With the imminent retirement of the Space Shuttle and the rise of corporate launch spacecraft, private companies are starting to think seriously about the next logical steps – orbital infrastructure. A few of them have even zeroed in on the next target in the business case by identifying a capability we don’t have: Orbital Tugs.
What do I mean by an “Orbital Tug”? -It’s a utility spacecraft designed to go to orbit and stay there to help with orbital logistics. This includes things like intercepting payloads lofted to low-Earth-orbit (LEO) and moving them to where they need to be, be it a higher orbit (saving on launch costs), the International Space Station, a rendesvous with another spacecraft or space station (Bigelow modules?), or even to someplace farther out like a Lagrange Point (gravitationally-stable points around and between the Earth and Moon.) Add to this the potential of tugs to offer service contracts to companies and governments for the salvage, rescue, or refueling of existing orbiting satellites (communication, GPS, weather, reconnaissance, etc.,) and suddenly the prospect is a very profitable one.
Who needs a Shuttle when you can pay much less for a LEO rocket delivery and have a Space Tug do the rest? Why build and launch a new satellite when you can pay a fraction and use a tug to extend the life of the one you already have in orbit?
Several companies are in the queue to get a tug into space first. Perhaps foremost amongst them is Russia’s S.P. Korolev Rocket and Space Corporation, Energia – the company responsible for the safest and most successful spacecraft of all time, Soyuz. They’ve had a space tug on the books since late 2001, called Parom, which is intended to replace their Progress cargo module, (an unmanned version of Soyuz that currently delivers shipments of supplies to the International Space Station.) The design of Parom is simple, based around a pressurized (i.e. habitable) cargo cylinder bracketed by two universal docking ports, one on each side. With its own engines rated to move objects up to 30 tons and fuel transfer lines so that it may refuel itself from a resupply shipment or, in turn, refuel another spacecraft, station, or satellite, Parom is an ambitious craft completely based on existing technology.
Second on my list of potential Space Tugs is a nuclear-powered satellite servicing tug from a private American firm called IoStar – though recent scandals and infighting make me worry that bankruptcy is in the company’s future. At the very least, a recent ruling against IoStar in favor of a former employee with allegedly “proprietary” information leads me to suspect an uphill battle – but I’m rooting for them.
Orbital Satellite Services is another private venture, based in Sweden, to keep your eyes on. Their SMART-OLEV or Orbital Life Extension Vehicle, while not pressurized or as burly as the Parom, may be able to make that weight savings its best advantage and take the fast track to orbit as the first functional space tug. SMART-OLEV is designed to target and dock with telecommunication satellites and extend their lifespans for up to 12 additional years by providing supplemental propulsion, navigation, and guidance.
Developing an orbital logistics infrastructure is the essential next step to the corporate development and utilization of space. Godspeed, tug-builders. Let’s get off this rock.