Orion and ATV

[Stinkk]

Hi,

Was wondering if anyone in the community could answer a few questions about the new NASA spacecraft.

What was the reason the Lockheed Martin Service Module was scrapped and ESA's ATV vehicle was chosen to be adapted instead (I'm guessing because classic Lockheed kept doubling the cost estimate and schedule every other week until it was unaffordable?)

Would the ATV like vehicle be the future Service Module, or is it just a stand in until either the Lockheed one is build or another design is made?

Also, what's the advantage/disadvantage of an Apollo like capsule over something like the Dream Chaser? I'm mean especially since the future plan is to include a habitat module instead of having the Crew Module be the habitat, wouldn't Orion then be just a glorified return vehicle?

Thanks in advance!

[SargeRho]

Mostly simplicity. A capsule is the perfect re-entry body, and is a very simple shape.

[Nibb31]

Hi,

Was wondering if anyone in the community could answer a few questions about the new NASA spacecraft.

What was the reason the Lockheed Martin Service Module was scrapped and ESA's ATV vehicle was chosen to be adapted instead (I'm guessing because classic Lockheed kept doubling the cost estimate and schedule every other week until it was unaffordable?)

The main advantage of the ATV-based service module is that some of the cost is paid for by ESA in exchange for seats on Orion for European astronauts. The secondary advantage of getting international partners is to make it harder for Congress to cancel the program.

Would the ATV like vehicle be the future Service Module, or is it just a stand in until either the Lockheed one is build or another design is made?

The agreement covers the joint development of the service module design, and delivery of two service modules for the only two Orion missions that are currently planned, EM-1 in 2017 and EM-2 in 2021.

NASA currently has no funding for further missions, and is still trying to figure out what they are going to do with SLS after those two flights. Future service modules might be mission-specific, or they might be based on the ATV design but built in the US.

Also, what's the advantage/disadvantage of an Apollo like capsule over something like the Dream Chaser? I'm mean especially since the future plan is to include a habitat module instead of having the Crew Module be the habitat, wouldn't Orion then be just a glorified return vehicle?

The difference is a bit like between an urban minivan and a land rover. They are different vehicles designed for different purposes.

The CCDev vehicles (Dream Chaser, Dragon, or CST-100) are designed to act as cheap LEO taxis, to deliver crew and supplies to the ISS. Orion is a deep-space exploration vehicle designed for a harsher environment and different mission requirements. Dream Chaser isn't made for long duration flights, it cannot withstand high-speed reentry, it has less shielding against radiation, and it cannot be depressurized for EVA like Orion.

Also, it's silly to bring a winged vehicle into deep space. The wings and landing gear are just a waste of payload mass and the TPS is much more exposed and fragile. A capsule is much better suited to the job.

Edited August 21, 2013 by Nibb31

[Stinkk]

Ah ok, thanks a lot for the reply!