Title:  UV Instrumentation and the
        Proposed HAWK Long-Duration Balloon Mission

Chuck Joseph (Rutgers University)

Abstract:

I will briefly discuss several envisaged NASA missions that
require substantial improvements in ultraviolet detector
technologies.  I will note the science drivers and their
associated UV image sensor requirements, along with efforts
to develop these technologies.  These missions range from 
a pair of 8 meter telescopes looking down at the earth's 
atmosphere, measuring ultra-high energy cosmic rays (UHECRs), 
to the next generation of UV-visible replacement mission for 
Hubble.  To measure UHECRs from space, the focal planes have 
to be 2 m x 2 m, a thousand times larger than any previously 
built detector.  The next generation of general-purpose UV-vis.
missions (e.g. SUVO or perhaps Terrestrial Planet Finder) will 
require image sensors with visible-blind efficiencies in excess 
of 80%, five times higher than current technologies.

I will give special emphasis to a Rutgers-led balloon proposal 
called HAWK - Hierarchical Assembly through Wide-field Kinematics.
HAWK will be a 1.8m near-UV to visible telescope mission with
a novel optical design that easily compensates for gondola sway,
allowing diffraction-limited performance.  HAWK will be a
long-duration balloon (LDB) flight, lasting 7-21 days/flight at
a floatation altitude of 120,000 ft (35 km).  The science goals
of HAWK are to measure 2-D velocity maps of hundreds of galaxies
as well as velocity maps of all gas components in 10 cubic-Mpc
volumes with a range of look-back times 0 < z < 1.5.  Current 
Lambda-CDM models do an excellent job of predicting structure on 
all scales, except galaxies.  HAWK will be able to measure the 
dark and luminous matter content in galaxies at moderate redshifts.
We will be able to measure empirically the assembly of galaxies 
from a time when most galaxies are barely recognizable and very 
irregular to the present well-ordered galaxies.