On Thursday, February 18th, NASA’s Mars 2020 mission delivered the rover Perseverance, carrying the helicopter drone Ingenuity, safely to the surface of Jezero Crater, Mars (see: Space Sunday: ‘Perseverance will get you anywhere’). Sine then, the rover has been going through its initial checks, and on Monday, February 22nd, members of the mission team gave the latest update on the rover’s status, which included a unique video and an audio recording.
The video was made up of images recorded by a suite of cameras specifically mounted on the rover and its landing systems specifically with the aim of recording the landing event in as much detail as possible. These cameras comprised:
A pair of camera on the top of the aeroshell that protected the rover and its “skycrane” descent stage through entry into, and initially deceleration and flight through, the upper atmosphere of Mars. These were intended to capture video of the supersonic parachute deployment.
A single camera attached to the skycrane that looked down on to the stowed rover, designed to record the process of winching it down in its harness and then delivering it to the ground.
A camera up the upper deck of the rover looking up at the skycrane to record the same, and the skycrane’s departure from the landing site.
A camera on the side of the rover and looking down, intended to record the vehicle’s descent via parachute and its approach for landing.
With the exception of one of the aeroshell cameras, which appears to have failed when the explosive “mortar” fired the parachute package clear of the aeroshell, all of these camera captured some incredible footage of the landing sequence.
Once retuned to Earth, the footage was poured over by the mission’s imaging team at the Jet Propulsion Laboratory (JPL), with elements combined with audio recorded at JPL’s mission control during the landing, to produce an incredible short film, that puts the audience right there with the rover as it landed on Mars, as you can see below.
The first part of the film showed the deployment of the parachute system. This comprised firing the 67 Kg parachute pack out of the top of the aeroshell at 150 km/h, detaching a protective cover from the aeroshell (parts of which broke off) in the process.
The package pulled the parachute harness out behind it until it reached its full extent (about 46 metres), which caused the 21.5m diameter parachute to deploy at a time when the vehicle was still travelling at around Mach 1.75. In all, this process took around 1.5 seconds to complete.
At this point the the rover down-look camera started recording, capturing the jettisoning of the heat shield that formed the lower part of the aeroshell. This demonstrated its aerodynamic nature by falling away without tumbling, leaving the rover’s look-down camera to film the inflow delta to one side of the crater – and the intended landing point – as the rover and aeroshell swayed under the parachute.
Not long after this, the rover and its skycrane descent stage dropped clear of the aeroshell, the view of the ground shifting dramatically as the descent stage used its motors to propel itself away from the areoshell to avoid any risk of collision before gently veering back to centre itself over the landing zone.
This footage – still via the rover’s down-look camera – then captures the thrust from the rocket motors as the skycrane comes to a hover some 20 metres above the ground, then there is a sharp jerk as the rover is released to be lowered to the ground by the skycrane and its harness.
As the rover is released by the descent stage, so the remaining camera systems come into play, one looking down from the skycrane as the rovers is lowered, and the other on the rover looking up as it leaves the skycrane as it hovers steadily over the landing zone.
It was also this up-look camera that caught the last images of the skycrane as, with the rover on the ground, the harness cables and data umbilical detached, it re-oriented itself to fly away to crash some 700m from the rover.
As well as cameras to record the images of the landing, it had been hoped that one of the rover’s two microphones would record the sounds of the descent and landing. Unfortunately, it failed to do so, but over the weekend, it did capture the sigh of a gust of wind passing over the rover at about 5 metres/second, giving us our first direct recording of the Martian wind.
Since landing, various checks have been performed on the vehicle, and instrument packs deployed. The most important of these has been the RSM – the Remote Sensing Mast. This houses a range of instruments, including the SuperCam, the Mastcam-Z high-resolution camera and the rover’s main navigation cameras (NavCams). The latter are, like their cousins on Curiosity’s RSM, designed to assist with rover driving and navigation. However, they are far more capable and much higher resolution, each one capable of take up to a 20 megapixel image.
