Sun Synchronous Medium Launcher

[edkyle99]

Atlas E/F, Titan 23G used to put military and civilian weather satellites into sun synchronous orbit from Vandenberg AFB.  Those DMSP and NOAA satellites weighed up to 1.1 tonnes on Atlas and 1.5 tonnes on Titan (not including the orbit inserting kick motor).  Modern versions have gotten heavier, up to 2.5 tonnes or so, but are still small payloads on an Atlas 5 or Delta 4 or Falcon 9 v1.1, which are overkill since they can lift 7-8 tonnes to sun synchronous orbit.  The only solid rocket concepts able to do the job would be Minotaur 6+, which would use six stages or Athena 2cS-4 or -6, which would need four core stages and four or six strap-on boosters.  Neither has flown.

I wondered what could be done with liquid stages and other bits and pieces.  If a first stage was powered by two Merlin 1D engines, 2 tonnes or more could be launched with a 320 sec ISP second stage.  A first stage with three Merlin 1D engines could probably get 3 tonnes to sun synchronous orbit using a similar second stage.  The 2 x Merlin could gross 125 tonnes while the 3 x Merlin could weigh 185 tonnes or so.  Adding a small third stage would fulfill most Delta 2 class mission requirements.

I wonder why this type of smaller/cheaper-than EELV/Falcon 9 size rockets haven't been developed. 

 - Ed Kyle

[Galactic Penguin SST]

Start with a Falcon 5 and cut down the # of engines with uprated engines?

Then again, a RTLS F9 is "only" Soyuz class and the X-company isn't afraid to put small payloads on much larger rockets.....

[bubbagret]

Antares 110 should be right in that range if launched from Vandenberg to an 800km SSO.

[deltaV]

Antares 110 should be right in that range if launched from Vandenberg to an 800km SSO.

Antares 110 has been retired but the replacement Antares 220 should work. See http://en.wikipedia.org/wiki/Antares_%28rocket%29#Configurations_and_numbering .

SpaceX was originally planning a Falcon 5 so they're obviously familiar with the idea of making a rocket like Falcon 9 but with fewer engines. The fact that they haven't done so suggests that there isn't enough of a market to justify the cost of developing and maintaining another rocket. They'll presumably launch this size of payload on a F9 with RTLS first stage.

[rayleighscatter]

There is performance data for the 1 series Antares from Kodiak. Presumably the 2 series should improve on these numbers somewhat.

[llanitedave]

How is such a rocket going to be reusable?  That's the requirement that needs to take precedence over everything else now.  This "smaller, cheaper" Falcon needs to be cheaper than a reusable F-9.

[edkyle99]

Antares comes closest to the idea among current rockets, but it has a relatively heavy first stage compared to the Merlin/Falcons.  It really wants to lift more than it does.  A 3xMerlin with a Falcon 9 like mass ratio topped by a Castor 30 type second stage and a small bipropellant third stage could get 3 tonnes to sun synchronous (800 km) while weighing 90-100ish tonnes less than Antares and producing 140-ish tonnes less thrust at liftoff. 

 - Ed Kyle

[arachnitect]

The steady cadence of launches in this payload category disappeared. Now the payloads are coming back a bit, and wonder where their cheap rides went. Even if the same number of payloads were available, a commercial replacement might still not be possible: 23g and Atlas E/F used surplus ICBM stages.

Titan 23G mostly launched NOAA and DMSP missions.

GPS and Comsats outgrew not only Atlas E/F but Delta II as well.

The DMSP successor (if it ever happens) might end up in a different payload class than NOAA's JPSS (which is much heavier than the Tiros-N and Adv. Tiros-N predecessors).

What will the future hold?
-If OrbATK puts a third stage on Antares it can launch these payloads, even from WFF (if the authorities approve the flight path) but Antares is expensive and will be ineligible to launch DoD payloads.
-Lockheed seems to be very very slowly reintroducing Athena.
-Minotaur rockets might start seeing more activity. I think USAF is looking at expanding the ORS office and giving them some real responsibilities.
-If Spacex can keep their prices down, they'll own this (small) market.
-Customers who don't need to buy an American LV have a lot of choices abroad (Vega, or one of the seventy billion retired Russian ICBMS, etc.)

