#225 - Gary Martin - Percy
This week we have a genuine Space legend, Gary Martin, Join Julio and Matt to tell all about Microgravity, ISS, being Nasa's first and only Space Architect, ISU, Luxembourg and soo much more. Before we get to the Interview we do a deep dive into the crazy journey of Perseverance rover.
"Mars tugs at the human imagination like no other planet. With a force mightier than gravity, it attracts the eye to the shimmering red presence in the clear night sky"
John Noble Wilford, author and science journalist for The New York Times.
Gary Martin has focused his career on sustainable exploration and development of space.
The International Space University’s Board of Trustees appointed Gary Martin as Vice President for North American Operations in January 2020.
He retired from NASA after 27 years supporting space science missions, advanced technology development, technology transfer, and human spaceflight. In 2002, he became NASA’s first Space Architect, leading strategic planning at NASA Headquarters, and his team provided the analysis used to develop the Vision for Space Exploration announced by President Bush in 2004.
In 2017, Gary Martin became the Senior Advisor to the Luxembourg Ministry of the Economy working in the area of space education and research, where he contributed to the establishment of the Luxembourg Space Agency, the development of a multidisciplinary space master degree at the University of Luxembourg and a first of its kind space resources research centre - European Space Resources Innovation Centre (ESRIC).
Thank you so much for the Patrons who joined the landing party this Thursday, what an amazing event to see.
A very international group, Neil had a great question during the chat about what our respective nations had built for Percy, He was rightly proud of the DPA mics that are present on the rover. Something I mentioned on Podcast 196, as I LOVE DPA mics.
Well during decent I found out that the parachutes were made here in Devon at a tiny town called Tiverton, by a company called Heathcoat Fabrics. Peter Hill the director said it was "very, very proud of the achievement, 15 years of hard work” He spent the 7 minutes of terror on his knees in front of his TV set, despite his dodgy rural wifi.
The parachutes have to withstand extreme heat while being strong enough to carry the heaviest object ever to land on Mars, all £1.93bn worth of it. It helps slow the spacecraft, as well as the atmosphere from the crazy 13,670mph (8 times faster than a bullet!!!) to the soft landing on Mars.
The fabric is a high-tenacity nylon yarn spun at high speed, washed, coloured and processed with a special finish to ensure its "rapid deployment" then sewn into parachutes in America, Nasa found Heathcote when they exhibited in America.
The parachute, which is 21.5 meters in diameter, deploys about 240 seconds after entry, at an altitude of about 7 miles (11 kilometers) and a velocity of about 940 mph (1,512 kph).
Let us know what your country made for Perseverance!!!
You have to land at a fairly low point on the mars surface so you have a chance that the parachute can slow you down enough. Hitting mars seems ridiculous, but hitting a tiny target on mars is mind-blowing. The landing spot Jezero is a basin, probably where a river used to flow into a lake., depositing sediments in a fan shape known as a delta. This spot was chosen, as there is a small chance that there is preserved signs of life that gained a foothold billions of years ago. Jezero is littered with boulders, steep cliffs and sand dunes, Question: How the hell does a spacecraft travel 300 million miles, and go straight into mars and with pretty much pinpoint accuracy land on the right spot? ...intact.
Answer: IT’S REALLY DIFFICULT, ....Only about 40% of all missions sent to Mars — by any space agency — have successfully landed
Scaling everything down by a factor of about 10 million
It’s the equivalent of shooting a coronavirus from the moving and spinning surface of a basketball, shooting it in a spiralling trajectory at a moving and spinning football from a 6-mile distance, and getting it to hit the dot of the i in the tiny “made in china” sign on the ball. Or shooting a bullet from a moving truck into a truck moving at a similar speed a million miles away. (4 times the distance to the moon)
The event of course all happen, because of the distance the signals have to travel from Mars to Earth, 11 minutes, 22 seconds earlier than we saw them.
So how the hell does it do it?
Well, a rocket launches the Rover from Earth.
The Perseverance rover lifted off successfully on 30 July 2020, at 11:50:00 UTC aboard a United Launch Alliance Atlas V launch vehicle from Space Launch Complex 41 at Cape Canaveral Air Force Station (CCAFS) in Florida and it blasts straight to Mars on a Hohman transfer? The spacecraft departs Earth at a speed of about 24,600 mph
The path is fine-tuned a few times so
Aug 15 Trajectory Correction Maneuvers - 1 - 15 days in fine-tune the path to mars. (already put on 27+ million miles on the clock)
The spacecraft travels approximately 40 kilometres per hour and the path relies heavily on the trajectory it achieved during launch with help of Earths gravity. At the same time relying on Mars as it gains proximity. It’s not just Earth and Mars that are doing the back and forth tug other planets and other celestial bodies affect the probe's path, a course correction has to be made.