For their initial testing, there were operated at one-quarter of this capacity, taking a series of images around the rover, which were shown at the February 22nd press conference without any colour processing or white-balancing, so they showed Mars exactly as it were appear to a human standing there.
Over the next few days, the remaining systems on the RSM will be tested, and the rover will also go into a data download mode.
Since launch, the on-board computers have been configured with software required to keep the rover safe during Mars transit and to allow it to play its part in the EDL phase of the mission. As this programming is no longer required, mission control will transmit the initial data sets required for the rover and its systems to go through their commissioning procedures – which are liable to take a few weeks – and prepared it for its initial science mission software. During this week, further tests will also be carried out, including allowing the rover to complete a short drive.
I’ll have more on all of these actives in future Space Sunday updates, but for now, why not scroll back up and what that video again?
NASA once again has more than one rover operating on the surface of Mars. On Thursday, February 18th, the Mars 2020 mission, comprising the rover Perseverance and the aerial technology demonstrator Ingenuity, arrived in Jezero Crater in the northern hemisphere of the red planet.
The landing followed the same profile as that of NASA’s other operational rover, Curiosity, which arrived on Mars as the physical element of the Mars Science Laboratory (MSL) mission in August 2012, and which is still exploring Aoelis Mons, the huge mound at the centre of Gale Crater, although there were some notable differences.
Referred to as “the seven minutes of terror”, the landing involved the rover and its helicopter payload and landing system packed within an aerodynamic aeroshell, slamming into the upper reaches of the tenuous Martian atmosphere at 20,000 km/h, then the rover and payload touching gently down on Mars on the end of a winch just seven minutes later.
Some ten minutes prior to atmospheric entry, the mission had separated from its supporting cruise stage – the component that that provided it with power, heat and communications with Earth. Small reaction control thrusters on the aeroshell fired shortly after, slowing the spin induced to assist with stability during the 3.4 million km cruise out from Earth so that it would interfere with the vehicle’s passage through the atmosphere.
Protected by the heat shield that formed the lower part of its aeroshell, Mars 2020 passed through the searing heat of atmospheric entry, the friction of its passage helping to decelerate it. From here on in, things happened fairly rapidly.
Just under five minutes from touchdown, the vehicle used programmed control checks to align itself onto a course towards its intended landing site and entered what NASA call the “straighten up and fly right” manoeuvre – jettisoning a final group of balance masses whilst using its aerodynamic shape to steady itself on course ready for parachute deployment. This occurred with the craft just 20.8 km up-range of its landing site and still travelling at more than 2,000 km/h – or supersonic speed.
With the parachute deployed, the heat shield could be jettisoned, exposing the rover vehicle and its instruments to Mars for the first time. This meant camera and radar systems could start operating (as could the on-board microphones), and the craft could enter an entirely new mode of robotic landing.
Given the distance between Earth and Mars, two-way communications are impossible, so Martian landing have to be programmed in advance and triggered triggered by events such as velocity, atmospheric pressure, elapsed time, etc., but without any means to deviate from programming in any way. However, Mars 2020 was equipped with Terrain Relative Navigation (TRN).
This essentially took readings of the ground below and ahead of the craft as it descended under its parachute, comparing the findings with high-resolution terrain maps of the landing site and surroundings. If it noted any potential hazard, it would cause the vehicle to use its thrusters to steer itself away from the hazard whilst maintaining its overall heading towards the landing site. TRN also allowed the vehicle to identity any obstructions within its target landing area and feed the data necessary to avoid them to the rover’s skycrane system that would handle the final part of the landing.
Weighing around a tonne, Perseverance, like Curiosity before it, is too heavy to rely solely on parachutes to make a landing. Instead, both rovers relied upon a jet-powered “backpack” – the skycrane. This, with the rover strapped underneath it, fell clear of the backshell and parachute just 1.6 km above the surface of Mars. Once safely clear of the backshell, rock motors on the skycrane fired, reducing the rate of descent from around 360 km/h to just 3 km/h whilst also flying the rover directly over the ideal landing point.
