Since December of 2017, NASA has been working towards the goal of sending “the next man and first woman” to the Moon by 2024, which will be the first crewed lunar mission since the Apollo Program. As part of this mission, known as Project Artemis, NASA has been developing both the Space Launch System (SLS) and the Orion spacecraft, which will allow the astronauts to make the journey.
Originally, it was hoped that the first uncrewed flight of the SLS and Orion (Artemis I) would take place later this year. But according to recent statements by Associate Administrator Steve Jurczyk, this inaugural launch will most likely take place “mid to late” in 2021. This is the latest in a series of delays for the high-profile project, which has been making impressive progress nevertheless.
On March 26th, 2019, during the fifth meeting of the reestablished National Space Council, Vice President Mike Pence challenged NASA to land astronauts on the Moon within the next five years. This represented an order to expedite Space Policy Directive-1 signed by President Trump on December 11th, 2017, which directed NASA to take all the necessary steps to send astronauts back to the Moon.
This announcement suggested that some shake-up might be taking place within the agency to make things happen. However, it appears that this now involves the demotion of two longtime NASA heads who have dedicated much of their lives to the advancement of human space exploration. Whether or not this decision came from the White House is unclear, but it is in keeping with the direction recently issued by VP Pence.
A dramatic week in space launcher politics has left NASA’s Space Launch System (SLS) with a vastly reduced launch manifesto and casts doubt on the prospects of future upgrades to the massive launch vehicle.
On Monday the White House’s budget request laid out the administration’s plans for NASA’s coming years. For SLS there were three significant changes.
As rockets become more and more powerful, the systems that protect them need to keep pace. NASA will use almost half a million gallons of water to keep the Space Launch System (SLS) safe and stable enough to launch successfully. The system that delivers all that water is called the Ignition Overpressure Protection and Sound Suppression (IOP/SS) water deluge system, and seeing it in action is very impressive.
In the coming decades, NASA intends to mount some bold missions to space. In addition to some key operations to Low Earth Orbit (LEO), NASA intends to conduct the first crewed missions beyond Earth in over 40 years. These include sending astronauts back to the Moon and eventually mounting a crewed mission to Mars.
To this end, NASA recently submitted a plan to Congress that calls for human and robotic exploration missions to expand the frontiers of humanity’s knowledge of Earth, the Moon, Mars, and the Solar System. Known as the National Space Exploration Campaign, this roadmap outlines a sustainable plan for the future of space exploration.
When it comes to the next generation of space exploration, a number of key technologies are being investigated. In addition to spacecraft and launchers that will be able to send astronauts farther into the Solar System, NASA and other space agencies are also looking into new means of propulsion. Compared to conventional rockets, the goal is to create systems that offer reliable thrust while ensuring fuel-efficiency. Continue reading “Aerojet Rocketdyne Tests Out its New Advanced Ion Engine System”
In recent years, NASA has been busy developing the technology and components that will allow astronauts to return to the Moon and conduct the first crewed mission to Mars. These include the Space Launch System (SLS), which will be the most powerful rocket since the Saturn V (which brought the Apollo astronauts to the Moon), and the Orion Multi-Purpose Crew Vehicle (MPCV).
Elon Musk has a reputation for pushing the envelop and making bold declarations. In 2002, he founded SpaceX with the intention of making spaceflight affordable through entirely reusable rockets. In April of 2014, his company achieved success with the first successful recovery of a Falcon 9 first stage. And in February of this year, his company successfully launched its Falcon Heavy and managed to recover two of the three boosters.
But above and beyond Musk’s commitment to reusability, there is also his longer-term plans to use his proposed Big Falcon Rocket (BFR) to explore and colonize Mars. The topic of when this rocket will be ready to conduct launches was the subject of a recent interview between Musk and famed director Jonathon Nolan, which took place at the 2018 South by Southwest Conference (SXSW) in Austin, Texas.
During the interview, Musk reiterated his earlier statements that test flights would begin in 2019 and an orbital launch of the full BFR and Big Falcon Spaceship (BFS) would take place by 2020. And while this might seem like a very optimistic prediction (something Musk is famous for), this timeline does not seem entirely implausible given his company’s work on the necessary components and their success with reusability.
