What is Hershel?
The "Herschel Space Observatory" - the mission formerly known as FIRST - will perform photometry
and spectroscopy in the 60-670 Ám range. It will have a radiatively cooled telescope and carry
a science payload complement of three instruments housed inside a superfluid helium cryostat.
It will be operated as an observatory for a minimum of three years following launch and transit
into a an orbit around the Lagrangian point L2 in the year 2007.
In April 2003 we submitted an application for an ESA fund to cover our
participation in the Herschel project. We offered 8 man-years of effort
for contribution to the pre-flight and in-flight calibration of the Photometer
Array Camera and Spectrometer (PACS) instrument. The major tasks would be
design of calibration procedures; analysis of test results; selection of
celestial standards; and contribution to the establishment of the in-flight
calibration plan. The planned start date of the project is September 2004.
A short Herschel mission overview
The `Herschel Space Observatory' (formerly
known as FIRST) is the fourth cornerstone mission in the European
Space Agency (ESA) science programme. It will perform imaging
photometry and spectroscopy in the far infrared and submillimetre
part of the spectrum, covering approximately the 60-670 µm
Herschel is the only space facility dedicated
to the submillimetre and far infrared part of the spectrum. Its
vantage point in space provides several decisive advantages, including
a low and stable background and full access to this part of the
Herschel has the potential of discovering
the earliest epoch proto-galaxies, revealing the cosmologically
evolving AGN-starburst symbiosis, and unraveling the mechanisms
involved in the formation of stars and planetary system bodies.
The key science objectives emphasise specifically the formation
of stars and galaxies, and the interrelation between the two,
but also includes the physics of the interstellar medium, astrochemistry,
and solar system studies.
Herschel will carry a 3.5 metre diameter
passively cooled telescope. The science payload complement - two
cameras/medium resolution spectrometers (PACS and SPIRE) and a
very high resolution heterodyne spectrometer (HIFI) - will be
housed in a superfluid helium cryostat.
Herschel will be placed in a transfer
trajectory towards its operational orbit around the Earth-Sun
L2 point by an Ariane 5 (shared with Planck) in early 2007. Once
operational FIRST will offer a minimum of 3 years of routine observations;
roughly 2/3 of the available observing time is open to the general
astronomical community through a standard competitive proposal
Herschel Science Instruments
The Herschel science payload has been
conceived and optimised with the prime science goals in mind,
but in addition it offers a wide range of capabilities for the
`general' observer. It consists of three instruments selected
on the basis of the response to an Announcement of Opportunity
(AO) issued in October 1997. The Principal Investigators (PIs)
and the instruments selected were:
- The Photodetector
Array Camera and Spectrometer (PACS) instrument will
be built by a consortium led by A. Poglitsch, MPE,
- The Spectral and Photometric
Imaging REceiver (SPIRE) instrument will be built
by a consortium led by M. Griffin, QMW, London, UK.
- The Heterodyne Instrument
for the Far Infrared (HIFI) instrument will be built
by a consortium led by Th. de Graauw, SRON, Groningen,
The PI consortia provide the instruments to
ESA under their own funding, in return for guaranteed observing
time. The scientific payload complement was selected by the ESA
Science Programme Committee in May 1998 and approved in February