Space Tugs and Ferries--Getting Real About Space

Up until now, human space launches have been faltering baby-steps. There has been no significant effort to develop an ongoing, versatile space-based infrastructure. So far, it is almost as if humans had no intention of staying in space. That needs to change.

Over at Selenium Boondocks, a recent posting takes an interesting look at Space Tugs and Space Ferries--what they are and what they would do.

In a nutshell, tugs allow you to take all of the most complicated parts of getting people, propellants, and provisions to a station, and offloads it to either the launch vehicle, or to a reusable vehicle that always stays in orbit, doesn't have to reenter, etc. Why lug all of that hardware with you each and every time if you can leave it at the destination. Why require each and every company that wants to launch stuff to a station to then also have to come up with their own prox-ops solution? Solve the problem once, and then you don't have to keep solving it again.

...By having a ferry that operates between LEO and GEO, that has refueling capabilities in LEO, you can launch the largest commercial and government exo-LEO missions without requiring anything bigger than a bottom-of-the-line EELV. In fact, you can even launch manned lunar missions using launchers no bigger than an Atlas V 401 or a Falcon IX...Ferries can be based around either chemical or solar electric propulsion systems. Some cargoes don't mind a slow spiral out through the van Allen belts, and thus can be shipped by the more mass efficient (and hopefully therefore more cost efficient) solar-electric "slow boat". Other cargoes (people, cryogens, and possibly GEO satellites) can be shipped via a much faster chemical ferry. ___SB

If you understand the issues involved--why it is so important to develop these capacities if humans expect to establish a permanent presence in space--you will want to read the entire article, along with the comments.

Imagine if every airliner flying to a city had to taxi down city streets to deliver each passenger to his individual hotel? No, you say, there are taxis and rental cars for that purpose. Exactly! Each vehicle is specialised for particular purposes.

That is what is needed in space. Tugs to receive and deliver cargo and passenger vehicles, and place them reliably into docking. Ferries to transfer satellites to higher orbits, or to transfer passengers and cargo to habitats and stations in other orbits.

Until this minimal infrastructure is developed, one can not truly say that humans are serious about space.