CCDev to CCiCAP to CCtCAP Discussion Thread

[BrianNH]

Doing an abort test does not necessarily mean that you are ahead.   Blue Origin did a pad abort test almost 2 years ago and I don't see anyone arguing that they are ahead of the others.

[rayleighscatter]

For NASA's use, i.e. 2 flights to the ISS a year

Just to pick nits, wouldn't it be closer to 4 flights a year? They're 6 month expeditions but they overlap quite a bit.

[Will]

For NASA's use, i.e. 2 flights to the ISS a year

Just to pick nits, wouldn't it be closer to 4 flights a year? They're 6 month expeditions but they overlap quite a bit.

I would expect Russia would continue to do Soyuz flights as well.

[MP99]

For NASA's use, i.e. 2 flights to the ISS a year

Just to pick nits, wouldn't it be closer to 4 flights a year? They're 6 month expeditions but they overlap quite a bit.

The current arrangement with expeditions staggered quarterly seems to work well.

It would make sense for Russia and the US to make a quid pro quo exchange, so that CC carries up one Russian, with the Soyuz in the following quarter carrying up one American or American partner.

Alternative is that both US & Russia will need to switch to switching their whole crew of three / four every six months (or to make more than two flights per year).

Cheers, Martin

[Will]

For NASA's use, i.e. 2 flights to the ISS a year

Just to pick nits, wouldn't it be closer to 4 flights a year? They're 6 month expeditions but they overlap quite a bit.

The current arrangement with expeditions staggered quarterly seems to work well.

It would make sense for Russia and the US to make a quid pro quo exchange, so that CC carries up one Russian, with the Soyuz in the following quarter carrying up one American or American partner.

Alternative is that both US & Russia will need to switch to switching their whole crew of three / four every six months (or to make more than two flights per year).

Cheers, Martin

That's pretty much what we did when STS was still flying.

[ChrisWilson68]

Doing an abort test does not necessarily mean that you are ahead.   Blue Origin did a pad abort test almost 2 years ago and I don't see anyone arguing that they are ahead of the others.

You're right that an abort test by itself doesn't mean one party is ahead overall if the other party is way ahead in some other way.  In the case of Blue Origin, they don't have a launch vehicle that has made it to orbit, or anywhere close to orbit.  That puts them far behind the other three, each of which has a launch vehicle that has done at least a few successful operational missions to orbit.

The pad and in-flight abort tests are big plusses for SpaceX over CST-100 and DC.  Do those others have some area in which they are so far ahead that it negates being behind in the abort tests?

[ChrisWilson68]

What if instead of NASA just saying they only need two flights a year and asking for bids on that, they said they had X dollars a year they were willing to spend and asked how many flights per year they could get for that?  Or if they asked for bids that included prices for 2, 3, 4, ... 50 flights per year?  If the marginal costs of additional flights were low, couldn't NASA find value in more than 2 flights a year?

Wouldn't it be interesting to have an ISS that was a busy transport hub, with visiting scientists coming and going every week, rather than a lonely outpost that only had a ship visit every six months?

[baldusi]

Doing an abort test does not necessarily mean that you are ahead.   Blue Origin did a pad abort test almost 2 years ago and I don't see anyone arguing that they are ahead of the others.

Boilerplate capsule with customized solids for test. It was not a capsule nor were those the actual abort engines. That's a huge difference from doing an actual flight abort, from the actual pad, with flight hardware.

[vt_hokie]

Wouldn't it be interesting to have an ISS that was a busy transport hub, with visiting scientists coming and going every week, rather than a lonely outpost that only had a ship visit every six months?

I have had the same thought!  You'd think that would be what we want to move toward as we build on our presence in low Earth orbit. 

[baldusi]

Wouldn't it be interesting to have an ISS that was a busy transport hub, with visiting scientists coming and going every week, rather than a lonely outpost that only had a ship visit every six months?

I have had the same thought!  You'd think that would be what we want to move toward as we build on our presence in low Earth orbit.