Entering a hover some 21.5 metres above the landing site, the skycrane held steady as it released the rover on a winch mechanism and lowered it towards the ground. This triggered the rover’s wheels, which had been folded stowed against its body, to deploy and lock themselves into their operational position. With the rover at the extent of the cables, the skycrane eased it down to deliver it to the surface.
Once the rover was able to confirm it was firmly on Mars – a matter of a second or so using sensors in its wheel mechanisms – it sent a message up the wire to the skycrane telling it to detach. This it did before carefully piloting itself away along a course that prevented the rocket motor exhausts washing over the rover and possibly damaging / contaminating it, before crashing into the surface of Mars.
The entire EDL – Entry, Decent and Landing – phase of the mission had been watched over by three of the craft currently in orbit around Mars. The first of these was the Mars Reconnaissance Orbiter (MRO – now approaching 15 years of continuous operations in Mars orbit) that was specifically tasked to act as both observer and communications relay. Also recording the event was NASA’s MAVEN spacecraft – it would transmit the data it received some time after the landing had been completed, whilst ESA’s Mars Express orbiter (currently the longest-running operational Mars orbital mission, with 17 years under its belt in Mars orbit) acting as a back-up relay.
In addition, it had been hoped that NASA’s InSight Lander, although over 2,000 km from Jezero Crater, might be able to hear the sonic booms of Mars 2020’s passage through the Martian atmosphere. However, at the time of writing, I’m not sure if this was successful.
At precisely 11:50 UTC (7:50am EDT) an Atlas 5 rocket thundered into near-perfect skies over Cape Canaveral Air Force Station in Florida, carrying aloft NASA’s Mars 2020 on the first stage of its 7-month trip to the red planet.
The launch marked the last of the “big three” missions to launch during the 2020 opportunity, following on the heels of China’s Tianwen-1 orbiter / lander / rover mission and the UAE’s Hope orbiter mission. Carrying the Perseverance rover and Ingenuity helicopter drone, Mars 2020 is the most scientifically complex of the three missions, and potentially set to be the longest running of all three: providing it doesn’t fall foul of any major issues, Perseverance (Or “Percy” as some have dubbed it) could be operational on Mars for 12-14 years, thanks to its nuclear power supply.
In the days leading up to departure, there had been concerns the attempt might have to be postponed thanks to the approaching Tropical Storm Isaias, but on the morning of the launch, conditions couldn’t have been better. There was, however, some pre-launch excitement on the other side of the United States, where the Jet Propulsion Laboratory in (JPL) – mission control for the mission once en route to Mars, was lightly shaken by a local 2.9 magnitude earthquake just 30 minutes prior to lift-off.
Just under 2 minutes after launch, the Atlas V dispatched its four strap-on boosters, allowing the core stage to continue towrds low earth orbit. Less then 2 minutes later, with the vehicle at an altitude of 392 km, the payload fairings were jettisoned, exposing the payload to space. The Centaur upper stage then commenced its “chill down” phase, readying its motor for operation once the Atlas core stage had detached.
BECO – Booster Engine Cut-Off – came 4 minutes and 20 seconds after launch, the core stage separating to allow the Centaur commence its work with and initial engine burn to further raise the vehicle’s orbit around Earth before the RL-10 motor was shut down and the reaction control system (RCS) was fired a number of times to set the stage and the payload rotating along their longitudinal axis, a move designed to ensure the payload would be spin-stabilised during its cruise to Mars.
This part of the journey started some 90 minutes after launch, on the “night” side of Earth relative to JPL. As this point, the RL-10 re-ignited, pushing the Centaur and its payload into a Trans-Mars Injection (TMI) orbit around the Sun before the two separated. As there was no “live” video of the separation, mission managers had to wait for NASA’s Tracking and Data Relay Satellites (TDRS) and Deep Space Network (DSN) on the ground to acquire a direct signal from the payload and its cruise “bus” to confirm they were safely on their way.
