Why Don’t We See the Curiosity Rover’s Arm When it Takes a Selfie?

Every time the Curiosity rover takes a ‘selfie’ on Mars, we get the same questions: “How was this picture taken?” “Why isn’t the rover’s arm or the camera visible in this picture?” “In all of Curiosity’s selfies, the camera mast is never visible… why?” And (sigh) “What is NASA hiding???”

The answer is simple and quite logical. Look any selfie image you’ve taken. Does your hand show up in the picture?

No, because it is behind the camera.

The same is true with the rover’s arm. For the most part, it is behind the camera, so it isn’t part of the picture. In your own selfies, if you’ve done a good job of positioning things, your arm doesn’t appear in the photo either. For example, take a look at this selfie taken last night by Astronomy Cast co-host Pamela Gay of her co-host (and Universe Today publisher) Fraser Cain, along with their fellow speakers at the Next Frontiers Symposium at Ohio State University.

You’ll notice Pamela’s arm isn’t showing, even though she took the picture of herself, just like the rover takes pictures of itself.

Just think of the rover’s arm as the ultimate interplanetary selfie stick. The best selfie-stick pictures are where the stick doesn’t show up in the image and it appears you had your own photographer. That’s what happens with the Curiosity rover self-portraits.

It’s important to note that while the rover selfies look like they are just one single image taken by the wide-angle camera on the rover, it is actually a series of individual images stitched together. The picture above is made from dozens of images the rover took of itself with the Mars Hand Lens Imager (MAHLI) camera at the end of the rover’s robotic arm. Curiosity moves its robotic arm around and over itself and the ground, taking pictures from every angle. These pictures are then stitched, just like panoramic images are put together to form a complete image of your total view. The rover’s arm isn’t long enough to make the camera’s field of view big enough to get the entire rover in one shot (similar to how it works if you hold your camera/phone close to your face you only get one feature, like your nose or eyes, not your entire body.)

Update: As for the questions of why the rover’s arm doesn’t show up in these rover selfie images, I conferred with Guy Webster from JPL and he said that portions of the arm do show up in some of the images used to create the selfie shots, but the portion of the arm pictured is very limited, and the team feels it would be even more confusing to include the small parts of the arm that are in some of the images and so have decided to leave it out entirely.

“Some of the component images do indeed show glimpses of the arm,” Webster said via email. “There’s selectivity in choosing which parts of which component frames to use in assembling the mosaic, to avoid having discontinuous bits of arm in the scene. That would cause confusion even quicker than making choices that leave out the arm.”

For example, here is one image from the series of pictures taken by the MAHLI to create the selfie, and it shows just a small piece of the arm, near the “shoulder”:

A small portion of the Curiosity rover's robotic arm (the white 'tube' on the top left of the image) shows up in one of the original raw images used to create the montage 'selfie.' Credit: NASA/JPL-Caltech/MSSS.
A small portion of the Curiosity rover’s robotic arm (the white ‘tube’ on the top left of the image) shows up in one of the original raw images used to create the montage ‘selfie.’ Credit: NASA/JPL-Caltech/MSSS.

You can see the entire collection of MAHLI images from Sol 1126 (Oct. 6, 2015) here. You can see how few images show parts of the arm, and how little of the arm shows up in the ones that do.

For the most part, though, because of the flexibility of the robotic arm and the way it is able to move, the arm ends up behind the camera. As Curiosity’s Engineering Camera Team Leader Justin Maki explains in the video below, “The rover is imaging the deck while the arm is behind the camera, and then to image the ground … again the arm is behind the camera when taking these pictures. When we stitch them all together, you don’t see the arm in any of the pictures.”

Click on the image to start the video (which shows very well why the arm isn’t in most of the shots):

It’s interesting to note, that while the lead image above — the latest rover selfie — does not include the rover’s robotic arm, the shadow of the arm is visible on the ground. You’ll notice there seems to be an extra “joint” in the arm, which is just part of the image editing, particularly the stacking of the images where the ground is, where the image editors used more than one image for that area. For the selfie image below, taken in 2012, the imaging team chose not to include any shadow of the arm.

