Turning a Jupiter first stage into a Propellant Depot

[A_M_Swallow]

A possible opportunity.

The smaller Jupiter first stage J-130 or J-140SH is a Single Stage To Orbit (SSTO) launch vehicle (LV).  The SSME engines of the DIRECT v3.0 burn the cryogenic propellants liquid hydrogen and liquid oxygen.  These liquids are stored in very large tanks that are covered in a heat insulating foam.  After launch the LV arrives in Low Earth Orbit (LEO) and the current plan is to deorbit the LV after payload separation.

The SSTO nature of the J-140SH would allow one of these LV to be converted into a propellant depot by simply leaving the empty stage in orbit.

There are some problems that need to be overcome:

The foam tends to fall off contaminating LEO so the LV would need a method of stopping this, possibly covering the tanks in a metal or composite leotard.  An extra 10 to 15 tons on the LV mass would normally be unacceptable but since the first stage is the payload this could be the exception.

The depot will need a docking port, an inspace reaction control system (RCS) possibly burning hydrogen, automated docking assistance avionics and a heat shield.  These can form part of the payload in the PLF.

The depot is likely to need additional plumbing and pumps since the engine's turbo pumps are probably too powerful for controlled fuel transfer.

Helium is used to pressurize the hydrogen during launch so the depot may be sell helium.

A small real payload or ballast could be carried to make up the payload mass.  A small amount of sell-able payload could be carried.

p.s. A tank to store Argon propellant for electric propulsion spacecraft.

[Warren Platts]

Too much trouble my friend. If Jupiter were to catch on, it will be used a bunch, but we only need a few fuel depots. There's those shading screens they need, and there own pumps and orientation and maneuvering systems that they'll need. Better to special order them, I think.

[cuddihy]

The foam tends to fall off contaminating LEO so the LV would need a method of stopping this, possibly covering the tanks in a metal or composite leotard. 

<snip>

A small real payload or ballast could be carried to make up the payload mass.  A small amount of sell-able payload could be carried.

I vote for composite leotard. That way you can contain your ballast or small payload without too much jiggling ;-)

This is fun idea. I mean, if we're going to be stuck with a low flight-rate HLV anyway, might as well have some fun with it, right?

I mean, the fact that a fuel depot doesn't need an HLV to launch, and also bypasses the whole need for an HLV in the first place, has already been discarded by the Powers That Be. So, since they're going to ram an HLV down our throats, why don't we come up with suggestions on how to use it truly heavy purposes?

tom

[HappyMartian]

A_M_Swallow has a great idea about "Turning a Jupiter first stage into a Propellant Depot."

Now if you can just get Japan or India or China or Russia or Germany to come up with some neat machines to scoop upper atmospheric gases, you would have some great storage tanks for that valuable gas. You would also need to need to add in a whole lot of solar power and VASIMR engines to maintain the scooping propellant depot's orbit.

Others are suggesting the propellant depot could capture small fuel carrying rockets fired from a sea based supergun.

See:   
A Cannon for Shooting Supplies into Space
http://forum.nasaspaceflight.com/index.php?topic=20098.0
   
See:
http://www.popsci.com/technology/article/2010-01/cannon-shooting-supplies-space

It really doesn't matter which system you use as long as you can cheaply resupply your orbiting depots with propellant. You could even use multistage plastic rockets launching fuel from a ship in the Pacific Ocean. Just do the resupply activity cheaply.

Since we are thinking about Jupiter Rockets, you might also be able to head off to Mars with a couple of refueled cores of J-140s that use two J-2Xs and two SSMEs as the main engines. As the J-140 lifts off from Earth, only the two SSMEs and solid fuel boosters would be providing thrust. Above 60,000 feet, the two J-2Xs are started to add their thrust to that of the two SSMEs.

Then, while refueling the J-140s at the LEO depot, remember to remove the two SSMEs. They aren't needed for the next step and can be shipped back to Earth for reuse on some other J-140s.

The dual capabilities of restarting and refueling would give two orbiting J-140 cores, each with its two remaining J-2Xs as its main engines, the combined capability of acting as a massive fuel tanker to GEO or as a lovely Earth departure stage for any spacecraft headed out from LEO or GEO.

