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DIR Return to: Beyond the Stars!: Dawn of the Space Age
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#Post#: 3879--------------------------------------------------
Test Game Six Events Thread
By: Thorgrimm Date: October 1, 2015, 5:00 pm
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April 3rd - Cape Canaveral - (AP - UPI)
[quote]"Today, NASA is announcing the launch of Mankind's first
Geosynchronous satellite put into orbit. The name of this wonder
is the J-Star-1." Director Jason DeShane announced in a short
press conference.
"J-Star-1 is scheduled to be launched on May 30th, by a Titan
III-C launch vehicle. The spacecraft will be inserted directly
in the geosynchronous orbit. This will reduce the on-board fuel
requirements to less than 80 lbs, for a total mass at launch of
nearly 2800 lbs. It is also hoped that the highly accurate
orbital insertion will further lower the amount of fuel required
for final positioning to 18 lbs. This will enable a life
extension from the original planned 2 years, to 5 years, even
accounting for the premature failure of the electric propulsion
subsystem. The station-keeping fuel requirement is expected to
be around 3lbs/year."[/quote]
After the short press conference was completed Director DeShane
released the following information on the first orbiting
man-made object above our planet in a Geosynchronous orbit.
President Nixon released a statement reaffirming his confidence
in the NASA Director, and feels the future is bright for the US
space effort under the Director's guidance.
[center]TITAN III-C:[/center]
The Titan IIIC consists of an enhanced Titan II core and an
assortment of upper stages. All Titan III launchers provide
assured capability and flexibility for launch of large-class
payloads.
The Titan IIIC weighs 1,380,000 lb (626,000 kg) at liftoff and
consists of a two-stage Titan core and upper stage called the
Titan Transtage, both burning hypergolic liquid fuel.
At liftoff, designated the Titan 3A-1, this stage was powered by
two Aerojet LR-87-11 engines that burned about 240,000 lb
(110,000 kg) of Aerozine 50 and nitrogen tetroxide (NTO) and
produced 526,000 lbf (2,340 kN) thrust over 147 seconds. The
Aerozine 50 and NTO were stored in structurally independent
tanks to minimize the hazard of the two mixing if a leak should
have developed in either tank.
The second core stage, the Titan 3A-2, contained about 55,000 lb
(25,000 kg) of propellant and was powered by a single Aerojet
LR-91-11, which produced 102,000 lbf (450 kN) for 145 seconds.
The upper stage, the Titan Transtage, also burned Aerozine 50
and NTO. Its two Aerojet AJ-10-138 engines were restartable,
allowing flexible orbital operations including orbital trimming,
Geostationary transfer and insertion, and delivery of multiple
payloads to different orbits. This required complex guidance and
instrumentation. The Transtage contains 22,000 lb (10,000 kg) of
propellant and its engines deliver 16,000 lbf (71 kN).
Size
Height: 137 feet
Diameter: 10 feet
Mass: 1,380,510 lb
Stages: 3
Capacity
Payload to LEO: 28,900 lbs
Payload to GTO: 6,600 lbs
Payload to TPI: 2,650- lbs
Performance
First Stage: Titan 3A-1
Engines: 2x LR87-11
Thrust: 526,000 lbf (2,340 kN)
Burn Time: 147 seconds
Fuel: Aerozine-50/N2O4
Second Stage: Titan 3A-2
Engines: 1xLR91-11
Thrust: 102,000 lbf (450 kN)
Burn Time: 205 seconds
Fuel: Aerozine-50/N2O4
Third Stage: Titan Transtage
Engines: 2xAJ-10-138
Thrust: 16,000 lbf (71 kN)
Burn Time: 440 seconds
Fuel: Aerozine-50/N2O4
[center]J-STAR-1[/center]
One of the major innovations of J-Star-1 is an in-flight
deployable antenna of more than 27 ft in diameter. The antenna
reflector will be furled during launch under the launch vehicle
fairing, and will deploy in orbit much like an umbrella.
The antenna reflector was built from 48 aluminum ribs,
supporting a metallized Dacron mesh. The antenna feeds, in C, S,
L, UHF and VHF bands, are placed on the spacecraft body, facing
the antenna reflector, and linked to the antenna and the solar
panels masts by a carbon-fiber reinforced plastic (CFRP) truss.
The solar panels are rigidly mounted on two deployable masts.
They are of a hemi-cylinder shape, thus providing a relatively
constant power, 595 W beginning of life. Electric power is
supplied during eclipses by two Nickel cadmium batteries of
15-A·h capacity, powering a regulated 30.5-V bus. The satellite
dimensions in orbit will be 50 ft in width by 25 ft in height.
The deployable antenna parabola was designed and developed by
Lockheed Missiles and Space Company (LMSC), under subcontract to
Fairchild Aerospace, after several years of small study
contracts at LMSC. The reflector surface is designed for optimal
operation at S-Band frequencies. It weighs 182 lbs at launch
and is stowed in a toroidal volume, doughnut shaped,
approximately 6 feet in diameter and 10 inches thick.
At the time of launch it will the largest parabolic surface
launched into orbit.
J-Star-1 will be the first geostationary satellite with
three-axis stabilization and pointing. This subsystem is capable
of a highly accurate pointing, better than 0.1° through the
inertial measurement units, down to 0.002° by using a
radio-frequency interferometer.
Furthermore, the satellite will be able to follow low earth
orbit satellites through slewing, by tracking the low
earth-orbit satellite through an S-band RF sensing. The system
is also able to perform orbitography of the tracked satellite.
This highly advanced pointing subsystem uses earth and sun
sensors, a star tracker pointed to the pole star, Polaris, and
three inertial sensors. The sensor measurements are fed to two
digital computers, nominal and redundant, as well to a back-up
analog computer.
It is also possible to orient the satellite by using
radio-frequency sensors. Actuators are three momentum wheels,
and hot gas, hydrazine mono-propellant, thrusters.
J-Star-1 is equipped with two electric thrusters based on the
acceleration of cesium ions, that were to be used for
North-South Station Keeping. This subsystem development followed
earlier failed attempts on a previous Comm Sat.
Each of the thrusters have a mass of 32 lbs, used 150 W of
electric power, and produced a thrust of 4 mN, with a specific
impulse of 2500s. The on-board supply of cesium is expected to
be sufficient for 4400 hours of thrust.
The main mission of J-Star-1 is to demonstrate the feasibility
of continuous communications with stations over the horizon from
the Broadcast Facility. To this end, in addition to the
high-gain antenna, the spacecraft payload is able to receive in
any of the VHF, C, S and L-bands, and to transmit in S-band (2
GHz) through a 20-W solid state transmitter, in L-band (1650
MHz) at 40W, in UHF (860 MHz) at 80W, and with a TWTA-based
transmitter of 20 W in C-band (4 GHz).
The satellite is expected to serve as a data-relay and tracking
satellite for low-orbit spacecraft.
[center]David Richlen
Science Desk, International News Network[/center]
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