Satellites are also getting larger, thus requiring greater capabilities of the rockets.
Quote from: spacenut on 05/19/2017 12:24 amSatellites are also getting larger, thus requiring greater capabilities of the rockets. So I would intuitively think too. But do you have any evidence of it actually happening? Help me out here. The viral malbrain says that miniaturization is the thing. That the future is credit card satellites.
Personally I believe that Wikipedia's range is a bit wide. I'm referring here to what I'm gonna call the "ELV Class", as apposed to EELV, or something along the lines of 3,000-7,000 kg to LEO. Rockets like the Delta II, Antares, Soyuz, and Zenit. It seems that this market is dying out in America. After the Delta II's last two launches in the next couple years, this size of rocket will basically be extinct in the States. Even Antares seems to not even be wanted by it's own company. Basically, this thread is here to discuss why that is, and what the future of this market is.
Quote from: JEF_300 on 05/18/2017 11:58 pmPersonally I believe that Wikipedia's range is a bit wide. I'm referring here to what I'm gonna call the "ELV Class", as apposed to EELV, or something along the lines of 3,000-7,000 kg to LEO. Rockets like the Delta II, Antares, Soyuz, and Zenit. It seems that this market is dying out in America. After the Delta II's last two launches in the next couple years, this size of rocket will basically be extinct in the States. Even Antares seems to not even be wanted by it's own company. Basically, this thread is here to discuss why that is, and what the future of this market is. There's a dearth of U.S. launcher in this payload class, perhaps, but Soyuz is going strong. It accounted for nearly 20 % of all worldwide launches during 2010-2016. It is the second-most-launched rocket so far this year.
In the U.S. a big issue is that the Pentagon had forced these former Delta 2 class payloads onto the EELVs (usually Atlas 5). Thus you have a rocket able to boost 8 tonnes to sun synchronous orbit used to loft 1.2 tonne DMSP F19 or 2.5 tonne WorldView 4, etc. Someone has to crack that nut if they plan to compete with a smaller rocket.
If I was in charge, I would create something like a "Falcon 3" or "Falcon 4", with 3 or 4 Merlin 1D type engines on the first stage and a Castor 30XL type second stage. A "Falcon 3" (GLOW 215 tonnes) could boost more than 3.5 tonnes to sun synchronous orbit (Delta 2 class), while "Falcon 4" (GLOW 287 tonnes) could loft more than 5 tonnes (Soyuz/Antares class).
Quote from: edkyle99 on 05/19/2017 03:45 pmIf I was in charge, I would create something like a "Falcon 3" or "Falcon 4", with 3 or 4 Merlin 1D type engines on the first stage and a Castor 30XL type second stage. A "Falcon 3" (GLOW 215 tonnes) could boost more than 3.5 tonnes to sun synchronous orbit (Delta 2 class), while "Falcon 4" (GLOW 287 tonnes) could loft more than 5 tonnes (Soyuz/Antares class). It makes more sense IMO to use F9, but with a fully reusable upper stage. Such an LV should be handle 3-5 tons territory. And if SpaceX can lower the refurbish time/cost as much as they hope, it should be pretty affordable.
Quote from: JEF_300 on 05/18/2017 11:58 pmPersonally I believe that Wikipedia's range is a bit wide. I'm referring here to what I'm gonna call the "ELV Class", as apposed to EELV, or something along the lines of 3,000-7,000 kg to LEO. Rockets like the Delta II, Antares, Soyuz, and Zenit. It seems that this market is dying out in America. After the Delta II's last two launches in the next couple years, this size of rocket will basically be extinct in the States. Even Antares seems to not even be wanted by it's own company. Basically, this thread is here to discuss why that is, and what the future of this market is. There's a dearth of U.S. launchers in this payload class, perhaps, but Soyuz is going strong. It accounted for nearly 20 % of all worldwide launches during 2010-2016. It is the second-most-launched rocket so far this year.In the U.S. a big issue is that the Pentagon had forced these former Delta 2 class payloads onto the EELVs (usually Atlas 5). Thus you have a rocket able to boost 8 tonnes to sun synchronous orbit used to loft 1.2 tonne DMSP F19 or 2.5 tonne WorldView 4, etc. Someone has to crack that nut if they plan to compete with a smaller rocket.If I was in charge, I would create something like a "Falcon 3" or "Falcon 4", with 3 or 4 Merlin 1D type engines on the first stage and a Castor 30XL type second stage. A "Falcon 3" (GLOW 215 tonnes) could boost more than 3.5 tonnes to sun synchronous orbit (Delta 2 class), while "Falcon 4" (GLOW 287 tonnes) could loft more than 5 tonnes (Soyuz/Antares class). - Ed Kyle
A single Raptor vehicle around 285 t GLOW with a single Broadsword upper stage could put at least 5500 kg to SSO, using tanks with the same total volume and mass as F9 v1.0. A pair or two of Broadswords could be a landing engines for the booster as well.
There's a dearth of U.S. launchers in this payload class, perhaps, but Soyuz is going strong. It accounted for nearly 20 % of all worldwide launches during 2010-2016. It is the second-most-launched rocket so far this year.
Quote from: edkyle99 on 05/19/2017 03:45 pmThere's a dearth of U.S. launchers in this payload class, perhaps, but Soyuz is going strong. It accounted for nearly 20 % of all worldwide launches during 2010-2016. It is the second-most-launched rocket so far this year.That's what I noticed too. It seems the Soyuz and, to a lesser extent, ISRO rockets have taken over this market. This seems to be mostly because of the cheaper labor they can use in Russia and India. The Shuttle showed us how much ground-time effects a rocket's end price.I wonder if perhaps a new rocket that didn't focus on technological advancement, but was designed from the ground up to be produced and built cheaply spending as little time on the ground as possible would be able to make it into this market. Also Soyuz is well up there in years, and the PSLV isn't exactly the most advanced vehicle. I wonder if a straight up modern rocket of this size would be able to get some of the launches in this range.
I am not seeing SpaceX investing in anything less powerful than the current F9. Rather, I expect the current F9 to handle this market. It may be that this market is where we first see reusable S2s
Quote from: Lar on 05/20/2017 10:38 pmI am not seeing SpaceX investing in anything less powerful than the current F9. Rather, I expect the current F9 to handle this market. It may be that this market is where we first see reusable S2sThe news that Orbital ATK's CRS-2 contract is for less money than that of SpaceX offers a counter point. It turned out that the smaller expendable rocket beat the bigger, partially recoverable rocket in that case. Makes me wonder if Antares really might be the answer to this question. The 231 model can lift 3 tonnes to sun synchronous orbit from the launch pad that already exists at Wallops. The 331 model, which will unleash Antares RD-181 engine's real potential, will lift more. - Ed Kyle