This TMI engine burn ensured Mars 2020 would cross the orbit of Mars, but it would do so before the planet reached the same point in space. This was because had both been on a course to intercept Mars, the Centaur booster would crash into the planet, potentially contaminating it. Instead, Mars 2020 will make two mid-course engine burns from the motors on its cruise “bus”, shifting its trajectory onto that will intercept the planet, leaving the Centaur to fly harmless by.
As well as searching for signs of ancient microbial life and advancing NASA’s quest to explore the past habitability, Mars 2020 will also form the first half of a sample return mission – as I’ve previously noted, it is equipped to leave up to 23 sealed sample containers on the surface of the planet, at least one of which may be retrieved by a future NASA/ ESA sample return mission, although such a mission has yet to be formally approved by either agency. In addition, Perseverance carries with it experiments geared towards learning more in preparation for the future human exploration of Mars.
The first of these forms a part of the SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) instrumentation. Primarily designed to seek organic compounds on Mars, SHERLOC also contains five small pieces of material that might be potentially used in the outer layers of a future Marts spacesuit. These will be monitored to see how well they deal with possible corrosion by Martian dust and atmosphere under the effects of solar radiation. As a part of its duties, the Mars Environmental Dynamics Analyser (MEDA) will also study the nature of Martian dust so engineers can make better decisions about materials to be used in spacesuits and surface equipment.
Then there is MOXIE – the Mars Oxygen ISRU Experiment – designed to produce oxygen out of the carbon dioxide that makes up 96% of the Martian atmosphere.
The idea has its roots in the 1996 Mars Direct mission profile developed by Robert Zubrin and David Baker. They recognised that the biggest encumbrance to a mission to Mars was the amount of fuel required to both get a crew to Mars and then bring them back to Earth. To reduce this, they proposed using the Martian atmosphere to produce both oxygen and methane that could be used to fuel the vehicle a crew would use to return to Earth – massively reducing the mass of a mission. The same technique could also be used to provide a human crew with additional oxygen supplies and fuel for surface vehicles once they get to Mars.
MOXIE is a more modest idea, designed to produce just oxygen from the Martian atmosphere. It’s a proof-of-concept designed to produce 22g of oxygen (O2) per hour with >99.6% purity continuously for around 1230 hours. If successful, it could pave the way for a much large nuclear-powered unit to be delivered to Mars that could be used to produce a large volume of stored oxygen that could be used to produce the atmosphere for a human outpost on Mars and as the oxidiser for powering Earth return vehicles. As with the Mars Direct proposal, the system could be extended to also produce Methane fuel.
Mars 2020 is now en route to Mars in the “cruise” phase of the mission, during which it will study interplanetary space. The next tense moment for the mission comes on February 18th, 2021, when the craft arrive at Mars, and Perseverance and Ingenuity enter the “seven minutes of terror” of the Entry, Descent and Landing (EDL) phase, which should culminate in both being safely delivered to Jezero Crater on the surface of Mars.
A Dragon Comes Home
Sunday, August 2nd, 2020 saw the Crew Dragon Demo-2 mission make its return to Earth. Launched to the International Space Station (ISS) on May 30th, 2020 (see: Space Sunday: how to fly your Dragon) carrying NASA astronauts Bob Behnken and Doug Hurley, the mission was intended to confirm the SpaceX crew dragon vehicle is ready to commence regular crew-carrying flights too and from the space station.
Since then, the vehicle has been docked at the ISS, allowing Hurley and Behnken work as a part of the Expedition 63 crew rotation. In particular, Behnken carried out four EVA space walks alongside of Expedition 63 commander Chris Cassidy, marking them as the third and forth US astronauts after Michael Lopez-Alegria and Peggy Whitson to have completed 10 EVAs during their careers.