A color self-portrait photo of Curiosity standing on Mars, on sol 84 (October 31, 2012). The photo is a mosaic of images shot with MAHLI, the camera on the end of the robotic arm. Credit: NASA/JPL/MSSS.
A color self-portrait photo of Curiosity standing on Mars, on sol 84 (October 31, 2012). The photo is a mosaic of images shot with MAHLI, the camera on the end of the robotic arm. Credit: NASA/JPL/MSSS.

Why does the rover imaging team take these rover selfies? Are they just joining in on the selfie craze here on Earth?

These images are actually a great way for the rover team to look at all the components on Curiosity and make sure everything looks like it’s in good shape. The wheels are of particular interest because there has been some damage to them from driving over sharp rocks. These images also document various areas where the rover has worked, and often include things like the holes the rover has drilled into the Martian rocks and soil.

Emily Lakdawalla at The Planetary Society has written an extremely detailed post on how the rover takes self-portraits. She created this composite image of the 72 individual frames the Mars Hand Lens Imager (MAHLI) had to take in order to cover the 360-degree view showing the rover’s underside, a “belly selfie“:

Curiosity's arm-mounted MAHLI camera took 72 individual photos over a period of about an hour in order to cover the entire rover and a lower hemisphere including 360 degrees around the rover and more than 90 degrees of elevation. It took 2 tiers of 20 images to cover the entire horizon, and fewer images at lower elevations to cover the bottom of the image sphere. The arm was kept out of most of the images but it was impossible to keep the arm's shadow from falling on the ground in positions immediately in front of the rover. Credit: NASA/JPL/MSSS/Emily Lakdawalla.
Curiosity’s arm-mounted MAHLI camera took 72 individual photos over a period of about an hour in order to cover the entire rover and a lower hemisphere including 360 degrees around the rover and more than 90 degrees of elevation. It took 2 tiers of 20 images to cover the entire horizon, and fewer images at lower elevations to cover the bottom of the image sphere. The arm was kept out of most of the images but it was impossible to keep the arm’s shadow from falling on the ground in positions immediately in front of the rover. Credit: NASA/JPL/MSSS/Emily Lakdawalla.

Here’s another longer video from JPL that explains all the rover’s cameras.

A mosaic of images from NASA's Curiosity rover shows what appears to be a "selfie" with a Martian mountain (Aeolis Mons)in the background. Credit: NASA/JPL-Caltech /MSS/ Image editing by Jason Major.
A mosaic of images from NASA’s Curiosity rover shows what appears to be a “selfie” with a Martian mountain (Aeolis Mons)in the background. Credit: NASA/JPL-Caltech /MSS/ Image editing by Jason Major.

Curiosity Rover Report: At Grandma’s House

MSL team member Colette Lohr, the Tactical Uplink Lead, provides the latest video update on the Curiosity rover. The rover is at a location fittingly dubbed “Grandma’s House” during the holidays, and there should be many more adventures during 2013.

Curiosity Scans ‘Yellowknife Bay’ on Sol 130. NASA’s Curiosity rover celebrated her 1st Christmas on the Red Planet at ‘Yellowknife Bay’ and is searching for her 1st rock target to drill into for a sample to analyze. She snapped this panoramic view on Dec. 17 which was stitched together from navigation camera (Navcam) images. Credit: NASA/JPL-Caltech/Ken Kremer/Marco Di Lorenzo

Could the Next Planetary Rover Come from Canada?

Prototype of the new Juno rover, a 300 kg rover for a mission to Mars or the Moon. Credit: CSA

The Canadian Space Agency is well known for its robotics but they’ve recently expanded from robotic arms to building prototypes for five new rovers, designed for future lunar and Mars missions. They range from microrovers to full-sized science missions and range in size from 30 kg up to 900 kg. The largest of them, the Lunar Exploration Light Rover, is designed to carry a scientific payload and can be fitted with a robotic arm. It has a range of 15 km, can be operated remotely, or can be used to carry astronauts across a planetary surface.

