NASA Selects Aerojet Rocketdyne to Develop Solar Electric Propulsion for Deep Space Missions

This prototype 13-kilowatt Hall thruster was tested at NASA's Glenn Research Center in Cleveland and  will be used by industry to develop high-power solar electric propulsion into a flight-qualified system.  Credits: NASA
This prototype 13-kilowatt Hall thruster was tested at NASA’s Glenn Research Center in Cleveland and will be used by industry to develop high-power solar electric propulsion into a flight-qualified system. Credits: NASA

NASA has selected Aerojet Rocketdyne to design and develop an advanced solar electric propulsion (SEP) system that will serve as a critical enabling technology for sending humans and robots on deep space exploration missions to cislunar space, asteroids and the Red Planet.

Under the 3 year, $67 million contract award, Aerojet Rocketdyne will develop the engineering development unit for an Advanced Electric Propulsion System (AEPS) with the potential for follow on flight units.

NASA hopes that the work will result in a 10 fold increase in “spaceflight transportation fuel efficiency compared to current chemical propulsion technology and more than double thrust capability compared to current electric propulsion systems.”

The SEP effort is based in part on NASA’s exploratory work on Hall ion thrusters which trap electrons in a magnetic field and uses them to ionize and accelerate the onboard xenon gas propellant to produce thrust much more efficiently than chemical thrusters.

The solar electric propulsion (SEP) system technology will afford benefits both to America’s commercial space and scientific space exploration capabilities.

For NASA, the SEP technology can be applied for expeditions to deep space such as NASA’s planned Asteroid Robotic Redirect Mission (ARRM) to snatch a boulder from the surface of an asteroid and return it to cislunar space during the 2020s, as well as to carry out the agency’s ambitious plans to send humans on a ‘Journey to Mars’ during the 2030s.

“High power SEP is a perfect example of NASA developing cross cutting technologies to enable both human and robotic deep space missions. Basically it enables high efficiency and better gas mileage,” said Steve Jurczyk, associate administrator of NASA’s Space Technology Mission Directorate (STMD) in Washington, at a media briefing.

“The advantage here is the higher power and the higher thrust.”

“Our plan right now is to flight test the higher power solar electric propulsion that Aerojet Rocketdyne will develop for us on the Asteroid Redirect Robotic Mission (ARRM), which is going to go out to an asteroid with a robotic system, grab a boulder off of an asteroid, and bring it back to a lunar orbit.”

ARRM would launch around 2020 or 2021. Astronauts would blast off several years later in NASA’s Orion crew capsule in 2025 after the robotic probes travels back to lunar orbit.

For industry, electric propulsion is used increasingly to maneuver thrusters in Earth orbiting commercial satellites for station keeping in place of fuel.

“Through this contract, NASA will be developing advanced electric propulsion elements for initial spaceflight applications, which will pave the way for an advanced solar electric propulsion demonstration mission by the end of the decade,” says Jurczyk.

“Development of this technology will advance our future in-space transportation capability for a variety of NASA deep space human and robotic exploration missions, as well as private commercial space missions.”

This 13-kilowatt Hall thruster is being evaluated at NASA’s Glenn Research Center in Cleveland for advanced solar electric propulsion.  Hall thrusters trap electrons in a magnetic field and use them to ionize the onboard propellant. Credits: NASA
This 13-kilowatt Hall thruster is being evaluated at NASA’s Glenn Research Center in Cleveland for advanced solar electric propulsion. Hall thrusters trap electrons in a magnetic field and use them to ionize the onboard propellant. Credits: NASA

“This is also a critical capability for enabling human missions to Mars, with respect to delivering cargo to the surface to Mars that will allow people to live and work there on the surface. Also for combined chemical and SEP systems on a spacecraft to propel humans to Mars,” elaborated Jurczyk at the briefing.

“Another application is round trip robotic science missions to Mars to bring back samples – such as a Mars Sample Return (MSR) mission.”

The starting point is NASA’s development and technology readiness testing of a prototype 13-kilowatt Hall thruster and power processing unit at NASA’s Glenn Research Center in Cleveland.

Under the contract award Aerojet Rocketdyne aims to carry out the industrial development of “high-power solar electric propulsion into a flight-qualified system.”

They will develop, build, test and deliver “an integrated electric propulsion system consisting of a thruster, power processing unit (PPU), low-pressure xenon flow controller, and electrical harness,” as an engineering development unit.

This engineering development unit serves as the basis for producing commercial flight units.

