Project Orion ground launch

[Sarevok]

The biggest problem with space program today is cost of hauling stuff into orbit. At current outrageous rates a 2 dollar ballpoint pen would probably be worth than an iPhone if it is sent into space. The economy today or in near future can not sustain the requirement for many thousands of tons that must be launched to put bases, factories and other means of permanent presence in space. Yet once that part is done space becomes cheaper. Stuff built in space would readily available instead of the added multi million dollar cost of a rocket to take it to orbit. So a better way of putting machines, supplies and equipment in space would be greatly beneficial into opening up that frontier.

One of the more outrageous methods suggested was using Orion style spacecraft to haul literally hundreds or thousands of tons at a time. While the idea of using nuclear bombs to blast things into space seem crazy it could be economical as well if a humongous tonnage could reach orbit at price of a bomb or two and a small chunk of uninhabited land,

So could it be done and if so what major technological challenges remain to be overcome before a Project Orion ground launch is possible within this century ?

[CaptainChewbacca]

So could it be done and if so what major technological challenges remain to be overcome before a Project Orion ground launch is possible within this century ?

It could be done. It could have been done in 1970. The main problems remain fallout and the fact that EMP in the upper atmosphere does really bad things to electronics. We really don't have a way around those, because hardening every satellite in orbit isn't feasible.

[Patrick Degan]

One alternative idea that was discussed was using ground-based lasers as a launching system. The "engine bell" of the rocket in this case being composed of material which would burn off as the laser hit it and provide thrust in the form of an ablative engine. Of course, this assumes a considerable degree of development in laser technology to produce a device of the required scale for such an operation.

[Ford Prefect]

In this thread, Sikon makes a number of posts about mass drivers as a plausible, affordable method of launching stuff (though not people) into orbit. Frankly, this strikes me as being a whole lot more sensible then detonating nuclear bombs under your ass just to get into space.

[Sky Captain]

So could it be done and if so what major technological challenges remain to be overcome before a Project Orion ground launch is possible within this century ?

It could be done. It could have been done in 1970. The main problems remain fallout and the fact that EMP in the upper atmosphere does really bad things to electronics. We really don't have a way around those, because hardening every satellite in orbit isn't feasible.

Would there be that much EMP from Orion pulse bombs? I have always thought significant EMP is produced only in high yield megaton class nuclear detonations. Most heavily studied Orion designs planned to use small ~20 kt bombs. Even if there is some problems with EMP it should be possible to avoid those by choosing a very remote launch site and launch timing when there are smallest number of important satellites in nearby orbits. Even if Orion launch busts some satellites it would be rather small price to pay for a ship potentially capable of reaching Saturn with thousands tons of usable payload.

The biggest problem with Orion is it uses "nuclear" and "bombs". If antinuclear environmentalists shit their pants when NASA launches probe with few innocent RTG`s imagine what would happen if NASA announced it`s going to build a 10 000 ton spaceship driven by thousands of nuclear explosions carrying more than enough bombs to level every major city in the world.

[Ryan Thunder]

The biggest problem with Orion is it uses "nuclear" and "bombs". If antinuclear environmentalists shit their pants when NASA launches probe with few innocent RTG`s imagine what would happen if NASA announced it`s going to build a 10 000 ton spaceship driven by thousands of nuclear explosions carrying more than enough bombs to level every major city in the world.

The thought of such a machine and the utter horror it would be to people like that brings tears to my eyes.

Does that make me a bad person?

[The Duchess of Zeon]

Of course, remember that most radioactive emissions would come from the very first initiation, since that one would creatre a crater which would suck atomized dirt and rock into the fireball and spew it out as radioactive matter. If we could just avoid a ground-burst to get the thing off the ground, it would be relatively clean. The guys designing Orion knew this, and actually planned to launch it from a huge graphite-coated steel assembly that would be able to mostly survive the initiation without severe ablation. Except they didn't consider one thing I'd thought of, though probably because chemical explosives weren't as good back then: You could not merely launch it on top of a tower, but the initial charge, instead of being a nuclear device, could be a chemical shaped charge simply massively built up in the tower to a strength of multiple kilotons, which is of course entirely feasable. Then you're launching from as much as 100 meters off the ground and the first initiation is a chemical one, which means you should with luck be able to get about 200 meters of altitude before the first nuke. That would substantially minimize the released quantity of radioactive material.