[GreenShrike]

I wonder why this type of smaller/cheaper-than EELV/Falcon 9 size rockets haven't been developed. 

I would presume because there are insufficient payloads available to justify the development expense, especially when the government seems perfectly happy buying Atlas 5s. And if the new medium isn't substantially cheaper than Atlas, then ULA just plays the ultra-reliable card to remain competitive.

Now that the F9 is on the scene, there's the additional complication of needing to not only beat Atlas 5 on price, but also F9. I rather get the impression that even though Antares was supposed to only be a Delta II replacement, it costs more to fly than the heavier Falcon 9, so I presume that succeeding at such a challenge will take a SpaceX-like attention to cost.

If a new medium is priced at, what, $20m or $30m or $40m to fly (half current F9 pricing, and playing in the ballpark of whatever SpaceX charges for a "proven" F9 core) what's the profit margin going to be? 10%? 30%?

Well, 30% of $30m is $9m, but how much money is it going to take to develop the rocket? F9 was supposedly dirt cheap to develop and it was still in the hundreds of millions. At $100m development costs, that's 11+ flights just to start recouping a profit. Are there that many payloads needing to fly? If there are, could the new rocket win the business consistently, versus the expensive-but-reliable Atlas 5; or the cheap-and-getting-to-be-reliable F9; or even international launchers like PSLV and Vega?

And, in the future, should a large SSO market emerge, there will be the spectre of SpaceX perhaps deciding that there's a large enough market in small sats to justify the engineering time to develop a reusable second stage -- or maybe just a lighter and cheaper expendable second stage. If not, S1 reuse will still make it harder to compete for a new medium expendable, though to be honest I expect that the market would have to grow quite large and quite competitive before SpaceX dedicated any market-specific development time.*

I guess what it comes down to is that larger launchers are capable of carrying the payloads, fly at an acceptable price, and apparently the market going forward isn't large enough to warrant the development a new, competitive launcher.


* Indeed, just like Rocketlabs and Firefly are running the risk of SpaceX deciding a Falcon 1 V2.0 has become viable. Actually, how much would the three-core Firefly Beta lift to SSO? Enough to compete in the SSO market?

[edkyle99]

I wonder why this type of smaller/cheaper-than EELV/Falcon 9 size rockets haven't been developed. 

I would presume because there are insufficient payloads available to justify the development expense, especially when the government seems perfectly happy buying Atlas 5s. And if the new medium isn't substantially cheaper than Atlas, then ULA just plays the ultra-reliable card to remain competitive.  ...

It is interesting to compare Angara with EELV and Falcon 9/Falcon Heavy.  The Russians decided to size their universal module so that it was small enough to be about right for the lighter, high inclination LEO missions, but also so that it could be clustered to create more powerful launchers up to the Heavy class.  I can only wonder if the Angara approach is more or less cost effective than the EELV/Falcon 9 common-core approach.  What is apparent is that EELV/Falcon 9 is largely wasted when used on these relatively light payloads.

 - Ed Kyle 

[Lars-J]

I wonder why this type of smaller/cheaper-than EELV/Falcon 9 size rockets haven't been developed. 

I would presume because there are insufficient payloads available to justify the development expense, especially when the government seems perfectly happy buying Atlas 5s. And if the new medium isn't substantially cheaper than Atlas, then ULA just plays the ultra-reliable card to remain competitive.  ...

It is interesting to compare Angara with EELV and Falcon 9/Falcon Heavy.  The Russians decided to size their universal module so that it was small enough to be about right for the lighter, high inclination LEO missions, but also so that it could be clustered to create more powerful launchers up to the Heavy class.  I can only wonder if the Angara approach is more or less cost effective than the EELV/Falcon 9 common-core approach.  What is apparent is that EELV/Falcon 9 is largely wasted when used on these relatively light payloads.

Only if one works under your assumption that the best launcher for a job is one that is *exactly* sized for that job - no more, no less. In reality almost all cargo shipped on water or roads is done in a standard vehicle that is much larger that technically needed. And it is still cheaper to do it that way than to special produce a vehicle that is a perfect fit. (Reusable or not)

[guckyfan]

Angara is designed the way it is with 1,3 or 5 cores because of transport restrictions. The launch site can only be reached by rail.

