# Presentation: 924152

## JWST Status

- Eric P. SmithJWST Program Scientist

## Topics

- JWST Cost Growth
- Science Assessment Team Findings and Program Response
- JWST Plans

- 11-October-2005

## Recent Programmatic Changes

- ~$1B net cost growth
- ~$180M at NGST and ~$35M at subs
- Reevaluation of I&T effort (metrology, GSE)
- Additional launcher-related testing requirements
- Reallocation of technical resources (e.g., mass and power budgets) among observatory elements
- ~$85M in instruments and related elements
- ~$160M of recommended added contingency funding
- ~$600M for 22 month launch slip to 6/2013
- Launch vehicle uncertainty and lack of TAA
- Budget profile limitations in FY06 and 07
- Schedule risk reduction (negotiated w/ NGST)
- Technology maturation efforts remain on schedule

- 11-October-2005

## Science Assessment Team (SAT) Findings

- “... the scientific case for the JWST mission has become even stronger since its highest ranking by the Decadal report in 2000.”
- Retain current 6.5 meter primary aperture
- Retain current instrument complement
- Priority on unique capabilities, i.e., performance longward of 1.7 microns, given the limitations of other future ground and space-based assets
- Use prioritization as a guide to reduce cost and risk

- 11-October-2005

## SAT-Endorsed Changes

| SAT Recommendation | Program Response |
| --- | --- |
| De-emphasize or eliminate low-priority instrument capabilities | See next chart |
| Simplify Integration & Test | Revising Integration & Test plan (e.g., “cup-up” testing) 
~$130M & 3 months savings (TBR) |
| Eliminate 1 μm encircled energy requirement | Eliminate Level 1 requirement (possible degradation of imaging performance at shortest wavelengths)
enables simplified I&T (see above) 
reduces mirror polishing schedule risk |
| Relax scattered light requirement | Change cleanliness levels (acceptable potential reduction in sensitivity)
enables “cup-up” layout, simplified I&T (see above) |
| Relax optical stability requirement | Change tstab = 30 days to tstab = 14 days  (reduce observing efficiency ~1%)
reduces telescope backplane development risk |
| Relax/eliminate anisotropy requirement | Eliminate Level 2 Point-Spread-Function anisotropy requirement (no expected science impact)
reduces telescope development risk |
| Maintain mission lifetime goal | No change |

- 11-October-2005

## SAT-Endorsed Changes:Science Instruments

| SAT Recommendation | Program Response |
| --- | --- |
| Maintain short wavelength (  < 1.7 μm) instrument capabilities, but eliminate JWST architecture (ISIM level and above) requirements for testing/verification of these capabilities | Revising Integration & Test and verification plans to comply with recommendation (fewer reverifications of lowest priority science modes, elimination of potentially infeasible tests)
specific cost and schedule benefits TBD |
| Maintain current MIRI coronography capabilities  | No change |
| Retain single channel tunable filter | Eliminate short wavelength portion of tunable filter (loss of lowest priority science capability)
saves 80kg; improves mass margin
reduces complexity; enhances likelihood of on-time delivery of FGS |

- 11-October-2005

## Moving Forward

- Consult scientists
- regarding JWST’s
- scientific significance,
- prioritize JWST’s
- capabilities

- Revise mission development plan
- Preliminary				Final

- Independent Assessment

- Formulate budget

- May’05

- Apr’06

*Science Assessment Team (SAT)*

*NASA’s Independent Program Analysis Office (IPAO)*

- 11-October-2005

## JWST Replan

- It’s not over...
- Additional study of I&T and verification plan forecast with ultimate conclusion around April 06
- Will this happen again?
- History of replans
- 8m  6m diameter requirement, Fall 2000
- Replan I, Fall 2002
- Replan II, Summer 2005
- (*see chart 9*)
- Will the science change?
- No, first light goal combined with NAS decadal position prohibits significant changes in observatory

- 11-October-2005

## HST Spending History

- (Projection)

- 11-October-2005

## JWST Program Today

- Early emphasis on vigorous technology development to retire risk
- Pacing items (primary mirror, detectors) already in Phase C/D and flight production
- ~$820M (~20% of Phase A through D total) invested so far

- 11-October-2005

## Summary

**Actions being taken to address JWST cost and schedule changes**
- Current estimated cost, inception through launch		$3.7B
- Current estimated cost, Oct’06 through launch		$2.9B
- Science assessment complete
- JWST reconfirmed as mission of paramount significance and priority
- Scientific capabilities prioritized
- Recommendations provide some cost savings and significant risk reduction; added flexibility for program management
- Preliminary replanning complete, FY07 budget adjusted and submitted
- Science assessment recommendations embraced, being implemented
- Launch in June 2013
- Preliminary stage of independent assessment found program work plan fundamentally sound, but likely to need more time and money
**Detailed replanning will be complete by April 2006**
- Fully implement embraced SAT changes
- Follow-up independent review and assessment
- Forms basis for FY08 budget development

- 11-October-2005

## James Webb Space Telescope (JWST)

- 	_Mission Objective_
- Study the origin and evolution of galaxies, stars and planetary systems
*Optimized for infrared observations (0.6 – 28 ****m)*
- 	_Organization_
- Mission Lead:  Goddard Space Flight Center
- International collaboration with ESA & CSA
- Prime Contractor: Northrop Grumman Space Technology
- Instruments:
- Near Infrared Camera (NIRCam) – Univ. of Arizona
- Near Infrared Spectrograph (NIRSpec) – ESA
- Mid-Infrared Instrument (MIRI) – JPL/ESA
- Fine Guidance Sensor (FGS) – CSA

- 	_Description_
- Deployable telescope w/ 6.5m diameter segmented adjustable primary mirror
- Cryogenic temperature telescope and instruments for infrared performance
- Launch NET June 2013 on an ESA-supplied Ariane 5 rocket to Sun-Earth L2
- 5-year science mission (10-year goal)

**James Webb Space Telescope (JWST)**

**www.JWST.nasa.gov**

- Phase A

- Phase B

- Phase C/D

- Phase E

**Telescope**

**Primary Mirror (PM)**

***Cold, space-facing side***

**Sunshield**

**Spacecraft Bus**

***Warm, Sun-facing side***

- scale:
- 1 meter