Fast Hyperbolic

Really Wild Stuff

There may be a class of urgent missions that require very fast, high acceleration delivery of small packages to high-earth-orbit destinations. Specialized medical supplies or unique repair parts, for example.

The launch loop will enable lavishly equipped projects with abundant spare parts and local fabrication tools, but it will be impossible to duplicate the wide range of manufacturing capabilities of an entire planet, and some objects (like bleeding edge semiconductor devices) require vast specialized factories and large technical staffs to produce. If a piece of vital equipment has a design flaw that manifests during a mission, and the spare has the same design flaw, the solution may be a different type of equipment that exists somewhere on Earth, and must be delivered fast to save a mission, perhaps save lives. For the following, assume advanced preparations, a huge budget, and ultra-high priority.

For this example, the goal is to deliver a unique 200 kilogram item from anywhere in the world to a manned station orbiting the Moon, in less than 24 hours from the detection of a life-critical problem. Assume the delivery network has been prepared in advance, and the mission design process is automated.

The first step is figuring out which item, anywhere in all the world, will fix the problem. A massive worldwide database search, computer modelling, financial negotiations, and delivery arrangements worked out in minutes (after years of advanced preparation). Perhaps the equipment is a specialized piece of medical gear in a urban research hospital in Belgium.

A team at the hospital disconnects and bubble-wraps the gear. A fast cargo helicopter (carrying a flying workshop and an adaptable launch shroud) lands at the hospital, collects the equipment, and an onboard team mates it to the launch shroud in flight, producing the cargo vehicle that will be delivered to the lunar station. The helicopter flies to a rural launch location in a forest or farm field far from the city. Not a prepared launch pad, just a cleared field away from the suburbs. There, a disarmed, re-purposed solid-fuel ICBM is stored on an old Soviet transporter-erector. Air traffic is diverted while the missile is erected and launched towards the launch loop. This highly-automated process could deliver material from anywhere on Earth to the loop in less than three hours.

• 1) This is a good way to "scrap" a Minuteman missile

• 2) From Brussels in particular, a better launch site might be a repurposed missile submarine off the coast.

At the surface station of the launch loop, a mission-specific three stage rocket (perhaps 4.7 tonnes, fueled) is assembled out of stock components, readied for the arrival of the launch shroud. A StratoCatcher aircraft is deployed to catch the incoming ICBM cargo package, and deliver it to the surface processing facility below launch loop west station. The launch shroud is mated to a new high per rocket launcher, and the combined vehicle is lifted up the elevator to west station. There, it is mated with a launch sled, then launched westward on the loop.

The loop accelerates the vehicle to near escape velocity (perhaps 11.5 km/s including the 0.47 km/s Earth rotation contribution). After launch from the loop, the first stage of the rocket accelerates the vehicle to perhaps 13 km/s. The rotating Earth is unlikely to be properly aligned for an optimum trajectory to the moon, and we are too hurried to wait for a better alignment, so perhaps 1 km/s of the delta V may be "wasted" deflecting the trajectory from launch loop horizontal to that optimum trajectory.

Leaving the vicinity of the Earth at 13 km/s, the travel time to the Moon is 15 hours. Approaching the destination, the arrival delta V is 7 kilometers per second; a two-stage rocket (the second and third stages launched from the loop) may be needed to shed enough delta V. This will be in zero gee and vacuum, so the engines can be small but highly expanded; with perhaps 2000 seconds to shed velocity, the acceleration can be half a gee and the initial thrust perhaps 20 KNewtons (WAG).

Hopefully, we can equip 99.9% of our space missions with enough redundancy and adaptability to avoid crises like this. But three minimum sized launch loops can launch 10 million tonnes per year, supporting perhaps 10 thousand large missions; that implies 10 crisis launches per year. Hopefully we will have superb on-site space manufacturing capability, and eliminate dependence on the Earth, about the time we use up all the world's military ICBMs.

Given our incredibly versatile global technological capacity, and our insane predilection to destroy that capacity, I'm not optimistic about either possibility.

A spreadsheet and some results. The first column of the spreadsheet is the "calculator", the table is manually created from that.