This SpaceX Competitor Just Unveiled a New Rocket

[Hanse]

http://fortune.com/2016/05/25/spacex-rocket-orbital/

"Orbital’s Next Generation Launcher is based on the solid-rocket strap-on boosters that flew on NASA’s space shuttles, Orbital Business Development Director John Steinmeyer said at the 2016 Space Congress conference in Cape Canaveral.

The company plans to buy the rocket’s second stage from Jeff Bezos’ space company, Blue Origin"

 

[flanker]

Yes, and USAF is funding it partly;

http://www.defense.gov/News/Contracts/Contract-View/Article/642983

Along with supporting Raptor development.

 

[bobbymike]

Couldn't find much information (diameter, thrust, ISP) for the GEM-63XL booster.

 

[Hanse]

Couldn't find much information (diameter, thrust, ISP) for the GEM-63XL booster.

This Orbital design would use some derivative of a Shuttle SRB. (Fewer segments I would imagine. Or maybe similar to the Ares IX.)

https://twitter.com/StephenClark1/status/735180704233971712/photo/1?ref_src=twsrc%5Etfw

 

[fredymac]

I wonder how much leeway you can get varying the surface area of the solids to adjust the thrust level. The SRB's put out around 3 million pounds of thrust. I would think they would want to dial that down a bit.

https://www.youtube.com/watch?v=gYYoXi91QtU

 

[Hanse]

I would think they would want to dial that down a bit.

Why? ???

 

[Hobbes]

The first stage is basically 2 segments of a Shuttle SRB, the second stage is 1 segment. So 1/2 and 1/4 the thrust of the Shuttle SRB.

GEM-63 is likely 63" in diameter. Isp will be similar to Shuttle SRB.

 

[Hanse]

The first stage is basically 2 segments of a Shuttle SRB, the second stage is 1 segment. So 1/2 and 1/4 the thrust of the Shuttle SRB.

GEM-63 is likely 63" in diameter. Isp will be similar to Shuttle SRB.

According to my handy dandy ATK product catalog a single segment motor would be 803k lbs thrust. A 2-segment would be 1.5 million.

 

[TomS]

Couldn't find much information (diameter, thrust, ISP) for the GEM-63XL booster.

This Orbital design would use some derivative of a Shuttle SRB. (Fewer segments I would imagine. Or maybe similar to the Ares IX.)

https://twitter.com/StephenClark1/status/735180704233971712/photo/1?ref_src=twsrc%5Etfw

If I'm reading that right, the first stage for the "Intermediate" version is two Common Booster Segments (Basically SRB segments), while the "heavy" version uses four segments. Then there's a second stage with another segment and a third stage based on the BE-3 engine.

So, similar to Liberty but with with the SRB broken into two stages with some variability in size instead of one big five-segment stage.

 

[fredymac]

I guess I'm not clear on how segments are being defined. I thought of segments as vertical stacks which essentially add more propellant capacity while linearly increasing burn volume. For a solid, I believe you vary the cross sectional surface area of propellant exposed to flame as the way you set and adjust thrust level. 3 million pounds of thrust is almost 50% more than a Delta 4 Heavy although you get that thrust for a much shorter interval.

 

[Hanse]

I guess I'm not clear on how segments are being defined. I thought of segments as vertical stacks which essentially add more propellant capacity while linearly increasing burn volume. For a solid, I believe you vary the cross sectional surface area of propellant exposed to flame as the way you set and adjust thrust level. 3 million pounds of thrust is almost 50% more than a Delta 4 Heavy although you get that thrust for a much shorter interval.

Assuming 2-segments have the same (or similar) core they'll give you roughly twice the thrust of one for the same amount of time. In this case that is what they're doing. If you Google ATK Solid Motors the second hit will lead you to a PDF of many of the motors they've built over the years and single and double segment motors are in there. Very interesting stuff.

 

[bobbymike]

I guess I'm not clear on how segments are being defined. I thought of segments as vertical stacks which essentially add more propellant capacity while linearly increasing burn volume. For a solid, I believe you vary the cross sectional surface area of propellant exposed to flame as the way you set and adjust thrust level. 3 million pounds of thrust is almost 50% more than a Delta 4 Heavy although you get that thrust for a much shorter interval.