All the time
Checking spacecraft health and maintenance
Monitoring and calibrating the spacecraft and its onboard subsystems and instruments
Performing attitude correction turns (slight spins to keep the antenna pointed toward Earth for communications, and to keep the solar panels pointed toward the Sun for power)
Sep 30 Trajectory Correction Maneuvers - 2 - 115 million miles on the clock
Dec 18 - Trajectory Correction Maneuvers - 3 To make sure the spacecraft travels at the right speed and direction to arrive at the correct location at the top of the Martian atmosphere before landing.
Just as Hope, Tianwen were getting into Orbit, Feb 10 Trajectory Correction Maneuvers - 4
Trajectory Correction Maneuvers - 5 ...6 DAYS LATER.
Were TCM-5x or 6 needed?
Preparing for entry, descent, and landing (EDL) and surface operations, a process which includes tests of communications, including the communications to be used during EDL
Cruise stage separation:
separated from the entry capsule at about 3:38 p.m. EST 8.38pm GMT
Atmospheric entry: The spacecraft hits the top of the Martian atmosphere traveling at about 12,100 mph (19,500 kph) at 3:48 p.m. EST
11 minutes later the spacecraft heats to about 1300c, The heat shield slows the spacecraft to under 1,000 miles per hour
3 minutes later - Parachute deployment: The spacecraft deploys its parachute at supersonic speed at around 4 minutes later, The exact deployment time is based on the new Range Trigger technology,
Previous rovers have landed in the general vicinity of areas targeted for study, but precious weeks and months can be used up just travelling to the location of interest.
The Range Trigger technology reduces the size of the landing ellipse (an oval-shaped area around the landing target) by more than 50 per cent,
Where the Mars Exploration Rovers could have landed anywhere within their respective 93-mile by 12-mile (150 by 20 kilometer) landing ellipses, curiosity landed within a 12-mile (20-kilometer) ellipse!
When to trigger the parachute. based on the spacecraft's position relative to the desired landing target
20 seconds later Heat shield separation: The protective bottom of the entry capsule will detach about 20 seconds after the parachute deployment. This allows the rover to use a radar to determine how far it is from the ground and employ its Terrain-Relative Navigation technology to find a safe landing site.
Neil Armstrong and Buzz of tech, two systems working together: the Lander Vision System and the Safe Target Selection system.
the Lander Vision System [LVS], which determines where the spacecraft is over the Martian surface, (Elvis Presley)
LVS's operational lifetime is all of 25 seconds. from about 13,000 feet (3,960 meters), commanding a camera on the rover to quickly take picture after picture
LVS scrutinizes one image a second, breaking each into squares that cover about 5,000 feet (1,520 meters) of surface area.
The system looks for unique patterns in contrasting light and dark created by surface features like cliffs, craters, boulder fields and mountains. It then compares any uncommon pattern with a map in its memory. When it finds five landmark matches during Coarse Landmark Matching mode, it takes another image and repeats the process.
After three successful image-to-map comparisons, LVS kicks into a mode called Fine Landmark Matching. The system breaks the surface into boxes 410 feet (125 meters) across, scanning for unique patterns and comparing them with the map. LVS is looking for at least 20 matches in that one second of eyeballing an image but usually makes much more — up to 150 — in order to generate an even more accurate plot of Mars 2020's trajectory.
"Each time a suitable number of matches is made in an image, in either Course or Fine Landmark Matching, LVS updates where the spacecraft is at that moment," said Johnson. "That update is then fed into the Safe Target Selection system."
The Terrain-Relative Navigation system uses LVS's position solution, calculates where it will land and then compares it to another onboard map, this one depicting areas within the landing zone understood to be either good for landing … or the kind with craters, cliffsides, boulders or rocks fields. If the plotted location isn't suitable, Safe Target Selection can change the rover's destiny, moving its landing point by up to 2,000 feet (600 meters)
They tested this system extensively in the Mohave desert. 659 test landings.
