Fuel, Water Are Priorities
In 2006, with the launch of Jules Verne, the Automated Transfer
Vehicle (ATV) will become the new European powerful automatic
re-supply spaceship able to bring an indispensable payload to the
International Space Station and its permanent crew. This first ATV
will carry a mix of supplies depending on the Station's needs and
its own payload capacity.
ESA, NASA and Russian counterparts are already defining the
priorities to accommodate the most appropriate combination of
different supplies for this inaugural flight. The combination is
quite flexible and can include different amounts of re-boost
propellant, refueling propellant for the Station's own propulsion
system, drinking water, air and dry cargo, which is stored in the
48 m3 pressurized section of the ATV.
In all Jules Verne will carry about seven tons of cargo to the
orbiting outpost 400 km or so above the Earth thanks to the Ariane
5 launcher, which is capable of boosting up to 20.5 tons into low
Payloads From Different Countries
Although ATV will dock to the Russian Zvezda module, it will
carry most of its dry payload for the US elements of the ISS. At
the launch site in Kourou, French Guiana, six weeks before flight,
Jules Verne will be loaded with 1 300 kg of dry cargo out of the 5
500 kg maximum capacity.
Most of the dry cargo provided by NASA will be clothes, food,
towels and wipes for the crew, logistics items such as batteries
and spare parts for maintenance of the Station. This cargo will
also include ESA experiments such as ANITA, which will constantly
monitor the cabin air, and some Russian hardware to be added to the
panels of the Station's Russian Service Module.
Contained in bags of different sizes, the cargo is loaded
horizontally through the large opening at the aft end of the
pressurized module, opposite the docking system at the front end.
At this stage of the launch preparations in Kourou, the ATV service
module, housing the avionics and the propulsion system, is not yet
attached to the pressurized cargo section.
The bags are neatly tied down with an adjustable belt into six
"racks" which are modular storage cargo elements and look like
metal shelving. About 2.3 tons of such cargo configurable hardware
including racks, pipes, tanks and bags are needed to store and
carry contents to the Station.
To add flexibility in the re-supply capability of ATV, a small
fraction of the dry cargo can be loaded through the docking hatch
just eight days before launch when the spaceship is undergoing
final launch preparations on top of the 50-meter Ariane 5, just
before being enclosed in the white aerodynamically-shaped
Payload Priority: Propellant
"Jules Verne's mission will be much more complex than the future
routine ATV missions since it will actually demonstrate that the
ATV can automatically and safely handle any contingency plans
designed to ensure the safety of the ISS crew, such as interrupting
the rendezvous, stopping its motion and flying away from the ISS",
explains Alberto Novelli, ESA operations manager of the payload for
the first ATV mission.
Novelli continues: "For the first ATV flight Jules Verne will use
the full capacity of the cargo ship and will carry even more fuel
than the following ATV missions. The extra fuel will allow this
demonstration flight to test several scenarios and maneuvers,
including contingency situations, such as going back to a parking
orbit and delaying the rendezvous until the following day. Such
situations require a new docking maneuver and would take a lot of
fuel – up to about 500 kg. Consequently, about one third of
the payload will be fuel."
The rest of Jules Verne's payload will be 860 kg of refueling
propellant for the Station's own propulsion system, 280 kg of
drinking water, 20 kg of oxygen and the large amount of re-boost
propellant already mentioned.
After a nominal and complex mission in orbit up to the docking,
Jules Verne will still carry two tons of propellant for re-boost of
the Station. The extra fuel not consumed for unexpected scenarios
during the free flight phase will automatically be used for extra
re-boost of the Space Station during the attached phase. The
purpose of the re-boost is to raise the ISS altitude, which
naturally decreases with time due to the residual atmospheric
Delivery Of "Russian" Type Water
The ATV is able carry two types of water to the ISS in
compliance with the different standards of NASA and the Russian
state space agency, Roskosmos:
- The NASA standard requires its water to have low dry residue like
the one produced – through reverse electrolyses process
– by the fuel cells on board the NASA Space Shuttle. It is
disinfected with iodine.
- The basis for Roskosmos standard water is to have some amount of
minerals such as calcium, magnesium and fluoride. It is disinfected
with silver obtained via electrolysis.
"For Jules Verne, the ISS partners have decided to bring only the
Russian type of water. We will have the water ready for delivery
less than three months before launch" says Cesare Lobascio, head of
Environmental Control and Life Support for Space Vehicles at Alenia
Spazio in Turin. The same Italian space firm builds the ATV's
pressurized Integrated Cargo Carrier in its Turin plant.
The Integrated Cargo Carrier has a maximum capacity for water of
840 kg, divided over three water tanks, but on Jules Verne only one
tank will be filled.
Waste Removal From The ISS
The ATV has about three times the payload capability of its
Russian counterpart, the Progress-M cargo vehicle. At the end of
its six-month mission, Jules Verne will offload solid waste and
wastewater from the Station and burn up during atmospheric re-entry
over the Pacific Ocean.
The offload payload has not yet been defined, but liquid waste ( up
to 840 kg ) cannot exceed one sixth of the dry waste ( up to 5 500
kg ). The ISS crew will steadily fill the cargo section with
unwanted material. Up to 6.3 tons of unwanted material can be
removed from the Station using the ATV.