Unmanned spacecraft include satellite communications, weather and military surveillance satellites as well as telescopes.
Landing on Mars can be an enormously complex challenge. NASA’s Curiosity rover demonstrated how difficult this task could be in 2012 by performing flawlessly through an incredibly complex sequence, including successfully deploying an elaborate sky crane system to lower itself onto Gale Crater’s surface.
Perseverance Rover
This car-sized rover’s mission is to explore Mars for signs of past life, particularly carbon-containing molecules which could have been preserved within rocks. Additionally, this technology tests will help future astronauts produce oxygen for breathing and rocket propellant production on its surface.
Perseverance has made its home in Jezero Crater, which scientists suspect once held a lake and river delta. Here it searches for fossilized signs of past microbiological life in rock layers that once held water in this watery ecosystem.
Perseverance features seven science instruments and the first sample-caching system ever sent into space; its cameras include 20-megapixel full-color ones that significantly outclass Opportunity’s one-megapixel B&W ones; each day NASA’s Deep Space Network provides instructions about where and what it should do, while Perseverance communicates back home via the Mars Reconnaissance Orbiter which relays this data back.
Jet Thrusters
NASA and its industrial partners continue their investigation of human missions to Mars, with engineers developing ways to get there faster. A key issue involves making sure rockets have enough chemical propellant for a roundtrip journey.
Engineers at Caltech’s Jet Propulsion Laboratory for NASA have made strides toward meeting this challenge, developing propulsion systems designed specifically for Mars missions to enable more payloads to travel on them while cutting costs.
Psyche employs solar electric propulsion powered by four Hall-effect thrusters that use charged ions of inert xenon gas as thrust. Each thruster produces approximately the same force as one AA battery. The spacecraft also carries three science instruments for exploring Psyche’s composition and history; among these instruments are a multispectral imager to photograph its surface as well as gamma-ray and neutron spectrometers that will assist scientists.
Parachutes
As thousands of individuals dedicate time and energy to building spacecraft, the end product often goes unnoticed once launched from Earth. But recently, Perseverance rover returned video footage showing its descent through Mars’ atmosphere and safe landing on its planet-near neighbor.
Heat shield exploded, parachute deployed and it decelerated from 21,000 miles per hour to approximately 400. A rocket-powered sky crane then separated and continued lowering it toward Earth surface.
Engineers at JPL are working on an innovative system for landing even larger spacecraft, such as those carrying supplies and habitats for human missions to Mars. But for that to work properly they require larger and stronger parachutes; during one test flight in Hawaii last June involving Manning and Clark-designed parachute bursting almost instantly despite subsonic tests showing it should withstand 80,000 pounds of drag – further compounding mystery when images from HiRISE began showing that dark marks left by it had begun fading over time.
Sky Crane
For those unfamiliar with NASA rover entry, descent, and landing processes, the Sky Crane maneuver may appear dangerous; however, it is actually one of the best methods of landing Curiosity safely on Earth.
At around one mile high and 322 miles per hour, Curiosity will descend under her parachute’s cover, sending its heat shield, back shell and descent stage whizzing away into space. Curiosity will remain connected to its descent stage by an array of nylon cords measuring 7.5 meters long called its “bridle.”
Once the bridle reaches the surface, sensors will use small charges to break loose the ties that secure its descent stage before sending it off into space to crash in a safe location. Although this may sound dangerous and unnecessary, this method is the only way to land a rover safely on Earth and commence its mission.