Most likely a Vulcan.
It's needed in August 2023 if they intend to stick to the established Cygnus launch cadence. Will NASA allow an actual CRS-2 operational Cygnus-on-Vulcan flight first, or will they require some sort of demo flight?
I suspect Falcon 9. Its not like they is a pile of extra vulcans laying around in the next 12-15 months.
Especially if NASA wants a test fligt. Though I suppose ULA loves the paperwork route, but can that even be completed by next summer when the rocket hasn't ever flown yet?
No extra Vulcans, but maybe quite a few idle F9s If SpaceX actually gets Starship operating by then. Putting Starlink on Starship would potentially free up half the F9 launches starting in Q2 2023. We'll see.
Please remember that DreamChaser should take some of the burden put on Cygnus. And also if Vulcan is available to Cygnus, is probably as available to Kuiper and they might squeeze a few extra satellites so they wouldn't mind switching.
I'm not a rocket scientist or even a rocket engineer. How hard is it to move Cygnus to another launcher as measured in time and money? My guess it that it's a bit harder in the real world than it is in Kerbal. Is NASA likely to require a demonstration launch or not? Cygnus has flown on Atlas. Does this mean it's easier to fly it on Vulcan or not?
The main time consuming thing is looking at the limitations of the payload with regard to how it handles the launch environment in the rocket fairing. ULA already knows all that information for Cygnus.
The next thing is working out how the payload connects to / separates from the upper stage. That should be minimal effort since ULA already has operational experience with a Centaur-Cygnus adapter.
So yes, it should be a lot easier to fly on Vulcan than with a new launch provider.
NASA didn't require a demonstration launch for Atlas, there's no reason it should need a non-operational demonstration Cygnus launch from Vulcan.
I'm not a rocket scientist or even a rocket engineer. How hard is it to move Cygnus to another launcher as measured in time and money? My guess it that it's a bit harder in the real world than it is in Kerbal. Is NASA likely to require a demonstration launch or not? Cygnus has flown on Atlas. Does this mean it's easier to fly it on Vulcan or not?
Cygnus Orb-3 (which failed) was launched on 28 October 2014; the next Cygnus mission (OA-4) launched on an Atlas V on 6 December 2015, so Orbital was able to switch launchers in just over 13 months. AFAIK Atlas V was not in the cards as a Cygnus launcher prior to the Orb-3 failure - Orbital had already been looking to upgrade the engines on Antares before the accident.
The OA-4 mission was also the first enhanced Cygnus vehicle to be launched; NASA didn't require a demonstration mission due to launching on an Atlas V or due to an upgraded Cygnus being used. Presumably there would be some sort of oversight required but this precedent does not suggest that they would require a demonstration for a Cygnus launched on Vulcan.
I would assume it would be easier/more straightforward, from an integration standpoint, for ULA to launch a Cygnus on a Vulcan than it would be for a different provider with a different rocket, if only because Cygnus has already flown on Atlas V and ULA has presumably already done some work on what kinds of payload adaptors would be needed to fly customers who have traditionally flown on Atlas V on Vulcan.
Caveat: I am not a rocket scientist or engineer, either.
This is true, and Vulcan is made specifically to launch Atlas V payloads with no or minimal adjustments. So Cygnus has already launched on Atlas V, it should be no problem to do so again.
Which is why it shouldn’t be a problem to use Falcon 9 in the meantime, assuming it’s affordable or cheaper and they don’t want to wait for Vulcan. If there IS a problem with Falcon 9, they can seamlessly do the next launch on Vulcan. ULA claims to be a fast response provider now, so it should take even less time than it did after the Antares failure.
So the least risk, lowest cost option is just to also launch on Falcon 9. If there’s a problem with Falcon 9, launch on Vulcan. It’s only problematic if Vulcan isn’t available yet… which avoiding Falcon 9 would make even worse.