A version of the Juno rover with tires. Credit: CSA

The two Micro-Rover prototypes, at 40 kg and 30 kg., are designed to be operated in conjunction with larger rovers, and can be tethered to them and lowered into otherwise inaccessible areas.

“On the Moon, permanently shadowed craters provide many interesting areas to find water and other volatiles, Jean-Claude Piedboeuf, Director of Space Exploration Development at the Canadian Space Agency told Universe Today. “These craters have steep slopes making it difficult and risky for a large rover. Therefore, sending a micro-rover tethered to its mother one gives us the ability to explore the bottom of these craters with a minimum risk. Sending only a micro-rover could be an option. However, they are very slow so it is more efficient to have them on a larger rover to cover long distance and deploy them when needed.”

The micro-rovers can also be used to work alongside astronauts, to gain access to small spaces like caves.

The rovers should be mission-ready by about 2020, and NASA is already interested. Most missions to Mars and the Moon involve geology, and sometime in the future, mining. For instance, NASA has an experiment under consideration that entails digging up soil on the Moon and making hydrogen and oxygen out of it. These designs are intended to fit in with those types of activities.

Space robotics technology has long been a point of pride for Canadians, Canadarm was a fixture on the Space Shuttles and made it possible to do things like deploying satellites like the Hubble Space Telescope and was instrumental in building the International Space Station. CSA also built the huge Canadarm 2 and Dextre, the highly dexterous dual-armed robot, both of which reside on the International Space Station. More recently, CSA contributed a robotic arm and other equipment to Curiosity, the newest NASA rover to land on Mars.

Artemis is a light-weight terrestrial prototype that can either be operated by a human nearby or at a remote location, or use its onboard sensors to scan its environment and navigate without the need for a human operator. Credit: CSA

The new rover designs will add to the fine lineage of Canadian space robotics. Once they are deployed on missions to the Moon or Mars, they may end up elbowing the Canadarm and Dextre out of the spotlight. If they do take centre stage, no feelings will be hurt. Many of the same people who worked on the Canadarms and Dextre are involved in the development of the rovers.

“MDA (MacDonald, Detwiler and Associates) was the prime contractor for Canadarm and Dextre and is prime on three rover prototypes,” said Piedboeuf.

With these rover prototypes, CSA has avoided the one size fits all approach to rover design.

“The fleet developed by the Canadian industry for the CSA covers the range of applications we envisage and that will be welcomed by our international partners,” said Piedboeuf.

Though the CSA doesn’t anticipate any other rover designs, these 5 prototypes could be focused “on more specific applications such as in-situ resource utilization or science,” explained Piedboeuf.

If you find the unveiling of 5 new rover prototypes exciting, you’re in good company.

“People in industry, academia and within the CSA were excited to develop these rovers that could be one day on the Moon or Mars,” said Piedboeuf. “The opportunity of working on prototypes of space rovers with challenging requirements and advanced autonomy was a great motivation.”

See more images and information on the fleet of rovers at CSA’s website.

A Memorial to 9/11… on Mars

Today, on the 11th anniversary of the World Trade Center attack, countless hearts and minds will be reflecting upon a day that changed our world forever and remembering those who lost their lives in the tragic collapse of the twin towers. Memorial events will be held in many locations around the planet… and even, in a small yet poignant way, on another planet. For, unknown to many, two pieces of the World Trade Center are currently on the surface of Mars: one affixed to the rover Spirit, now sitting silently next to a small rise dubbed “Home Plate”, and the other on its sister rover Opportunity, still actively exploring the rim of Endeavour crater.

Even more than scientific exploration tools, these rovers are also interplanetary memorials to all the victims of 9/11.

(The following is a repost of an article first featured on Universe Today in 2011, on the 10th anniversary of 9/11.)

