Heavy-lift boosters?

[lpetrich]

The first step in spaceflight is to get off the Earth, and Comparison of orbital launch systems - Wikipedia is a good reference for the rockets developed for getting into low Earth orbit (LEO) and beyond.

However, the active systems max out at a little over 20 metric tons to LEO: US Delta IV-H, EU Ariane 5 ES, Russian Proton M. That is also true of the US Space Shuttle and the US Titan IV-B, both decommissioned over the last decade. The ones with greater payload have been one-off so far:

• NASA Saturn V: 118 mt to LEO -- Apollo and Skylab. The last three Apollo missions were canceled and some of their hardware reused for other projects.
• Soviet Energia: 100 mt to LEO -- only one flight, with Buran space shuttle.
• Soviet N1: 95 mt to LEO -- four flights, all failures. Intended to send cosmonauts to the Moon.

The US has two systems in development:

• SpaceX Falcon Heavy: 53 mt to LEO -- should have some test flights this year. Two payloads lined up for it.
• NASA Space Launch System, successor of Ares I and Ares V. Block 1: 70 mt to LEO, Block 2: 130 mt to LEO -- in development for Orion return to the Moon. First flight proposed for 2017.

The Falcon Heavy will use 3 Falcon 9 first stages side by side, and a Falcon 9 second stage. That's expected to lower its launch costs compared to a one-off design.

The SLS will use first-stage engines and solid rocket boosters derived from Space Shuttle designs, much like Ares I and Ares V.

It seems to me that the Falcon Heavy is likely to enter service, but that the SLS risks the fate of Ares I and Ares V: cancellation before any launches.

[NEOWatcher]

THowever, the active systems max out at a little over 20 metric tons to LEO

Yep, without sending man and all the support needed for them out of LEO, there's little need for more.

It seems to me that the Falcon Heavy is likely to enter service, but that the SLS risks the fate of Ares I and Ares V: cancellation before any launches.

Time will tell. The debate about needing a NASA HLV has always been heated, but the people with the money have their own priorities on which pockets they want to fill.

ETA:
Sometimes, it seems like the people with the money don't even care if the program succeeds, as long as money is flowing into their own interests.

[cjl]

You could make a case that the shuttle is more like ~100 mt to orbit, not 20. Yes, 78 mt of the payload consisted of the orbiter itself, but if all you care about is the actual launch mass to orbit capability, it's actually a very heavy lift system.

[lpetrich]

Yes, if one replaced the Orbiter with a payload with a fairing and the Orbiter's main engines, one would likely get a capacity of around 100 metric tons -- Saturn V territory. Thus making the Shuttle the heavy-lift booster that never was.

[John Mendenhall]

What about strapping a bunch of shuttle style solid fuel boosters together? Would it work?

[NEOWatcher]

What about strapping a bunch of shuttle style solid fuel boosters together? Would it work?

Yes, if one replaced the Orbiter with a payload with a fairing and the Orbiter's main engines, one would likely get a capacity of around 100 metric tons -- Saturn V territory. Thus making the Shuttle the heavy-lift booster that never was.

Early in the development of the shuttle there were variations considered.
Heres an interesting pdf that show some of those ideas.
The cargo version would have been 77 metric tons. (a little less than your 100mt, because they wanted to make the engines recoverable)
They also considered stretch versions of various components (even the orbiter)
One interesting one was the humpback version. I'm sure it would have been called the Beluga orbiter.

[Swift]

Early in the development of the shuttle there were variations considered.
Heres an interesting pdf that show some of those ideas.
The cargo version would have been 77 metric tons. (a little less than your 100mt, because they wanted to make the engines recoverable)
They also considered stretch versions of various components (even the orbiter)
One interesting one was the humpback version. I'm sure it would have been called the Beluga orbiter.

Figure 12 looks like a prototype for the Starship Enterprise.

[lpetrich]

Thanx, NEOWatcher. Seems like the main-engine module would weigh about 30 mt. The three main engines are 3.5 mt each, making 10.5 mt total.

I found another launch of the Energia. Here are all its launches:

Polyus (spacecraft) - Wikipedia - 15 May 1987 - the Energia worked correctly, but the Polyus mis-oriented itself before firing its rocket. Instead of going into orbit, it went into the Pacific Ocean.

Buran (spacecraft) - Wikipedia - 15 Nov 1988 - it flew successfully, but neither it nor the Energia ever flew again.

Both the Polyus and the Buran were motivated by the Cold War, and when that conflict ended, both programs ended. That left the Energia without payloads to launch.

[wd40]

Being that a nuclear rocket has twice the specific impulse of a chemical rocket, given the improvements in safety since the 60s, is there any way an atomic heavy-lift booster could yet fly?

