George Diller: Satellites play vital roles in everyday life.
From weather observations to navigation to communications, Earth-orbiting spacecraft
now are
so prevalent they could easily be taken for granted.
Since April 2011, engineers at NASA's Kennedy Space Center in Florida have partnered with
the Satellite Servicing Capabilities Office at the Goddard Space Flight Center in Maryland
to develop robotic satellite servicing technologies necessary to bring in-orbit inspection,
repair, refueling, component replacement and assembly capabilities to extend the life of
these
important spacecraft.
The orbital path of 22,000 miles above Earth is home to more than 400 satellites serving
customers worldwide, but occasionally these spacecraft fail or
simply run out of maneuvering propellant.
A team at Kennedy, collaborating with counterparts at Goddard, recently demonstrated
groundbreaking technology that could add years of service to these satellites.
Pepper Phillips: "As Kennedy has matured its expertise in servicing spacecraft and launch
vehicles, we've worked with a number of centers in servicing their particular aspect and
spacecraft."
George Diller: Engineers at Goddard want to take advantage of Kennedy's experience in
launch
vehicle and satellite processing, as well as propellant loading.
This expertise is being applied to help design refueling components
of a robotic servicing spacecraft.
Brian Nufer: "Goddard came to KSC near the end of the shuttle program so we could leverage
all of our expertise in hypergolics."
George Diller: Kennedy's know-how gained from processing and launching spacecraft
developed at other NASA centers now is allowing its employees to branch out and become a
part of the process of designing a satellite.
Pepper Phillips: "We've primarily been servicing spacecraft and vehicles using our
ground systems and doing some spacecraft repair.
For this particular aspect,
we're actually designing flight hardware."
George Diller: Over the past few years, the team at Kennedy has been developing and testing
the critical hypergolic propellant transfer system for a servicing satellite.
Thomas Aranyos: "We are actually starting a unique role which is designing,
developing and testing eventual satellite hardware that will be used in future
refueling a satellite."
George Diller: The most recent run-through took place in the Florida spaceport's
Payload Hazardous Servicing Facility, or PHSF, and focused on moving from a proof-of-concept
phase to building the first engineering development unit.
During February 2014, a flight-like prototype demonstrated that a robotically operated satellite
could remotely refuel another orbiting spacecraft not originally designed to be refueled.
Brian Nufer: "This is an extremely unique test that's never been done, as far as we
know,
anywhere in the world.
We’re testing with hypergolic oxidizer, nitrogen tetroxide.
An end-to-end system that does the servicing of a satellite in orbit."
George Diller: The demonstration was called RROxiTT for Remote Robotic Oxidizer Transfer
Test.
A Goddard-built robotic arm was shipped to Kennedy for the operation.
It has the capability to connect to a simulated satellite servicing panel, including its propellant
fill
and drain valves.
For the operation, the Kennedy team developed
the propellant transfer assembly, also called the PTA.
From 800 miles away in Maryland, Goddard engineers remotely controlled the robotic arm's
connection to the Kennedy-provided propellant transfer system and hose delivery assembly
hooking it up to the simulated client satellite's fill-drain valve,
all located in Kennedy's PHSF in Florida.
Thomas Aranyos: "This project has not only been a challenge, but it's been a lot of fun
for the entire team.
And I have to say, I've never had to ask for a volunteer for this project.”
Pepper Phillips: "KSC has largely focused on ground processing and ground ops., and
we've
earned our expertise in that area.
In this realm, it's literally spacecraft development work and it's
venturing out beyond traditionally KSC.
For our team it's expanding their capabilities.
It's making them better engineers and better scientists."