Lowell II, Candor Chasma Base Station Mission Backstory

Transcription

1 Mission Backstory - 1 of 12 Lowell II, Candor Chasma Base Station Mission Backstory Sources and Resources NASA s Journey to Mars Plan as of 2016 o o Evolvable Mars Campaign, NASA PowerPoint Hohmann Transfer Orbit Equations: Gale Crater and Curiosity Rover: o n/aboutgalecrater o Candor Chasma: o ndor_chasma o Utopia Planitia: o s&newsid=1951 Davila, Alfonso and Willson, David, et. al (2013). Perchlorate on Mars: A chemical hazard and resource for humans. International Journal of Astrobiology. Dr. Steve Lee, DMNS Curator of Planetary Science Note: Much of this plan was inspired by the 2016 NASA Journey to Mars plan to send humans to Mars and Phobos. While solidly grounded in the science of space exploration, the elements of this mission backstory which happen in the future are purely speculative. To clarify this, sections describing what has actually happened, or is actually happening, are marked fact. Those which, though scientifically plausible, have not actually occurred, are marked story.

2 Mission Backstory - 2 of 12 Purpose of Mars Exploration Program Mars has always been a source of inspiration for explorers and scientists. Robotic missions have found evidence of water, but if life exists beyond Earth still remains a mystery. Robotic and scientific robotic missions have shown that Mars has characteristics and a history similar to Earth's, but we know that there are striking differences that we have yet to begin to understand. Humans can build upon this knowledge and look for signs of life and investigate Mars' geological evolution, resulting in research and methods that could be applied here on Earth. A mission to our nearest planetary neighbor provides the best opportunity to demonstrate that humans can live for extended, even permanent, stays beyond low Earth orbit. The technology and space systems required to transport and sustain explorers will drive innovation and encourage creative ways to address challenges. As previous space endeavors have demonstrated, the resulting ingenuity and technologies will have long lasting benefits and applications. The challenge of traveling to Mars and learning how to live there will encourage nations around the world to work together to achieve such an ambitious undertaking. The International Space station has shown that opportunities for collaboration will highlight our common interests and provide a global sense of community. From NASA Why We Explore NASA s Steps in the Mars Exploration (fact) Through the exploration of Mars via satellites and landers, we have found evidence that liquid water once existed on the surface of Mars. This exciting discovery is one step in the search for life on Mars. All of NASA s robotic exploration of Mars so far have been

3 Mission Backstory - 3 of 12 focused on searching for this evidence and Following the Water. More recent missions have also been investigating if Mars was, or is, habitable for life. Future missions will focus on searching for signs of life as well as helping us to prepare for future human exploration of Mars. NASA plans to execute human exploration of Mars, known as the Journey to Mars program, in three phases: The first phase, known as Earth Reliant, primarily focuses on research on the International Space Station. There, astronauts test different technologies that will be needed for future deep space missions as well as learn more about the challenges of living and working in space for long periods of time. The Proving Ground phase will be a series of missions near the moon, in a region known as cislunar space, that will test the capabilities needed to live and work at Mars. During this phase, astronauts will be days away from Earth. This is a natural stepping stone to a mission to Mars which will put astronauts months away from Earth. The proving ground missions will all use NASA s Space Launch System and Orion spacecraft. Astronauts will first do missions shorter than a month in cislunar space before completing a yearlong mission to cislunar space in the 2020s. This will help test our readiness for missions to Mars. Another part of this phase of exploration, is the Asteroid Redirect Mission where NASA will send robotic spacecraft to capture an asteroid and put it into orbit around the moon. There, astronauts will explore the asteroid and return samples to Earth. The final phase, called Earth Independent, will build on what was learned at the International Space Station and the proving ground deep space missions to send humans to Phobos in the early 2030 s. During this phase, tests of the entry, descent, and landing techniques that will be used for Mars surface missions will be tested as well as study what is needed to use the resources already on Mars for surface missions. Adapted from NASA Journey to Mars Overview

4 Mission Backstory - 4 of 12 Getting to Mars and Back (story) Astronauts will not travel directly from the surface of Earth to the surface of Mars. Instead, they will use three different spacecraft. The crew will launch in a small spacecraft from earth to lunar orbit, where they will rendezvous with the Mars Transport Hab. The large Mars Transport Hab has been assembled in lunar orbit, and is built of interlocking modules much like the International Space Station was. The living space of the Mars Transport Hab is about the size of a large school bus. It will transport Mars astronauts to and from Mars but will never land on Mars or Earth. The Mars Transport Hab will then leave lunar orbit and travel for a little more than 8.5 months. Carried with this vehicle is the Mars Lander. Once the Mars Transport Hab injects into Mars orbit, astronauts will board the Mars Lander and undock from the Mars

