Benjamin Reed

3) I fell into this job after working for 10 years as a materials engineer for the American Dental Association. Not the typical route for my colleagues.

Actually, I never followed space closely until after I took the job with NASA. Since then, it's all I can think about. I am a Hubble Hugger and a workaholic, and love every minute of it. My first twelve years at NASA were as the lead materials engineer for the Hubble Space Telescope Servicing Missions.

Robotic satellite servicing technologies could help to extend the lifespan of satellites that provide us with services that we use every day - weather reports, cell phone service, broadband internet, search and rescue at sea, direct broadcast tv, GPS, etc. Through the prolonged use of existing assets, these things may be more reliable and less costly for the end user.

1) Robots have been used by NASA with nearly every shuttle mission, with the International Space Station, and with rovers on Mars. This rich and diverse use of technology will continue. The intent of the Robotic Refueling Mission is to show that present-day robotic technology could be used to service satellites that were not designed to be repaired or refueled. This is important because all but two (ISS and the Hubble Space Telescope) of the 1,000 satellites in orbit right now were not designed to be serviced. More to come on other questions...

4) I would rather fight a single ISS-sized robot because it would move incredibly slowly, being that massive. The inertial properties of translating a mass of that magnitude would restrict it from rapid movement - assuming present-day technology.

And yes, we do debate this often...

Fantastic! We are always look for bright, hard-working folk. By all means, please have him apply here, as Goddard is the world's leading institution for astrophysics, heliophysics, and Earth Science (besides robotics). With 300 successful missions under its belt, Goddard is continuing its rich legacy.

More information on Goddard internships at: http://www.nasa.gov/centers/goddard/education/internships.html.

Liquid ethanol. It was chosen because it has nearly identical viscosity to hydrazine (a common satellite propellent).

For this audience only: it's actually 90% ethanol, 5% methanol, and 5% isopropanol.

2) Propellant systems inside satellites are under non-trivial pressure (250 psi). To be able to "crack into" one of these systems, give it more liquid propellant, and reseal it safely - while traveling in the harsh environment of space - led to some unique challenges for the engineers on my team. Many other challenges in other areas, but this is one example of why it's hard to refuel in space.

RRM on space station is doing a set of practice runs, at reduced pressure (50 psi). We're also using specialized tools to snip tiny wires, remove recalcitrant caps, etc. - the steps you'd need to to refuel a triple-sealed satellite. Some detail on these steps are at http://ssco.gsfc.nasa.gov/.

Your artwork has left me speechless - in a good way. Great rendition of RRM! Mind if we share?

On a real servicing mission, the robot would be able to perform a wide variety of servicing tasks via a quick-change-out tool drive system. I.e., one tool drive that could pick up a dozen or more tools.

For example, on RRM - on orbit right now - we have four tools that interface with six adapters, all of which are picked up by one robot, the Canadian Space Agency's Dextre.

There are additional tasks that we'll be executing on the RRM module later this year. They include cutting thermal blanket tape, removing small fasteners and electrical termination caps. Subsequently, we are going to launch additional "task boards" which will be mounted to the RRM module so we can practice more tasks on orbit. Ground simulations of space operations are only so good - sometimes you need to practice in orbit.