Xenon Loading Cart
cryogenic insulation
Ground
Support
Equipment
for Xenon
spacecraft
loading or
equipment
testing
Spacecraft electric propulsion is increasingly used as a
result of the high performance and the maturity and
availability reached by this new technology. For plasmic
propulsion systems, Xenon filling, draining and pressure
testing are needed during ground operations. Due to the
specific thermodynamic characteristics of Xenon and the
high storage pressure required by the spacecraft (150 bar to
be compared to 60 bar in available cylinders), a new
XENON GROUND SUPPORT EQUIPMENT (Xe GSE) was
developed by AIR LIQUIDE DTA.
www.dta.airliquide.com
Functions of the Xe GSE
•
Loading of the spacecraft tanks with Xenon propellant up to a specified
pressure and within a specified temperature range
Rear side of the Xe GSE
•
Draining of the spacecraft tanks
•
System conditioning with Argon or Helium
•
Pressure and temperature control of the delivered propellant
•
Measurement of loaded Xenon mass
•
Control of Xenon purity
•
Storage of the Xenon to be transferred to the spacecraft tanks
•
Evacuation of the propellant tanks and of the Xe GSE itself.
Moreover, the Xe GSE :
•
allows easy interfaces with the operator
•
guarantees safety of personnel and of spacecraft components through
passive and active safety devices. The Xe GSE complies with Mechanical
and Electrical European and American Standards.
Description of the thermal compressor
The thermal compressor comprises a pressure vessel equipped with an LN2
heat exchanger, an electrical heater and a weighing system. The LN2 is
pressurized between 3 and 5 bar. When the mass of the liquefied Xe, measured
with a weighing system, reaches a given value, the LN2 flow is stopped and the
electrical heater is switched on. As soon as the pressure inside the compressor
reaches the pressure of the spacecraft tanks, a valve is opened and a Xenon
flow is delivered to the tanks. The compressor pressure is kept above the
Spacecraft tank pressure using the electrical heater. As the temperature of the
Xe leaving the compressor reaches 310K, the heater is switched off and an
other cycle starts again. As the first compressor is in the cooling phase (LN2
on), the second compressor is in the heating phase (heater on), so as to have a
nearly continuous flow rate towards the spacecraft tanks.
Performances
Thermal compressor
•
Maximum pressure :
150 bar
•
Loading mass :
300 kg in less than 16 hours at 150 bar
•
Mass of the cart :
< 700 kg (excluding the PC)
•
Volume of the cart :
1200 x 1500 x 1800 mm (H x W x L)
•
Operating power :
7,5 kW
(208/220 of 380/460 Vdc,
3 phases electrical transformer)
•
Instrumentation accuracy :
- loaded mass : 200 g for 300 kg loaded
- pressure : 0,2 bar in the 0-180 bar range
- temperature : 1°C in the 0-40°C range
Contacts
Air Liquide DTA
2, rue Clémencière — BP 15
38 360 Sassenage, France
Phone +33 4 76 43 62 11
Fax +33 4 76 45 62 71
E-mail [email protected]
- mass flow : 0,2 % in the 0-30 g/s range
•
Vacuum pumping capacity :
1000 - 10 mbar
•
Operated with the LABVIEW @ software
•
Transportation container :
-3
designed for a 100 mm drop and
3 g vibration