5 Mission Backstory - 5 of 12 Transport Hab. The Mars Lander carries Mars astronauts to the Martian surface where they will remain for their surface mission, which lasts approximately 15 months. The return to Earth will reverse these steps, and involve a transit time of about 9 months back to the Earth/Moon system. Launch Windows (fact) Missions to Mars can be launched only during specific time spans called launch windows, which are when energetically favorable alignments of Earth and Mars occur. Though various trajectories to Mars can be used, including sling-shotting around Venus, the most fuel-efficient path is called the Hohmann Transfer (see diagram above). Launch windows for the Hohmann Transfer happen every time Mars is approximately 44 ahead of Earth in its orbit. This planetary arrangement occurs approximately every 26 months. So missions take place every two years or so, but not in between. Total mission duration is also controlled by launch windows. The trip to and from Mars will require between eight and nine months each way. So, astronauts will need to stay on Mars for fifteen to sixteen months, regardless of mission progress. Burning extra fuel can reduce flight time to Mars by a few weeks, but every flight path to Mars is still constrained by available launch windows.

6 Mission Backstory - 6 of 12 The return trip to Mars also takes between eight and nine months. The launch opportunity to Earth occurs when Earth is approximately 75 behind Mars. Please note the dates below are idealized dates for the Hohmann Transfer, and for the purpose of our story, we can assume the launches occurred on the optimum day for this particular transfer method. In reality, launch windows are open for several days or even weeks and are still considered energetically favorable. Launch Windows to and from Mars (fact) Mission Leave Earth Arrive Mars Surface Leave Mars Arrive Earth Mission Duration Phobos 4/11/ /26/ Days 3/24/ /9/2035 Lowell I 9/7/2039 5/22/ Days 8/20/2041 5/5/2042 Lowell II 12/15/2043 8/30/ Days 11/28/2045 8/13/2046 Lowell III 3/22/ /7/ Days 3/5/ /20/2050 Note: A robotic supply mission arrived a year or so before each of these missions. These were not launched during Hohmann Transfer Windows. DMNS Plans for the Exploration of Mars (story) Phobos, 2033 The first human mission to the Mars system was not to Mars itself, but to its largest and innermost moon, Phobos. Phobos is the larger of the two Martian moons being approximately 14 x 17 x 11 miles in diameter. This could easily fit within the city limits of Denver. It orbits Mars three times a day at a distance of only 5,862 miles from the surface (for comparison Earth s moon is approximately 250,000 miles from the Earth). Due to the lower gravity, takeoff and landing is much easier on Phobos than Mars, which made it a valuable proving ground for future human missions to the Martian surface. During this mission, technologies such as the Habitat (Hab-Lab) and rovers were tested. During this mission, astronauts were also able to manage un-manned Mars surface missions with almost real-time communication. Scientific studies of the surface of Phobos were also conducted during this mission that provided valuable insight into the composition of the moon.

7 Mission Backstory - 7 of 12 Lowell I, Gale Crater, 2039 The Mars Surface missions, known as the Lowell Program, began in Lowell I returned to a familiar site, Gale Crater, which was explored by the Curiosity Rover in the 2010 s. Gale Crater was chosen for both the Curiosity and Lowell I missions because of the history of water at this site as well as the layered geology of Mount Sharp at the center of the crater. Gale Crater formed when a meteor hit Mars in its early history, about 3.5 to 3.8 billion years ago. Today, the crater spans 96 miles across and at the center, rising 3 miles above the floor of the crater, is Mount Sharp. Layering of Mount Sharp suggests it is the surviving remnant of an extensive sequence of deposits. Some scientists believe the crater filled in with sediments and, over time, the relentless Martian winds carved Mount Sharp. The Curiosity Rover not only confirmed that Gale Crater once had water, but it also helped scientists learn more about the history of the Martian atmosphere and the past habitability of Mars. One of the major discoveries was that Mars had the right chemistry to support living microbes. In a sample of mudstone, Curiosity detected sulfur, nitrogen, oxygen, phosphorus and carbon, all of which are key ingredients necessary for life. This sample also contained clay minerals with not too much salt, which suggests that possibly fresh drinking water once flowed in Gale Crater. Other evidence that supported the concept that flowing water once was in Gale Crater was the discovery of smooth, rounded rocks that likely were eroded as they moved downstream. Rock layering was also consistent with a steady stream of flowing water. Lowell I astronauts continued the investigations at Gale Crater and discovered more about the history of water at this site.