If successful, NASA has an option to purchase up to four integrated flight units for actual space missions. Engineers from NASA Glenn and the Jet Propulsion Laboratory (JPL) will provide technical support.

“We could string together four of these engine units to get approximately 50 kilowatts of electrical propulsion capability and with that we can do significant orbital transfer operations. That then becomes the next step in deep space exploration operations that we are trying to do,” said Bryan Smith, director of the Space Flight Systems Directorate at NASA’s Glenn Research Center in Cleveland, at the media briefing.

“We hope to buy four of these units for the ARRM mission.”

What were some of NASA’s research and development (R&D) activities and further plans for Aerojet Rocketdyne?

“NASA is driving out the technology itself for feasibility. So we produced a developmental device to operate at these levels,” Smith told Universe Today during the briefing.

“Other key characteristics we were looking for is the ability to do magnetic shielding. The purpose was to allow for a long life thruster operation. We investigated attributes like thermal problems and balancing the erosion mechanisms in developmental units. So we were looking for things to get longer life and feasibility in developmental units.”

“Once we were comfortable with the feasibility in developmental units, we are now transferring the information, technology and knowhow into what is a production article, in this contract.”

Robotic sampling arm and capture mechanism to collect a multi-ton boulder from an asteroid are under development at NASA Goddard and other agency centers for NASA’s unmanned Asteroid Redirect Vehicle and eventual docking in lunar orbit with Orion crew vehicle by the mid 2020s.   Credit: Ken Kremer/kenkremer.com
Robotic sampling arm and capture mechanism to collect a multi-ton boulder from an asteroid are under development at NASA Goddard and other agency centers for NASA’s unmanned Asteroid Redirect Vehicle and eventual docking in lunar orbit with Orion crew vehicle by the mid 2020s. Credit: Ken Kremer/kenkremer.com

Solar electric ion propulsion is already being used in NASA’s hugely successful Dawn asteroid orbiter mission.

Dawn was launched in 2007. It orbited and surveyed Vesta in 2011 and 2012 and then traveled outward to Ceres.

Dawn arrived at dwarf planet Ceres in March 2015 and is currently conducting breakthrough science at its lowest planned science mapping orbit.

This image was taken by NASA's Dawn spacecraft of dwarf planet Ceres on Feb. 19 from a distance of nearly 29,000 miles (46,000 km). It shows that the brightest spot on Ceres has a dimmer companion, which apparently lies in the same basin. See below for the wide view. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
This image was taken by NASA’s Dawn spacecraft of dwarf planet Ceres on Feb. 19 from a distance of nearly 29,000 miles (46,000 km). It shows that the brightest spot on Ceres has a dimmer companion, which apparently lies in the same basin. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

A key part of the Journey to Mars, NASA will be sending cargo missions to the Red Planet to pave the way for human expeditions with the Orion crew module and Space Launch System.

Aerojet Rocketdyne states that “Solar Electric Propulsion (SEP) systems have demonstrated the ability to reduce the mission cost for NASA Human Exploration cargo missions by more than 50 percent through the use of existing flight-proven SEP systems.”

“Using a SEP tug for cargo delivery, combined with NASA’s Space Launch System and the Orion crew module, provides an affordable path for deep space exploration,” said Aerojet Rocketdyne Vice President, Space and Launch Systems, Julie Van Kleeck.

Aerojet Rocketdyne artists concept for solar electric propulsion system for deep space missions. Credit: Aerojet Rocketdyne
Aerojet Rocketdyne artists concept for solar electric propulsion system for deep space missions. Credit: Aerojet Rocketdyne

Another near term application of high power solar electric propulsion could be for NASA’s proposed Mars 2022 telecom orbiter, said Smith at the media briefing.

Other NASA technology work in progress includes development of more efficient, advanced solar array systems to generate the additional power required for the larger electric thrusters.

Orbital ATK was part of the development effort and already used some of its technology development in the ultraflex solar arrays on the recent Cygnus cargo ships delivering supplies to the ISS.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

NASA Completes Welding on Lunar Orion EM-1 Pressure Vessel Launching in 2018

Welding together of Orion EM-1 pressure vessel was completed on Jan. 13, 2016 at NASA’s Michoud Assembly Facility in New Orleans. The pressure vessel is the primary structure of the Orion spacecraft destined for human missions to deep space and Mars.  Credits: NASA
Welding together of Orion EM-1 pressure vessel was completed on Jan. 13, 2016 at NASA’s Michoud Assembly Facility in New Orleans. The pressure vessel is the primary structure of the Orion spacecraft destined for human missions to deep space and Mars. Credits: NASA

In a major step towards flight, engineers at NASA’s Michoud Assembly Facility in New Orleans have finished welding together the pressure vessel for the first Lunar Orion crew module that will blastoff in 2018 atop the agency’s Space Launch System (SLS) rocket.