[Starglider]

You could not merely launch it on top of a tower, but the initial charge, instead of being a nuclear device, could be a chemical shaped charge simply massively built up in the tower to a strength of multiple kilotons, which is of course entirely feasable.

No need for that. A 4000 tonne mid-sized Orion could be lofted to 200,000 feet by a cluster of six Shuttle SRBs. That eliminates essentially all of your fallout concerns and substantially reduces the number of devices needed as well.

[Surlethe]

What would the cost of lofting it chemically be? Isn't the entire point of using nuclear bombs that chemical boosting doesn't give enough kJ per dollar spent on the fuel?

[Starglider]

What would the cost of lofting it chemically be? Isn't the entire point of using nuclear bombs that chemical boosting doesn't give enough kJ per dollar spent on the fuel?

No, chemical fuels are very efficient in kJ/dollar terms, almost certainly moreso than nuclear devices given the massive cost of designing, testing, manufacturing and safely handling that many devices in today's world. The problem with chemical fuels is that they have low energy density, which means that you need a ridiculous amount of fuel to put something all the way into orbit. Getting up to 200,000 feet requires only a seventh of the delta-V (roughly, allowing for air drag) of going all the way into LEO. The other six-sevenths of the energy would come from the Orion drive.

[Sea Skimmer]

If the first stage was solid rocket motors, that'd also mean we could then launch the Orion craft off a barge in the ocean, which would make the launch process a whole lot safer in the event the ship fails and crashes. You could get similar range safety from a coastal launch as we do with normal rockets in the US, but most coastal areas are far too heavily populated and the water offshore too shallow for that to be acceptable with Orion.

[The Duchess of Zeon]

Ooh, now that's sexy. We could probably cluster even more SRBs for larger Orions, up to 12 or so (what's the largest number of boosters someone's ever put on an operating rocket? I will go check), and the radioactive effects of initiations at 200,000 feet will simply be more or less nonexistent. The first Orions could be used to replace the satellites knocked out by the EMP with EMP-harden satellites, all in one go, and then the next series would be designed as the modular components of a large ring-type station with artificial gravity. Once that's up, we can launch two Orions and combine them in orbit as a solar system exploration vehicle (build a second as a rescue ship, potentially), and then fuel them by sending up a cargo orion with their devices, to make them of the maximum possible size, and other equipment.

[Duckie]

Of course, other countries might be a bit mad that we knocked theirs down, and even if we offer to replace them I doubt that Russia or China would be happy to put their spy satellites in our cargo holds for an indefinite period of time before we launched.

Also global destruction of all GPS and telecom satellites sounds a bit disruptive, you'd have to carefully plan the "Cell Phones, GPS, etc. Is Out Day/Week" carefully.

[Starglider]

Also global destruction of all GPS and telecom satellites sounds a bit disruptive, you'd have to carefully plan the "Cell Phones, GPS, etc. Is Out Day/Week" carefully.

Even if there is any EMP damage at all, and I am not sure that there will be (see MKSheppard's series of 'EMP is overrated' posts), it will be restricted to a relatively small area (and certainly to line of sight, it isn't going to magically wrap around the earth and kill satellites on the other side). So even assuming very fragile satellites (remember these things are hardened to withstand solar storms) and powerful EMP, you'd be looking at 10% of LEO satellites out per launch, only a minor degredation of service for GPS, Irridium etc (and probably replaceable near-immediately with on-orbit spares). There's also the possibility of simply moving the relevant satellites into different orbits temporarily for the launch; that might knock off a few years of life due to thruster fuel usage but it'd avoid losing any completely.

