A Proposed Public-Private Partnership for the Funding of Robotic In-Orbit Servicers

Abstract

There is little doubt that astronauts have proved highly effective in performing in-orbit servicing tasks, the most well-known being the first Hubble Space Telescope (HST) Repair Mission in 1993. As a consequence of this and other servicing EVAs (extravehicular activity), spacecraft are now being designed with modular architectures to allow in-orbit servicing to be performed through the replacement of orbital replacement units (ORU). Certainly, humans have proven to be useful in space but EVA does expose astronauts to a number of potential hazards. Furthermore, it is very clear that using astronauts as in-orbit "cable repairmen" is not an effective use of resources [Ellery 2001]. The costs of a Space Shuttle mission are vast and often difficult to obtain - $245M, $420M, $1B have been quoted in different quarters, but these figures vary according to whether they factor in hidden costs such as astronaut training, etc. The astronauts trained for 400 hours in the neutral buoyancy tank at MSFC and JSC in preparation for the first HST repair mission. The cost to the insurers of the Intelsat VI repair mission by astronauts was $150M but the cost of the first HST repair mission was quoted as $700M. It would be far more cost-effective if in-orbit servicing were performed robotically as part of a growing Earth orbit infrastructure. Finally, astronauts only have access to low-inclination low earth orbit (LEO) whereas most commercial spacecraft operate in other orbits inaccessible to astronauts - communications satellites mostly reside in geostationary equatorial orbit (GEO) and Earth Observation satellites generally reside in high inclination (polar) orbits. Many scientific satellites (which are not generally insured) reside in medium altitude orbits of ∼1000+ km altitude beyond reach of the Shuttle.