AOS Overview for Market Research.pdf

AOS Study Architecture

AOS

Mission Lifetime 1 Year + 60-day (TBR) Commissioning Phase

Consumables 3 Years

Launch Date 8/2030

Instruments CNES Microwave Radiometer

Orbit 430 km ± 10km 55-degree inclination

Attitude Target Geodetic nadir with dynamic yaw steering

AOS Spacecraft

JAXA PMM

CNES Radiometer

~7.2m

Dual-Manifested Launch with JAXA PMM

Key Payload Accommodations Parameters

Parameter Value Mass 85 kg (75 kg + 10 kg mission reserve)

Volume 900 mm (along XIU axis) x 550 mm (along YIU axis) x 600 mm (along ZIU axis)

Operational Power (Orbit Avg) 105W (95W + 10W mission reserve)

Survival Power (Orbit Average) 95W (85W + 10W mission reserve)

Voltage 28V (Interested in any heritage capability for higher voltage)

Radiator Keep Out Zone ±70 deg cone with origin on radiator

FOV/FOR ZFOV, YFOV plane à field of view of 138° (from Nadir-92° to Nadir+46°).

ZFOV, XFOV plane à field of view of +/- 3 degrees (around Nadir).

Data Generation Rate 400 kbps

Data Interfaces 2x LVDS* 2 x RS-422* 2 x PPS*

Pointing Accuracy (Spacecraft Allocation)

0.25° around XIU (TBC) 0.25° around YIU (TBC) 1.5° around ZIU (TBC)

Pointing Knowledge (Spacecraft Allocation) 0.04° around XIU, around YIU and around ZIU (TBC)

Pointing Stability 0.025° (TBR) over one scan (0.5 sec)

Self-Induced Disturbances

- Exported force along YIU and ZIU shall be less than 70 mN

- The angular moment (around XIU axis) shall be less than 0.14 N*m*s TBC (constant value).

- Exported couple shall not exceed 35 mN*m (TBC) along YIU and ZIU axis.

* Can be reduced to 1 for a single-string S/C

Driving Requirements

Driving Requirement S/C Capability Required Comments

Formation Fly with PMM Propulsion Chemical prop studied and is acceptable SEP under evaluation

• Unknown maneuver strategies with PMM and uncertain if able to be in Science mode during longer burns dV 215 m/s This excludes any propulsion needed for de-orbit. Based off conservative estimate for 3 years

LV Compatibility Mass, volume, and environments envelope Falcon, New Glenn, and Vulcan

• SMD RUG requires 75 Hz 1st mode. AOS relaxed this to 50 Hz

• Volume constrained by ESPA-Grande height and Falcon Fairing (see backup slides)

• Mass limited by ESPA-Grande port capability

Stability/Jitter 0.025° over one scan (0.5 sec) Radiometer has a unbalanced, spinning mirror that causes self-induced force/torque (details on previous slide)

Orbit – High drag environment

Additional prop for drag makeup Actuator control authority

430km altitude may be below the typical operating range for COTS Spacecraft

Orbit – Beta Angle Yaw flips 180 deg rotation about nadir vector to maintain radiator cold view to space

Operational Availability 95% (TBR) operational availability Radiometer operates at 100% duty cycle after commissioning Spacecraft must be capable of maintaining Science mode for long durations

SHAPE FILL

WITH IMAGE

Backup

Goals

• NASA pivoting from imposing NASA-typical processes to relying on industry best practices o Looking for a cost-effective means to host CNES Radiometer

• How do we procure a high-heritage, low cost Commercial spacecraft?

• Focus on a Commercial offering that is compatible with mission and payload requirements with no/minimal NRE

• How are we achieving this?

o Streamlined, minimal requirements o Leveraging Inherited item process

• At the highest level of assembly (Up to including entire spacecraft)

• Do not deviate from vendors successfully proven processes

• Minimal NASA oversight only in areas of new development or high risk o Evaluate Risk Class to more readily align with industry practices

Inherited Items

• The spacecraft industry is producing large numbers of like spacecraft to support many constellation efforts

• The manufacturing, test and verification methods have evolved using the trend data from actual performance on orbit

• At GSFC, we recognize that typical past requirements provide the best chance of success for one-off spacecraft builds, and are not as applicable to the new environment of a COTS spacecraft

• Consequently, GSFC policy has been revised to take advantage of the on-orbit successes of commercial spacecraft

• Inherited items are based on the principle that a manufacturer whose products have proven reliability can be trusted to deliver standard products without outside interference in their processes

• The intent is to reduce the amount of government processes levied on a vendor who shows reliability of and item through inheritance

• Application of the Inherited Items Process, allows the vendor to build hardware per their internal processes and relieves NASA Mission Assurance Requirements (MAR) and oversight

• Inherited Items Process 2.0 (Package and Video) https://rsdo.gsfc.nasa.gov/vendor.html

Inherited Items Package

Typical Inherited Items Package includes:

1. List of inherited items and statement of approach – rebuild, modification of previous build, or use of existing hardware. If the inherited item is an entire spacecraft, name the spacecraft model.

a. State any modifications since the previous flight or modifications that must be made to meet the requirements of the mission.

2. Summary results of qualification and acceptance testing completed as was performed on the inherited design, including environments, required design margins, and life for the last few flights of the inherited design.

3. Flight history of the items or spacecraft and specific attributes for no less than the few flights, including environments

a. Show how the previous environments compare to the AOS defined environment, including duty cycle and general concept of operations.

4. Ground and On-orbit anomaly/failure history including the determination of root causes or information that root cause was not determined for the last two flights. Corrective action for stated anomalies shall be included. Anomalies included in this package shall meet the following requirements.

a. Anomalies that occurred during the period starting at the beginning of on orbit operations through the end of required mission life.

b. Only include Anomalies which threatened the ability to meet or that resulted in an inability to meet mission life requirements and/or mission success requirements.

c. Ground anomalies may be restricted to major anomalies which impacted mission success requirements.

5. The reliability analyses performed for products that do not have more than one prior flight in the current mission environment and lifetime.

Observatory Launch Vehicle Compatibility

• Allocated Volume assuming ESPA-Grande o Larger than allocation from RUG, since project “owns” the ring as a dual manifest launch vs. typical rideshare

• Observatory MPV mass limited by ESPA port capability

• AOS-Storm observatory 50 Hz first mode requirement to prevent coupling with PMM

• Environments provided by LSP to envelope 3 candidate

LV’s o Falcon 9, New Glenn, Vulcan

• Modification of this volume may be possible through different ESPA and/or spacer options