[CaptainChewbacca]

Incidentally, Orion drives don't use 'bombs', they use 'Nuclear Pulse Units'. Big semantical difference.

[Sky Captain]

Here is an animation of Orion mission to Mars. It uses 14 SRBs to clear the densest part of atmosphere then engages nuclear drive thus mostly avoiding issue with fallout and lands on Mars apparently with a help of some chemical retro rockets.

http://www.youtube.com/watch?v=V1vKMTYa40A

By the way here is some cool images with a giant rocket I made some time ago in Orbiter space flight simulator just for the purpose of putting 5800 ton Orion ship in low Earth orbit so I could start my atomic trip with full load of pulse units.

http://img16.imageshack.us/my.php?image=nexus1.jpg

http://img19.imageshack.us/my.php?image=nexus111yd3.jpg

http://img18.imageshack.us/my.php?image=nexus112wt4.jpg

http://img17.imageshack.us/my.php?image=nexus113pu8.jpg

http://img10.imageshack.us/my.php?image=nexus15.jpg

http://img17.imageshack.us/my.php?image=nexus13xk6.jpg

in reality it`s clearly more practical to just lift Orion out of the densest atmosphere with some SRB`s and then use Orion`s nuclear engine for orbital insertion and then simply replenish spent pulse units with several heavy lift rockets or smaller cargo Orion ship, but in Orbiter it`s extremely fun to strap dozens of huge boosters to already giant rocket and fly it all the way to orbit.

[The Romulan Republic]

The biggest problem with Orion is it uses "nuclear" and "bombs". If antinuclear environmentalists shit their pants when NASA launches probe with few innocent RTG`s imagine what would happen if NASA announced it`s going to build a 10 000 ton spaceship driven by thousands of nuclear explosions carrying more than enough bombs to level every major city in the world.

The thought of such a machine and the utter horror it would be to people like that brings tears to my eyes.

Does that make me a bad person?

To be fair that sounds like a rather legitimate safety issue to me, though I am no expert on nuclear technology.

Its not like their are no other ways to reach orbit, and for a lot less than using the old chemical rockets.

[tchizek]

[quote="The Romulan RepublicTo be fair that sounds like a rather legitimate safety issue to me, though I am no expert on nuclear technology.

Its not like their are no other ways to reach orbit, and for a lot less than using the old chemical rockets.[/quote]

Well except that if we are going to really get into space for real we need some kind of nuclear power for our spacecraft.

Maybe not at launch, but I really like the idea of getting some altitude with chemical rockets then kicking in your "nuclear space drive" or "atomic pulse jet"

(to give less blow the anti-nuke crowds brains out names for the Orion or "boom jet" )

[The Romulan Republic]

[quote="The Romulan RepublicTo be fair that sounds like a rather legitimate safety issue to me, though I am no expert on nuclear technology.

Its not like their are no other ways to reach orbit, and for a lot less than using the old chemical rockets.

Well except that if we are going to really get into space for real we need some kind of nuclear power for our spacecraft.

Maybe not at launch, but I really like the idea of getting some altitude with chemical rockets then kicking in your "nuclear space drive" or "atomic pulse jet"

(to give less blow the anti-nuke crowds brains out names for the Orion or "boom jet" )[/quote]

Oh I agree that their's a lot of stuff we simply can't do without nuclear. I recall hearing (probably from Zubrin's books) that you need nuclear to go into the Outer Solar System at all, for example, because the Sun is too weak to use Solar power. Plus you can get far faster space craft using nuclear power than you can through any other means. For the space program to achieve its full potential (and I believe that it must), nuclear is pretty much required.

I'm just saying that I understand the concerns over safety when it comes to using nuclear bombs for the initial launch.

[The Duchess of Zeon]

An alternative to get stuff into orbit cheaply is to simply mass produce disposable rockets using off the shelf parts. The individual rocket would be less efficient than a special made shuttle like we are using now, but this would be made up for by launching hundreds of them. If they are all the same design, this lets you spread R&D and other operational costs out over all the launches.

