Jules Verne about to launch
Published on Mar 7, 2008 at 11:37 am.
2 Comments.
Filed under space exploration, space station.
Nearly a month ago I wrote about the author Jules Verne. Today, I am writing about another Jules Verne. Only this one is not a person. It is the European Space Agency’s (ESA) Automated Transfer Vehicle (ATV).
ESA’s ATV is a cargo vessel designed to ferry supplies to the International Space Station (ISS). One of the problems with a permanently manned facility in space is that, at present, such an installation is not self sufficient. They can not grow their own food, produce their own air, recycle 100% of their water, and so forth. For short duration flights, the spacecraft carrying the crew can also carry enough supplies. But, that is not the case for a long duration space mission. The Soviet Union faced that issue with their earliest generation of space stations, the Salyut series. The answer to that problem was the Progress unmanned resupply craft.
But, the ISS is far larger than the Salyut stations. It requires far more consumables. Originally, the ISS was to have a crew of a half dozen or more humans, but for safety reasons a decision was made to limit the crew complement to no more than could be safely evacuated using a “lifeboat” docked with the station. That lifeboat is a Russian Soyuz spacecraft, which holds three crew members. NASA was supposed to develop a crew escape module capable of holding a larger crew, or a crew transfer vehicle that would also hold more than three crew members. That never happened. So, we are limited to a crew of three. But, even a crew of three stretches the capabilities of the venerable Progress spacecraft, which can carry only about 2.6 metric tons of supplies. When the Space Shuttle quit flying for a while after the Columbia accident, the ISS crew had to be reduced to two crew members. That was all that could be supplied using a Progress. Now that the Space Shuttle is flying again, the crew complement has been raised back to three. But, the shuttle fleet is due to be retired in 2010. That is not far into the future. At present, NASA has no immediate replacement for the Space Shuttle. The Soyuz can continue to transport crew members to and from the space station, for a few more years. But, what about the supply issue? That is where the ATV comes in.
There may not be a replacement available yet for crew transfers, but the European Space Agency has been building a replacement (or supplement) to the Progress modules. This is the Automated Transfer Vehicle. It is launched from the Centre Spatial Guyanais (Guiana Space Center) in French Guiana on an Ariane 5 heavy lift rocket.
The ATV is essential to ISS operations. Without the Space Shuttle, the Progress craft are unable to supply the space station properly. With a cargo weight of 9 metric tons, the ATV carries more than three times the cargo of a Progress module. The ATV docks with the Russian built Zvezda module of the ISS. The ATV is pressurized and so the ISS crew simply float into it and remove the cargo as needed. The ATV can remain docked with the ISS for about six months, basically becoming like a temporary space station module for that time. While docked, supplies are removed and garbage and other waste is loaded onto the ATV. Also, while docked, the ATV will fire its thrusters from time to time to alter the space station’s orbit as needed. After undocking, the ATV is guided into a decaying orbit that will cause it to reenter and burn up over a remote part of the Earth where danger to anyone below from surviving pieces of the craft is minimized (typically over a remote part of the Pacific Ocean). The first ATV mission is named Jules Verne, and is scheduled lift off in the morning of March 9, 2008 (at 04:03 UT). As of now, it looks good for launch on schedule.
Normally, the ATV would launch and then dock with the ISS soon thereafter. However, the Space Shuttle Endeavour is scheduled to launch on March 11, 2008, also headed to the ISS, on Space Shuttle mission STS-123. Endeavour is scheduled to remain docked with the ISS until March 24. The ATV will not be able to dock while the Shuttle is docked to the station. But, this is the first ATV, anyway, and the ATV needs to go through various on-orbit maneuvering tests before it is allowed to approach the ISS. So, ESA won’t be just sitting around while waiting for the Endeavour to undock. Rather, the Jules Verne will be put through a series of tests preparing it to dock with the ISS. These tests would have had to be performed anyway, whether the Shuttle was there or not. If the ATV checks out just fine, and nothing usual happens, then the Jules Verne will dock with the ISS on April 3, 2008.
-Astroprof
Images courtesy ESA
Keith on March 7, 2008 at 12:47 pm: 1
Hi Astroprof,
Thanks for the article! That is pretty neat. Out of curiosity, how hard would it be to make vehicles like the ATV re-usable? It seems like it would be useful to have a way to recover the unit after it’s mission, rather than simply let it burn up in the atmosphere.
Also, off-topic, but, have you considered adding some social networking (e.g. Digg) buttons to your article? It should be pretty straight-forward to do and would make it easier to pass along your posts.
Keep up the good work.
Take care,
Keith
ATV guy on March 8, 2008 at 2:05 pm: 2
What an exciting project this is.