks)

* Mass and power pointing mechanism very uncertain. Polarization issues will make this much more complicated than traditional systems.

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• Programs too far in the development life cycle to accommodate the addition of an OCO instrument (i.e., in Phase D or equivalent)

– NASA (National Aeronautics and Space Administration)▪ Glory - Launch is currently scheduled for NET 01 Oct 2009▪ Aquarius/SAC-D

- The observatory includes a full-complement of instruments

- Launch is currently scheduled for NET 22 May 2010▪ NPP [NPOESS (National Polar-orbiting Operational

Environmental Satellite System) Preparatory Project]- The observatory includes a full-complement of

instruments- Launch is currently scheduled for June 2010

• An airborne option for the OCO instrument was investigated, but appears to provide only limited science benefit [e.g., better understanding of the BRDF (Bi-Directional Reflectance Distribution Function)]. No further work warranted.

Pre-Screened Service Platform Options

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• Dedicated and shared service platforms that did not meet technical requirements or the capabilities unknown

– Thales Alenia Space PROTEUS– Thales Alenia Space Globalstar-2– STP (Space Test Program) SIV (Standard Interface Vehicle)

“Heavy” version– Iridium-2– General Dynamics Spectrum Astro Space Systems– USAF ORS (Operationally Responsive Space)– GCOM-W1 (Global Change Observation Mission, Water No.1)– GCOM-C1 (Global Change Observation Mission, Carbon No.1)– IceSat-2– International Space Station

Other Service Platforms Screened Later

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• Dedicated and shared service platforms that did not meet technical requirements or the capabilities unknown

– Thales Alenia Space PROTEUS– Thales Alenia Space Globalstar-2– STP (Space Test Program) SIV (Standard Interface Vehicle) “Heavy”

version– Iridium-2– General Dynamics Spectrum Astro Space Systems– USAF ORS (Operationally Responsive Space)– GCOM-W1 (Global Change Observation Mission, Water No.1)– GCOM-C1 (Global Change Observation Mission, Carbon No.1)– IceSat-2– International Space Station

• The two most likely solutions– Shared platform with the TIRS (Thermal Infrared Sensor) instrument– OSC (Orbital Sciences Corporation) LeoStar-2 [The Baseline]

Other Service Platforms Considered

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OCO and TIRS Instruments on a Shared Bus

• JPL, along with GSFC and USGS, participated in a NASA ESD-lead joint OCO-TIRS (Thermal Infrared Sensor) mission study that was documented in a report issued on 19 June 2009

• Two options were examined

– Option 1: OCO and TIRS instruments on a shared, nadir-pointed platform▪ Co-registration of TIRS-LDCM/OLI (Operational Land Imager) data

drives cost▪ Scenario requires OCO pointing and polarization mechanisms

– Option 2: OCO and TIRS instruments on a time-shared platform▪ Scenario is incompatible with stringent TIRS thermal stability

requirements

– However, a third option was examined: Dual-manifest launch with OCO and TIRS on separate platforms

▪ An initial assessment identified a fairing envelope violation

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OCO Instrument on a Dedicated Platform

• Build a “Carbon Copy” of OCO (instrument and spacecraft bus) to the extent possible

• This lowest risk approach leverages the original OCO design, management approach, key personnel, and processes to the maximum degree to provide the shortest path to launch

• Minimize change!!

– JPL successfully delivered OCO and met all the cost and schedule commitments outlined in the revised plan presented at the 05 April 2007 NASA SMD (Science Mission Directorate) DPMC (Directorate Program Management Council)

– Carbon Copy is based on the OCO implementation approach and is, to the extent possible, a recurring implementation task

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Primary Access to Space Considerations

• Assumptions bearing upon the choice of launch vehicle (minimum requirements)

– Injection orbit: altitude and inclination▪ Equatorial altitude: 550 km (was 640 km for OCO

mission)▪ Orbit Inclination: 80 deg (was 97.95 deg for OCO

mission)– Observatory mass to injection orbit: 447 kg– Observatory launch configuration dimensions

▪ Length: 246 cm▪ Diameter: 140 cm

– Observatory contamination control requirements: GN2instrument purge

– Injection orbit errors:▪ ∆SMA ≤ 30 km, 3σ▪ ∆Inc ≤ 0.15, 3σ

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• OSC– Pegasus Air-Launched Vehicle: Does not meet mass

requirements– Taurus II: New, not yet certified

• Space X Falcon 9: New and launches from VAFB are uncertain• ULA (United Launch Alliance): All cost-prohibitive

– Delta II– Delta IV– Atlas V

• A number of shared rides were also examined, but none ‘fit the bill’

• The two most likely solutions– OSC Minotaur IV– OSC Taurus XL [The Baseline]

Access to Space Options

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Minotaur IV Launch Vehicle

• Must be provided by USAF through either

– The DoD SERB (Space Experiments Review Board) process (e.g., NASA SMAP mission), or

– As a direct procurement through the USAF Space Development & Test Wing (e.g., NASA LADEE mission)

• NASA KSC LSP assessed use of Minotaur IV/V for NASA Class C:

– Mission risk is appropriately mitigated after one successful flight of a vehicle in this family and USAF post flight data review

– First Minotaur IV flight scheduled for late 2009

• Use must comply with U.S. Commercial Space Transportation Act

• A 27-month procurement cycle from ATP to ILC (Initial Launch Capability) appears feasible

• Must verify loads (i.e., lateral) compatibility

Minotaur IV Rocket System on test stand

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Taurus XL Launch Vehicle

• The Taurus XL is the existing baseline

• A 28-month life cycle from RFP to ATP to ILC can be supported

• May incur risks associated with infrequent launches

– 4.5 years between ROCSAT-2 and OCO– 1-2 years between OCO and Glory– 1-3 years between Glory and OCO Re-flight

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• NASA has provided funding to the OCO Project to– Procure some instrument and spacecraft bus EEE parts

mitigate parts obsolescence issues, etc…– Assess and evaluate required changes (e.g., use of a substrate-

removed HgCdTe detector for the instrument A-band channel and adaptation/use of a split, pulse tube cryocooler)

– Collaborate with the GOSAT (Greenhouse gases Observing SATellite) team▪ Assist them in producing the best possible retrieval

estimates of atmospheric carbon dioxide concentration levels

▪ Mitigate risk by exercising OCO science data processing capabilities developed pre-launch with actual in-flight data

• These and other tasks serve to place the OCO Project in a more robust posture/position in the event a re-flight is authorized

While We Await Authorization to Start

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• No guarantees - Spaceflight is a risky business, and with calculated risks failures occasionally occur

• Keep the team intact – Corporate knowledge resides with people. Fortunately, many on the OCO Project have a sense of unfinished business and are committed to the re-flight efforts.

• Believe in your cause and others will believe - The OCO mission continues to receive endorsements, support, and encouragement by NASA and other agencies/entities

• Due diligence for the American taxpayer - An objective evaluation of re-flight options was completed

• Make it work, not make it better - Even though a direct rebuild or carbon copy is the leading re-flight option, the project is challenged by change each and every day

• Patience, and make the best of the situation – The project team is using the available time and resources to reduce implementation risk while awaiting a decision on a re-flight

Summary/Conclusions

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OCO-2 Can be a Reality