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Antares launch capabilities compared to other vehicles in its class?
by
Star One
on 04 Oct, 2012 20:41
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Is there much known about how its payload to LEO & GTO stacks up in comparsion to other rockets in the same launch class as it?
All it gives on Wiki for it is a very rough figure to LEO of 5,000Kg & nothing else.
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#1
by
Prober
on 04 Oct, 2012 22:58
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Is there much known about how its payload to LEO & GTO stacks up in comparsion to other rockets in the same launch class as it?
All it gives on Wiki for it is a very rough figure to LEO of 5,000Kg & nothing else.
comparable to a Delta II class
we need to see the first launch to see how everything pans out.
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#2
by
strangequark
on 04 Oct, 2012 23:24
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#3
by
Star One
on 05 Oct, 2012 19:51
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#4
by
strangequark
on 05 Oct, 2012 20:06
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Is there much known about how its payload to LEO & GTO stacks up in comparsion to other rockets in the same launch class as it?
All it gives on Wiki for it is a very rough figure to LEO of 5,000Kg & nothing else.
http://www.orbital.com/NewsInfo/Publications/Antares_Brochure.pdf
Page 6.
Thanks for that link.
Maybe I am reading this wrong but it does compare that equally to its commercial rival the Falcon 9 going by this.
http://www.spacex.com/Falcon9UsersGuide_2009.pdf
I'm not sure I understand your comment. Antares in its current configuration is a Delta-II comparable. Falcon 9 is more like an Atlas V 401.
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#5
by
Star One
on 07 Oct, 2012 12:18
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Is there much known about how its payload to LEO & GTO stacks up in comparsion to other rockets in the same launch class as it?
All it gives on Wiki for it is a very rough figure to LEO of 5,000Kg & nothing else.
http://www.orbital.com/NewsInfo/Publications/Antares_Brochure.pdf
Page 6.
Thanks for that link.
Maybe I am reading this wrong but it does compare that equally to its commercial rival the Falcon 9 going by this.
http://www.spacex.com/Falcon9UsersGuide_2009.pdf
I'm not sure I understand your comment. Antares in its current configuration is a Delta-II comparable. Falcon 9 is more like an Atlas V 401.
My fault here was I had made the assumption before I saw the figures on this that the two launchers picked for the commercial cargo contract by NASA would be similiar in performance. But obviously my assumption was incorrect as they are not comparable at all and not the same class of vehicle.
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#6
by
ugordan
on 07 Oct, 2012 12:29
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But obviously my assumption was incorrect as they are not comparable at all and not the same class of vehicle.
Antares and F9 1.1 are not in the same class, but I wonder if the same holds true for the current F9 1.0.
I've been eagerly waiting for the NASA ELV page to finally include Antares performance data after the vehicle was included in the NLS-II contract.
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#7
by
Star One
on 07 Oct, 2012 20:00
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But obviously my assumption was incorrect as they are not comparable at all and not the same class of vehicle.
Antares and F9 1.1 are not in the same class, but I wonder if the same holds true for the current F9 1.0.
I've been eagerly waiting for the NASA ELV page to finally include Antares performance data after the vehicle was included in the NLS-II contract.
Subconsciously maybe this is what had steered me in the direction of thinking that they were the same or a similar class of vehicle.
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#8
by
sdsds
on 07 Oct, 2012 22:10
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Has Orbital talked much recently about the potential performance of Antares with a liquid second stage? They're doing the "right thing" with their focus on meeting NASA's CRS mission requirements using Castor-30 variants. But would Antares performance jump much closer to Atlas V 401 if it used something more like a Centaur?
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#9
by
strangequark
on 08 Oct, 2012 14:56
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Has Orbital talked much recently about the potential performance of Antares with a liquid second stage? They're doing the "right thing" with their focus on meeting NASA's CRS mission requirements using Castor-30 variants. But would Antares performance jump much closer to Atlas V 401 if it used something more like a Centaur?
Depends on the path taken. Speaking in a completely unofficial capacity, I've gotten Antares with liquid upper stage to throw upwards of 10000kg with kerosene, doing back-of-the-spreadsheet calculations. So, yeah, with an optimal upper stage, it's probably Atlas class.
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#10
by
Robotbeat
on 08 Oct, 2012 16:25
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Has Orbital talked much recently about the potential performance of Antares with a liquid second stage? They're doing the "right thing" with their focus on meeting NASA's CRS mission requirements using Castor-30 variants. But would Antares performance jump much closer to Atlas V 401 if it used something more like a Centaur?
Depends on the path taken. Speaking in a completely unofficial capacity, I've gotten Antares with liquid upper stage to throw upwards of 10000kg with kerosene, doing back-of-the-spreadsheet calculations. So, yeah, with an optimal upper stage, it's probably Atlas class.
Awesome. I know Dr. Elias has mentioned here on NSF that he kind of regrets not being able to go with a liquid upper for
Taurus II Antares. But nothing says you couldn't do it in the future!
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#11
by
strangequark
on 08 Oct, 2012 18:58
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Awesome. I know Dr. Elias has mentioned here on NSF that he kind of regrets not being able to go with a liquid upper for Taurus II Antares. But nothing says you couldn't do it in the future!
