Mars Exploration News
MARSDAILY
Engineers put a Mars lander legs to the test
This setup is being used at JPL to test a 16-inch-diameter (40-centimeter-diameter) footpad for a future Mars lander. The footpad was plunged into a testbed filled with 10,000 pounds (4,536 kilograms) of simulated Martian soil in order to see how deep it would sink. Credit: NASA/JPL-Caltech
Engineers put a Mars lander legs to the test
by Staff Writers
Pasadena CA (JPL) Aug 11, 2023

Sturdy legs are needed to absorb the impact of the heaviest spacecraft to ever touch down on the Red Planet. NASA's Perseverance rover continues to rack up tubes filled with rock core samples for the planned Mars Sample Return campaign. The joint effort by NASA and ESA seeks to bring scientifically selected samples back from Mars to be studied on Earth with lab equipment far more complex than could be brought to the Red Planet. Engineers are busy designing the Sample Retrieval Lander that would help bring those samples to Earth. As part of that effort, they've been testing prototypes of the lander's legs and footpads at NASA's Jet Propulsion Laboratory in Southern California.

NASA is taking what it has learned over decades of successful Mars landings and applying those lessons to the Sample Retrieval Lander concept, which would be the largest spacecraft yet to land on Mars - as much as 5,016 pounds (2,275 kilograms). Along with relying on next-generation parachutes and 12 rocket engines to slow the spacecraft's descent to Mars, the lander would need its legs to help absorb the impact of touchdown.

The spacecraft would carry a rocket that would launch Perseverance's carefully packaged samples to an awaiting orbiter. An 8-foot (2.5-meter) robotic arm, to be provided by ESA, would load those sample tubes into the rocket. The lander could carry up to two mini-helicopters to serve as backups to retrieve tubes deposited in a sample depot. So the lander needs to be hefty.

To understand how energy would be absorbed during landing, JPL engineers conducted drop tests earlier this year that will inform the design and subsequent tests. One series of tests involved dropping a three-eighths scale early-concept lander model onto a hard floor, while the other centered on slamming a full-size footpad into simulated Martian soil. The team can apply what they observe during testing as they refine the design.

Starting Small
"There's already a night-and-day difference between this lander and the design we started with," said Morgan Montalvo, a JPL engineer working on the tests.

The team has to think of every possible landing scenario, including what would happen if the spacecraft touched down at an angle and "stubbed a toe" on a rock. To try and create such a challenge during one series of tests, they dangled a prototype from a pendulum that sent the mini-lander to the ground at an angle. Cameras on tripods ringed the landing surface, a large black metal plate on the floor. A low guardrail doubled as the rock.

Montalvo called out a 3-2-1 countdown, and the lander swooped down with a bang, slamming into the guardrail. When the team studied the high-speed video later, they were surprised to find a perceptible wobble in one of the leg's main struts. Increase the lander's size, and this wobble would be even more noticeable. In response, stronger flight struts will be designed to handle those forces.

The team has also tested the lander's "load limiters" - steel rods connecting its chassis to its legs. When the legs move during touchdown, the rods are forced to bend, absorbing some impact. The limiters were used on past landers like InSight, but they're bigger on this prototype and will be even bigger on the final design.

"You'd never be able to bend these steel rods with just your hands," Montalvo said. "It's pretty insane seeing just how much force goes into them, bending them nearly in half after a drop."

Heavy-Footed Spacecraft
Testing of the lander's full-size foot pads has been taking place in a box filled with 10,000 pounds (4,536 kilograms) of powdery, Mars-like soil. About 16 inches (41 centimeters) in diameter, the flat, round footpad attaches to an assembly with nearly a half-ton of iron weight plates.

Patrick DeGrosse, the test bed lead, kept watch during one test as the lander foot plunged into the soil, leaving a deep indentation while tossing a cloud of dust. The impact shook the walls of the building. Afterward, high-speed cameras showed how energy radiated out from the pad.

"We don't want the lander's feet to sink so far that the bottom of the lander hits the surface," DeGrosse said. "And we want to make sure the lander is very even on the surface. It needs to be sturdy, because the lander is also a platform for the rocket to lift off from."

After each test, DeGrosse rebuilds the soil bed 4 inches at a time, tamping down the material to make sure it's compressed the way scientists expect it to be on Mars. The conditions also need to be consistent for the team to understand how the footpad interacts with the soil. So DeGrosse repeats this time-consuming process four times a month.

"You have to rebuild Mars multiples times to do this test," he said.

Video: Mars Sample Return: How Do You Test the Legs of NASA's Heaviest Mars Spacecraft?

Related Links
Mars Sample Return
Mars News and Information at MarsDaily.com
Lunar Dreams and more

Subscribe Free To Our Daily Newsletters
Tweet

RELATED CONTENT
The following news reports may link to other Space Media Network websites.
MARSDAILY
Phoenix's Red Planet Selfie
Pasadena CA (JPL) Aug 11, 2023
NASA's Mars Phoenix Lander gathered images of itself for this selfie from June 5 through July 12, 2008, with its Surface Stereo Imager (SSI). This mosaic is made up of more than 100 different SSI pointings, with images taken through three different filters at each pointing. 15 years ago in August 2008, Phoenix completed its three-month mission studying Martian ice, soil, and atmosphere. The goals of the Phoenix Mars Lander were to study the history of water in the Martian arctic, search for eviden ... read more

MARSDAILY
A Framework for Optimized, Integrated Lunar Infrastructure

NASA's Lunar Trailblazer gets final payload water hunt

Chandrayaan-3 nears landing with successful orbital adjustments

NASA may delay crewed lunar landing beyond Artemis 3 mission

MARSDAILY
China to launch "Innovation X Scientific Flight" program, applications open worldwide

Scientists reveal blueprint of China's lunar water-ice probe mission

Shenzhou 15 crew share memorable moments from Tiangong Station mission

China's Space Station Opens Doors to Global Scientific Community

MARSDAILY
Hera's mini-radar will probe asteroid's heart

NASA's $985 million Psyche mission to all-metal asteroid nears liftoff

Winchcombe meteorite is helping us to understand more about asteroids

A Banner Year For The Perseid Meteor Shower

MARSDAILY
NASA's Europa probe gets a hotline to Earth

All Eyes on the Ice Giants

Hundred-year storms? That's how long they last on Saturn.

Looking for Light with New Horizons

MARSDAILY
Studying rivers from worlds away

Saturn's Rings shine in Webb's observations of Gas Giant

Key building block for life found at Saturn's moon Enceladus

MARSDAILY
GHGSat taps Spire Global for four more 16U CubeSats

HALO investigates transport of polluted air masses over the Pacific Ocean

Global collaboration leads to new discoveries in lightning research

NASA TechRise Student Challenge tests experiments in stratosphere

MARSDAILY
Indian lunar lander splits from propulsion module in key step

NASA challenges students to fly Earth and Space experiments

Virgin Galactic rockets its first tourist passengers into space

Embracing the future we need

MARSDAILY
Watch an exoplanet's 17-year journey around its star

Exoplanet surveyor Ariel passes major milestone

The oldest and fastest evolving moss in the world might not survive climate change

Chemical contamination on International Space Station is out of this world

Subscribe Free To Our Daily Newsletters




The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.