Undocking came at 23:35 UTC (19:35 EDT) on August 1st, 2020, 19 hours ahead of the planned splashdown, although concerns about Tropical Storm Isaias initially meant that the undocking might have been delayed to avoid rough weather and seas in the Gulf of Mexico south of Pensacola, Florida.
Following departure from the ISS the Dragon vehicle, comprising the capsule Endeavour and its service module (called the “trunk” by SpaceX) that provides long-duration power, life support and primary propulsion, raised itself up and over the ISS to allow it to “drop behind” the space station in their relative orbits prior to dropping down into a lower orbit. This formed the first of several flight manoeuvres that placed the vehicle in the correct orbit before the crew took a meal and had a sleep period.
Final preparations for the re-entry and splashdown commenced just shy of an hour before the vehicle started its descent into Earth’s atmosphere on August 2nd, with the unclamping of the “claw” mating capsule to trunk and relaying power, fluids and atmosphere from one to the other, allowing the capsule to separate from the trunk, which was left to burn-up in the upper atmosphere. Flying free, the capsule then flipped itself over to point its nose in the direction of flight once more. This facilitated the opening of the nose cap to expose the four forward-facing Draco engines.
The latter were then used in a 11-minute de-orbit burn that placed the vehicle on a path of descent into the denser layers of the Earth’s atmosphere. Immediately following this, and still under automated control, Endeavour re-oriented itself to put its heat shield pointing into the direction of travel as the nose cone cover closed and latched. This started a 20-minute descent phase through the upper atmosphere unless Endeavour reached a point where plasma generated by the increasing friction against the atmosphere reached a maximum, blacking out all communications for a 6-minute period.
By the time the blackout ended, Endeavour had reduced its velocity from some 28,000 km/h to just 640 km/h, slowing the capsule to a point where its two drogue chutes could be deployed, stabilising the vehicle in its descent and allowing the four main ‘chutes to be deployed. These slowed the capsule during its final couple of kilometres of descent to just 25.6 km/h, allowing it to splash down precisely on target off the coast of Pensacola.
SpaceX recovery teams using fast motor boats were quickly on the scene and proceeded to carry out checks on the vehicle and the air around it to ensure it was not venting toxic gases while others chased down a recovered the main and drogue parachutes. Check-out operations on the capsule, which is designed to float upright on the water, was somewhat impeded by idiots trying to get close to it in their own power boats, but the support crew were able to rig Endeavour with a recovery harness as the main recovery ship, the Go Navigator, approached in readiness to lift the capsule aboard.
This was achieved using the a-frame hoist at the stern of the ship, which lifted Endeavour out of the water and onto a special “nest”, a platform that could move the capsule to the crew egress area, an operation completed less than 30 minutes after splashdown. – in less than 30 minutes after splashdown. Opening the vehicle’s hatch, however was delayed as a result of small traces of potentially toxic Nitrogen Tetroxide fuel vapours from the engine burns remaining in the service space of the capsule where things like the propellant tanks, etc., reside. To avoid risk, this area needed to be purged before the astronauts could exit the vehicle.
This meant it was a further 30 minutes after splashdown that Bob Behnken, the mission pilot, and mission commander Doug Hurley could be lifted from the the capsule and transferred to the ship’s medical area, where NASA flight surgeons carried out a post-flight medical. After this, both men were given time to adjust back to Earth’s gravity, take a show, get into more relaxed clothing than their pressure suits. They then transferred to a helicopter that rendezvoused with Go Navigator to fly them to Pensacola Naval Air Station and onward transfer to Ellington Field Joint Reserve base and the Johnson Space Flight Centre to be reunited with their families.
Endeavour, meanwhile, will be taken back to SpaceX facilities where it will be refurbished and prepared for the second operational Crew Dragon flight, following NASA’s change of mind and allow SpaceX to re-use their capsules for multiple crewed flights to the ISS. In the meantime, the first operational flight of Crew Dragon is set to fly NASA astronauts Shannon Walker,Michael Hopkins and Victor Glover, together with Japanese astronaut Soichi Noguchi to the ISS in September 2020.