[swampyankee]

Being that a nuclear rocket has twice the specific impulse of a chemical rocket, given the improvements in safety since the 60s, is there any way an atomic heavy-lift booster could yet fly?

No. Politically, it would be impossible.

[Van Rijn]

Being that a nuclear rocket has twice the specific impulse of a chemical rocket, given the improvements in safety since the 60s, is there any way an atomic heavy-lift booster could yet fly?

No. Thrust is more important than specific impulse in this case. On a purely technical level, the NERVA nuclear thermal rocket (the only one to get real hardware and serious testing) would simply not have had sufficient thrust to lift itself off the Earth. There are other possible solid core designs that might, but that's never been verified. There are some more extreme nuclear concepts that never got very far, and generally would have unacceptable amounts of radioactive material in the exhaust.

Further, the only use seriously pursued was to only light up a nuclear thermal rocket once it reached stable orbit. Once the reactor is lit up it starts producing the more dangerous short half-life fission products. Until that happens though, it wouldn't be all that dangerous if it crashed.

But as swampyankee says, even that use would be politically impossible, considering the fuss that the extremely low risk RTGs have gotten.

[Local Fluff]

The first step in spaceflight is to get off the Earth, and Comparison of orbital launch systems - Wikipedia is a good reference for the rockets developed for getting into low Earth orbit (LEO) and beyond.

I think the the top list there needs to be updated with the latest Atlas V launch which put 29.4 tons in LEO, which makes it the second largest launcher ever after Saturn V, since the Soviet projects didn't work out all that well. (N1, the largest human made non-nuclear explosion ever, ouhm!)

[Local Fluff]

What's the deal with this:
http://www.space-travel.com/reports/..._Back_999.html

Constellation is back? What is actually financed? That lousy news site gives poor links. Does anyone know anything about this?

[NEOWatcher]

What's the deal with this:
http://www.space-travel.com/reports/..._Back_999.html

Constellation is back? What is actually financed? That lousy news site gives poor links. Does anyone know anything about this?

The byline is "Staff Writers". Probably interns that have no clue as to what is going on.
Space.com has more detail.

My guess is they only heard "big rocket" or "shuttle derived" thinking AresV, and Orion thinking AresI.

[cjl]

I think the the top list there needs to be updated with the latest Atlas V launch which put 29.4 tons in LEO, which makes it the second largest launcher ever after Saturn V, since the Soviet projects didn't work out all that well. (N1, the largest human made non-nuclear explosion ever, ouhm!)

Citation for that mass? They haven't launched an Atlas Heavy (or even fully developed it beyond just some initial studies) yet, and the 552 (the heaviest current config) can only loft around 20 mt, not 29 (putting it behind Proton-M, Ariane 5, and the Delta IV Heavy, to name a few). Even if it were to have launched 29 mt though, it would still be behind the Shuttle and Energiya-Buran for the title of largest launcher, so absolute best case, it would be 4th.

[Local Fluff]

Citation for that mass? They haven't launched an Atlas Heavy...

Indeed I cannot easily find much more about it than a broken link from Wikipedia. That's funny! Good of you to point that out, thank you!

Maybe a question emailed to Lockheed Martin would clarify it. But I'd suppose that a good answer would be something much more composite than a single tonnage figure. Seems to be a very massively capitalized little company they are running there. Their little side business of launching some of the largest rockets in the world, out of this world, doesn't even make it to their web front page.

Heard over the phone:
(Covering the microphone after my asking the question)
"-Doctor Gretchen, do we launch the biggest rockets in the world? Oh, yeah? Do we really!? That's fantastic!"

Speaking clerarly over the soundpower again:
"Yes sir, we do!"

[cjl]

There is some stuff on the ULA website (http://www.ulalaunch.com/site/default.shtml), including a fairly detailed Atlas user's guide (http://www.ulalaunch.com/site/docs/p...sGuide2010.pdf). It states a max payload (pp. 59) of 18,814 kg though for the heaviest flown configuration (500 series w/5 boosters). It does show 29,400 kg for the heavy, but as I mentioned above, that configuration has never flown. Also, for what it's worth, the Delta IV user's guide (http://www.ulalaunch.com/site/docs/p...une%202013.pdf) show 28,790 kg capability to LEO for the Delta IV heavy (pp. 34), which is (I believe) the heaviest configuration of any rocket that has flown from ULA.

[Elukka]

But as swampyankee says, even that use would be politically impossible, considering the fuss that the extremely low risk RTGs have gotten.

I'm not so sure. Yes, some people would make noise, but would it amount to anything? We keep launching RTGs and to my knowledge we've never refrained from using them due to people fussing about it.

[Trakar]

Figure 12 looks like a prototype for the Starship Enterprise.