Cygnus on Falcon 9 might have some late-load cargo issues. With Antares they have specific fairing entry points and rigs. With a vertical integration facility is also pretty easy, but you need different fairing door and rig. But on Falcon 9, specially now that they are recovering them, it might get pretty expensive.
This is true, and Vulcan is made specifically to launch Atlas V payloads with no or minimal adjustments. So Cygnus has already launched on Atlas V, it should be no problem to do so again.
Which is why it shouldn’t be a problem to use Falcon 9 in the meantime, assuming it’s affordable or cheaper and they don’t want to wait for Vulcan. If there IS a problem with Falcon 9, they can seamlessly do the next launch on Vulcan. ULA claims to be a fast response provider now, so it should take even less time than it did after the Antares failure.
So the least risk, lowest cost option is just to also launch on Falcon 9. If there’s a problem with Falcon 9, launch on Vulcan. It’s only problematic if Vulcan isn’t available yet… which avoiding Falcon 9 would make even worse.
I don't understand. Apparently there is design work involved to launch Cygnus on F9: i.e., some sort of payload adaptor and some analysis of the "launch environment". This effort would need to start very soon in order to use F9 in August 2023 if a Vulcan is not available then. It might be cheaper overall to just skip that flight and let NASA use a Cargo Dragon in the fairly unlikely event that neither Cygnus-on-Vulcan nor Cygnus-on-Atlas are available. The drawbacks are:
--Cygnus is probably a better re-booster for ISS than is Cargo Dragon
--The berthing port used by Cygnus permits slightly larger cargo containers than the docking port used by Cargo Dragon
--possible revenue loss (mitigated by avoidance of the F9 option study cost)
--minor embarrassment of not flying Cygnus
I think that the Cygnus-on-F9 study effort will only be done if NG concludes that Vulcan may continue to be unavailable until after the Spring 2024 flight.
I'm not a rocket scientist or even a rocket engineer. How hard is it to move Cygnus to another launcher as measured in time and money? My guess it that it's a bit harder in the real world than it is in Kerbal. Is NASA likely to require a demonstration launch or not? Cygnus has flown on Atlas. Does this mean it's easier to fly it on Vulcan or not?
NASA is buying a service - delivery of goods to the ISS. It does not really care how the goods get there. Switching the launcher should not matter.
The "only" thing which REALLY matters to NASA is behaviour of the spacecraft (Cygnus) in the ISS exclusion zone. (See: SX CRS-1 mission Orbcomm loss).
Cygnus would be the same - already tested -> no need to do another demo launch.
(Yes, I know I'm simplifying a little bit)
This is true, and Vulcan is made specifically to launch Atlas V payloads with no or minimal adjustments. So Cygnus has already launched on Atlas V, it should be no problem to do so again.
Which is why it shouldn’t be a problem to use Falcon 9 in the meantime, assuming it’s affordable or cheaper and they don’t want to wait for Vulcan. If there IS a problem with Falcon 9, they can seamlessly do the next launch on Vulcan. ULA claims to be a fast response provider now, so it should take even less time than it did after the Antares failure.
So the least risk, lowest cost option is just to also launch on Falcon 9. If there’s a problem with Falcon 9, launch on Vulcan. It’s only problematic if Vulcan isn’t available yet… which avoiding Falcon 9 would make even worse.
I don't understand. Apparently there is design work involved to launch Cygnus on F9: i.e., some sort of payload adaptor and some analysis of the "launch environment". This effort would need to start very soon in order to use F9 in August 2023 if a Vulcan is not available then. It might be cheaper overall to just skip that flight and let NASA use a Cargo Dragon in the fairly unlikely event that neither Cygnus-on-Vulcan nor Cygnus-on-Atlas are available. The drawbacks are:
--Cygnus is probably a better re-booster for ISS than is Cargo Dragon
--The berthing port used by Cygnus permits slightly larger cargo containers than the docking port used by Cargo Dragon
--possible revenue loss (mitigated by avoidance of the F9 option study cost)
--minor embarrassment of not flying Cygnus
I think that the Cygnus-on-F9 study effort will only be done if NG concludes that Vulcan may continue to be unavailable until after the Spring 2024 flight.