Assuming 2-segments have the same (or similar) core they'll give you roughly twice the thrust of one for the same amount of time. In this case that is what they're doing. If you Google ATK Solid Motors the second hit will lead you to a PDF of many of the motors they've built over the years and single and double segment motors are in there. Very interesting stuff.

Sorry for the off topic question I probably should know at this point in my life ;D but how does a small solid rocket motor like Spartan/Sprint/Super Road Runner produce such high thrust in a small package? Is it all propellant formulations, tailored burn rates, special additives, don't have to worry about vehicle because it is one shot?

 

[Hanse]

Sorry for the off topic question I probably should know at this point in my life ;D but how does a small solid rocket motor like Spartan/Sprint/Super Road Runner produce such high thrust in a small package? Is it all propellant formulations, tailored burn rates, special additives, don't have to worry about vehicle because it is one shot?

The Shuttle SRB burns for 2 minutes. Roadrunner for a second or two as I recall. OBB would probably have the best answer but in short, there are burn modifiers that can be added that will increase burn rate. This includes both chemicals in the mix and things like metallic wires, "staples", and such. My understanding is the metallic objects work by transferring heat to unburnt propellant and "preheating" it. Then you can do things with the core. The more surface area you have burning at once the more thrust will be produced (and the quicker the propellant will be burned up). Say you have a burn rate of 12" per second. If you put that in a "cigarette" or "end burner" configuration, where the motor is completely full of propellant and burns from the back end to the front end, a 10 foot motor would burn for 10 seconds. Now make the motor shorter and fatter, with lots of core/fin area inside so that the cross section is 3" thick. That same amount of propellant would burn in 0.25 seconds. (Assuming same pressure, temp, etc.)

 

[Michel Van]

Orbital twitter this picture of the new rocket

what i can read

is look like beefed up version of ESA Vega rocket
that use Castor 600 and 300 solid rockets
third stage use BF-3 engine from Blue Origin (it burns Oxygen/Hydrogen)

seems they try outbid SpaceX with low-cost solids

 

[bobbymike]

Sorry for the off topic question I probably should know at this point in my life ;D but how does a small solid rocket motor like Spartan/Sprint/Super Road Runner produce such high thrust in a small package? Is it all propellant formulations, tailored burn rates, special additives, don't have to worry about vehicle because it is one shot?

The Shuttle SRB burns for 2 minutes. Roadrunner for a second or two as I recall. OBB would probably have the best answer but in short, there are burn modifiers that can be added that will increase burn rate. This includes both chemicals in the mix and things like metallic wires, "staples", and such. My understanding is the metallic objects work by transferring heat to unburnt propellant and "preheating" it. Then you can do things with the core. The more surface area you have burning at once the more thrust will be produced (and the quicker the propellant will be burned up). Say you have a burn rate of 12" per second. If you put that in a "cigarette" or "end burner" configuration, where the motor is completely full of propellant and burns from the back end to the front end, a 10 foot motor would burn for 10 seconds. Now make the motor shorter and fatter, with lots of core/fin area inside so that the cross section is 3" thick. That same amount of propellant would burn in 0.25 seconds. (Assuming same pressure, temp, etc.)

Thanks Scott much obliged.

 

[Hanse]

No webcast? Usually they're up by now. ???

 

[merriman]

Yeah ... what's this about? Where's the TV?

 

[Hanse]

"Tonight's #SpaceX launch is in a delay. No T-0 time has been set."

 

[merriman]

Thanks. Still no webcast. Fire that PR guy!

 

[Hanse]

""Port Canaveral talking with 120 foot yacht. They are moving away north. Launch delayed until end of today's window" "

Sounds like somebody who should receive a giant bill for the delay.

 

[Hanse]

"JUST IN: SpaceX launch officially delayed until 7:40 p.m." (EST) Webcast countdown has restarted.

 

[Hanse]

"Out of an abundance of caution, launch postponed until no earlier than tomorrow for addtl data review - Falcon 9 & spacecraft remain healthy "

 

[XP67_Moonbat]

Doh!