8 Mission Backstory - 8 of 12 Lowell II, Candor Chasma, 2043 X Candor Chasma is part of a larger canyon system known as Valles Marineris. Valles Marineris is made up of many individual canyons or chasmas. It extends over 2,500 miles east to west and up to 500 miles north to south. If Valles Marineris were in the United States, it would stretch all the way from the east coast to the west coast. In places it is nearly 5 miles deep, which is 5 times deeper than the Grand Canyon. The image above shows Valles Marineris as well as Candor Chasma. The x is the approximate location of the Candor Chasma Base Station, the location for the Lowell II mission. This location was chosen because of the layered rocks of the canyon walls and mesas within rover range. These layers could hold keys to not only the history of this region, but Mars overall, especially the several mile-high canyon walls. Observations from orbit indicate that some of these layered features could have potentially been caused by water, wind, or even episodic volcanic activity. Orbiters have also detected the presence of sulfates and other minerals that could indicate there was once water in Candor Chasma. The astronauts main scientific objective will be to study the geology of the canyon walls and mesas within Candor Chasma. As part of this study, they will also try

9 Mission Backstory - 9 of 12 to answer the question: what happened to all of the sediment that was once in Valles Marineris after it formed? MESA A MESA B Mars Global Surveyor Image of Candor Chasma. Note the layered features, including Mesa A and Mesa B, which are visible from Candor Chasma Base Station. This image is displayed in the Visitor Center area of Space Odyssey. Along with studying the geologic history of this site, astronauts on the Lowell II mission will continue work on dust mitigation and purification. Study of Martian regolith done by landers and orbiters prior to Lowell I had indicated that it has a high concentration of perchlorates and silica in the regolith. Perchlorates are a salt derived from perchloric acid that can be dangerous to humans at high levels, since it disrupts thyroid function. Silica, which was discovered in Martian rock by the Curiosity Rover, is also present in high concentrations at some localities on Mars and is a well known carcinogen. Lowell I astronauts advanced many mitigation techniques to ensure the dust was not tracked into living spaces to preserve the health and safety of the astronauts. Lowell II will also be experimenting with growing plants in Martian regolith with added nutrients to investigate how the perchlorates effect the growth of the plant as well as the uptake of this salt into the plant. This may affect whether plants grown this way could be a source of food on future missions.

10 Mission Backstory - 10 of 12 Candor Chasma Base Station Energy Storage North Visitor Center Mars Lander Landing Site When visitors to Candor Chasma Visitor Center arrive, they will notice that Mars behind the glass is not pristine. There are footprints, prototype bricks waiting to be tested, a portable atmospheric monitoring unit (PAM), as well as a habitat and laboratory (HabLab) where the astronauts live and work. The base station is slightly larger than what is viewed from Visitor Center. To the south of the HabLab is the nuclear power plant that powers the HabLab. Nuclear power was chosen over solar because it would have required several solar panels to power operations (due to Mars being further away from the Sun) as well as concerns about dust. It would have taken a significant amount of the astronauts time to keep the solar panels clean. Valles Marineris has also been known to fill with dust during large dust storms, which would have severely limited the amount of power the solar panels could generate. Our current astronauts on Mars arrived in Mars orbit on August 30, They spent a couple of weeks in orbit before taking the lander to the surface. Astronauts have been working on the surface for about a month getting the base set up. It is now Sol 47 on their mission and they are just starting their scientific experiments on the surface.

11 Mission Backstory - 11 of 12 Energy Storage Facility Mesa A, Wedding Cake Rock Brick Making Experiments Magnets collecting Iron from airborne dust View of Candor Chasma Base Station from the steps the astronauts use to get in and out of the hab-lab. Far Canyon Wall (~11mi away) Mesa B Phobos and Deimos in Sky Hab Lab Cargo Bay PAM View of Candor Chasma Base Station from the brick experiment (which is on the left side of the diorama as viewed from Visitor Center)

12 Mission Backstory - 12 of 12 Lowell III, Utopia Planitia, 2048 Utopia Planitia For the third mission, astronauts will be sent to the southern edge of Utopia Planitia. Utopia Planitia is a large basin (about 2050 miles in diameter) that was formed by an impact early in Mars history. Utopia Planitia was previously explored by the Viking 2 lander in 1970 s. In 2016, scientists using the Mars Reconnaissance Orbiter discovered a large deposit of water ice less than 30 feet below the surface. The deposit is more extensive in area than the state of New Mexico and holds a little more than the volume of water in Lake Superior (which holds 3 quadrillion gallons of water). It represents approximately 1% of the total volume of water ice on Mars. The large deposit of subsurface ice at Utopia Planitia was likely formed by snowfall accumulating into an ice sheet that was mixed with dust at a time when Mars axial tilt was higher than it is today. The Lowell III astronauts goal on this mission will be to directly sample this ice to learn more about the climate history of Mars, in particular the Martian Ice Ages. This abundance of water also has the potential to serve as a great resource for the Lowell III Mission as well as future missions.