As Musk emphasized during the course of the interview:
“People have told me that my timelines have historically been optimistic. So I am trying to re-calibrate to some degree here. But I can tell what I know currently is the case is that we are building the first ship, the first Mars or interplanetary ship, right now, and I think we’ll probably be able to do short flights, short sort of up-and-down flights probably in the first half of next year.”
To break it down, the BFR – formerly known as the Interplanetary Transport System – consists of a massive first stage booster and an equally massive second stage/spaceship (the BFS). Once the spacecraft is launched, the second stage would detach and use its thrusters to assume a parking orbit around Earth. The first stage would then guide itself back to its launchpad, take on a propellant tanker, and return to orbit.
The propellant tanker would then attach to the BFS and refuel it and return to Earth with the first stage. The BFS would then fire its thrusters again and make the journey to Mars with its payload and crew. While much of the technology and concepts have been tested and developed through the Falcon 9 and Falcon Heavy, the BFR is distinct from anything else SpaceX has built in a number of ways.
For one, it will be much larger (hence the nickname, Big F—— Rocket), have significantly more thrust, and be able carry a much larger payload. The BFR’s specifications were the subject of a presentation Musk made at the 68th International Astronautical Congress on September 28th, 2017, in Adelaide, Australia. Titled “Making Life Interplanetary“, his presentation outlined his vision for colonizing Mars and presented an overview of the ship that would make it happen.
According to Musk, the BFR will measure 106 meters (348 ft) in height and 9 meters (30 ft) in diameter. It will carry 110 tons (~99,700 kg) of propellant and will have an ascent mass of 150 tons (~136,000 kg) and a return mass of 50 tons (~45,300 kg). All told, it will be able to deliver a payload of 150,000 kg (330,000 lb) to Low-Earth Orbit (LEO) – almost two and a half times the payload of the Falcon Heavy (63,800 kg; 140,660 lb)
“This a very big booster and ship,” said Musk. “The liftoff thrust of this would be about twice that of a Saturn V (the rockets that sent the Apollo astronauts to the Moon). So it’s capable of doing 150 metric tons to orbit and be fully reusable. So the expendable payload is about double that number.”
In addition, the BFR uses a new type of propellant and tanker system in order to refuel the spacecraft once its in orbit. This goes beyond what SpaceX is used to, but the company’s history of retrieving rockets and reusing them means the technical challenges this poses are not entirely new. By far, the greatest challenges will be those of cost and safety, since this will be only the third reusable second stage spacecraft in history.
The other two consist of the NASA Space Shuttles, which were officially retired in 2011, and the Soviet/Russian version of the Space Shuttle known as the Buran spacecraft. While the Buran only flew once (an uncrewed flight that took place in 1988), it remains the only Russian reusable spacecraft to have even been built or flown.
Where costs are concerned, the Space Shuttle Program provides a pretty good glimpse into what Musk and his company will be facing in the years ahead. According to estimates compiled in 2010 (shortly before the Space Shuttle was retired), the program cost a total of about $ 210 billion USD. Much of these costs were due to maintenance between launches and the costs of propellant, which will need to be kept low for the BFR to be economically viable.
Addressing the question of costs, Musk once again stressed how reusability will be key:
“What’s amazing about this ship, assuming we can make full and rapid reusability work, is that we can reduce the marginal cost per flight dramatically, by orders of magnitude compared to where it is today. This question of reusability is so fundamental to rocketry, it is the fundamental breakthrough that’s needed.”
As an example, Musk compared the cost of renting a 747 with full cargo (about $500,000) and flying from California to Australia to buying a single engine turboprop plane, – which would run about $1.5 million and cannot even reach Australia. In short, the BFR relies on the principle that it costs less for an entirely reusable large spaceship to make a long trip that it does to launch a single rocket on a short trip that would never return.
“A BFR flight will actually cost less than our Falcon 1 flight did,” he said. “That was about a 5 or 6 million dollar marginal cost per flight. We’re confident the BFR will be less than that. That’s profound, and that is what will enable the integration of a permanent base on the Moon and a city on Mars. And that’s the equivalent of like the Union Pacific Railroad, or having ships that can quickly cross the oceans.”