Solar powered VASIMR engines might also be a useful form of rocket propulsion for some missions coming back from Lunar or Mars orbit. Eventually, refueling J-2X powered J-140 cores in Lunar orbit, and on the Moon, Deimos, Phobos, and Mars should be feasible. With the availability of lots of cheap fuel, a space based J-2X powered J-140 core can do many interesting things.

Buck Rogers is alive and well. He’s been known to smile when he sees a picture of the modern day Orion spacecraft.

Have Jupiter Based Propellant Depot = Do Game Changing Refueling of the J-140 = Homes On the Moon and Mars by 2032.

See:
Scooping atmospheric air (PROFAC revisited).

http://forum.nasaspaceflight.com/index.php?topic=17984.0

Cheers!

[Downix]

Problem with this idea is simple, the insulation.  It would become a debris field, damaging anything seeking to refuel.

[Jim]

Just better to put a purpose designed depot on top of the Jupiter. 

[A_M_Swallow]

Problem with this idea is simple, the insulation.  It would become a debris field, damaging anything seeking to refuel.

To prevent problems with the insulation (=foam) the 10 to 15 ton leotard was proposed.

[A_M_Swallow]

Just better to put a purpose designed depot on top of the Jupiter. 

Possibly but I suspect that the propellant tanks would be smaller.

[Robotbeat]

An ACES-based depot makes a lot of sense because it's being designed with low-boil-off and even depot applications in mind. Perhaps the Jupiter first stage could be used as a propellant tanker, instead? You'd still need to solve the insulation-shedding, though. It doesn't seem like a good use, though, since the Jupiter will almost surely never be a commercial vehicle.

[MP99]

An ACES-based depot makes a lot of sense because it's being designed with low-boil-off and even depot applications in mind. Perhaps the Jupiter first stage could be used as a propellant tanker, instead? You'd still need to solve the insulation-shedding, though. It doesn't seem like a good use, though, since the Jupiter will almost surely never be a commercial vehicle.

The Jupiter core will be designed to carry a payload, and will need to do so even if it's just prop.

But maybe that payload could be held within a stretched O2 tank, ie forget the H2 and just deliver O2, which is the majority of the prop mass.

However, I think Jupiter needs to avoid orbiting too high (popcorning) and te depot probably needs to avoid orbiting too low (atmospheric drag), so the core may not be suitable for this.

cheers, Martin

[jongoff]

While technically feasible, I've never really been sold on the "turn an ET into a depot" line of thought.  The biggest problem is it is just way too big compared to demand.  It's probably going to be better to stage deep-space, Mars, and other interplanetary missions from L1/L2 anyway, so for most missions beyond LEO, you're better off using a small depot in LEO which gets cycled as much as possible, combined with another depot in L2.  They don't have to be anywhere near as big, and can be a lot better prepackaged before launch.  There's really just no need anytime soon for a 740mT depot in orbit.  75-115mT is a much more reasonable starting point.

~Jon

[HappyMartian]

Jim notes, "Just better to put a purpose designed depot on top of the Jupiter."

True, but we are quite willing to refurbish and reuse old DC-3s, A-10s, B-52s, bicycles, cars, trucks, buses with holes in their floorboards, and suboptimal folks like me for a wide variety of reasons. "Just better" can be too expensive for current and future budgets. An increasing number of Americans are old and yet they still manage to vote. They usually don't like the idea that used or old means disposable. Reusing things and making do with what you already have are going to be politically popular ideas for a long time into the future. Most of the readers of this forum understand that politics is often one of the main factors in what gets funded, built, and sent into space.

Jongoff notes, "'While technically feasible, I've never really been sold on the "turn an ET into a depot' line of thought.  The biggest problem is it is just way too big compared to demand."

If we do not want to assemble a large Martian bound expedition or someday build homes on the Moon, Deimos, Phobos, and Mars, Jongoff is correct. However, if you want national, international, and private spaceships regularly heading off to here and there and everywhere, an External Tank based propellant depot and refurbishing facility isn't too big.

Some may strongly disagree, but one way or another, with America vibrantly alert and sometimes asleep at the wheel that steers the future, the world is in the business of creating an Earth-Moon-Mars-NEO civilization. Propellant depots in LEO, GEO, L1, and L2 seem reasonable. The transportation requirements for propellant in such a space based civilization will eventually dwarf the capacity of even depots with several External Tanks.