This Orion is going to the Moon and back.

The 2018 launch of NASA’s Orion on an unpiloted flight dubbed Exploration Mission, or EM-1, counts as the first joint flight of SLS and Orion, and the first flight of a human rated spacecraft to deep space since the Apollo Moon landing era ended more than 4 decades ago. Continue reading “NASA Completes Welding on Lunar Orion EM-1 Pressure Vessel Launching in 2018”

US Heavy Lift Mars Rocket Passes Key Review and NASA Sets 2018 Maiden Launch Date

Artist concept of NASA’s Space Launch System (SLS) 70-metric-ton configuration launching to space. SLS will be the most powerful rocket ever built for deep space missions, including to an asteroid and ultimately to Mars. Credit: NASA/MSFC
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After a thorough review of cost and engineering issues, NASA managers formally approved the development of the agency’s mammoth heavy lift rocket – the Space Launch System or SLS – which will be the world’s most powerful rocket ever built and is intended to take astronauts farther beyond Earth into deep space than ever before possible – to Asteroids and Mars.

The maiden test launch of the SLS is targeted for November 2018 and will be configured in its initial 70-metric-ton (77-ton) version, top NASA officials announced at a briefing for reporters on Aug. 27.

On its first flight known as EM-1, the SLS will also loft an uncrewed Orion spacecraft on an approximately three week long test flight taking it beyond the Moon to a distant retrograde orbit, said William Gerstenmaier, associate administrator for the Human Explorations and Operations Mission Directorate at NASA Headquarters in Washington, at the briefing.

Previously NASA had been targeting Dec. 2017 for the inaugural launch from the Kennedy Space Center in Florida – a slip of nearly one year.

But the new Nov. 2018 target date is what resulted from the rigorous assessment of the technical, cost and scheduling issues.

This artist concept shows NASA’s Space Launch System, or SLS, rolling to a launch pad at Kennedy Space Center at night. SLS will be the most powerful rocket in history, and the flexible, evolvable design of this advanced, heavy-lift launch vehicle will meet a variety of crew and cargo mission needs.   Credit:  NASA/MSFC
This artist concept shows NASA’s Space Launch System, or SLS, rolling to a launch pad at Kennedy Space Center at night. SLS will be the most powerful rocket in history, and the flexible, evolvable design of this advanced, heavy-lift launch vehicle will meet a variety of crew and cargo mission needs. Credit: NASA/MSFC

The decision to move forward with the SLS comes after a wide ranging review of the technical risks, costs, schedules and timing known as Key Decision Point C (KDP-C), said Associate Administrator Robert Lightfoot, at the briefing. Lightfoot oversaw the review process.

“After rigorous review, we’re committing today to a funding level and readiness date that will keep us on track to sending humans to Mars in the 2030s – and we’re going to stand behind that commitment,” said Lightfoot. “Our nation is embarked on an ambitious space exploration program.”

“We are making excellent progress on SLS designed for missions beyond low Earth orbit,” Lightfoot said. “We owe it to the American taxpayers to get it right.”

He said that the development cost baseline for the 70-metric ton version of the SLS was $7.021 billion starting from February 2014 and continuing through the first launch set for no later than November 2018.

Lightfoot emphasized that NASA is also building an evolvable family of vehicles that will increase the lift to an unprecedented lift capability of 130 metric tons (143 tons), which will eventually enable the deep space human missions farther out than ever before into our solar system, leading one day to Mars.

“It’s also important to remember that we’re building a series of launch vehicles here, not just one,” Lightfoot said.

Blastoff of NASA’s Space Launch System (SLS) rocket and Orion crew vehicle from the Kennedy Space Center, Florida.   Credit: NASA/MSFC
Blastoff of NASA’s Space Launch System (SLS) rocket and Orion crew vehicle from the Kennedy Space Center, Florida. Credit: NASA/MSFC

Lightfoot and Gerstenmaier both indicated that NASA hopes to launch sooner, perhaps by early 2018.

“We will keep the teams working toward a more ambitious readiness date, but will be ready no later than November 2018,” said Lightfoot.

The next step is conduct the same type of formal KDP-C reviews for the Orion crew vehicle and Ground Systems Development and Operations programs.

The first piece of SLS flight hardware already built and to be tested in flight is the stage adapter that will fly on the maiden launch of Orion this December atop a ULA Delta IV Heavy booster during the EFT-1 mission.