Yeah, I would love to hear his opinion on XCOR's piston engines. Granted, they're still strolling in the gentle foothills of the mountain range of qualifying an engine as flight hardware.
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#12
by
Robotbeat
on 08 Oct, 2012 20:33
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Awesome. I know Dr. Elias has mentioned here on NSF that he kind of regrets not being able to go with a liquid upper for Taurus II Antares. But nothing says you couldn't do it in the future!
Yeah, I would love to hear his opinion on XCOR's piston engines. Granted, they're still strolling in the gentle foothills of the mountain range of qualifying an engine as flight hardware.
Yeah, I was thinking the same thing.
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#13
by
Star One
on 08 Oct, 2012 22:50
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Has Orbital talked much recently about the potential performance of Antares with a liquid second stage? They're doing the "right thing" with their focus on meeting NASA's CRS mission requirements using Castor-30 variants. But would Antares performance jump much closer to Atlas V 401 if it used something more like a Centaur?
Depends on the path taken. Speaking in a completely unofficial capacity, I've gotten Antares with liquid upper stage to throw upwards of 10000kg with kerosene, doing back-of-the-spreadsheet calculations. So, yeah, with an optimal upper stage, it's probably Atlas class.
Awesome. I know Dr. Elias has mentioned here on NSF that he kind of regrets not being able to go with a liquid upper for Taurus II Antares. But nothing says you couldn't do it in the future!
What are the reasons they have gone with a solid upper stage, why not something like an off the shelf Centaur instead? Wouldn't a liquid upper stage bring a big boost in performance?
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#14
by
Jim
on 08 Oct, 2012 23:04
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What are the reasons they have gone with a solid upper stage, why not something like an off the shelf Centaur instead?
Because there is no such thing. ULA is not going help them become a competitor.
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#15
by
strangequark
on 09 Oct, 2012 04:03
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What are the reasons they have gone with a solid upper stage, why not something like an off the shelf Centaur instead?
Because there is no such thing. ULA is not going help them become a competitor.
Haha, indeed. It'd be a cold day in hell. Centaur is also quite expensive, even if it were available. Castor 30XL was a much easier proposition. As to the future, it depends on how well Antares goes.
EDIT: Come to think of it, wouldn't ULA be forbidden from selling Centaurs without going through Lockheed, even if they wanted to do so?
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#16
by
sdsds
on 09 Oct, 2012 04:47
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What are the reasons they have gone with a solid upper stage
The short answer is, "Because they could." Or perhaps, "Because they didn't want to bite off more than they could chew." But since those aren't really helpful, here are my somewhat educated guesses at factors that contributed to the decision:
1) Orbital has a lot of experience with solid upper stages.
2) Orbital has a lot of experience with Castor motors.
3) Castor 30 was seen as a "safe" evolution of e.g. Castor 120.
4) Another potential customer of Castor 30 (USAF) was already contributing towards its development, and contributing its expertise in assuring the stage will function properly.
5) Solids require less plumbing at the launch pad.
All of those contribute to reducing Antares schedule risk.
6) Antares with Castor 30 meets the NASA CRS requirement. (Here I wave away considerations of 30A, 30B, 30XL, extended super-Cygnus, etc.)
7) Adding an Antares configuration with a liquid upper stage would be a relatively straightforward upgrade of the pad and vehicle. When the time comes they might well be tempted to borrow the SpaceX phrase, "We designed from the start for this." (Maybe to use Jim's term the pad is already "scarred" for it?)
8
) The cost of developing a liquid stage could become unpredictably large.
9) A solid stage was available from a U.S. source.
10) For missions where a liquid vehicle would restart the upper stage, adding a third stage can sometimes meet the same requirement.
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#17
by
baldusi
on 09 Oct, 2012 21:34
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Let me point out that the Antares first stage is roughly 85% of an Atlas V first stage (both thrust and mass). So it wouldn't sound too difficult to get in the ball park of performance. Particularly for LEO. My only question is: is there a market for it?
If Falcon 9 becomes a reliable work horse, and adapts to DoD's needs, then there will be a surplus of rocket models between EELV and F9/FH. And that's just for the US. Then you have Angara and LM-5 also entering the market. I simply don't see much space for them.
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#18
by
Robotbeat
on 09 Oct, 2012 21:40
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Let me point out that the Antares first stage is roughly 85% of an Atlas V first stage (both thrust and mass). So it wouldn't sound too difficult to get in the ball park of performance. Particularly for LEO. My only question is: is there a market for it?
If Falcon 9 becomes a reliable work horse, and adapts to DoD's needs, then there will be a surplus of rocket models between EELV and F9/FH. And that's just for the US. Then you have Angara and LM-5 also entering the market. I simply don't see much space for them.
Orbital can only hope for such a scenario. They make their dough on satellites. They pretty much developed Antares in order to have a good domestic vehicle to launch their birds into orbit that's cheaper than Atlas V. They wanted a cheap Delta II replacement.
