HERSCHEL

Link to the Herschel Web site

I. General project/facility description

1. Overview of the facility/project
   Herschel is a 3.5m aperture, space-borne observatory passively cooled to 80K that will orbit the earth-sun L2 point and have imaging and spectroscopic capabilities in the wavelength range from 60 to 670 µ. Its primary mission will be to study the formation of galaxies, investigate the creation of stars, and examine the chemistry of the universe.

2. Managing institution and organization
   The mission is presently managed by the European Research and Technology Center (ESTEC) in the Netherlands for the European Space Agency (ESA). Management of the mission will be transferred to the Villafranca Satelite Tracking Station (VILSPA), Spain for the post launch phase of the mission.
   The U.S. portion of the mission is being managed by JPL for NASA. During the post launch phase U.S. observers will interact with the NASA Herschel Science Center (NHSC) at the Infrared Processing and Analysis Center (IPAC) at Caltech.

3. Funding source(s)
   The mission is funded primarily by ESA with a large NASA participation. During the post launch phase, NASA will be funding a grants program similar to other NASA flight missions ( e.g. HST, Chandra).

4. Construction history and cost
   NASA contribution through launch in real year dollars in millions of dollars . The primary assumption here is that the launch date will be met.

   Prior	FY01	FY02	FY03	FY04	FY05	FY06	FY07	total
   30.8	15.2	13.7	20.3	18.3	5.3	6.9	12.6	126.9

5. Operational history and cost
   Future facility. Budgeted costs are as follows:

   FY08	FY09	FY10	FY11	FY12	FY13	FY14	FY15	total
   Total(inc grants)
   28.0	27.4	25.9	tbd	tbd	tbd	tbd	tbd	tbd

II. Technical details

1. Specifics of telescope/instrument
   
   • Spacecraft.
     • Telescope Aperture = 3.5m
     • Telescope Temperature = 80K
     • Spacecraft Mass = 3300 kg at launch
     • Dimensions = 9m high, 4m x 4m overall cross section
     • Launcher = Ariane 5
     • Launch Date = August 2007
     • Mission Lifetime = 3 years nominal, 5 years extended
     • Wavelength = Infrared 60 to 670 µ
   • Instruments
     • Heterodyne Instrument for the Far Infrared (HIFI)
       • Frequency Coverage:
         480 - 1250 GHz (625 - 240 µ) [Bands 1-5]
         1410 - 1910 GHz (212 - 157 µ) [Bands 6L, 6H]
       • Near-quantum noise limit sensitivity (goal < 3 hv/k)
       • Instantaneous IF bandwidth: 4 GHz
       • Frequency Resolution: 140 kHz - 280 kHz - 1 MHz
       • Calibration Accuracy: 10% baseline; 3% goal
         
       • NASA funded contributions to the instrument (Caltech/JPL):
         
         1. Band 5 SIS Mixer
         2. LO Chains for Band 5 and 6
         3. Band 6 HEB Mixer kit
         4. LO Components for Band
         5. Power Amplifiers, Isolators
       
       
     • Spectral and Photometric Imaging Receiver (SPIRE)
       Imaging photometer / imaging Fourier transform spectrometer.
       • Simultaneous 3 band imaging:
         

         Wavelengths	250 µ	350 µ	500 µ
         Beam(FWHM)	17"	24"	35"
         Field of View	4'×4'	4'×4'	4' ×4'
         Scan Map FOV	4'×8'	4'×8'	4'×8'

       • Imaging Fourier Transform Spectrometer (FTS):
         

         Wavelength range	200-315 µ, 315-670 µ
         Field of View	2.6'×2.6'
         Maximum Spectral resolution (cm-1)	0.04

         
         
       • NASA/JPL contributions to the instrument:
         The focal plane for SPIRE will be using detectors developed by Dr. J. Bock at JPL who is a co-I on SPIRE. These are called Spider Web bolometers and polarization sensitive bolometers and are the most sensitive detectors in this wavelength range. Such detectors have never before flown in space.
     
     
     • Photodetector Array Camera and Spectrometer (PACS)
       Imaging photometer and medium resolution grating spectrometer working in the 60 to 210 micron range.
       (no direct U.S. participation in this instrument)

2. New capabilities anticipated/planned in next 5-10 years
   Future facility: see above.

III. User profile

1. % of "open skies" time
   Approximately 67% of the facility observing time will be openly competed internationally. 33% of the facility observing time is reserved for the guaranteed time observers (=instrument teams, ESA Project Scientist, and the mission and telescope scientists).

2. Institutional affiliations of users
   Decisions on the allocation of observing time is made by the Herschel Time Allocation Committee. Any person affiliated with an American institution will be eligible to propose for observing time associated with funding through the grant program.

3. Student access, involvement, usage
   Other than the openly competed time and the U.S. portion of guaranteed time, no special arrangements have been made for students.

IV. Science Overview

1. Current forefront scientific programs
   Future facility: NA

2. Major discoveries (through 1999)
   Future facility: NA

3. Science highlights of last 5 years
   Future facility: NA

4. Main future science questions to be addressed
   
   • Study the formation of galaxies in the early universe and their subsequent evolution.
   • Investigate the creation of stars and their interaction with the interstellar medium.
   • Observe the chemical composition of the atmospheres and surfaces of comets, planets, and satellites.
   • Examine the molecular chemistry of the universe.

5. Synergies with other major forefront facilities
   
   • Herschel will provide a number of new galaxies at high redshift similar to those discovered by SCUBA for follow-up by ground based optical and near-IR telescopes.
   • Large sky surveys conducted by Herschel will provide a whole host of targets for follow-up by ALMA and SOFIA , both for higher resolution imaging and for spectroscopy.
   • Herschel will follow-up Spitzer results at long wavelengths with higher resolution and spectroscopic capability.

6. Unique contributions
   
   • Herschel will be able to image and take spectra in wavelength regions not accessible from the ground and never before observed from space.
   • In the Far-IR (60 - 160 µ), with its 3.5 m dish, Herschel will provide the highest resolution images ever obtained.
   • Herschel's orbit at L2 will allow for long and continuous observations at very low backgrounds.

V. Education/Outreach activities

1. Visitor facility
   EPO will be conducted at the NASA Herschel Science Center (IPAC/Caltech) in a manner similar to that which is presently being performed for Spitzer.

2. Student programs
   Future facility: NYA.

VI. Documentation/website URLs

1. URL of facility website
   
   • http://sci.esa.int/science-e/www/area/index.cfm?fareaid=16
   • http://herschel.jpl.nasa.gov/
   • http://www.ipac.caltech.edu/Herschel/

2. URL of EPO website
   
   • http://herschel.jpl.nasa.gov/
   • http://www.ipac.caltech.edu/Herschel/

3. URL(s) of any brief overviews of project/facility
   http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=34682

4. URL(s) of miscellaneous documentation
   See above.