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?