Earth Departure Stage
![](https://upload.wikimedia.org/wikipedia/commons/thumb/0/0e/Earth_Departure_Stage_with_Altair_and_Orion_02-2008.jpg/220px-Earth_Departure_Stage_with_Altair_and_Orion_02-2008.jpg)
The Earth Departure Stage (EDS) was the upper stage of the Ares V rocket announced by NASA as part of the Constellation program . With the termination of the Constellation program, the construction of the Ares missiles also ceased. The EDS should provide the propulsion for future flights to the moon , Mars and possibly other destinations.
construction
Developed by NASA's Marshall Space Flight Center in Huntsville, Alabama, the EDS was essentially an enlarged Saturn upper stage (S-IVB) with larger tanks. It would have been powered by a J-2X main engine powered by liquid oxygen ( LOX ) and liquid hydrogen ( LH2 ) fuel . As the top tier of the Ares V, it would have carried an Altair lunar module, which would have been protected by a payload fairing when it took off .
Moon mission
Unlike the Apollo lunar missions , when the third stage (S-IVB) of the Saturn V rocket pushed the Apollo spacecraft and the Apollo lunar module together into Earth orbit and then on their way to the moon, EDS would be Altair first flew in a park orbit around the earth. The Orion spaceship with a crew of up to four would then have been launched into space on an Ares I and coupled to the lunar module with the waiting EDS. After that, the J-2X engine would have ignited a second time and would have accelerated the Altair lunar module and Orion spacecraft on a path to the moon.
Web links
- Description of NASA (English)
- Ares-V-Factsheet (English, PDF; 4.8 MB)
- NASA J-2X factsheet (English, PDF; 3.0 MB)