Small tip: think of what each visiting vehicle requires in attitude changes, orbital boosts, actual vehicle i pact, etc. Now think of the effects on microgravity. Now add that each VV eats about two to three days crew. And you'd see why they don't want many visits and also why they'd rather increase CRS-2 payload requirement per launch rather than allow more launches.

[Ronsmytheiii]

Wouldn't it be interesting to have an ISS that was a busy transport hub, with visiting scientists coming and going every week, rather than a lonely outpost that only had a ship visit every six months?

And then the microgravity environment of the station would be appalling.  Remember that every-time a vehicle docks, the entire structure of the station shakes, and you have to orient it in certain ways.  That effects experiments that need to be left alone, just adding flights to station to drive up the flight rates will diminish ISS science returns.

[ChrisWilson68]

Wouldn't it be interesting to have an ISS that was a busy transport hub, with visiting scientists coming and going every week, rather than a lonely outpost that only had a ship visit every six months?

I have had the same thought!  You'd think that would be what we want to move toward as we build on our presence in low Earth orbit.

Small tip: think of what each visiting vehicle requires in attitude changes, orbital boosts, actual vehicle i pact, etc. Now think of the effects on microgravity. Now add that each VV eats about two to three days crew. And you'd see why they don't want many visits and also why they'd rather increase CRS-2 payload requirement per launch rather than allow more launches.

And then the microgravity environment of the station would be appalling.  Remember that every-time a vehicle docks, the entire structure of the station shakes, and you have to orient it in certain ways.  That effects experiments that need to be left alone, just adding flights to station to drive up the flight rates will diminish ISS science returns.

The fact that each visiting vehicle requires two to three days of ISS crew time just says ISS hasn't developed a system that scales for handling visiting vehicles.  There's no fundamental reason they couldn't do so.

As to the ISS having to be re-oriented for visiting vehicles, that also sounds like a solvable problem.

About vibrations: with vehicles docking rather than berthing, vibrations could be diminished.  There's no lower limit on how much they could be diminished.  And experiments could be isolated from the vibrations of the station itself.

It comes down to a question of what the purpose of the ISS is.  Is it just a dead-end outpost for zero-gravity experiments that cannot stand vibrations?  Or is it also meant as a step toward more routine human presence in space?  Can we not find a way to grow our presence in space without sacrificing all microgravity research?

[vt_hokie]

Maybe what it shows is that ISS support was a poor basis for trying to foster a new commercial human spaceflight industry then.

[Robotbeat]

Maybe what it shows is that ISS support was a poor basis for trying to foster a new commercial human spaceflight industry then.

Any port in a storm. Nothing else has worked.

[su27k]

I don't see it as a budget buster, because NASA is spending less per year for SLS/Orion than it spent for Shuttle.

I'm not sure the comparison with Shuttle make sense...

It is spending 35% of that total for commercial crew annually, but that is for a system that will only weigh about 10% as much as the SLS lifting capability to LEO,

It's not for "a" system, it's for 3 different systems. And the lifting capability is irrelevant if the mission doesn't need it.

never mind that SLS/Orion is going to deep space which commercial crew will not. 

No, it's not going to deep space, it's going to lunar orbit. For deep space missions you'll need a habitat module and in space propulsion, it's a complete different set of technologies from SLS/Orion, and it's not being worked on, so deep space is a pipe dream.

If you really want to do deep space, you'll want to reuse the deep space hardware to keep the cost down, which means the deep space ship needs to go back to Earth orbit after the mission is done, at which point any commercial crew spacecraft can be used to ferry the crew, this makes Orion redundant.

[Oli]

If you really want to do deep space, you'll want to reuse the deep space hardware to keep the cost down, which means the deep space ship needs to go back to Earth orbit after the mission is done, at which point any commercial crew spacecraft can be used to ferry the crew, this makes Orion redundant.

If at all it will go back to EML-2. Direct reentry from there or BEO in general makes sense,  you safe lots of fuel.

Edit: Although compared to the fuel you need for the rest of the mission its probably peanuts.

[ncb1397]

No, it's not going to deep space, it's going to lunar orbit.

lunar orbit is about 1000x deeper into space than humans have gone in the last 50 years.