Without TRN, the odds of a successful landing at a good location for the rover are approximately 85%. With TRN, around 99%
During Curiosity’s descent, its engineering team captured a valuable record of their heat shield’s performance. They did this using MEDLI, a sensor package whose name stands for "MSL Entry, Descent, and Landing Instrumentation. Perseverance takes the next step with MEDLI2, a next-generation sensor suite that collects data from both the heat shield and backshell
1.5 mins later - Backshell separation: The back half of the entry capsule that is fastened to the parachute will separate from the rover and its “jetpack” (known as the descent stage) at 3:54 p.m. EST (12:54 p.m. PST). The jetpack will use retrorockets to slow down and fly to the landing site.
Touchdown: The spacecraft’s descent stage, using the sky crane manoeuvre, will lower the rover down to the surface on nylon tethers. The rover is expected to touch down on the surface of Mars at human walking speed (about 1.7 mph, or 2.7 kph) at around 3:55 p.m. EST (12:55 p.m. PST).
FACTS ABOUT Perseverance
About the size of an SUV
Length 2.9 m (9 ft 6 in)
Diameter 2.7 m (8 ft 10 in)
Height 2.2 m (7 ft 3 in)
Launch mass 1,025 kg (2,260 lb)
Power 110 W (0.15 hp) a Tesla is 6000 times more powerful.
At 2,260 pounds (1,025 kilograms), Perseverance is about 278 pounds (126 kilograms) heavier than Curiosity
Perseverance carries seven scientific investigation instruments and possesses a total of 19 cameras and two microphones, The other parts of the spacecraft involved in
entry, descent and landing carry four additional cameras, potentially allowing engineers to put together a high-definition view of the landing process after the rover safely touches down on Mars
To show appreciation for healthcare workers who helped during the pandemic, an 8 cm × 13 cm (3.1 in × 5.1 in) plate with a staff-and serpent symbol was placed on the rover.
Jezero, Between 3 billion and 4 billion years ago, a river there flowed into a body of water the size of Lake Tahoe, depositing sediments packed with carbonite minerals and clay
Perseverance is the first rover to bring a sample caching system to Mars that will package promising samples for return to Earth by a future mission. Rather than pulverizing rock the way
Curiosity’s drill does, Perseverance’s drill will cut intact rock cores that are about the size of a piece of chalk and will place them in sample tubes that it will store until the rover reaches an appropriate drop-off location.
Perseverance also carries a technology demonstration — a proof-of-concept experiment — called MOXIE (Mars Oxygen In-Situ Resource Utilization Experiment). This instrument will produce oxygen from Mars’ carbon dioxide atmosphere, demonstrating a way that future explorers might produce oxygen for rocket propellant as well as for breathing
Two 4-foot-long (1.2- meter-long) rotor system that
spins up to 2,400 revolutions per minute
Weighs 4 pounds (1.8 kg)
• Solar-powered and recharges on its own
• Wireless communication system
The helicopter, which will remain attached to the rover for 30 to 60 days, and its base station (an electrical box on the rover that stores and routes communications between the rotorcraft and Earth) are operating as expected.
Charging the batteries from Percy to 30% soon (hour charge) then try again to 35% and then weekly charges while attached to the rover. (these charging data compared to in cruise charging data)
Like much of the 4-pound (2-kilogram) rotorcraft, the six lithium-ion batteries are off-the-shelf. They currently receive recharges from the rover’s power supply. Once Ingenuity is deployed to Mars’ surface, the helicopter’s batteries will be charged solely by its own solar panel.
After Perseverance deploys Ingenuity to the surface, the helicopter will then have a 30-Martian-day (31-Earth-day) experimental flight test window. If Ingenuity survives its first bone-chilling Martian nights – where temperatures dip as low as minus 130 degrees Fahrenheit (minus 90 degrees Celsius) – the team will proceed with the first flight of an aircraft on another world.
If Ingenuity succeeds in taking off and hovering during its first flight, over 90% of the project’s goals will have been achieved. If the rotorcraft lands successfully and remains operable, up to four more flights could be attempted, each one building on the success of the last.
“We are in uncharted territory, but this team is used to that,” said MiMi Aung, project manager for the Ingenuity Mars Helicopter at JPL. “Just about every milestone from here through the end of our flight demonstration program will be a first, and each has to succeed for us to go on to the next. We’ll enjoy this good news for the moment, but then we have to get back to work.”
HiRISE was approximately 435 miles (700 kilometers) from Perseverance and traveling at about 6750 mile per hour (3 kilometers per second) at the time the image was taken