The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

418 Starlight
Starlight
A NASA mission being developed by JPL (Jet Propulsion
Laboratory) as part of the Origins program. Starlight
consists of two spacecraft that will fly in formation to
test techniques and instrumentation needed to carry
out multiple-spacecraft interferometry. Following their
expected launch in 2005, the two initially conjoined
spacecraft will be placed in a solar orbit matching Earth’s
but trailing behind at a distance of up to 17 million km.
After a brief checkout, the spacecraft will separate—the
“daughter” to be parked at a nearby position, while the
“mother” makes test interferometer observations for three
months using its self-contained optics. Then the two
spacecraft will perform experiments of the autonomous
formation flying system, at separation distances ranging
from 40 to 600 m. Finally, the technology for formationflying
optical interferometry will be put through its paces
by making observations of specific target stars using both
spacecraft. Previously known as Space Technology 3 and
the New Millennium Interferometer, Starlight will validate
the technique of space-based optical interferomety
that will be used by later missions, such as the Terrestrial
Planet Finder, to search for extrasolar Earth-like worlds
and any life that may inhabit them.
STARSHINE (Student Tracked Atmospheric
Research Satellite for Heuristic International
Networking Equipment)
An educational microsatellite, built and launched to
encourage optical tracking and satellite observation by
students. STARSHINE was a passive, polished 48-cmdiameter
hollow aluminum sphere, manufactured by the
U.S. Naval Academy and covered by 878 25-mm-diameter
mirrors that were ground at many participating American
and international schools. Deployed from a hitchhiker
slot on the Shuttle, STARSHINE was visible from the
ground with the naked eye, flashing every few seconds
due to its spin. It decayed on February 18, 2000.
Shuttle Deployment
Date: June 5, 1999
Mission: STS-96
Mass: 38 kg
Orbit (circular): 360 km × 52°
starship
A large, crewed spacecraft capable of rapid transit between
stars.
Start-1
A small, four-stage Russian launch vehicle developed
from the Topol intercontinental launch vehicle under a
conversion program in the early 1990s. The first Start-1
was successfully launched in 1993, delivering a non-
commercial payload to orbit. Several more launches have
since taken place.
Length: 22.9 m
Diameter: 1.8 m
Payload (to LEO): about 400 kg
START (Spacecraft Technology and Advanced
Reentry Test)
A U.S. Air Force program to experiment with lifting bodies
that began after the cancellation of the Dyna-Soar
project. It began in 1960, using subscale models of the
X-20 Dyna-Soar to test materials, and continued with the
ASSET and PRIME suborbital tests of subscale lifting
body designs and B-52 drop tests of the X-24A and X-24B
lifting bodies into the 1970s.
static firing
The firing of a rocket motor, rocket engine, or an entire
stage in a hold-down position to measure thrust and to
carry out other tests.
static testing
The testing of a device in a stationary or held-down position
as a means of testing and measuring its dynamic
reactions.
stationary orbit
See geosynchronous orbit.
station-keeping
Minor maneuvers that a satellite in geostationary orbit
(GSO) must make over its mission life to compensate for
orbital perturbations. The main source of perturbation is
the combined gravitational attractions of the Sun and
Moon, which cause the orbital inclination to increase by
nearly one degree per year. This is countered by a northsouth
station-keeping maneuver about once every two
weeks so as to keep the satellite within 0.05° of the equatorial
plane. The average annual velocity change (delta ν)
needed is about 50 m/s, which represents 95% of the
total station-keeping propellant budget. Additionally, the
bulge of the Earth causes a longitudinal drift, which is
compensated by east-west station-keeping maneuvers
about once a week, with an annual delta ν of less than 2
m/s, to keep the satellite within 0.05° of its assigned longitude.
Finally, solar radiation pressure caused by the
transfer of momentum from the Sun’s light and infrared
radiation both flattens the orbit and disturbs the orientation
of the satellite. The orbit is compensated by an
eccentricity control maneuver that can sometimes be
combined with east-west station-keeping, whereas the
satellite’s orientation is maintained by momentum wheels
supplemented by magnetic torquers and thrusters.