Go to any large airport in the world. Look around. Think how strange and preposterous such a facility and the airplanes that are regularly arriving and departing would have looked to most of the people who lived in the world a hundred years ago. Variants of the Delta, Atlas, and Jupiter rockets may be around for more than the next hundred years... Obviously, we already have, or soon will have, a wide variety of human rated spacecraft and rockets. What we currently lack are the large refueling depots that are needed to make full use of what Jim and Jongoff, and their counterparts around the world, can already build.

Cheers.

[Jorge]

Jim notes, "Just better to put a purpose designed depot on top of the Jupiter."

True, but we are quite willing to refurbish and reuse old DC-3s, A-10s, B-52s, bicycles, cars, trucks, buses with holes in their floorboards, and suboptimal folks like me for a wide variety of reasons. "Just better" can be too expensive for current and future budgets. An increasing number of Americans are old and yet they still manage to vote. They usually don't like the idea that used or old means disposable. Reusing things and making do with what you already have are going to be politically popular ideas for a long time into the future. Most of the readers of this forum understand that politics is often one of the main factors in what gets funded, built, and sent into space.

Note that we're not reusing the Queen Mary II as a submarine, or an Abrams tank as a sports car. There is reuse that makes sense and reuse that doesn't make sense. Reusing an ET as a propellant depot is not necessarily cheaper than a purpose-built depot, due to the need to completely re-engineer the insulation so that it doesn't create an orbital debris hazard while still fulfilling the multiple functions it performs on the pad and during ascent.

[kraisee]

Much, much, much easier to turn a Jupiter Upper Stage into a Depot.

Barrel Stretching that tanking for a low-production-rate Depot isn't all that hard.   And a standard J-1xx has plenty of performance to loft it dry, along with whatever sub-systems it may require (ACS, RCS, RCS Propellant, Thermal Shielding, Electronics, Communications, Canadarm, Docking Interface(s), Solar Arrays, Cryogenic Cooling Systems etc).

From our studies, there appears to be an optimum capacity around 300-350mT or so, which is about half the size of the ET.   That works very well for multiple Lunar missions every year, as well as Mars Staging for chemical combustion architectures.

Ross.

[HappyMartian]

Jorge Notes "There is reuse that makes sense and reuse that doesn't make sense."

It would be interesting to see an evaluation of the idea by a team of experts. Popcorning insulation should be a resolvable issue...

Cheers!

[Jorge]

Jorge Notes "There is reuse that makes sense and reuse that doesn't make sense."

It would be interesting to see an evaluation of the idea by a team of experts. Popcorning insulation should be a resolvable issue...

Cheers!

Yes, it would be interesting. But any panel of experts would have to include many of the folks who worked on the ET insulation issues after Columbia. They are *the* experts on the issue. And even after several years and billions of dollars, they were only able to *mitigate* the problem, not completely resolve it. And that only for the period of ascent where foam shedding is a threat to the Orbiter TPS. Long-duration orbit is another issue entirely. I doubt that their conclusion would be any different than Jim's or mine: a purpose-built depot would be cheaper because it could avoid the problem entirely.

[A_M_Swallow]

Much, much, much easier to turn a Jupiter Upper Stage into a Depot.

Barrel Stretching that tanking for a low-production-rate Depot isn't all that hard.   And a standard J-1xx has plenty of performance to loft it dry, along with whatever sub-systems it may require (ACS, RCS, RCS Propellant, Thermal Shielding, Electronics, Communications, Canadarm, Docking Interface(s), Solar Arrays, Cryogenic Cooling Systems etc).

From our studies, there appears to be an optimum capacity around 300-350mT or so, which is about half the size of the ET.   That works very well for multiple Lunar missions every year, as well as Mars Staging for chemical combustion architectures.

Ross.

A propellant depot made from a Jupiter upper stage can probably fly itself to Phobos.

According to this card the burnt out upper stage weighs 13 mT, adding all the depot hardware say 25 metric tons.
http://www.launchcomplexmodels.com/Direct/documents/Baseball_Cards/J246-41.4004.08001_EDS_090606.pdf

Delta-V LEO to Phobos 3.22 + 0.6 + 0.9 + 0.2 + 0.3 + 0.5 = 5.72 km/s
Plus "docking" to Phobos.