In September of 2001 workers at Honeybee Robotics in lower Manhattan were busy preparing the Rock Abrasion Tools that the twin rovers Spirit and Opportunity would each be equipped with, specialized instruments that would allow scientists to study the interiors of Martian rocks. After the World Trade Center attacks occurred, the company wanted a way to memorialize those who had lost their lives.

Through what was undoubtedly some incredibly skillful use of contacts, Honeybee founder and MER science team member Stephen Gorevan – on a suggestion by JPL engineer Steve Kondos and with help from the NYC mayor’s office and rover mission leader Steve Squyres – was able to procure two pieces of aluminum from the tower debris. These were fashioned into cylindrical cable shields by a contracted metal shop in Round Rock, Texas, and had American flags adhered to each by Honeybee engineer Tom Myrick.

The image above, taken in 2004, shows the cable shield with American flag on the Rock Abrasion Tool attached to Spirit. At right is an image of the flag shield on Opportunity, acquired on September 11, 2011.

The rovers were launched in the summer of 2003 and have both successfully operated on Mars many years past their planned initial mission timelines. Spirit currently sits silent, having ceased communication in March 2010, but Opportunity is still going strong in its exploration of the Martian surface.

“It’s gratifying knowing that a piece of the World Trade Center is up there on Mars. That shield on Mars, to me, contrasts the destructive nature of the attackers with the ingenuity and hopeful attitude of Americans.”

– Stephen Gorevan, Honeybee Robotics founder and chairman

These memorials will remain on Mars long after both rovers have ceased to run, subtle memorials to thousands of lives and testaments to our ability to forge ahead in the name of hopefulness and discovery.

Original source: OnOrbit.com

Image credit: NASA / JPL-Caltech

Photo of Manhattan taken from orbit on September 11, 2001. (NASA)

A Martian Memorial to 9/11

As we approach the tenth anniversary of the September 11 World Trade Center attacks (has it already been ten years??) countless hearts and minds will be remembering the fateful day our world changed forever, and the many people who tragically lost their lives in the catastrophic collapse of the twin towers. Memorial events will be held in many locations around the world… and even, in a small yet poignant way, on another world. For, unknown to many, two pieces of the World Trade Center are on the surface of Mars: one affixed to the rover Spirit which sits silently in its permanent position near a small plateau called “Home Plate” and the other on its sister rover Opportunity, currently exploring the rim of the vast Endeavour crater.

Much more than scientific exploration tools, these rovers are also interplanetary memorials to the victims of 9/11.

In September of 2001 workers at Honeybee Robotics in lower Manhattan were busy preparing the Rock Abrasion Tools that the twin rovers Spirit and Opportunity would each be equipped with, specialized instruments that would allow scientists to study the interiors of Martian rocks. After the World Trade Center attacks occurred, the company wanted a way to memorialize those who had lost their lives.

Through what was undoubtedly some incredibly skillful use of contacts, Honeybee founder and MER science team member Stephen Gorevan – on a suggestion by JPL engineer Steve Kondos  and with help from the NYC mayor’s office and rover mission leader Steve Squyres – was able to procure two pieces of aluminum from the tower debris. These were fashioned into cylindrical cable shields by a contracted metal shop in Round Rock, Texas, and had American flags adhered to each by Honeybee engineer Tom Myrick.

The rovers were launched in the summer of 2003 and have both successfully operated on Mars many years past their planned initial mission timelines. Spirit currently sits silent, having ceased communication in March 2010, but Opportunity is still going strong in its exploration of the Martian surface.

“It’s gratifying knowing that a piece of the World Trade Center is up there on Mars. That shield on Mars, to me, contrasts the destructive nature of the attackers with the ingenuity and hopeful attitude of Americans.”

– Stephen Gorevan, Honeybee Robotics founder and chairman

The image above, taken in 2004, shows the cable shield with American flag on the Rock Abrasion Tool attached to Spirit.

These memorials will remain on Mars long after both rovers have ceased to run, subtle memorials to thousands of lives and testaments to our ability to forge ahead in the name of hopefulness and discovery.

Read the full story by Keith Cowing on OnOrbit.com.

Image credit: NASA / JPL-Caltech