Artist concept of NASA’s Space Launch System (SLS) on the left, and the Orion Multi-Purpose Crew Vehicle (right). Credit: NASA
Beyond manufacturing and refurbishing costs, the BFR will also need to have an impeccable safety record if SpaceX is to have a hope of making money from it. In this respect, SpaceX hopes to follow a development process similar to what they did with the Falcon 9. Before conducting full launch tests to see if the first stage of the rocket could safely make it to orbit and then be retrieved, the company conducted short hop tests using their “Grasshopper” rocket.
According to the timeline Musk offered at the 2018 SXSW, the company will be using the spaceship that is currently being built to conduct suborbital tests as soon as 2019. Orbital launches, which may include both the booster and the spaceship, are expected to occur by 2020. At present, Musk’s earlier statements that the first flight of the BFR would take place by 2022 and the first crewed flight by 2024 still appear to be on.
For comparison, the Space Launch System (SLS) – which is NASA’s proposed means of getting to Mars – is scheduled to conduct its first launch in 2019 as well. Known as Exploration Mission 1 (EM-1), this launch will involve sending an uncrewed Orion capsule on a trip around the Moon. EM-2, in which a crewed Orion capsule will delver the first module of the Lunar Orbital Platform-Gateway (LOP-G, formerly the Deep Space Gateway) to lunar orbit, will take place in 2022.
The ensuing missions will consist of more modules being delivered to lunar orbit to complete construction of the LOP-G, as well as the Deep Space Transport (DST). The first interplanetary trip to Mars, Exploration Mission 11 (EM-11), won’t to take place until 2033. So if Musk’s timelines are to be believed, SpaceX will be beating NASA to Mars, both in terms of uncrewed and crewed missions.
As for who will be enabling a permanent stay on both the Moon and Mars, that remains to be seen. And as Musk emphasized, he hopes that by showing that creating an interplanetary spaceship is possible, agencies and organizations all over the planet will mobilize to do the same. For all we know, the creation of the BFR could enable the creation of an entire fleet of Interplanetary Transport Systems.
The South by Southwest Conference began on Friday, March 9th and will continue until Sunday, March 18th. And be sure to check out the video of the interview below:
NASA is in an awkward in-between time right now. Since the beginning of the space age, the agency has had the ability to send its astronauts into space. The first American to go to space, Alan Shepard, did a suborbital launch on board a Mercury Redstone rocket in 1961.
Then the rest of the Mercury astronauts went on Atlas rockets, and then the Gemini astronauts flew on various Titan rockets. NASA’s ability to hurl people and their equipment into space took a quantum leap with the enormous Saturn V rocket used in the Apollo program.
It’s difficult to properly comprehend just how powerful the Saturn V was, so I’ll give you some examples of things this monster could launch. A single Saturn V could blast 122,000 kilograms or 269,000 pounds into low-Earth orbit, or send 49,000 kilograms or 107,000 pounds on a transfer orbit to the Moon.
Instead of continuing on with the Saturn program, NASA decided to shift gears and build the mostly reusable space shuttle. Although it was shorter than the Saturn V, the space shuttle with its twin external solid rocket boosters could put 27,500 kilograms or 60,000 pounds into Low Earth orbit. Not too bad.
And then, in 2011, the space shuttle program wrapped up. And with it, the United States’ ability to launch humans into the space. And most importantly, to send astronauts to the continuously inhabited International Space Station. That task has fallen to Russian rockets until the US builds back the capability for human spaceflight.
Space Shuttle Columbia launching on its maiden voyage on April 12th, 1981. Credit: NASA
Since the cancellation of the shuttle, NASA’s workforce of engineers and rocket scientists has been developing the next heavy lift vehicle in NASA’s line up: the Space Launch System.
The SLS looks like a cross between a Saturn V and the space shuttle. It has the same familiar solid rocket boosters, but instead of the space shuttle orbiter and its orange external fuel tank, the SLS has the central Core Stage. It has 4 of the space shuttle’s RS-25 Liquid Oxygen engines.
Although two shuttle orbiters were lost in disasters, these engines and their liquid oxygen and liquid hydrogen performed perfectly for 135 flights. NASA knows how to use them, and how to use them safely.
The very first configuration of the SLS, known as the Block 1, should have the ability to put about 70 metric tonnes into Low Earth Orbit. And that’s just the beginning, and it’s just an estimate. Over time, NASA will increase its capabilities and launch power to match more and more ambitious missions and destinations. With more launches, they’ll get a better sense of what this thing is capable of.