If SpaceX wins like you said, so does Orbital. But SpaceX hasn't won, yet. And we don't know for sure that it will.
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#19
by
baldusi
on 09 Oct, 2012 22:01
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I never said SpaceX would have "won". I only stated that both in the domestic and international market there's a trend that points to "oversupply". I know Dr Elias specifically said they would make a killing if they had cheap domestic LV. But the question of bringing the Antares to EELV class is very difficult to answer positively from both current and prospective competition.
Antares could get a place in the science LEO market, but it would need a new pad (to SSO). And for GTO and planetary missions it would need a new upper stage. So, as an economist, I don't think they have the most promising business case, save for the COTS program. Of course I would love them to make it cheaper than a Falcon 9, or at least cheaper and almost as capable as an Atlas V 401 if SpaceX fails. But I just think that it's too early and they are not in the most promising position.
Luckily, they don't need to, apparently. I've even wondered if they could contract Aliena for a 4.4m pressure vessel for Cyygnus and launch on Atlas 521 for the COTS 2 program. It would be expensive but have an amazing payload capability.
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#20
by
sdsds
on 10 Oct, 2012 07:15
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both in the domestic and international market there's a trend that points to "oversupply"
I respect your economics view, and as you go on to mention: lower prices are the "solution" to an oversupply problem. But space launch is not a commodity service. SpaceX will likely be the cost leader, and Orbital will try to differentiate its offering to justify their slightly higher prices. They can do that by pointing to their track record.
Has SpaceX ever launched two vehicles in the same configuration and gotten the same result? Orbital has done that dozens of times!
Also, although the SpaceX corporate culture is attractive to many, it might not be a good fit for some customers. For example, have they sold anything to a Japanese customer yet? Orbital has sold satellites to customers in Japan multiple times.
So I think Orbital can compete successfully using Antares, even if not on price.
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#21
by
Robotbeat
on 10 Oct, 2012 22:56
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both in the domestic and international market there's a trend that points to "oversupply"
I respect your economics view, and as you go on to mention: lower prices are the "solution" to an oversupply problem. But space launch is not a commodity service. SpaceX will likely be the cost leader, and Orbital will try to differentiate its offering to justify their slightly higher prices. They can do that by pointing to their track record.
Has SpaceX ever launched two vehicles in the same configuration and gotten the same result? Orbital has done that dozens of times!
Also, although the SpaceX corporate culture is attractive to many, it might not be a good fit for some customers. For example, have they sold anything to a Japanese customer yet? Orbital has sold satellites to customers in Japan multiple times.
So I think Orbital can compete successfully using Antares, even if not on price.
I'm not sure I buy the reliability argument working in Orbital's favor at the moment.
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#22
by
simonbp
on 11 Oct, 2012 00:00
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Launching rockets is hard, and OSC has had their share of sorrows.
CRS ensures that a lot of Antarii (?) will be flown over the next few years, and unlike SpaceX they are not changing their rocket halfway through. By the end of that, they should have a pretty well-established rocket. It could continue afterwards as just a NASA science mission rocket, like Pegasus.
Indeed, the relatively small upper stage could be an advantage if combined with one or two more smaller solids for a NASA-specific escape-optimized rocket.
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#23
by
Jim
on 11 Oct, 2012 00:03
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Launching rockets is hard, and OSC has had their share of sorrows.
CRS ensures that a lot of Antarii (?) will be flown over the next few years, and unlike SpaceX they are not changing their rocket halfway through.
The second stage motor is being changed after a few flights.
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#24
by
Lurker Steve
on 11 Oct, 2012 17:12
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Launching rockets is hard, and OSC has had their share of sorrows.
CRS ensures that a lot of Antarii (?) will be flown over the next few years, and unlike SpaceX they are not changing their rocket halfway through.
The second stage motor is being changed after a few flights.
But the change from the Castor 30 to the Castor 30XL isn't as dramatic as a new engine design and stretched tanks, right ?
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#25
by
baldusi
on 11 Oct, 2012 18:55
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Launching rockets is hard, and OSC has had their share of sorrows.
CRS ensures that a lot of Antarii (?) will be flown over the next few years, and unlike SpaceX they are not changing their rocket halfway through.
The second stage motor is being changed after a few flights.
But the change from the Castor 30 to the Castor 30XL isn't as dramatic as a new engine design and stretched tanks, right ?
The move from 30A to 30B is a change in the grain. Castor 30XL is longer. Which in a solid means a new tank/chamber.
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#26
by
strangequark
on 11 Oct, 2012 19:35
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The move from 30A to 30B is a change in the grain. Castor 30XL is longer. Which in a solid means a new tank/chamber.
Yes, but stretching a monolithic grain, filament-wound solid is relatively simple.
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#27
by
baldusi
on 11 Oct, 2012 19:43
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But the change from the Castor 30 to the Castor 30XL isn't as dramatic as a new engine design and stretched tanks, right ?
The move from 30A to 30B is a change in the grain. Castor 30XL is longer. Which in a solid means a new tank/chamber.
Yes, but stretching a monolithic grain, filament-wound solid is relatively simple.
But that's a different question
