As NASA managers continue to work through the evaluations into an exploration roadmap for the agency, the end goal of sending humans to Mars is starting to show a level of consistency. Per documentation, the key Design Reference Mission (DRM) evaluations are pointing to the \u201cFlexible Path\u201d approach of visiting a Martian moon, prior to landing humans on Mars itself.<\/p>\n
Design Reference Mission \u2013 Roadmap Work:<\/p>\n
As the plan currently stands, 14 Design Reference Missions (DRM) have been created as part of the ongoing SLS Concept Of Operations (Con Ops) process and Exploration Roadmap evaluations, under what is known as \u201cCycle C\u201d evaluations. (Update Area \u2013 L2 Link).<\/p>\n
Opening with the politically-requested support for the International Space Station (ISS) \u2013 which would result in the overkill of using the Space Launch System (SLS) Heavy Lift Launch Vehicle (HLV) being used to send what is now a Beyond Earth Orbit (BEO) Orion to the orbital outpost, in the event of a major failure of the commercial ISS support contracts \u2013 the plan quickly moves on to the Moon.<\/p>\n
![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z213.jpg\" "\\"Z2\\"")
With SLS-1 and SLS-2 trips to Lunar Orbit effectively being the test flights for the uncrewed and crewed opening missions, refinements have been made to bring the Deep Space Hab (DSH) earlier into the roadmap, pointing once again at the ambitious \u201cGateway Platform\u201d potentially becoming part of what is tagged as the CIS_LP1_1A\/B\/C DRMs.<\/p>\n
Again showing its strength of late, the push to return humans to the lunar surface are listed as LUN_SOL_1A for Polar Access and LUN_CRG_1A for cargo to be sent to the surface of the Moon.<\/p>\n
It is hoped that such missions could be enabled by the early 2020s, with an eye on setting up a lunar base, likely via international cooperation and commercial ambitions.<\/p>\n
\u201cMinimum\u201d to \u201cFull\u201d capability missions to a Near Earth Asteroid (NEA) have five DRMs currently under evaluation, likely ahead of being traded down.<\/p>\n
Space Technology (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n These missions would all require its own giant leap in planning \u2013 not least from the aspect of life support and contingency evaluations \u2013 as the flights would result in crews traveling the great ever distance from Earth in human history.<\/p>\n These DRMs will be expanded on in future articles during the evaluations to solidify the roadmap.<\/p>\n Design Reference Mission \u2013 Mars:<\/p>\n By far the greatest challenge, Mars is not being shown as part of the Cycle C evaluations, as much as they are listed under \u201cForward Work\u201d \u2013 with the DRM tags of MAR_PHD_1A and MAR_SFC_1A.<\/p>\n However, these DRMs alone provide clues into the thinking of the Exploration Roadmap team, which appears to be following the Flexible Path approach \u2013 a presentation which remains the most recent and comprehensive outline into achieving a crewed mission to Mars, built out of the recommendations from the Augustine Committee into Human Space Flight.<\/p>\n \u201cA human Mars Orbit\/Phobos Mission represents an intermediate step between human exploration missions in near-Earth space and human missions to explore the surface of Mars,\u201d opened the expansive section on the manned missions to Mars\/Phobos in the 65 page NASA internal \u201cFlexible Path\u201d presentation (available to download in L2 \u2013 Link).<\/p>\n The debut manned mission to the Mars region would likely use a \u201cshort stay\u201d trajectory (\u201copposition class\u201d). Total mission durations for the short-stay missions range from 550-650 days, with 30 to 40 days in the vicinity of Mars.<\/p>\n During this scenario, over 95 percent of the total mission time is spent in the deep-space interplanetary environment with the balance spent in the vicinity of Mars. Duration of the transit legs ranges from a minimum of 190 days and maximum in excess of 400 days.<\/p>\n Conjunction-class missions (about 20-40 percent longer in total but with over 12 times the stay) are also feasible for a Phobos mission.<\/p>\n Phobos also presents a number of Mars-like challenges to a manned mission, allowing NASA engineers and astronauts to learn how to approach a subsequent Mars mission.<\/p>\n \u201cOne of the significant advantages a Phobos mission would be to demonstrate many of the technical and operational approaches needed for Mars missions without yet having all the required systems, or committing the crew to a full-duration surface stay,\u201d added the presentation. <\/p>\n \u201cA Phobos mission could drive and demonstrate solutions of these items.\u201d<\/p>\n The Phobos element is reviewed in greater detail via the previous article covering this element of the Flexible Plan.<\/p>\n For additional Flexible Path articles \u2013 See also: Multiple Launches and Challenges For Mars Surface Mission:<\/p>\n A fleet of SLS\u2019 would be required for a single crewed mission to Mars mission, including other numerous vehicles, most of which are very much at the conceptual stage of design.<\/p>\n NASA Glenn teams are understood to be reworking a baseline video into a Mars mission (Nine minute CGI video available on L2 \u2013 Link), in order to provide a general baseline using SLS \u2013 a video which already shows the challenges of an actual crewed mission to Mars.<\/p>\n \u201cDue to the wide variability of the short stay class trajectories the number of propulsive stages varies with opportunity, as will the number of HLV launches. Assuming hydrogen-oxygen in-space propulsion, the number of HLV launches varies between 10 and 15,\u201d noted the Flexible Path approach.