The above picture may not look that spectacular, just a couple of stars against the backdrop of space – exception the two disks it shows are not stars, they are planets – exoplanets, in fact, orbiting a star 310 light years away. As such, it is the first visible light photograph of multiple planets orbiting a Sun-like star taken from Earth.
Called TYC 8998-760-1, the star in question is of the G2V spectral class, and the closest Sun-like star to the solar system. However, whereas the Sun is some 4.6 billion years old, TYC 8998-760-1 is a mere stripling – just 17 million years old. It lies within the southern hemisphere constellation of Musca – a constellation which though small, contains a number of notable stars including Alpha, Beta, Gamma and Zeta Muscae, part of a group of hot blue-white stars that seem to share a common point of origin and motion within the galaxy, HD 100546, a blue-white Herbig Ae/Be star that is surrounded by a complex debris disk containing a large planet or brown dwarf and possible protoplanet, and Theta Muscae, a triple star system, the brightest member of which is a Wolf–Rayet star.
The image was taken by the European Southern Observatory’s (ESO) Very Large Telescope (VLT) using the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE). This instrument utilises a coronagraph to block out much of the light from a star, allowing the light reflected by any planetary bodies to be visible.
TYC 8998-760-1 is an interesting planetary system for a number of reasons. Given the relative youth of the parent star, it might be said that the system represents a glimpse of the early formation of the solar system. However, it is on a scale far vaster than our own. Both of the planets are gas supergiants, the innermost, called TYC 8998-760-1 b, being some 14 times the mass of Jupiter, whilst the outermost, TYC 8998-760-1 c, is around 6 times Jupiter’s mass. Both also orbit their parent at incredible distances in comparison to the planets of our own system: TYC 8998-760-1 b averages 162 AU (1 AU being the average distance the Earth is from the Sun), and TYC 8998-760-1 c averages some 320 AU. By comparison, Neptune, the most distant of our major planets, averages a “mere” 30 AU from the Sun.
These vast distances make both planets curiosities: exoplanets that are large and orbiting far from their host stars are very difficult to fit into the protoplanetary and accretion disk model(s ) that are generally used to explain planetary formation. Further, both planets appear to occupy relatively stable, circular orbits. Astronomers believe this could indicate that the two planets formed more-or-less where they are now and their near-circular orbits may indicate the presence of a still-to-be discovered third large body orbiting even further from the star (and TYC 8998-760-1 c was unknown prior to SPHERE capturing it) – or that their orbits might indicate their are the result of very specific ejections from an unseen stellar companion to TYC 8998-760-1.
Further study is required to determine exactly how the planets may have formed, but their presence does raise the questions on whether smaller, rocky planets might orbit closer to the star – possibly within its habitable zone. As it is, SPHERE’s ability to gather data on planets has yielded a lot of information on the two gas giants that will keep astronomers busy. And while this is only the third image of exoplanets currently on record, with the upcoming generation of high-powered Earth and space-based telescopes, that number will increase over the coming decades.
Heavenly Questions En-route to Mars
In my previous Space Sunday update I covered the launch of the UAE’s Hope mission to Mars, launched as that article was being written, and the (then) forthcoming launch of China’s ambitious Tianwen-1 (“Quest for Heavenly Truth” or “Questions for Heaven”) orbiter / lander / rover mission.
At that time, it wasn’t clear just when China’s mission would lift-off, but going on past launches of the Long March 5 booster that would be hefting the mission away from Earth have generally been within 6 days of the rocket being delivered to the launch pad, speculation was that the Tianwen-1 launch would come in he week of July 20th through 24th, given its launcher arrived on the pad on July 17th.