The initial 70-metric-ton (77-ton) version of the SLS stands 322 feet tall and provides 8.4 million pounds of thrust. That’s already 10 percent more thrust at launch than the Saturn V rocket that launched NASA’s Apollo moon landing missions, including Apollo 11, and it can carry more than three times the payload of the now retired space shuttle orbiters.

The core stage towers over 212 feet (64.6 meters) tall with a diameter of 27.6 feet (8.4 m) and stores cryogenic liquid hydrogen and liquid oxygen. Boeing is the prime contractor for the SLS core stage.

The first stage propulsion is powered by four RS-25 space shuttle main engines and a pair of enhanced five segment solid rocket boosters (SRBs) also derived from the shuttles four segment boosters.

The pressure vessels for the Orion crew capsule, including EM-1 and EFT-1, are also being manufactured at MAF. And all of the External Tanks for the space shuttles were also fabricated at MAF.

The airframe structure for the first Dream Chaser astronaut taxi to low Earth orbit is likewise under construction at MAF as part of NASA’s commercial crew program.

The first crewed flight of the SLS is set for the second launch on the EM-2 mission around the 2020/2021 time frame, which may visit a captured near Earth asteroid.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

See This Orange Smudge? This Could Be NASA’s Target For The Asteroid Mission

In the center of the image above is an orange smudge. It may not look like much to the untrained eye, but to NASA it represents potential. It’s a candidate asteroid target for a mission the agency badly wants to happen, even though nobody knows for sure yet if things will line up for humans to visit there one day.

This is a picture of asteroid 2011 MD taken by NASA’s Spitzer Space Telescope. It’s about 6 meters (20 feet) across and appears to have a low density, the agency said in a statement. While NASA is still looking for other candidates for its asteroid initiative, the agency added this would be the sort of asteroid it’s looking to visit.

“The asteroid appears to have a structure perhaps resembling a pile of rocks, or a ‘rubble pile.’Since solid rock is about three times as dense as water, this suggests about two-thirds of the asteroid must be empty space,” NASA stated in this press release.

“The research team behind the observation says the asteroid could be a collection of small rocks, held loosely together by gravity, or it may be one solid rock with a surrounding halo of small particles.”

Artist's conception of the structure around 2011 MD, a candidate asteroid for NASA's proposed asteroid redirect mission. Credit: NASA/JPL-Caltech
Artist’s conception of the structure around 2011 MD, a candidate asteroid for NASA’s proposed asteroid redirect mission. Credit: NASA/JPL-Caltech

You can read more about this asteroid in Astrophysical Journal Letters. There was another study done on 2011 MD earlier this year that was also in ApJL, or in preprint version in Arxiv.

Announcing this asteroid candidate was just one of several things NASA made public today. It added that it plans to send off an ARM (Asteroid Redirect Mission) robotic spacecraft in 2019, and about one year before that it will decide which asteroid to send this spacecraft to.

NASA has two concept ideas for ARM, and it’s planning to award $4.9 million (it had initially planned for up to $6 million) for others to make more detailed investigations into which is the more feasible. Read the full list of recipients at this NASA website.

One idea is to pick up a small asteroid, and the other is to carve off a small portion of a bigger asteroid. Whatever the choice, it would involve coming up with an object that is less than 32 feet (10 meters) across to move to the moon’s orbit. NASA will decide what to do later this year.

“The studies will be completed over a six-month period beginning in July, during which time system concepts and key technologies needed for ARM will be refined and matured. The studies also will include an assessment of the feasibility of potential commercial partners to support the robotic mission,” NASA stated.

An astronaut retrieves a sample from an asteroid in this artist's conception. Credit: NASA
An astronaut retrieves a sample from an asteroid in this artist’s conception. Credit: NASA

Also, some more details about other candidates: NASA has found nine so far that it deems suitable, and size estimates have been made on three of those nine candidates. A fourth, 2008 HU4, will be close to Earth in 2016 and allow for “interplanetary radar” to learn more about its size and rotation, NASA said. The other ones will not get close enough to Earth for a better look before the mission selection is done.

NASA added that it expects to add more through its Near-Earth Object program, as one to two asteroids get close enough to our planet every year for analysis. Further, the agency hopes to learn more about asteroid makeup through its planned Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer (OSIRIS-REx) mission, which is on its way to asteroid Bennu in 2018 after a launch in 2016.

All of this, of course, is dependent on NASA’s budgetary situation for the years to come, which in turn depends on support in Congress.