[ChrisWilson68]

If you really want to do deep space, you'll want to reuse the deep space hardware to keep the cost down, which means the deep space ship needs to go back to Earth orbit after the mission is done, at which point any commercial crew spacecraft can be used to ferry the crew, this makes Orion redundant.

If at all it will go back to EML-2. Direct reentry from there or BEO in general makes sense,  you safe lots of fuel.

Edit: Although compared to the fuel you need for the rest of the mission its probably peanuts.

You can still do aerobraking, but brake to help establish orbit.  Then you don't need much propellent and you still get to keep your spaceship for your next mission.  And you don't have to optimize your spaceship to survive re-entry and landing.

[su27k]

No, it's not going to deep space, it's going to lunar orbit.

lunar orbit is about 1000x deeper into space than humans have gone in the last 50 years.

Yes, but what is the cause of this sorry state of HSF? Could it be that all the budget was tied up by a super expensive LEO transportation system and there's no money left for anything else? At least last time they did this the goal was to reduce the cost of access to LEO, this time around they don't even pretend this is the goal.

[baldusi]

Wouldn't it be interesting to have an ISS that was a busy transport hub, with visiting scientists coming and going every week, rather than a lonely outpost that only had a ship visit every six months?

I have had the same thought!  You'd think that would be what we want to move toward as we build on our presence in low Earth orbit.

Small tip: think of what each visiting vehicle requires in attitude changes, orbital boosts, actual vehicle i pact, etc. Now think of the effects on microgravity. Now add that each VV eats about two to three days crew. And you'd see why they don't want many visits and also why they'd rather increase CRS-2 payload requirement per launch rather than allow more launches.

And then the microgravity environment of the station would be appalling.  Remember that every-time a vehicle docks, the entire structure of the station shakes, and you have to orient it in certain ways.  That effects experiments that need to be left alone, just adding flights to station to drive up the flight rates will diminish ISS science returns.

1.The fact that each visiting vehicle requires two to three days of ISS crew time just says ISS hasn't developed a system that scales for handling visiting vehicles.  There's no fundamental reason they couldn't do so.

2.As to the ISS having to be re-oriented for visiting vehicles, that also sounds like a solvable problem.

3.About vibrations: with vehicles docking rather than berthing, vibrations could be diminished.  There's no lower limit on how much they could be diminished.  And experiments could be isolated from the vibrations of the station itself.

4.It comes down to a question of what the purpose of the ISS is.  Is it just a dead-end outpost for zero-gravity experiments that cannot stand vibrations?  Or is it also meant as a step toward more routine human presence in space?  Can we not find a way to grow our presence in space without sacrificing all microgravity research?

0) Fix your quotes, second one is from Ronsmitheiii.
1) some of the thing they need time for is practice for procedures and contingencies, loading and unloading, checking comm and VV performance, etc. ISS is a very expensive lab. Not a VV hub, and it was too expensive as it is, adding more capabilities and automation is beyond current budgets and expected life.
2) you clearly don't understand orbital mechanics. Each orbit takes some 90min. So, you have to come exactly on se same plane. Even a few meters of difference would mean that if you were coming slightly to port, then 20minutes later you'd be on the same line, which might intersect the station (i.e. Crash). And you can only go from below to catch or above is you were further ahead.
But then there's the issue of the station's attitude. If you let an orbiting object to itself, and let's say that at a certain time there's a fore side, and a nadir side, 1/4 of and orbit later, fore would be pointing to nadir, the former nadir would be now fore. That's because while you orbit there's no force to change your attitude.
Now, once you mix this problems, you'll see why  VV have to come from either from fore and slightly above or from aft and slightly below. And the station has to keep doing active attitude adjustments and keepings. So it can be solved.
3) yes there is and you're mixing concepts. Berthing is done with the arm, and is as gentle as possible. And yet it shakes (slightly) the station. For docking, you basically have to ram the vehicle in the station. Even LIDS was worse than berthing. And as long as you have the Russians with their drogue and probe, the US side is the "gentle" side.
4) go read about the ISS, is a microgravity laboratory. Period. There's no discussion about it.