... and ESA, the European Space Agency, naming its first-ever genuine spacecraft the Jules Verne. Indeed, on March 9, 2008, a powerful Ariane V rocket lifted the 20.7 tonne ATV-001, as it has been coded (with ATV standing for Automated Transfer Vehicle), into space from ESA's launch base in Kourou, French Guyana, with a heavy payload of propellant, water, air and supplies for the ISS. To be sure, ATV's are unmanned cargo resupply spacecraft, but unlike lab modules like Columbus, which are incapable of independent movement, an ATV, once in orbit, can perform all the tasks - and more - of typical manned spacecraft. Given that it was the first of its series, the Jules Verne first underwent three weeks of testing before it began its rendezvous operations with the ISS, to which it finally docked on 3 April. The following video, albeit from the hacks over at the Biased Broadcasting Company, is well worth watching:
The ATVs, of which the development cost an estimated 1.35 billion EUR, are not only designed to supply the International Space Station (ISS). Another important feature is their ability to, if necessary, boost the station into a higher orbit. Four more have been ordered already, to be used until 2015, with an option for a further two. The small number implies that the ATV's are meant to complement, not subsitute, the existing Russian-made Progress spacecraft, of which it has three times the capacity. Like a Progress, an ATV carries both bulk liquids and relatively fragile freight, stored in a pressurized shirt sleeve environment in a cargo section so that astronauts can have access to it without having to put on a spacesuit. Docking to the ISS is done using two videometers and two telegoniometers built by Sodern, an EADS subsidiary. Additional (actually redundant) monitoring data is provided by a Russian-made antenna originaly designed for the Ukranian-built Kurs, an automatic docking system comparable to those used on the Progress ships and the Soyuz manned ferries. A camera mounted on the ISS's Zvezda module provides visual imagery.
Some more technical data about the ATV's: each one weighs 20.7 tonnes at launch, of which the cargo comprises 8 tonnes in various distribution schemes: up to 5.5 tonnes of dry goods like supplies, scientific payload etc), up to 840 kilograms (1,900 lb) of water, up to 100 kilograms (220 lb) of gas (nitrogen, oxygen, air) and up to 4.7 tonnes (10,000 lb) of propellant for re-boost manoeuvring and refueling the ISS. The propellant for re-boost is monomethylhydrazine (MMH, also used in the Space Shuttle) and N2O4 oxidizer. "Re-boost" in this context is the ATV's capacity to "push" the entire ISS to a higher orbit since its course gradually lowers because of atmospheric drag, even at such an altitude (!). Contrary to what one would generally assume, re-boosting is not really "pushing higher up" but an indirect process, by enhancing the ISS's speed. The resulting higher centrifugal force ensures that the orbital altitude enhances. Even when "getting higher up" is not immediately necessary to avoid "falling down", the feature enables the ISS to get out of the way of the orbital paths of space debris, of which there is more every year. On April 25, the Jules Verne pushed the 280-ton ISS 4.7 kilometers higher up in a re-boost maneuver that took 13 minutes. To this end the ATV accelerated the ISS's speed from 7,700 meters per second with just 2.67 meters per second... but it sufficed, and only two of the ATV's four main engines were needed. Re-boost manoeuvres have to be carried out periodically (about once a month) and until now this was done using that brave little workhorse of the Russians, the Progress. Actually a Progress M1, an update of the Progress M, which is in itself a descendant of the famous Soyuz spacecraft. Below you find a comparison between an ATV and the Apollo and Progress spaceships respectively.
And here is a magnificent pic (courtesy of Wikipedia, just like the drawing above) of the ISS. Visible "on top" is the ATV, coupled to Zvezda. Zvezda, meaning "star", was the first fully Russian ISS contribution, and an early "building block" (actually the third one, in July 2000). It houses some of the ISS's lifes support systems as well as living quarters for two crew members. Original Russian info on Zvezda here.
(to be continued)