Those speculations proved to be correct, because Long March 5 launch Y4 took to the skies from the Wenchang Satellite Launch Centre on Hainan Island in the South China Sea, at 04:41 UTC on the Morning of July 23rd (11:41 local time).
late July and early August mark the period of the 2020 Mars opposition launch window, once again offering opportunities to send missions to the Red Planet. This period occurs once every 26 months, when the orbits of Earth and Mars are both on the same side of the Sun (so Mars and the Sun are on “opposite sides” of Earth, hence the name “opposition”) and positioned relative to one another (with Earth “catching up” with Mars as they both move around the Sun) such that the flight time from Earth to Mars is at its shortest – around 6-7 months.
Because of this, these periods tend to be fairly busy, and 2020 is particularly so, with three missions heading for Mars. The most prominent of this missions in terms of publicity is NASA’s Mars 2020 Perseverance rover, scheduled for a July 30th 2020 launch. The second is China’s ground-breaking orbiter / lander / rover mission (of which more below), whilst the third – and first to launch – is possibly the most overlooked of the three: the Hope, or Al-Amal, orbiter mission developed by the United Arab Emirates.
Hope is a remarkable mission for the UAE; the mission was announced in 2014, literally as the country formed its fledgling space agency, employing just 75 people – a number that has since grown to 150. At that time the UAE had developed and flown – in partnership with other nations – a total of 5 communications satellites and two Earth observation platforms, so the idea for the country’s new space agency setting its sights on Mars was seen as incredibly ambitious.
However, over the course of the last six years the United Arab Emirates Space Agency (UAESA) has worked steadily on the the project, and has drawn on space development expertise in France, Japan, the UK and USA both for its own development and for the Hope spacecraft, moving the project forward and at minimum cost – just US $200 million.
Roughly cubic in shape, Hope measures 2.37m wide and 2.90m in length and has a mass of just under 1.4 tonnes (including its propellant fuel load). Solar-powered, it is billed as the “first true weather satellite for Mars” and is intended to develop a complete picture of the Martian atmosphere.
To do this, the satellite has a primary mission period of a full Martian year (approx. two terrestrial years), with the option for mission extensions through to 2025. During this time, the spacecraft will study the Martian climate and weather on a daily basis from a 55-hour equatorial orbit around the planet that will vary between 20,000 and 43,000 km from the planet’s surface. This high orbit will afford it the best view of weather patterns in both the northern and southern hemispheres, and observe how weather patterns interact along the equatorial regions of the planet. In particular, Hope will be able to study seasonal weather / climate cycles and record weather events in the lower atmosphere such as dust storms, and the weather at different geographic areas of Mars.
To achieve this, the mission carries a relatively modest number of science packages compared to other missions, comprising:
The Emirates eXploration Imager (EXI): developed with assistance from two US research facilities, this is a multi-band camera capable of taking high resolution images with a spatial resolution of better than 8 km. Equipped with a set of 6 filters, it can image in both RGB colour wavelengths and in the ultraviolet bands, and measure properties such as water, ice, dust, aerosols and abundance of ozone in the Martian atmosphere.
Emirates Mars Infra-red Spectrometer: developed with the assistance of the Arizona State University, this is an interferometric thermal infra-red spectrometer. It is designed to examine temperature profiles in the Martian atmosphere and record ice, water vapour and dust in the lower to mid-level of the atmosphere.
Emirates Mars Ultraviolet Spectrometer (EMUS): is a far-ultraviolet imaging spectrograph for measuring global characteristics and variability of the Martian thermosphere.
As well as carrying out a genuine science mission that will produce data that will be of significant use for future missions up to and including eventually sending human to Mars, Hope is also seen as an inspirational programme intended to “send a message of optimism to millions of young Arabs” and encourage them to consider careers in science, technology, engineering and maths (STEM).
Nor, given the traditional conservative nature of Arab nations, is this inspirational element of the mission directed solely at young men: the deputy project manager and lead science investigator for the mission is Sarah Amiri, who is also is the Chair of the United Arab Emirates Council of Scientists. She has managed the mission’s objectives and overseen the development and integration of the mission’s science packages, and and will continue in that role throughout the mission. Her role is seen as pivotal to encouraging other Arab nations in allowing women greater access to leadership roles and in encouraging young Arab women to consider STEM-based studies and careers.
