# Presentation: 704628

## Micro-Arcsecond Imaging Mission, Pathfinder (MAXIM-PF)

**Code 302**
**May 13-17, 2002**

**Micro-Arcsecond Imaging Mission, Pathfinder (MAXIM-PF)**

**Mission Success**

## Summary

**Mission Success**
- Even with Fully Redundant S/C buses, the continuing Phase I & II operation is expected to have low probability of completing the full four (4) Year mission
**Design Considerations**
- Hub S/C
- Recommend either redundant Laser ranger devices or Laser beams from at least (2) separate Laser devices of both wide & narrow beam
- Detector S/C
- Redundant design looks good
- Free Flyer S/Cs
- Redundant design looks good
**Mission Success Alternatives**
- From a Reliability standpoint, other designs should be considered
- Two separate Detector S/C (single string) with:
- Single Hub S/C (Fully Redundant) with Free Flyers or:
-  Two separate Hubs ( single string ) without Free Flyers
**R&S Support Cost**
- 1 Million $ To support both Reliability & System Safety effort for at least 3 years

## Assumptions

**Mission Length**
- Phase I
- Mission length to be 1 Yr with Phase II to follow. Six (6) Months to get in orbit
- Phase II
- Mission length to be 3 Yrs / 5 Year Goal
- Total ( Phase I & II )
- Four (4) Years with 5 Year Goal
**Redundancy**
- Hub S/C –-Put Redundancy into Hub design & not Free Flyer
- Detector S/C –Fully redundant design needed

## S/C Components

**Phase I**
**Lens S/C (Hub)**
**Tunable X-Ray Optical System**
**Star Tracker**
**S/C Bus**
**Propulsion System**
**ACS**
**Laser Ranger to Detector S/C**
**Six(6) attached Free Flyers acting as extra X-Ray reflectors**
**Detector S/C**
**RF Com to Earth**
**Propulsion System**
**ACS**
**##############################################**
**Phase II**
**Lens S/C (Hub****)**
**Tunable X-Ray Optical System**
**Star Tracker**
**S/C Bus**
**Propulsion System**
**ACS**
**Laser Ranger**
**Detachable Lens sections ( 6 units )**
**Release Mech.**
**Tunable X-Ray Optical System**
**Detector S/C**
**Super Star Tracker**
**Cryo Cooler**
**RF Com to Earth**
**Propulsion System**
**ACS**

## Reliability Block DiagramPhase I

**Hub S/C**
**Bus**

**Detector S/C Bus**

**FF Bus**

**Hub Devices**

**Detector **
**Devices**

- Launch Vehicle
- Delta IV

- Hydrazine
- Injection Propulsion
- System

## Reliability Block DiagramPhase II

**Detector **
**Devices**

**Detector **
**S/C Bus**

**Hub**
**Devices**

**FF Bus**

**Hub Tunable**
**Mirrors**

**Hub S/C**
**Bus**

**FF Laser**
** ****Com**

**FF #2**

**FF #** 3

**FF #** 4

**FF #** 5

**FF #** 6

**Free Flyer (FF #1)**
**S/C #1 of 6**

- Detector S/C

- Hub S/C

- Launch Vehicle
- Delta IV

- Hydrazine
- Injection
- Propulsion
- System

## Quick Mission Reliability Estimate

**Phase I**
- Best Case Est. Mode I ( 2 Yr Mission ) 1?
**Without LV & Injector Prop. :   .9 X.98 X.9 X.98 = ****78% @ 1 Yr**
**With LV & Injector Prop.:   .78 X .94 X .99 = ****72 % @ 1 Yr**
**Phase I & II**
- Best Case Est. Mode I & II ( 4 Yr Mission Total )
**Without LV & Injector Prop. :  .9 X.95 X.9 X.95 = ****63% @ 4 Yrs**
**With LV & Injector Prop.:  .63 X .94 X .99  = ****58.6% @ 4 Yrs**
**LV=Launch Vehicle**

## Launch Vehicle

**Delta IV**
- 94% Launch success Est. by Mfg.
- Air Force committed to future launches
- 1st stage is new design
**Hydrazine Propulsion L-2 Orbit Injection System**
- No Reliability info, assume similar to S/C Hydrazine propulsion system
- 99% or better

## Deployments

**Hub S/C**
- Laser Lens Cap
- 6 Detachable Free Flyers
**Detector S/C**
- 2 RF X-Band High Gain (dish) Antennas
**Free Flyer S/Cs**
- None on S/C
**Separation Systems**
- Separation of Hydrazine Propulsion Orbit Insertion System
- Separation of Hub from Detector & attached Free Flyers
- Separation of Six(6) separate Free Flyer units from the Hub

## PRA Support & CostsReliability & System Safety

**Full PRA Version Requirement Assumed**
- Will likely include Fault Tree Success Diagram
- Full Reliability evaluation for both Spacecraft Bus & all Instruments
**Reliability**
- GSFC Code 302 would likely play the coordinator of the operation even if an RSDO bus was chosen
- Instrument Reliability will likely be done by design & builder of each.
**System Safety**
- GSFC Code 302 would likely play the coordinator of the Safety Data Package ( Only one(1) expected to cover all) even if an RSDO bus was chosen
**Cost Estimate: 1.0 Million $**
-  Basis is: 1 FTE ( based on GSFC  contractor $ ) for each discipline for 3 years .
- Likely more if GSFC Code 302 monitors or supervises coordination of effort by other contractors

**PRA Support & Costs****Reliability & System Safety**

## Back-Up Slides

**See RSDO S/C Bus Reliability Information Graph**

## RSDO S/C Bus Reliability For One (1) Year Mission

**S/C Bus Reliability Curve**

- Fully Redundant

- Single String

**RSDO S/C Bus Reliability For ****One (1) Year Mission**

- Reliability %

- Failure Rate in Failures / Million Hrs

## Single S/C 3 YearBus Reliability

**Fully Redundant S/C Bus**

**Single String S/C Bus**

**Partially Redundant S/C Bus Area**

**3 Year Mission—Spacecraft Bus Only (Based On RSDO S/C Bus Reliability Info)**** **

## RSDO S/C Bus Reliability For Four (4) Year Mission

- Fully Redundant
- S/C Bus area

- Reliability

- Failure Rate