Revolutionary Robotic Refueling Experiment Opens New Research Avenues at Space Station

Astronuats Install Robotic Refueling Mission experiment during Shuttle Era's Final Spacewalk. Spacewalker Mike Fossum rides on the International Space Station's robotic arm as he carries the Robotic Refueling Mission experiment. This was the final scheduled spacewalk during a shuttle mission. Credit: NASA

NASA’s new Robotic Refueling Experiment (RRM) is a revolutionary technology demonstration device – brought aloft by the final shuttle mission – that will test out and prove whether existing Earth orbiting spacecraft that were never intended to be serviced can be successfully refueled and repaired robotically.

The RRM payload is a state of the art path finding experiment that promises to open exciting new avenues of station science research that potentially could save and extend the lifetime of orbiting commercial, government and military satellites valued at billions of dollars.

RRM was delivered to the International Space Station (ISS) by the four person crew of STS-135, the shuttles grand finale. The project is a joint effort between NASA and the Canadian Space Agency (CSA).

During the very final spacewalk of the Space Shuttle Era, RRM was temporarily installed by US astronauts Mike Fossum and Ron Garan onto a platform on the Dextre robot – the Special Purpose Dexterous Manipulator – which functions as a “handyman” in space.

Dextre is a two armed robot provided by CSA which is also a key component of the experiment because it enables the performance of repair and maintenance tasks at the heart of the RRM experiment.

RRM wire cutter experiment tool equipped with integral camera and LED lights on display at Kennedy Space Center Press Site: Credit: Ken Kremer

The washing machine sized unit weighs 500 pounds and was tucked inside the payload bay of Space Shuttle Atlantis and attached to the Lightweight Multipurpose Carrier (LMC) for the one way trip to space.

After Atlantis departs, the RRM will be transferred to a permanent attach point on the stations truss and mounted on the Exterior Logistics Carrier 4 (ELC-4) of the million pound orbiting outpost.

RRM is NASA’s first ever such technology demonstration intended to test the feasibility of on orbit servicing operations on satellites that were not built to ever be worked upon and maintained after blasting off to space, according to Justin Cassidy, RRM Hardware Manager at the NASA Goddard Spaceflight Center in Greenbelt, Maryland.

The RRM box will simulate both the satellite to be serviced and the maintenance techniques required to perform both robotic refueling and repair work.

Full size Mock up of RRM box and experiment tool at KSC Press Site
Equipment Tool movements and manipulations by Dextre robot are simulated by NASA Goddard RRM manager Justin Cassidy. Credit: Ken Kremer

“The Dextre robot will manipulate four specially designed ‘Tools’ stored in bays inside the RRM,” said Cassidy in an interview at the Kennedy Space Center.

Using a high fidelity RRM mockup on display at the Kennedy Space Center Press Site, Cassidy spoke to me in detail about the RRM mission and objectives.

The four unique RRM tools have heritage in the Hubble Servicing Missions and were developed at NASA Goddard; The Wire Cutter and Blanket Manipulation Tool, The Multifunction Tool, the Safety Cap Removal Tool, and the Nozzle Tool.

“Dextre will grapple the tools and move them around with its ‘hands’ to perform refueling and maintenance tasks on activity boards and simulated satellite components mounted on the exterior walls of the RRM,” Cassidy told me. “The activity boards can be swapped in the future to carry out new experiments.”

High Fidelity Mock up of RRM experiment box at KSC Press Site. RRM was delivered to ISS during STS-135 mission. Credit: Ken Kremer

The RRM assignment marks the first use of Dextre beyond routine maintenance chores aboard the ISS. Indeed, the research project working with RRM is actually a new R & D function beyond what was originally planned and envisioned for Dextre, said Mathieu Caron, CSA Mission Operations manager.

Tasks planned for RRM include working on and manipulating caps, valves and screws of assorted shapes and sizes, cutting wires, adjusting thermal blankets and transferring fluids around fuel reservoirs. Ethanol will be used to simulate the flow of hydrazine fuel, said Cassidy.

“RRM will be operated by controllers on the ground at NASA Goddard, the Marshall Space Flight Center in Huntsville, Ala., and also in Canada by the Canadian Space Agency,” explained Cassidy.

Each RRM tool is equipped with integral cameras housing six built in LED’s to aid ground controllers precisely guide the tools.

“The RRM experiment phase to demonstrate robotic refueling and maintenance operations at the ISS is set to last two years and could continue for perhaps ten or more years,” said Cassidy.

President Obama asked the STS-135 crew about the RRM experiment during an Oval Office phone call from the White House to the ISS. Watch Obama’s phone call on YouTube

NASA hopes that the small investment in RRM technology demonstration will pave the way for advanced follow missions and private development of commercial robotic refueling and maintenance vehicles – in the not too distant future – that will reap billions of dollars in cost savings and dividends.

