NOORDWIJK,
Netherlands -- After three years of tests, Europe's Automated Transfer Vehicle
(ATV), an unmanned space tug, is scheduled to begin a two-week journey to its
French Guiana launch site for a 16- to 18-week-long launch preparation
campaign.
The
vehicle, along with up to 881,849 pounds (400,000 kilograms) of
equipment, is scheduled to leave the European Space Agency's (ESA) Estec
technology center here July 13 for Rotterdam, where it will be loaded onto a
ship for the ocean voyage to the Guiana Space Center, on South America's
northeast coast. Departure from Rotterdam is scheduled to take place July 17,
followed by arrival at the launch base on July 29.
The ATV
currently is scheduled to be launched, aboard a specially designed Ariane 5
rocket, to the International Space Station in January, where it will dock after
a series of tightly controlled approaches.
The
inaugural ATV, called
Jules Verne, will be the first of a scheduled five ATV vehicles that Europe
will send to the space station in the coming years to pay its share of station
operating costs.
ESA has
spent about 1.3 billion euros ($1.76 billion) building and testing ATV and its
control center, a figure that also includes its Ariane 5 launch.
John
Ellwood, ESA's ATV program manager, said the agency expects to spend around 325
million euros ($442 million dollars) to build and launch each of the four
follow-on vehicles to be built by a large contracting team led by Astrium Space
Transportation.
If launched
as scheduled in January, the ATV would arrive at the orbital complex several
weeks after Europe's Columbus habitable
laboratory, which is scheduled to be launched by a U.S. space shuttle in
December.
ESA
Director-General Jean-Jacques Dordain has said he would prefer ATV to launch
before Columbus - a way of signaling ESA's ability to pay for its
station-related resources in kind before its major station component, Columbus,
arrives to begin using those resources.
But during
briefings at ESA's ESTEC technology center here June 28, agency officials
dismissed this as a non-issue, saying their relations with NASA, the station's
prime contractor, are sufficiently friendly and flexible to permit even a
substantial time lapse between Columbus' arrival and the start of ATV service
to the station.
Alan
Thirkettle, ESA's space station program manager, said ESA's obligations to NASA
are to provide 44,092 pounds (20,000 kilograms) of ATV-delivered payload
to the station in the form of water, fuel and other gear for the station's
astronauts.
Once ESA's
own payload demands are accounted for, that 20,000-kilogram debt to NASA - and
an estimated 1,763 pounds (800 kilograms) of payload owed to Russia - is
covered by four additional ATVs beyond the first one.
In the
station's early development, ESA and NASA had roughly calculated that a
kilogram of payload delivered to the station should be valued at about 16,149
euros ($22,000). Thirkettle said this figure no longer means much as the
agencies have moved to a pure barter relationship. ESA's 20,000-kilogram debt
is expected to be paid by 2015, Thirkettle said.
Dordain has
said that ATV's arrival at the Guiana Space Center will be such a drain on the
spaceport's resources - also used to maintain a particularly busy
commercial-launch schedule this year - that everyone involved will be motivated
to complete the work as quickly as possible.
Ellwood
said the launch campaign as currently planned would make it possible for a
December launch, but that the earlier date would leave insufficient margin for
glitches, should they occur.
One
example, Ellwood said, is the relatively complex procedure that involves
stripping out the nitrogen that accompanies Russian-provided fuel to arrive for
ATV at the launch site. ATV will be docking to the Russian end of the station
and must comply with Russian ways of doing business in space. It's one of many
examples of culture clash that confront space station managers.
Beyond the
five ATV vehicles planned, ESA and NASA have opened talks on whether an
additional ATV might be contracted to propel the station on a controlled
re-entry into the Earth's atmosphere at the end of its service life.
One of
ATV's principal functions on each of its missions will be to raise the
station's orbit, which degrades because of contact with residual atmosphere at
its orbiting altitude of 320 to 350 kilometers.
The space
station partners - NASA, Russia's Roskosmos, ESA, Japan's JAXA space agency and
the Canadian Space Agency - have not yet determined how long the station will
operate once its assembly is completed by 2010 - the year the U.S. space
shuttle fleet is scheduled to be retired.
It also
remains unclear whether additional ATVs will be needed at the station. With a
payload capacity of about 20,943 pounds (9,500 kilograms), ATV is three
times the size of Russia's Progress vehicle and about one-third larger than
Japan's HTV space tug, now in development. In addition to these vehicles, NASA
has contracted with commercial companies to provide services to the station in
the post-shuttle era.
Ellwood
said ESA has no objection to selling ATV capacity once its own needs and its
debt to NASA and Russia have been settled. The agency has contracted for nine
ATV launches with the Arianespace commercial launch consortium, even though it
currently has no firm plans to use all nine reservations.
