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The language is all conditional. ULA/Bigelow want a hand-out to launch this. I'll be impressed when they just do it.

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The Bigelow YT vid shows a shakedown in LEO, with a dragon arriving. Which is fine. They then refuel and ACES (cool), and send it to LLO. Also cool. The problem is it shows Orion bringing crew. Orion cannot do LLO, right? The EUS is expended on the trans lunar burn, right? The ESM has to to the insertion burn, and it lacks the dv to do that and still come home, as it has about 1km/s less dv than the Apollo CSM.

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1 hour ago, tater said:

The Bigelow YT vid shows a shakedown in LEO, with a dragon arriving. Which is fine. They then refuel and ACES (cool), and send it to LLO. Also cool. The problem is it shows Orion bringing crew. Orion cannot do LLO, right? The EUS is expended on the trans lunar burn, right? The ESM has to to the insertion burn, and it lacks the dv to do that and still come home, as it has about 1km/s less dv than the Apollo CSM.

according to the ULA release, the station will function as a depot, maybe they mean a propellant depot?

Edited by insert_name

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B330 isn't a prop tank, that would have to be added.

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2 hours ago, tater said:

The Bigelow YT vid shows a shakedown in LEO, with a dragon arriving. Which is fine. They then refuel and ACES (cool), and send it to LLO. Also cool. The problem is it shows Orion bringing crew. Orion cannot do LLO, right? The EUS is expended on the trans lunar burn, right? The ESM has to to the insertion burn, and it lacks the dv to do that and still come home, as it has about 1km/s less dv than the Apollo CSM.

I think Orion can do LLO. Not sure, however.

The Apollo CSM was likely over engineered for its ultimate purpose.

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I had thought that part of the orbit choice for Orion was the fact that it could not do LLO.

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13 minutes ago, Bill Phil said:

I think Orion can do LLO. Not sure, however.

The Apollo CSM was likely over engineered for its ultimate purpose.

I could be wrong about this but I though Apollo CSM was originally envisioned as a direct ascent vehicle right?

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7 minutes ago, Racescort666 said:

I could be wrong about this but I though Apollo CSM was originally envisioned as a direct ascent vehicle right?

It was, but the only part of that concept that survived was the SPS engine. So the Apollo CSM ended up with a lot more thrust than it needed, but the overall mass and propellant loads were appropriate for missions to lunar orbit, not direct ascent.

A cursory search of the internet shows that the Apollo CSM had a total delta v of around 2,800 m/s. A similar search suggests Orion's total delta v is around 1,850 m/s. 

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Yeah, short of instantly dismissing Orion, I don't know if the quoted dv for Apollo is as flown, or just the CSM... It had to do the orbital insertion with the full LEM attached, is what I mean.

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17 minutes ago, Racescort666 said:

I could be wrong about this but I though Apollo CSM was originally envisioned as a direct ascent vehicle right?

I could be wrong too, but the direct mission was (i think) an earlier idea that did not really go far into the designing phase, i think the CSM wouldn't be very different if the direct idea never came to be.

Just a geuss.

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4 minutes ago, tater said:

Yeah, short of instantly dismissing Orion, I don't know if the quoted dv for Apollo is as flown, or just the CSM... It had to do the orbital insertion with the full LEM attached, is what I mean.

That's a good point. That 2,800 m/s was from Apollo 7. 

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22 minutes ago, Ten Key said:

It was, but the only part of that concept that survived was the SPS engine. So the Apollo CSM ended up with a lot more thrust than it needed, but the overall mass and propellant loads were appropriate for missions to lunar orbit, not direct ascent.

A cursory search of the internet shows that the Apollo CSM had a total delta v of around 2,800 m/s. A similar search suggests Orion's total delta v is around 1,850 m/s. 

That makes sense. The engine was probably one of the more complex parts of the system and the engine supplier (Rocketdyne I think) presumably made the case for sticking with their design and moving forward.

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A NASA PDF I looked at said the dv was closer to 1200, and another page says 1338. I have no idea where the 1800 is coming from, or which is correct. From what I can tell, the bare minimum dv budget for LOI and TEI from the trajectory the EUS leaves it in is ~1800 m/s.

PDF for ref:

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150019648.pdf

 

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1 hour ago, tater said:

I had thought that part of the orbit choice for Orion was the fact that it could not do LLO.

You mean L-2? As far as I can tell, that has more to do with launch vehicle limitations than Orion's limits. SLS can't throw as much mass to TLI as the Saturn V, but it can throw a decent amount to L-2.

The biggest Delta-V cost for LLO is the initial transfer from LEO, which EUS should handle. Braking and returning don't take nearly as much. Although the margins may be a bit small.

The Apollo CSM alone had more Delta V, but with an LM it was much less. About 1500 m/s. Of course, it only had to brake into LLO with the LM and make course corrections, so it had more on its way back. Maybe they plan on refueling Orion? Or potentially using a larger vehicle?

2 minutes ago, tater said:

A NASA PDF I looked at said the dv was closer to 1200, and another page says 1338. I have no idea where the 1800 is coming from, or which is correct. From what I can tell, the bare minimum dv budget for LOI and TEI from the trajectory the EUS leaves it in is ~1800 m/s.

PDF for ref:

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150019648.pdf

 

The astronautix article on Orion is where the 1800 number is coming from, I believe.

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LLO = Low Lunar Orbit. 100km or lower. Like Apollo, or some of the "frozen" orbits possible at the right inclinations.

It is my understanding that Orion when originally designed with lunar landings in mind used the Altair lander to provide the orbital insertion burn.

FWIW, wiki says 1340 m/s for the Orion CSM.

Edited by tater

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Ok, so they are saying that this station can be NASA's in 2022 for the low, low price of 2.3 B$. Vulcan doesn't exist yet.0

This is entirely within the realms of BFR flying at some level without any expense by NASA at all. How would we rate the chances of BFR being operational in 2022 if the government wrote spacex a check for 2 billion $?

 

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