NG already has the Cygnus, though. They can’t replace it with a Dragon. They CAN replace the rocket, as they already had to do once before.
I don’t think launching Cygnus on F9 would be particularly expensive to setup. Falcon 9 is made to launch lots of commercial (and government) satellites (Including those which previously launched on Atlas V), which is what Cygnus is.
SoaceX has pretty rapid ops already, so they may just do late-load in the hangar.
SoaceX has achieved really good turnaround times for Falcon 9, so it wouldn’t surprise me if they could go from hangar to launch within 24 hours.
What’s the fastest time from roll out to launch for Falcon 9?
Lack of late load was issue on Atlas as it was integrated with fairing 2weeks before launch. Something they would want to address with any long term replacement launch.
Those fresh fruit and veggies are an important part of cargo deliveries. One benefit of the private Axiom missions was extra fresh food deliveries.
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Lack of late load was issue on Atlas as it was integrated with fairing 2weeks before launch. Something they would want to address with any long term replacement launch.
Those fresh fruit and veggies are an important part of cargo deliveries. One benefit of the private Axiom missions was extra fresh food deliveries.
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Late load on Atlas was discussed starting at post 57 of this thread. Jim pointed out a few posts later that Atlas has a solution.
https://forum.nasaspaceflight.com/index.php?topic=55886.msg2345509#msg2345509

who makes the pressurized segment of Cygnus? ... Thales Alenia Space in Italy.
Cygnus can launch pressurized cargo and very small unpressurized cargo on Antares.
The ISS program has been extended by NASA from 2024 to 2030.
Since the fifth ATV flight, ESA's contribution to the ISS (barter element) have been the Orion service module.

ESA/ it's member states still have to approve extension of the ISS, and what their barter element will be.
May I propose: launching Cygnus NG-20 to -25 on Ariane 62. I think they can mount external payloads (Gold-2) on the outside of Cygnus so it can deliver more unpressurized payload.
This could lower cost for NASA. It was NASA/US policy that preferred CRS above continuing ATV flights. And requested Europe to develop and supply the Orion service module.
JAXA was allowed to continue HTV launches and the development of HTV-X.
So Cygnus becomes a mainly ESA cargo resupply vehicle. (ESA launch and pressurized cargo module; Northrup Grumman is design lead and build the service module.) Thus lower cost for the US.
Side benefit for NG: they can sell their Antares launch facilities to Rocketlab. Remove the burden from that from their operations.
who makes the pressurized segment of Cygnus? ... Thales Alenia Space in Italy.
Cygnus can launch pressurized cargo and very small unpressurized cargo on Antares.
The ISS program has been extended by NASA from 2024 to 2030.
Since the fifth ATV flight, ESA's contribution to the ISS (barter element) have been the Orion service module.

ESA/ it's member states still have to approve extension of the ISS, and what their barter element will be.
May I propose: launching Cygnus NG-20 to -25 on Ariane 62. I think they can mount external payloads (Gold-2) on the outside of Cygnus so it can deliver more unpressurized payload.
This could lower cost for NASA. It was NASA/US policy that preferred CRS above continuing ATV flights. And requested Europe to develop and supply the Orion service module.
JAXA was allowed to continue HTV launches and the development of HTV-X.
So Cygnus becomes a mainly ESA cargo resupply vehicle. (ESA launch and pressurized cargo module; Northrup Grumman is design lead and build the service module.) Thus lower cost for the US.
Side benefit for NG: they can sell their Antares launch facilities to Rocketlab. Remove the burden from that from their operations.
There is the small issue of loading the cargo and experiments at Kourou when the payload processing is at Kennedy and Wallops.
AIUI Northrop Grumman leases from the facilities at Mid Atlantic Regional Spaceport from a Virginia state agency. RocketLab need to have a working Neutron launcher before they need the MARS facilities.