After the Block 1 is launching, NASA will develop the Block 1b, which puts a much larger upper stage on top of the same core stage. This upper stage will have a larger fairing and more powerful second stage engines, capable of putting 97.5 metric tonnes into low Earth orbit.
Graphic shows all the dome, barrel, ring and engine components used to assemble the five major structures of the core stage of NASA’s Space Launch System (SLS) in Block 1 configuration. Credits: NASA/MSFC
Finally, there’s the Block 2, with an even larger launch fairing, and more powerful upper stage. It should blast 143 tonnes into low Earth orbit. Probably. NASA is developing this version as a 130 tonne-class rocket.
With this much launch capacity, what could be done with it? What kinds of missions become possible on a rocket this powerful?
The main goal for SLS is to send humans out, beyond low Earth orbit. Ideally to Mars in the 2030s, but it could also go to asteroids, the Moon, whatever you like. And as you’ll read later on in this article, it could send some amazing scientific missions out there too.
The very first flight for SLS, called Exploration Mission 1, will be to put the new Orion crew module into a trajectory that takes it around the Moon. In a very similar flight to Apollo 8. But there won’t be any humans, just the unmanned Orion module and a bunch of cubesats coming along for the ride. Orion will spend about 3 weeks in space, including about 6 days in a retrograde orbit around the Moon.
NASA’s Orion spacecraft. Credit: NASA
If all goes well, the first use of the SLS with the Orion crew module will happen some time in 2019. But also, don’t be surprised if it gets pushed back, that’s the name of the game.
After Exploration Mission 1, there’s be EM-2, which should happen a few years after that. This’ll be the first time humans get into an Orion crew module and take a flight to space. They’ll spend 21 days in a lunar orbit, and deliver the first component of the future Deep Space Gateway, which will be the subject of a future article.
From there, the future is unclear, but SLS will provide the capability to put various habitats and space stations into cislunar space, opening up the future of human space exploration of the Solar System.
Now you know where SLS is probably headed. But the key to this hardware is that it gives NASA raw capability to put humans and robots into space. Not just here on Earth, but way across the Solar System. New space telescopes, robotic explorers, rovers, orbiters and even human habitats.
In a recent study called “The Space Launch System Capabilities for Beyond Earth Missions,” a team of engineers mapped out what the SLS should be capable of putting into the Solar System.
For example, Saturn is a difficult planet to reach, and it order to get there, NASA’s Cassini spacecraft needed to do several gravitational slingshots around Earth and one past Jupiter. It took almost 7 years to get to Saturn.
SLS could send missions to Saturn on more direct trajectory, cutting the flight time down to just 4 years. Block 1 could send 2.7 tonnes to Saturn, while Block 1b could loft 5.1 tonnes.
An artist’s interpretation of NASA’s Space Launch System Block 1 configuration with an Orion vehicle. Image: NASA
NASA is considering a mission to Jupiter’s Trojan asteroids. These are a collection of space rocks trapped in Jupiter’s L4/L5 Lagrange points, and could be a fascinating place to study. Once put into the Trojan region, a mission could visit several different asteroids, sampling a vast range of rocks that detail the Solar System’s early history.
The Block 1 could put almost 3.97 tonnes into these orbits, while the Block 1b could do 7.59 tonnes. That’s 6 times the capability of an Atlas V. A mission like this would have a cruise time of 10 years.
In a previous video, we talked about future Uranus and Neptune missions, and how a single SLS could send spacecraft to both planets simultaneously.
Another idea that I really like is an inflatable habitat from Bigelow Aerospace. The BA-2100 module would be a fully self-contained space habitat. No need for other modules, this monster would be 65 to 100 tonnes, and would go up in a single launch of SLS. Once inflated, it would contain 2,250 cubic meters, which is almost 3 times the total living space of the International Space Station.
One of the most exciting missions, to me, is a next generation space telescope. Something that would be the true spiritual successor to the Hubble Space Telescope. There are a few proposals in the works right now, but the idea I like best is the LUVOIR telescope, which would have a mirror that measures 16 meters across.
The SLS Block 1b could put 36.9 tonnes into Sun-Earth Lagrange Point 2. Really there’s nothing else out there that could put this much mass into that orbit.
