Commercial Crew - Discussion Thread 1

[rayleighscatter]

From safety point of view the boarding before fueling seems better, if any goes wrong the crew have LAS.

It is not obvious. So far it seems that the act of fuelling was regarded dangerous, less so the fuelled launch vehicle. So they did fuelling first and then access the capsule. What has changed to change the procedure? Or was it always wrong to fuel first?

A bit of an irony. It was always critisized that SpaceX is not following established procedures. Now they stick to established procedures and it is wrong again.

As Trevor pointed out, what changed was the LAS. Shuttle had none so leaving astronauts on top during the fueling process with no means of escape was the greater risk. Now with both CC providers using LAS the greater risk is having additional people around a fueled vehicle. Evolve safety and retire risk.

Unless people want to argue SpaceX should be copying old space, which would be just as ironic.

[JBF]

I think SpaceX is not so much looking at the dragon as the MCT.  Having 5-7 people sitting around for a couple hours is not that big of deal, having a hundred is a different story.

Not counting how long it will take to fuel the larger rocket.

[rayleighscatter]

NASA wouldn't have any say in MCT launches.

[nadreck]

I think SpaceX is not so much looking at the dragon as the MCT.  Having 5-7 people sitting around for a couple hours is not that big of deal, having a hundred is a different story.

On a Dragon one hour represents 2% of the trip to ISS on an MCT 3 hours represents probably < .1% of the voyage to Mars.  I think waiting for a Dragon is more significant than the MCT.  However airliners undergoing deicing, or departing busy airports often keep passengers on the tarmac for 30 minutes to an hour after boarding and the longest flights there are 14-15 hours or so.

[oldAtlas_Eguy]

To add some data about Atlas and Mercury, the Atlas as an ICBM had to go from standby (only the RP1 loaded) to launch in 30 minutes. This meant that the Atlas was designed for rapid LOX loading in about 15-20 minutes. NASA used this to their advantage for Mercury although the first MA launch sat on the pad for hours with the astronaut inside.

[Robotbeat]

Yeah, just the idea that we used to (and still do!) launch astronauts on ICBMs should be proof enough there's more than one "right" way of doing something (or rather, that there is no "right" way of doing things, just better or worse ways).

[A_M_Swallow]

On a Dragon one hour represents 2% of the trip to ISS on an MCT 3 hours represents probably < .1% of the voyage to Mars.  I think waiting for a Dragon is more significant than the MCT.  However airliners undergoing deicing, or departing busy airports often keep passengers on the tarmac for 30 minutes to an hour after boarding and the longest flights there are 14-15 hours or so.

I assume the Dragons and Orions can be fed breathable oxygen and electricity whilst their launch vehicle is being fuelled.

[manboy]

How long will the first demonstration flights last? I am assuming that the demo flights will not stay up the six months they need to replace Soyuz.

John

The uncrewed flight will last for 30 days, the crewed flight will last for 14 days.

http://www.nasaspaceflight.com/2015/03/commercial-crew-demo-missions-dragon-cst-100/

[John-H]

Thanks.  So, a few more years of Soyuz anyway.

John

[erioladastra]

How long will the first demonstration flights last? I am assuming that the demo flights will not stay up the six months they need to replace Soyuz.

John

The uncrewed flight will last for 30 days, the crewed flight will last for 14 days.

http://www.nasaspaceflight.com/2015/03/commercial-crew-demo-missions-dragon-cst-100/

TBD - each partner determines the needs.  May be anywhere from 3-30 days.  Not defined yet.

[Rocket Science]

Yeah, just the idea that we used to (and still do!) launch astronauts on ICBMs should be proof enough there's more than one "right" way of doing something (or rather, that there is no "right" way of doing things, just better or worse ways).

At least they're nice enough to remove the warheads first...

[Brovane]

From safety point of view the boarding before fueling seems better, if any goes wrong the crew have LAS.

It is not obvious. So far it seems that the act of fuelling was regarded dangerous, less so the fuelled launch vehicle. So they did fuelling first and then access the capsule. What has changed to change the procedure? Or was it always wrong to fuel first?

A bit of an irony. It was always critisized that SpaceX is not following established procedures. Now they stick to established procedures and it is wrong again.

As Trevor pointed out, what changed was the LAS. Shuttle had none so leaving astronauts on top during the fueling process with no means of escape was the greater risk. Now with both CC providers using LAS the greater risk is having additional people around a fueled vehicle. Evolve safety and retire risk.

Unless people want to argue SpaceX should be copying old space, which would be just as ironic.

Why would LAS make any difference?  The Saturn-1B and Saturn-V launches the crew boarded after the vehicle was fueled.  The Titan II for Gemini launches was fueled before the crew boarded. 

Is NASA going to have the crew board the Orion Capsule and then start fueling the SLS?  They might want to bring a sandwich and a book while they wait. 