The Isp of the 6 off RL-10B-2 engines is 459

Fuel to fly itself to Phobos 25 * (exp(5720/(459*9.81))-1) = 64 mT

The J-246 is rated as having a payload of 91,670 kg so this is viable.

[HappyMartian]

Jorge notes, "Yes, it would be interesting. But any panel of experts would have to include many of the folks who worked on the ET insulation issues after Columbia. They are *the* experts on the issue. And even after several years and billions of dollars, they were only able to *mitigate* the problem, not completely resolve it. And that only for the period of ascent where foam shedding is a threat to the Orbiter TPS. Long-duration orbit is another issue entirely. I doubt that their conclusion would be any different than Jim's or mine: a purpose-built depot would be cheaper because it could avoid the problem entirely.”

That particular panel of experts worked under the constraints of possible modifications not having a major impact on the Space Shuttle's other systems, payload carrying capacity, and the attachment of the Space Shuttle to the External Tank.

The J-140SH has strong Space Shuttle heritage, but it is also a different system. Adding an extra metal skin and/or using other types of heavier insulation material wouldn't overtax the ability of the J-140 to achieve orbit.

Ross notes, “Much, much, much easier to turn a Jupiter Upper Stage into a Depot.”

Ross also notes, “From our studies, there appears to be an optimum capacity around 300-350mT or so, which is about half the size of the ET.   That works very well for multiple Lunar missions every year, as well as Mars Staging for chemical combustion architectures.”

How many depots and where would the initial depots be located?

What would be the expected life cycle of all the various possible types of depots?

Is turning a Jupiter Upper Stage “easier” or less costly than using the ET?

What are the short term and long term costs?

How do these costs vary in terms of the number of depots?

If a Jupiter Upper Stage depot would have half the capacity, would it have half the cost?

What are the many options?

Are there any new insulation materials that are currently being studied that might need to be considered?

What are the political issues?

Did the Direct Team consider selling propellant to international and private spacecraft?
 
And which rocket engines and other issues would be important if we wanted to land such a Jupiter 140SH or Upper Stage depot in a dark crater near the South Pole of the Moon or near a Martian polar region?

Maybe Jorge nor Ross nor anyone else can say for sure what the decision parameters should be for considering the various types of depots because this subject has not been thought about or studied to the degree that is needed.

There are more questions about using the External Tank for Depots. These questions are beyond our ability to quickly answer them, and that is quite reasonable because these posts are in the Advanced Concepts section of this forum. Keeping an open mind on this idea might be useful.

Cheers!   

[MP99]

Much, much, much easier to turn a Jupiter Upper Stage into a Depot.

Barrel Stretching that tanking for a low-production-rate Depot isn't all that hard.   And a standard J-1xx has plenty of performance to loft it dry, along with whatever sub-systems it may require (ACS, RCS, RCS Propellant, Thermal Shielding, Electronics, Communications, Canadarm, Docking Interface(s), Solar Arrays, Cryogenic Cooling Systems etc).

From our studies, there appears to be an optimum capacity around 300-350mT or so, which is about half the size of the ET.   That works very well for multiple Lunar missions every year, as well as Mars Staging for chemical combustion architectures.

Ross.

NASA's opposition-class crewed Mars mission needs less than 300mT of prop.

Would it be feasible to put engines on the "depot" and replace this forest of five stages with a single depot? Would a depot be able to maintain low boiloff when mostly empty, ie after TMI / in Mars orbit?

cheers, Martin

Edit: looks like this would easily be achieved with 4x Jupiter SH launches, with a lot of margin prop, too.

[A_M_Swallow]

How many depots and where would the initial depots be located?

Suggestions for propellant depot locations.

1.  In LEO at 28.5 degrees +/- 2 degrees so it can be supply payloads launched from KSC.  Other spaceports may want their own in-space depot.

2.  At Earth-Moon Lagrange Point L1 or L2, co-located with a spacestation.

3.  A virtual depot at KSC for keeping the propellant cold until the LV and weather are ready.  (This may already exist but will need to co-ordinate with operators of the depots being supplying.)

4.  A depot on the Moon to refuel the landers.  Eventually each base may want its own.

5.  A depot on Phobos to refuel the returning Mars Transfer Vehicles and Mars Landers.

6.  A depot on Mars to refuel the landers.  Eventually each base may want its own.


The two depots at LEO and EML-1/2 will support an initial exploration architecture.