Just for comparison, Hubble has a mirror of 2.4 meters across, and James Webb is 6.5. With LUVOIR, you would have 10 times more resolution than James Webb, and 300 times more power than Hubble. But like Hubble, it would be capable of seeing the Universe in visible and other wavelengths.
A telescope like this could directly image the event horizons of supermassive black holes, see right to the edge of the observable Universe and watch the first galaxies forming their first stars. It could directly observe planets orbiting other stars and help us determine if they have life on them.
An artist’s illustration of a 16 meter segmented mirror space telescope. There are no actual images of LUVOIR because the design hasn’t been finalized yet. Image: Northrop Grumman Aerospace Systems & NASA/STScI
Seriously, I want this telescope.
At this point, I know this is going to set off a big argument about NASA versus SpaceX versus other private launch providers. That’s fine, I get it. And the Falcon Heavy is expected to launch later this year, bringing heavy lift launch capabilities at an affordable price. It’ll be able to loft 54,000 kilograms, which is less than the SLS Block 1, and almost a third of the capability of the Block 2. Blue Origins has its New Glenn, there are heavier rockets in the works from United Launch Alliance, Arianespace, the Russian Space Agency, and even the Chinese. The future of heavy lift has never been more exciting.
If SpaceX does get the Interplanetary Transport Ship going, with 300 tonnes into orbit on a reusable rocket. Well then, everything changes. Everything.
Vice President Mike Pence (holding Orion model) receives up close tour of NASA’s Orion EM-1 deep space crew capsule (at right) being manufactured for 1st integrated flight with NASA’s SLS megarocket in 2019; with briefing from KSC Director/astronaut Robert D. Cabana during his July 6, tour of NASA’s Kennedy Space Center – along with acting NASA Administrator Robert M. Lightfoot, Jr., Senator Marco Rubio and Lockheed Martin CEO Marillyn Hewson inside the Neil Armstrong Operations and Checkout Building at KSC. Credit: Ken Kremer/kenkremer.com
KENNEDY SPACE CENTER, FL – Vice President Mike Pence, during a whirlwind visit to NASA’s Kennedy Space Center in Florida, vowed that America would fortify our leadership in space under the Trump Administration with impressive goals by forcefully stating that “our nation will return to the moon, and we will put American boots on the face of Mars.”
“American will once again lead in space for the benefit and security of all of our people and all of the world,” Vice President Mike Pence said during a speech on Thursday, July 6, addressing a huge crowd of more than 500 NASA officials and workers, government dignitaries and space industry leaders gathered inside the cavernous Vehicle Assembly Building at the Kennedy Space Center – where Apollo/Saturn Moon landing rockets and Space Shuttles were assembled for decades in the past and where NASA’s new Space Launch System (SLS) megarocket and Orion deep space crew capsule will be assembled for future human missions to the Moon, Mars and beyond.
Pence pronounced the bold space exploration goals and a reemphasis on NASA’s human spaceflight efforts from his new perch as Chairman of the newly reinstated National Space Council just established under an executive order signed by President Trump.
“We will re-orient America’s space program toward human space exploration and discovery for the benefit of the American people and all of the world.”
Vice President Mike Pence speaks before an audience of NASA leaders, U.S. and Florida government officials, and employees inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida. Pence thanked employees for advancing American leadership in space. Behind the podium is the Orion spacecraft flown on Exploration Flight test-1 in 2014. Credits: NASA/Kim Shiflett
However Pence was short on details and he did not announce any specific plans, timetables or funding during his 25 minute long speech inside the iconic VAB at KSC.
It remains to been seen how the rhetoric will turn to reality and all important funding support.
The Trump Administration actually cut their NASA 2018 budget request by $0.5 Billion to $19.1 Billion compared to the enacted 2017 NASA budget of $19.6 Billion – including cuts to SLS and Orion.
By contrast, the Republican led Congress – with bipartisan support – is working on a 2018 NASA budget of around 19.8 Billion.
“Let us do what our nation has always done since its very founding and beyond: We’ve pushed the boundaries on frontiers, not just of territory, but of knowledge. We’ve blazed new trails, and we’ve astonished the world as we’ve boldly grasped our future without fear.”
