Artemis
Advanced Relay and Technology Mission
Launched failed to deliver the satellite in GTO. It was slowly be upped to GEO
with its conventional motors (by mid-2002). First the orbit was raised into a
circular 31000 km orbit, and in Feb 2002 the final push was made with the ion
engines (200 days are needed, orbit raised by 1 km per hour!). It reached its
final location on 31 Jan 2003.
The satellite was developed by a consortium headed by the Italian company
Alenia Aerospazio. Italy had a 40 percent share, France 21.25 percent, Germany
12 percent, Spain 7.5 percent, Britain 6.7 percent and Belgium four percent.
The satellite was worth approx. EUR 820 million. ESA's most expensive
satellite.
Artemis also provided data relay links at Ka-Band (23 to 27 GHz) and S-Band (2
GHz). It carried an advanced L-Band (1,61 GHz) payload providing communications
to mobile users. Some L-band capacity was used to send EGNOS signals (see
Galileo).
Artemis was used as relay by
Spot 4,
Envisat 1,
Oicets,
Adeos 2
etc.
It succeeded the optical link demonstration with
Oicets.
A navigation terminal to guide civilian aircraft, boats and land vehicles was
placed onboard at a cost of $8 million.
In Dec 2006, the French military achieved several two-way optical links from an
Aircraft in flight with Artemis.
Still operational 10 years after launch.
In 2013, the satellite was sold to
Avanti
Out
of service
|
planned
in 2014, but started drifting East in May 2016
|
Cause
|
|
http://telecom.esa.int/artemis/
http://www.esa.int/artemislaunch/
sat-index articles
Prime
contractor
|
Alenia
Spazio
|
Platform
|
Italsat
|
Mass
at launch
|
3100
kg
|
Dry
mass
|
1500
kg
|
Dimension
|
|
Solar
array
|
|
Stabilization
|
3-axis
|
DC
power
|
2750
W
|
Design
lifetime
|
10
years
|
Has got liquid-propellant motors (1 of 410 N and 16 of 10 N thrust) and ion
propulsion (15 mN and 18 mN). Tanks contain 1538 kg ergols and 40 kg Xenon.
Four beams will cover Europe, North Africa, and Near East and will be able to
handle up to 400 bi-directionnal links.
Main
transponders
|
Ka
band (20/ 30 GHz)
S band (2 GHz) and Ka band (23/26 GHz)
|
Backup
transponders
|
|
Power
|
|
Bandwidth
|
|
Coverage
|
|
EIRP
max
|
|
G/T
max
|
|
Polarization
|
|
Frequencies
|
20/30
GHz
23-26 GHz (interorbit)
2 GHz (interorbit)
|
The antenna is 2.85 m diameter, aimed at
Envisat 1
SILEX (Semi-conductor Inter-satellite Link Experiment) uses optical
frequencies; it works with
Spot 4
and
Oicets.
It was successfully tested in Nov 2001 at 50 Mbps.
Main
transponders
|
L-band
(1.5/1.6 GHz):
Ku-band (12/14 GHz):
|
Power
|
|
Bandwidth
|
L-band:
4 MHz?
Ku-band: 0.9 MHz?
|
Coverage
|
Europe
|
EIRP
max
|
|
LLM will be leased to Eutelsat.
A navigation payload (25 kg) was also added. It is part of the
Egnos
program (
European Geostationnary Navigation Overlay Service). Two
Inmarsat
3 satellites are also part of this program.