Artist concept of Robotic Refueling Mission experiment and Dextre robot (right) at work testing feasibility of satellite refueling at ISS. Credit: NASA

Demonstration of wire cutter tool snipping wires and multilayer insulation (MLI). Credit: Ken Kremer

Tagged as: Robotic Refueling Mission, robotics, RRM, space shuttle atlantis, STS-135

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Where Did Early Cosmic Dust Come From? New Research Says Supernovae

This layout compares two pictures of a supernova remnant called SN 1987A -- the left image was taken by the Herschel Space Observatory, and the right is an enlarged view of the circled region at left, taken with NASA's Hubble Space Telescope. Image credit: ESA/NASA-JPL/UCL/STScI

From a JPL Press Release:

New observations from the infrared Herschel Space Observatory reveal that an exploding star expelled the equivalent of between 160,000 and 230,000 Earth masses of fresh dust. This enormous quantity suggests that exploding stars, called supernovae, are the answer to the long-standing puzzle of what supplied our early universe with dust.

“This discovery illustrates the power of tackling a problem in astronomy with different wavelengths of light,” said Paul Goldsmith, the NASA Herschel project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., who is not a part of the current study. “Herschel’s eye for longer-wavelength infrared light has given us new tools for addressing a profound cosmic mystery.”

Cosmic dust is made of various elements, such as carbon, oxygen, iron and other atoms heavier than hydrogen and helium. It is the stuff of which planets and people are made, and it is essential for star formation. Stars like our sun churn out flecks of dust as they age, spawning new generations of stars and their orbiting planets.

Astronomers have for decades wondered how dust was made in our early universe. Back then, sun-like stars had not been around long enough to produce the enormous amounts of dust observed in distant, early galaxies. Supernovae, on the other hand, are the explosions of massive stars that do not live long.

The new Herschel observations are the best evidence yet that supernovae are, in fact, the dust-making machines of the early cosmos.

This plot shows energy emitted from a supernova remnant called SN 1987A. Previously, NASA's Spitzer Space Telescope detected warm dust around the object. Image credit: ESA/NASA-JPL/UCL/STScI

“The Earth on which we stand is made almost entirely of material created inside a star,” explained the principal investigator of the survey project, Margaret Meixner of the Space Telescope Science Institute, Baltimore, Md. “Now we have a direct measurement of how supernovae enrich space with the elements that condense into the dust that is needed for stars, planets and life.”

The study, appearing in the July 8 issue of the journal Science, focused on the remains of the most recent supernova to be witnessed with the naked eye from Earth. Called SN 1987A, this remnant is the result of a stellar blast that occurred 170,000 light-years away and was seen on Earth in 1987. As the star blew up, it brightened in the night sky and then slowly faded over the following months. Because astronomers are able to witness the phases of this star’s death over time, SN 1987A is one of the most extensively studied objects in the sky.

A new view from the Hubble Space Telescope shows how supernova 1987A has recently brightened.

Initially, astronomers weren’t sure if the Herschel telescope could even see this supernova remnant. Herschel detects the longest infrared wavelengths, which means it can see very cold objects that emit very little heat, such as dust. But it so happened that SN 1987A was imaged during a Herschel survey of the object’s host galaxy — a small neighboring galaxy called the Large Magellanic Cloud (it’s called large because it’s bigger than its sister galaxy, the Small Magellanic Cloud).

After the scientists retrieved the images from space, they were surprised to see that SN 1987A was aglow with light. Careful calculations revealed that the glow was coming from enormous clouds of dust — consisting of 10,000 times more material than previous estimates. The dust is minus 429 to minus 416 degrees Fahrenheit (about minus 221 to 213 Celsius) — colder than Pluto, which is about minus 400 degrees Fahrenheit (204 degrees Celsius).

“Our Herschel discovery of dust in SN 1987A can make a significant understanding in the dust in the Large Magellanic Cloud,” said Mikako Matsuura of University College London, England, the lead author of the Science paper. “In addition to the puzzle of how dust is made in the early universe, these results give us new clues to mysteries about how the Large Magellanic Cloud and even our own Milky Way became so dusty.”

Previous studies had turned up some evidence that supernovae are capable of producing dust. For example, NASA’s Spitzer Space Telescope, which detects shorter infrared wavelengths than Herschel, found 10,000 Earth-masses worth of fresh dust around the supernova remnant called Cassiopea A. Hershel can see even colder material, and thus the coldest reservoirs of dust. “The discovery of up to 230,000 Earths worth of dust around SN 1987A is the best evidence yet that these monstrous blasts are indeed mighty dust makers,” said Eli Dwek, a co-author at NASA Goddard Space Flight Center in Greenbelt, Md.

Herschel is led by the European Space Agency with important contributions from NASA.

See also the ESA press release on this research.

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