This is by far the simplest solution to the problem.

No, it would be more efficient. The shuttle is massively inefficient, in fact, all reusable vehicles are for the most part because of the massive weight of the recovery systems, which otherwise could be used for more tonnage to orbit.

Orion remains the way to go for this reason, and the idea of using an SRB cluster to get it off the ground and up to 200,000 feet is particularly brilliant, especially with ocean launch for range safety, and the best part is that in this case (unlike with other Orion ocean launch proposals) the barge is actually reusable. Think about all the massive amount of money we can save by building, say, a 6,000 - 7,000 ton Orion lifted to 200,000 feet by 12 - 14 SRBs or similar dedicated rockets. The thing could literally be built to the standards of a submarine instead of an aircraft. No need for aluminium, advanced composites and all that other expensive crap, we can weld the thing together out of HY-100 in a submarine yard, and provide a submarine's nuclear reactor for onboard systems electrical power and ion thrusters for fine manoeuvring. Then design two of those vessels to be welded together permanently in orbit and we have an Orion with an engine on each end to make maneouvring easier and a reactor in each hull for maximum survivability, and the crew can live and work in one hull while the other is designed primarily for storing scientific and research equipment. There, we have our solar system explorer.

[PeZook]

A better question about Orion is thus: Can the crews survive radical, sudden bouts of acceleration that come with NPP?

[The Duchess of Zeon]

A better question about Orion is thus: Can the crews survive radical, sudden bouts of acceleration that come with NPP?

The acceleration was mediated through the massive shock absorbers which essentially transmitted the energy of the blast of an extended period of time as the pusher plate was shoved up toward the main body of the Orion, and in doing so steadily increased velocity instead of a short spurt of acceleration. Also remember that to some extent the Orion would ride the nuclear blast effect as well, so that the full impulse of one charge would be spread out even without the massive shock absorbers.

[The Duchess of Zeon]

Sea Dragon from the 1960s is basically what you're proposing; Todd Shipyards (up here in Washington State) concluded they could build the things, being not beyond the capabilities of any yard capable of building submarine hulls from the 1960s, and that it would have a cost per kilogramme to low earth orbit one-fourth that of Saturn V.

[Sky Captain]

How feasible would be something like scramjet engine powered by nuclear heat? I`m thinking about reusable nuclear spaceplane that for most of the ascent uses atmospheric air as a reaction mass and onboard propellant only for final orbital insertion. Such a craft if feasible potentially could have very high payload fraction because it would need to carry very little onboard propellant. If it uses wings for lift then it even do not need to have thrust to weight greater than 1 allowing to use safer less powerful engines.

[kinnison]

I find it interesting to read some of the really old (early 60s) design studies for Orion. It is noted that the fallout problem gets rapidly easier, certainly per unit mass launched, with increasing vehicle size. Why? Simply because the larger designs really have to use pulse units with an ever-increasing fusion component to the yield, and fusion explosions produce less fallout as a proportion of yield than do fission ones.

This would mean that the takeoff has to use a nuke (how many SRBs can one get to light at once anyway?) but it does mean that one can launch something REALLY BIG. The largest vehicle in the studies was one of eight million tons (about three million tons payload) launched using megaton-range explosions. For reference, this thing has about four times the mass of the Great Pyramid. It would, because some of it has to be hollow, have to be about a kilometre high. Right out of the space operas, huh? Multiple-million ton spaceships a kilometre long, with lots of really big mechanical parts (bomb-launching guns, skyscraper-sized shock absorbers...)

I wish someone would write an alternate-history story with this sort of stuff as the setting. It needs a new name, though - steampunk is taken. I would do it myself but have neither the skill nor the time.

One possible feature that might make things interesting is that using such technologies for space travel would convince any hypothetical aliens witnessing it that the human race is irretrievably insane...