Later this month an Atlas V launch vehicle should depart Canaveral Air Force Station at the start of what will be a 6+ month cruise to Mars for its payload, the Mars 2020 rover Perseverance. A twin to the Mars Science Laboratory (MSL) rover Curiosity that has been operating on the red planet since 2012, the Mars 2020 vehicle carries a range of updated systems and a science package designed, among other things, to investigate the possibility of past life on Mars, and the potential for preservation of biosignatures within accessible geological materials.
I’ll have a lot more to say about the rover – already nicknamed “Percy” in some circles – but here I’d like to focus on the rover’s travelling companion, Ingenuity, the perfectly named Mars helicopter.
Weighing just 1.8 kilogrammes, Ingenuity will make the trip to Mars mounted on the underside of Perseverance, where it will sit until such time in the rover’s surface mission – probably around the 60-day mark – will hopefully be in a position to deploy the helicopter ready to undertake up to five flights under its own power.
The helicopter is very much a proof-of-concept vehicle, but if it proves successful, it will pave the way for future helicopter drones to assist in Mars surface missions. Such drones could, for example, be used to provide better terrain images and mapping when planning routes for future rovers to take, scout locations that may be suitable for more detailed study by rovers, and even undertake the recovery of samples obtained by other missions and left for collection, and return them to the craft that will carry them back to Earth for analysis.
Such future helicopter systems would likely be larger and heavier than Ingenuity, and capable of carrying their own science packages for use for studying things like the atmosphere around them. Further, their use is neither restricted to automated missions or to Mars. There is no reason why, if successful, Ingenuity shouldn’t pave the way for helicopter drones that could be used in conjunction with human missions on Mars, or in automated missions to Titan.
First, however, Ingenuity has to safely get to the surface of Mars – and that means experiencing the same “seven minutes of terror” of the entry, decent and landing (EDL) phase of the rover’s. mission. After that, it has to survive 60 days slung under the rover’s belly, with just 13 centimetres clearance between its protective shield and whatever is under the rover before it is liable to be a a location where it can be deployed. And then the fun begins.
Ingenuity has to be placed on ground that is relatively flat and free from significant obstacles – an area roughly 10 metres on a side. The shield protecting the helicopter will then be dropped by the rover at the edge of the location, and checks will be made to confirm the shield has fallen clear of both helicopter and rover and that the helicopter’s systems are in working order, a process that will take several days. After this, the rover will be commanded to roll forward several metres in readiness for actual helicopter deployment.
After this, the actual deployment process can commence. Due to its shape, the helicopter is stowed on its side under the rover, relative to the ground. This means the locking system that holds it in place must be released to allow the helicopter to drop through 90º, bringing two of its landing legs parallel to the ground. The remaining two legs will then be released to drop and lock into position, a the helicopter itself released from its restraining clips and literally drops down to the ground, and the rover drives clear, leaving Ingenuity to go through final checks head of its first flight.
The reason the helicopter is carried horizontally under the rover is because its rotor system makes it taller than it is wide, and the engineering team didn’t want to complicate the design by making it such that rotors would have to be unpacked / unfolded / deployed; they are instead ready for use once the helicopter is upright.
Ingenuity has two contra-rotating main rotors, one above the other. These not only provide lift and motion; the fact that they are contra-rotating means they each cancel the torque they would each induce in the helicopter’s body, something that would otherwise require a tail rotor to prevent it from also spinning when flying.
Once ready to go, Ingenuity is expected to fly up to five times, as noted, reaching heights of between 3 and 10 metres and potentially covering 300 metres per flight. Data from each flight will be shared from the helicopter and the rover using the Zigbee wi-fi low-power communications protocol, with Perseverance acting as the helicopter’s communications relay with Earth. Cameras on the helicopter should also provide the first ever bird’s eye view of low-level flying above Mars.