“From this ‘Bridge to Space,’ our nation will return to the moon, and we will put American boots on the face of Mars.” Pence declared.
Lined up behind Pence on the podium was the Orion spacecraft flown on Exploration Flight Test-1 (EFT-1) in 2014 flanked by a flown SpaceX cargo Dragon and a mockup of the Boeing CST-100 Starliner crew capsule.
The crewed Dragon and Starliner capsules are being developed by SpaceX and Boeing under NASA contracts as commercial crew vehicles to ferry astronauts to the International Space Station (ISS).
Pence reiterated the Trump Administrations support of the ISS and working with industry to cut the cost of access to space.
Vice President Mike Pence (holding Orion model) tours manufacturing of NASA’s Orion EM-1 crew capsule during July 6 KSC visit – posing with KSC Director/astronaut Robert Cabana, acting NASA Administrator Robert M. Lightfoot, Jr., Senator Marco Rubio, Lockheed Martin CEO Marillyn Hewson and KSC Deputy Director Janet Petro inside the Neil Armstrong Operations and Checkout Building. Credit: Julian Leek
Acting NASA Administrator Robert Lightfoot also welcomed Vice President Pence to KSC and thanked the Trump Administration for its strong support of NASA missions.
“Here, of all places, we can see we’re not looking at an ‘and/or proposition’,” Lightfoot said.
“We need government and commercial entities. We need large companies and small companies. We need international partners and our domestic suppliers. And we need academia to bring that innovation and excitement that they bring to the next workforce that we’re going to use to actually keep going further into space than we ever have before.”
View shows the state of assembly of NASA’s Orion EM-1 deep space crew capsule during inspection tour by Vice President Mike Pence on July 6, 2017 inside the Neil Armstrong Operations and Checkout Building at the Kennedy Space Center. 1st integrated flight with NASA’s SLS megarocket is slated for 2019. Credit: Ken Kremer/kenkremer.com
After the VAB speech, Pence went on an extensive up close inspection tour of KSC facilities led by Kennedy Space Center Director and former shuttle astronaut Robert Cabana, showcasing the SLS and Orion hardware and infrastructure critical for NASA’s plans to send humans on a ‘Journey to Mars’ by the 2030s.
“We are in a great position here at Kennedy, we made our vision a reality; it couldn’t have been done without the passion and energy of our workforce,” said Kennedy Space Center Director Cabana.
“Kennedy is fully established as a multi-user spaceport supporting both government and commercial partners in the space industry. As America’s premier multi-user spaceport, Kennedy continues to make history as it evolves, launching to low-Earth orbit and beyond.”
Vice President Mike Pence holds and inspects an Orion capsule heat shield tile with KSC Director/astronaut Robert Cabana during his July 6, 2017 tour/speech at NASA’s Kennedy Space Center – accompanied by acting NASA administrator Robert M. Lightfoot, Jr., Senator Marco Rubio and Lockheed Martin CEO Marillyn Hewson inside the Neil Armstrong Operations and Checkout Building at KSC. Credit: Ken Kremer/kenkremer.com
Pence toured the Neil Armstrong Operations and Checkout Building (O & C) where the Orion deep space capsule is being manufactured for launch in 2019 on the first integrated flight with SLS on the uncrewed EM-1 mission to the Moon and back – as I witnessed for Universe Today.
Vice President Mike Pence tours manufacturing of NASA’s Orion EM-1 crew capsule during July 6, 2017 KSC visit with KSC Director/astronaut Robert Cabana inside the Neil Armstrong Operations and Checkout Building. Credit: Julian Leek
Watch for Ken’s onsite space mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Orion crew module pressure vessel for NASA’s Exploration Mission-1 (EM-1) is unveiled for the first time on Feb. 3, 2016 after arrival at the agency’s Kennedy Space Center (KSC) in Florida. It is secured for processing in a test stand called the birdcage in the high bay inside the Neil Armstrong Operations and Checkout (O&C) Building at KSC. Launch to the Moon is slated in 2019 atop the SLS rocket. Credit: Ken Kremer/kenkremer.com
NASA’s Space Launch System (SLS) blasts off from launch pad 39B at the Kennedy Space Center in this artist rendering showing a view of the liftoff of the Block 1 70-metric-ton (77-ton) crew vehicle configuration. Credit: NASA/MSFC