The 20-meter space telescope mirror lenticular cargo variant! LOL, I knew there had to be some logical reason for the Enterprise's design, it was built using left over junk in orbit. Makes the Klingon insults more understandable.

"I didn't mean to say that the Enterprise should be hauling garbage, I meant to say that the Enterprise should be hauled away AS garbage!"

[ravens_cry]

No. Thrust is more important than specific impulse in this case. On a purely technical level, the NERVA nuclear thermal rocket (the only one to get real hardware and serious testing) would simply not have had sufficient thrust to lift itself off the Earth. There are other possible solid core designs that might, but that's never been verified. There are some more extreme nuclear concepts that never got very far, and generally would have unacceptable amounts of radioactive material in the exhaust.

Further, the only use seriously pursued was to only light up a nuclear thermal rocket once it reached stable orbit. Once the reactor is lit up it starts producing the more dangerous short half-life fission products. Until that happens though, it wouldn't be all that dangerous if it crashed.

But as swampyankee says, even that use would be politically impossible, considering the fuss that the extremely low risk RTGs have gotten.

Rarely have I seen NERVA even posited as a first stage, though the competing DUMBO design could have I believe. Instead, as top stage, the high ISP more than makes up for the relatively low thrust, with a NERVA Saturn variant potentially putting twice Saturn-V's already prodigious (compared to anything else anyway) payload into orbit. There is further places we could go, gas core 'nuclear lightbulbs' have some truly awesome potential. Yes, there is danger, and you don't want it falling on your head, but I don't think you want any rocket falling on your head. Storable liquid propellents are nasty things.
But, nope, we're stuck here because the n-word has people terrified beyond the capacity for rational thought.

[Local Fluff]

What about putting six Falcon 9 first stage boosters in a ring around a seventh?
Mass producing boosters and using them for a whole range of payload sizes should help cut costs and it doesn't seem to require a giant leap to do. Going from 3 to 7 first stages, what kind of increase would one expect in terms of mass to LEO?

What plans does SpaceX have for landing first stages Grasshopper style? Could that be implemented on Falcon 9 (heavy) or would it require a completely new rocket system?

A problem might be that 7 mid sized liquid fuel rockets are more likely to fail than 1 or 3 larger. Heavy lift and mass produced mid sized boosters both have economic advantages in principle. Dockings have been done 100s of times in LEO and not one of them has ever failed, so heavy lift is not a necessity for large missions, even if a logistician would love it.

[Garrison]

What about putting six Falcon 9 first stage boosters in a ring around a seventh?
Mass producing boosters and using them for a whole range of payload sizes should help cut costs and it doesn't seem to require a giant leap to do. Going from 3 to 7 first stages, what kind of increase would one expect in terms of mass to LEO?

What plans does SpaceX have for landing first stages Grasshopper style? Could that be implemented on Falcon 9 (heavy) or would it require a completely new rocket system?

A problem might be that 7 mid sized liquid fuel rockets are more likely to fail than 1 or 3 larger. Heavy lift and mass produced mid sized boosters both have economic advantages in principle. Dockings have been done 100s of times in LEO and not one of them has ever failed, so heavy lift is not a necessity for large missions, even if a logistician would love it.

The core in the Falcon 1.1 is designed to be compatible with the Grasshopper system, and with the Falcon Heavy. I suspect though the FH will want to max out the payload so they may not use Grasshopper there even it does work out on the F9. For bigger payloads SpaceX are planning a new larger engine.

[ravens_cry]

Hmm, I've asked this before but didn't get an answer one way or another, but would plasma windows be any improvement over fused quartz for 'nuclear lightbulbs'?

[lpetrich]

Plasma windows? Fused quartz? Nuclear lightbulbs?

Any good references on these?


Nuclear thermal rocket - Wikipedia mentions that some proposed nuclear-thermal engines could get thrust-to-weight ratios up to about 7:1. But that's not nearly as good as what some chemical engines can do: 70:1. So a nuclear-thermal rocket won't make a good lower stage. In fact, I don't know of any good alternatives to chemical-reaction rocket engines for getting off the Earth's surface into outer space. The Earth's gravity requires high thrust to escape it, and the Earth's atmosphere interferes with alternatives to rockets like linear-motor guns.

[Noclevername]

Plasma windows? Fused quartz? Nuclear lightbulbs?

A nuclear lightbulb primer.

https://en.wikipedia.org/wiki/Plasma_window

A plasma window's viscosity allows it to separate gas at standard atmospheric pressure from a total vacuum, in fact it is reported that it can withstand a pressure difference of up to nine atmospheres.[2] At the same time, the plasma window will allow radiation such as lasers and electron beams to pass.

