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Author
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Topic: Alternative boosters for space shuttle
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holcombeyates
Member Posts: 243
From: UK
Registered: Dec 2010
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posted 02-20-2018 03:47 PM
   
Is it feasible that the solid rocket boosters on the space shuttle could have been replaced with a derivative of the Falcon 9 recoverable first stage technology?Imagine having liquid-fuelled boosters that recovered back to the same location from which they launched and minimal disassembly required. Clearly greater size would be needed, or two boosters each side, bit of external tank redesign needed, but an interesting question. If only the shuttle were still flying. |
Robert Pearlman
Editor Posts: 42988
From: Houston, TX
Registered: Nov 1999
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posted 02-20-2018 05:14 PM
Prior to the loss of Columbia in 2003, NASA was preparing to convene a meeting on space shuttle upgrades to extend the use and capability of the vehicle through 2020. Among the topics to be discussed were booster upgrades, including possible liquid fuel replacements and flyback designs. |
garyd2831
Member Posts: 640
From: Syracuse, New York, USA
Registered: Oct 2009
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posted 02-20-2018 05:22 PM
So how come this SpaceX type technology isn't being implemented on the SLS program versus using solids that have to be refurbished on the other side of the country in Utah? |
Robert Pearlman
Editor Posts: 42988
From: Houston, TX
Registered: Nov 1999
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posted 02-20-2018 05:32 PM
When Congress legislated the creation of the Space Launch System, it required that NASA integrate shuttle hardware to simplify development. The initial SLS configuration will use five-segment solid rocket boosters, but the evolved 130 ton SLS vehicle will require an advanced booster with more thrust, for which NASA has said both solid- and liquid-fueled solutions will be considered. |
garyd2831
Member Posts: 640
From: Syracuse, New York, USA
Registered: Oct 2009
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posted 02-20-2018 06:13 PM
One would think with predicted delays in any government program (as currently witnessed) why this upgrade option wasn't drafted from the get go of the program. |
Cozmosis22
Member Posts: 968
From: Texas * Earth
Registered: Apr 2011
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posted 02-20-2018 06:33 PM
It is interesting to watch the novelty of the controlled landings of Falcon 9 boosters. How many of those rocket casings have been re-used so far?It is one thing to verify proof of concept broadcast live worldwide. It is quite another thing to actually put them to use and save time and money as advertised. |
garyd2831
Member Posts: 640
From: Syracuse, New York, USA
Registered: Oct 2009
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posted 02-20-2018 06:57 PM
You're totally correct, but I think we are starting to see something that says yes it's possible. Musk is proving the concept, but it is still in infancy, but I'm keeping track on this. |
Robert Pearlman
Editor Posts: 42988
From: Houston, TX
Registered: Nov 1999
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posted 02-20-2018 07:25 PM
To date, eight Falcon 9 first stages have been re-flown, including the two that were modified to become the side mounted boosters on the Falcon Heavy. Each were only re-flown once.To date, it is unclear if any of those re-flights resulted in a cost savings, as SpaceX has not offered its customers a price cut for using a "flight proven" booster. The advantage to (re-)using one, at least for now, has been time, reducing the wait to be ready to fly. |
Jim Behling
Member Posts: 1463
From: Cape Canaveral, FL
Registered: Mar 2010
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posted 02-20-2018 07:53 PM
quote:
Originally posted by garyd2831:
...wasn't drafted from the get go of the program.
The Falcon 9 had only flown twice at the inception of the SLS program and at the time, Atlas V or Delta IV would have been better candidates. Also, any of the three aforementioned vehicles would need to be greatly enlarged to match to impulse of the SRBs. Not to mention that liquid boosters are not drop in replacements for solid motors. quote:
...refurbished on the other side of the country in Utah?
SLS solids are expendable and are not being reused. |
garyd2831
Member Posts: 640
From: Syracuse, New York, USA
Registered: Oct 2009
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posted 02-20-2018 08:36 PM
I did not know that. Well, we should have stuck with the Saturn V, had we known what the future would look like.  |
Skylon
Member Posts: 274
From:
Registered: Sep 2010
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posted 02-21-2018 07:32 AM
quote:
Originally posted by Robert Pearlman:
The initial SLS configuration will use five-segment solid rocket boosters...
To connect this back to the shuttle extension comment, the five-segment solid rocket motor itself was part of those planned discussions for extending the shuttle into the 2020s. The five-segment SRM in addition to its payload benefits, would have eliminated the RTLS abort — personally in terms of "what-if scenarios" — I see this option as the most likely one NASA would have chosen given its ease of implementation compared to the liquid, or fly-back boosters. I am surprised to hear the SLS solids will not be recoverable. What is the technical reason? Designing a parachute? The altitude the rockets will be jettisoned at? |
Robert Pearlman
Editor Posts: 42988
From: Houston, TX
Registered: Nov 1999
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posted 02-21-2018 08:06 AM
No technical reason; the boosters will be expended as a cost-saving maneuver. |
Jim Behling
Member Posts: 1463
From: Cape Canaveral, FL
Registered: Mar 2010
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posted 02-21-2018 10:39 AM
quote:
Originally posted by garyd2831:
...we should have stuck with the Saturn V
No, the Saturn V was too expensive to use, itself and its payloads. |
garyd2831
Member Posts: 640
From: Syracuse, New York, USA
Registered: Oct 2009
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posted 02-21-2018 08:06 PM
The smiling face should have set the tone of my response. But, how much has the SLS cost us so far? How many SLS launch vehicles are slated to be built?What is the estimated cost per SLS launch? (True nature will come out after the fact — much like the shuttle.) |
Robert Pearlman
Editor Posts: 42988
From: Houston, TX
Registered: Nov 1999
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posted 02-21-2018 10:02 PM
Provisional charts released last year by NASA proposed 12 SLS flights through 2030 (one Block 1, three Block 1B cargo, five Block 1B crew, one Block 2 cargo and two Block 2 crew), which would complete construction of the Lunar Orbit Gateway and launch the Europa Clipper. That is in flux though, given the refocus on the moon. As for a per launch cost, it is estimated to be $1.5 to $2.5 billion, depending on the vehicle configuration. |
damnyankee36
Member Posts: 37
From: Alamogordo, NM USA
Registered: Aug 2017
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posted 02-22-2018 01:23 PM
quote:
Originally posted by Robert Pearlman:
No technical reason; the boosters will be expended as a cost-saving maneuver.
My knowledge and view of the whole picture might be simplistic but I don't understand why they are expendable. Doesn't sound cost effective to me. Sounds like NASA is status quo and not learning while SpaceX is leading the way! |
Robert Pearlman
Editor Posts: 42988
From: Houston, TX
Registered: Nov 1999
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posted 02-22-2018 02:24 PM
The space shuttle-era solid rocket boosters were reusable once they were returned from the ocean and refurbished at Orbital ATK's facilities in Utah. The recovery and transport infrastructure, as well as the work to prepare the hardware for reuse were major expenditures.As the legacy boosters are not powerful enough for the evolved SLS configurations, the supply of solid rocket motors left over from the shuttle program was deemed sufficient without having to reuse them. As such, it is more cost effective to fly them as expendable. As an aside, SpaceX has not yet demonstrated that its reusable Falcon 9 first stages are cost effective. To date, there have been no significant discounts offered to clients for using flight-proven (re-flown) boosters. SpaceX says that will change with the introduction of its Block 5 Falcon 9, but it is still to be seen. |
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