[edkyle99]

Angara is designed the way it is with 1,3 or 5 cores because of transport restrictions. The launch site can only be reached by rail.

The URM is only 2.9 meters diameter.  Proton's core is 4.1 meters diameter and is shipped by rail, so I think that URM sizing was not rail-restricted.

 - Ed Kyle

[edkyle99]

Only if one works under your assumption that the best launcher for a job is one that is *exactly* sized for that job - no more, no less. In reality almost all cargo shipped on water or roads is done in a standard vehicle that is much larger that technically needed. And it is still cheaper to do it that way than to special produce a vehicle that is a perfect fit. (Reusable or not)

The difference is that a single ground transport move doesn't cost 10s of millions of dollars.

 - Ed Kyle

[baldusi]

Angara is designed the way it is with 1,3 or 5 cores because of transport restrictions. The launch site can only be reached by rail.

The URM is only 2.9 meters diameter.  Proton's core is 4.1 meters diameter and is shipped by rail, so I think that URM sizing was not rail-restricted.

 - Ed Kyle

Actually, 4.1m on train requires to prevent opposite trains using the same track on certain parts, and was only available to Baikonour. The specs for Voistochny was 3.8m. I believe that length was also an issue since the Eastern track had some tighter turning radius. In any case the Rus-M modules might have been the biggest possible to the East, which was still plenty bigger than the Angara URM. Basically, they could have done twice as big modules with no transport issues. And used the already developed RD-180 to boot, but I'm not going into that discussion. Your point that they sized for the SSO case and then tried to scale to the most demanding missions is perfectly true.

[Lars-J]

Only if one works under your assumption that the best launcher for a job is one that is *exactly* sized for that job - no more, no less. In reality almost all cargo shipped on water or roads is done in a standard vehicle that is much larger that technically needed. And it is still cheaper to do it that way than to special produce a vehicle that is a perfect fit. (Reusable or not)

The difference is that a single ground transport move doesn't cost 10s of millions of dollars.

This is irrelevant when a new launch vehicle development will cost in the neighborhood of $1 billion (or more) - You then have to judge that cost against A) just producing more of the slightly more powerful LV (reducing its marginal cost) and B) the possibility of dual manifesting. Or doing both.

Then the decision to build a brand new less capable LV starts to look questionable. The tool that you have may be overbuilt, but it is one that you have, and using it makes sense.

[Comga]

Let's suppose that Ms. Shotwell is off by 100% and a reuseable Falcon 9 really costs $12M to $14M instead of her $6M to $7M. 
It has an nexisting launch pad with SSO access at Vandenberg. 
What could be developed to compete with that?

[QuantumG]

Let's suppose that Ms. Shotwell is off by 100% and a reuseable Falcon 9 really costs $12M to $14M instead of her $6M to $7M. 
It has an nexisting launch pad with SSO access at Vandenberg. 
What could be developed to compete with that?

Anything that can launch while their backlog is still full?

I don't understand why people seem to think SpaceX can service all the launch demand in the entire world.. even today's demand is beyond them, let alone the massive launch demand they expect to create after they lower these prices so much. There will always be people willing to pay more to fly sooner.

[guckyfan]

Anything that can launch while their backlog is still full?

That won't be long now.

I don't understand why people seem to think SpaceX can service all the launch demand in the entire world.. even today's demand is beyond them, let alone the massive launch demand they expect to create after they lower these prices so much. There will always be people willing to pay more to fly sooner.

That's the market SpaceX is aiming for. Barry Matsumori has announced very recently that this is why they need 3 east coast launch facilities and ramp up production. Once Boca Chica is ready they will be able to launch at short notice like no other launch provider can. Maybe the smallsat companies will be able to match it but not the traditional launch providers.

[QuantumG]

That won't be long now.

That's the nature of a backlog.. either you have one or you're out of business.

That's the market SpaceX is aiming for. Barry Matsumori has announced very recently that this is why they need 3 east coast launch facilities and ramp up production. Once Boca Chica is ready they will be able to launch at short notice like no other launch provider can. Maybe the smallsat companies will be able to match it but not the traditional launch providers.

I don't think you understand.. there will always be a waiting period for the lowest priced launcher. Either that, or SpaceX will not be able to pay the bills. That's the nature of making price your market differentiator. To repeat myself there will always be people willing to pay more to fly sooner.