[Elukka]

Nuclear thermal rocket - Wikipedia mentions that some proposed nuclear-thermal engines could get thrust-to-weight ratios up to about 7:1. But that's not nearly as good as what some chemical engines can do: 70:1. So a nuclear-thermal rocket won't make a good lower stage. In fact, I don't know of any good alternatives to chemical-reaction rocket engines for getting off the Earth's surface into outer space. The Earth's gravity requires high thrust to escape it, and the Earth's atmosphere interferes with alternatives to rockets like linear-motor guns.

The Timberwind program specified a thrust-to-weight ratio of 30 for an NTR with an isp of 1000 seconds. The later SNTP program went for 20-25 after provisions for reusability and additional safety factors. At the end of the program they found the Russians had developed better, higher temperature fuel elements and were prepared to sell them so that may have given it some extra performance. With LOX injection it's possible to increase thrust by 50% (or as much as 100% if you want to be optimistic) but that will knock down your isp a bit. An advantage is that a LOX injection system could be turned on and off as needed, for either more thrust or more isp.

Most of the low thrust-to-weight ratio NTRs are either very early designs (NERVA) or designed solely for in-space use, which means issues such as the suitability of the reactor for power generation might overtake maximum thrust as a concern.

[ravens_cry]

Yes, that's the kind of thing I meant, Nocleavername. The reason I ask is because plasma windows are very transparent and, I blieve, have higher temperature tolerances, potentially allowing higher temperatures than a fised quartz closed cycle gas-core fission reactor could. Another potential 'lightbulb' material is transparent aluminium oxide, perhaps?

[cjl]

Nuclear thermal rocket - Wikipedia mentions that some proposed nuclear-thermal engines could get thrust-to-weight ratios up to about 7:1. But that's not nearly as good as what some chemical engines can do: 70:1. \

Some chemical engines are even close to double that - the Merlin 1D used for the latest SpaceX launches is up around 150:1.

[NEOWatcher]

What about putting six Falcon 9 first stage boosters in a ring around a seventh?

I'm sure someone can chime in on this, but from what I know, it wouldn't be that simple.

It seems to me that inboard engines have different issues in the first place. Now you're placing another ring of 63 engines around the central core. Now; maybe you don't fire the central core until the ring is done, but that's another set of issues too. The entire cluster needs to be considered.

[publiusr]

Figure 12 looks like a prototype for the Starship Enterprise.

I have some old papers for Shuttle-C solid aerobrake disks at home. I think the site Beyond Apollo may have more on that.

One of the advantages of side mount payloads is that the payloads can be much wider than can be had for top mount designs. There is a section in the book "spaceflight in the era of aerospaceplanes" that talks about the threat of increased pitch loads and bending moments upon top mount spaceplanes. This is why X-37 is enclosed in a shroud.

Dream chaser is the first craft that will be launched "naked."

An engine equipped Shuttle external tank allows a simpler orbiter, and a simpler payload pod. With side mount, the aerodynamics aren't the best, but the attachment points are well away from the engines--and all the engines are close to ground level, free and clear--out in the open and not obscured by shrouds, fairings etc.

Energiya Buran was the right concept made by the wrong country. What I would have loved to see would be an Energiya core block, and each orbiter be a bit different. One could be a Faget straight wing, another a lifting body, Columbia/Buran type for a third, a large orbiter scale hypersonic boilerplate still another.
With the shuttle stack being a giant Navaho, large scale testing could be had. Once the best design is found, that design could be scaled up into an RLV.

Now, most hypersonic research craft are about the size of surfboards.

Here are a few other shuttle follow-ons: http://forum.nasaspaceflight.com/index.php?topic=6348.0
Wayne Ordway advocated for an Energiya/Buran type system
http://www.nasa.gov/centers/kennedy/...es/ordway.html (His NTRS page is long gone it seems)

Ah--found it:
http://www.wired.com/wiredscience/20...iew-1989-1993/
http://ntrs.nasa.gov/archive/nasa/ca...1991018890.pdf


As far as HLLVs go, people have been looking at it for quite some time. Nice PDF here
http://www.ntrs.nasa.gov/archive/nas...1996058483.pdf
http://buzzaldrin.com/space-vision/r...cience/aquila/

What's the deal with this:
http://www.space-travel.com/reports/..._Back_999.html

Constellation is back? What is actually financed? That lousy news site gives poor links. Does anyone know anything about this?

I don't think Ares I is to make a comeback--I think Falcon could fit that bill fine.

SLS is a bit bigger than Magnum, but smaller than Ares V, which would have had a 10 meter core, instead of 8+ for SLS. The wider core needed more LH2 since the RS-68, while much simpler than SSME, was also a bit more thirsty. Even larger concepts were looked at:
http://www.nasaspaceflight.com/2010/...vehicle-noted/