[TrevorMonty]

The problem with boarding a fully fuelled LV is crew and ground crew are vulnerable while boarding.
It takes a considerable amount of time to access pad, go up tower, board the capsule and get strapped in. Once hatch is closed the crew has LAS but ground crew still has get to ground and exit pad.
The crew would also be reluctant to abort while ground crew are in the area.
The Saturn tower had a flying fox but it takes minutes for everybody to go down it, while a fire to explosion can takes seconds.

It will be interesting to see how Blue Origin approaches this issue with New Shepard.

[Brovane]

The problem with boarding a fully fuelled LV is crew and ground crew are vulnerable while boarding.
It takes a considerable amount of time to access pad, go up tower, board the capsule and get strapped in. Once hatch is closed the crew has LAS but ground crew still has get to ground and exit pad.
The crew would also be reluctant to abort while ground crew are in the area.
The Saturn tower had a flying fox but it takes minutes for everybody to go down it, while a fire to explosion can takes seconds.

It will be interesting to see how Blue Origin approaches this issue with New Shepard.

Make sure the crew packs a sandwich in-case they get hungry while the LV is fueling.   

[catdlr]

New Crew Access Tower Takes Shape at Cape

Published on Jun 25, 2015
The metal segments that will be stacked to form a complete crew access tower later this year are taking shape a few miles from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida. The work by Boeing and United Launch Alliance is critical in readying the launch site for a crew flight test to certify their systems in 2017 for operational missions to the International Space Station for NASA’s Commercial Crew Program.

[darkenfast]

Regarding fuel-after-boarding: I'm still curious if anyone knows whether Boeing/ULA has been asked to do this?  Can Atlas V fuel this quickly?  If SpaceX says: "Okay, we can make it work", and Boeing/ULA says: "Won't work", then will this have a bearing on any attempts to downselect to one provider?  Besides the really obvious difference in price, I mean.

[arachnitect]

Regarding fuel-after-boarding: I'm still curious if anyone knows whether Boeing/ULA has been asked to do this?  Can Atlas V fuel this quickly?  If SpaceX says: "Okay, we can make it work", and Boeing/ULA says: "Won't work", then will this have a bearing on any attempts to downselect to one provider?  Besides the really obvious difference in price, I mean.

I'm guessing they'll load RP-1 the night before or before the crew arrives at the pad, then do all the cryo tanking with the crew in place and the pad evacuated.

[the_other_Doug]

Reminds me of Mike Collins' observation from when he and the rest of the Apollo 11 crew boarded their vehicle.  He basically said that every other time he had been to the pad, it was swarming with busy workers.  When they approached the pad and got into the elevator on launch morning, he was impressed by the fact that all the busy-bee workers were gone, now.  He realized that, because the Saturn was fueled (or being fueled), the pad was now not as safe a place to hang out, and wondered if those missing workers knew something he didn't...

[jongoff]

I'm just gunna remind y'all that CCDev1 was $50M, CCDev2 was $270M, CCiCap was $1112M and CCtCap is $6800M, for a grand total of $8232M. NASA most recently paid $76.3M/seat for Soyuz. So the cost of the Commercial Crew program is 107 Soyuz seats. For shuttling astronauts to a station that will be dumped into the Pacific in 2028, at the latest, even if the program had been fully funded so it could start flying this year (and completely ignoring the potentially low price per seat of Commercial Crew) it would still have been cheaper to just buy more Soyuz seats.

The argument that Commercial Crew is cheaper than the Soyuz just doesn't work. That's why Bolden stopped making it. A much worse calculation than mine was presented to him in the House (relying on the non-extended ISS retirement date) and he failed to respond to it. He can't even make the sunk cost argument, because the payments to Blue Origin and Sierra Nevada have torpedoed it. The Commercial Crew program budget has ballooned, as all NASA programs seem to do, and now the only argument he can make is nationalism. Russia is even making it incredibly easy to make that argument, and Bolden still can't sell it.

This keeps ignoring the fact that with CCrew, they can increase the population of the USOS side of ISS from 3 to 4. While this doesn't sound like a big deal, currently 2 people worth of time is tied up in maintaining the ISS, and only ~2000 man hours per year of research is happening on the USOS side. If there were 4 astronauts, they could nearly double the amount of available research hours per year, and yes right now astronaut time is one of the scarcest commodities on the ISS. So "just buying more Soyuz seats" doesn't cut it on an apples-to-apples basis.

~Jon

[QuantumG]

This keeps ignoring the fact that with CCrew, they can increase the population of the USOS side of ISS from 3 to 4. While this doesn't sound like a big deal, currently 2 people worth of time is tied up in maintaining the ISS, and only ~2000 man hours per year of research is happening on the USOS side. If there were 4 astronauts, they could nearly double the amount of available research hours per year, and yes right now astronaut time is one of the scarcest commodities on the ISS. So "just buying more Soyuz seats" doesn't cut it on an apples-to-apples basis.

That's why there was an agreement to ramp up Soyuz production, which coincidentally would have provided more seats for Space Adventures.. but NASA didn't like that, so they locked them out of the deal. That made it "too expensive" compared to the false promise of a COTS-like procurement of commercial crew seats.