<\/p>\n The Mars campaign video shows seven HLVs launching the major elements of three vehicles using NTR (Nuclear Thermal Rocket) propulsion, namely the MLV Cargo Vehicle \u2013 created from two HLV launches, the MLV Habitat Vehicle \u2013 created from two HLV launches, and the MTV Crew Transfer Vehicle \u2013 created from three HLV launches. All three vehicles are assembled in Low Earth Orbit.<\/p>\n HLV launches 3 and 4 are used to deliver the Habitat and Cargo Landers, large elements of hardware which are depicted as sitting on top of the HLV without the need for a fairing.<\/p>\n Each of these elements rendezvous and dock with their propulsion stages in LEO and depart enroute to Mars, each displaying one large solar array and two smaller arrays.<\/p>\n Numerous vehicles are hosted on the cargo lander, including Space Exploration Vehicles (SEV) which may debut during a Moon surface mission.<\/p>\n As seen in the video, a robotic cart can be seen leaving the cargo lander and setting up the deployment of the Fission Surface Power System (FSPS) and radiators, again working under the notion of a mission utilizing nuclear power.<\/p>\n The most mass-efficient means of providing high power for surface missions is through the use of nuclear fission systems.<\/p>\n With the stage set on the Martian surface for the arrival of the crew, three HLVs are tasked with launching the major elements of the Mars Transport Vehicle (MTV), with the hardware deployed and rendezvous in LEO.<\/p>\n The crew is then launched to the assembled vehicle on another Orion, which is undocked as the crew ingress the MTV.<\/p>\n Ahead of departing LEO, the MTV is seen deploying four large solar arrays for the transit to Mars.<\/p>\n This mission profile does concur with the Flexible Path approach, as much as it is obvious: \u201cOnce all of the in-space propulsive stages are assembled in LEO, the crew is launched via Orion and the crew departs for Mars.\u201d<\/p>\n However, with no Ares I available \u2013 since its cancellation \u2013 and the HLV being mainly used to launch the large MTV\/Cargo elements, a potential change may be to launch the Orions via a Delta IV-H, for example.<\/p>\n The crew then enter the attached Orion, undock from the MTV and dock with the orbiting Habitat Lander waiting for them in Mars orbit.<\/p>\n The Orion then undocks unmanned and redocks with the MTV, as the Habitat Lander \u2013 now containing the crew \u2013 begins its descent to the Martian surface.<\/p>\n Using Hypersonic Aero-assisted Deceleration, the lander enters the Martian atmosphere, separates its aeroshell and carries out Supersonic Retro-Propulsive braking \u2013 again deploying three large parachutes prior to a powered landing.<\/p>\n The other lander is staged at a distance from the base structures, which is where the astronauts will translate to during their final moments on the planet.<\/p>\n Per the video, this vehicle uses three large engines to launch the crew off the surface and back into Mars orbit where they rendezvous and dock with the MTV.<\/p>\n Shortly after docking, the MAV \u2013 along with any contingency consumables \u2013 are jettisoned whilst still in Mars orbit.<\/p>\n The MTV again fires its three engines and the crew begin their trip back to Earth.<\/p>\n Upon arrival back in the vicinity of Earth, the crew leave the MTV\u2019s DSH for a final time and ingress into the Orion, which undocks and re-enters Earth\u2019s atmosphere for a splashdown in the Pacific Ocean under parachutes.<\/p>\n \u201cOn arrival at Mars the crew propulsively captures into orbit and eventually maneuvers to Phobos rendezvous. After a 40 day stay in the vicinity of Mars, the crew departs for Earth return. The return leg is targeted for a Venus flyby to reduce the propulsive requirement,\u201d added the Flexible Path approach.<\/p>\n \u201cSince this leg likely passes inside the orbit of Venus, such a mission would include the closest approach to the Sun by a human crew. Small asteroid flyby opportunities may also exist on such trajectories. The crew can participate in science investigation of flyby objects from a unique perspective.<\/p>\n \u201cThe Orion used to launch and board the crew is also used to return them to Earth via direct entry. The Crew Transfer Vehicle (or MTV) is targeted to flyby Earth and is expended in deep space.\u201d<\/p>\n Making the case for Phobos first, the Flexible Path again stresses the challenges with a Mars surface mission, and the need to learn how to safely carry out such an ambitious deep space missions before taking on the ultimate challenge of the Red Planet itself.<\/p>\n \u201cSuch a mission is suggested by the Augustine Committee as a possible element of a Flexible Path strategy, so it bears examination.<\/p>\n \u201cAssessment of the value of such a mission compared to the risk of sending crew on a multi-year, deep-space mission is a function not only of the potential science return, inter-operation with parallel robotic Mars surface missions, and direct feed-forward to human Mars surface missions, but also of the unique technical challenges and risks it would impose, and also how \u201cfast\u201d the program intends to get to the surface of Mars.\u201d<\/p>\n As such, it appears that the 2011-2012 effort to create an Exploration Roadmap via the use of SLS has initially sided with recommendations made at the Augustine Committee review, placing a Martin mission to one of its moons ahead of a Mars surface mission.<\/p>\n \u201cAt the completion of this mission, design solutions for and demonstrations of in-space hardware elements designed for human Mars surface mission will have been accomplished, as will significant scientific and exploration objectives at Mars and Phobos. Significant such objectives include gathering and preliminary analysis of samples from both Mars and Phobos, including samples from candidate landing site for future human crews.<\/p>\n \u201cThis mission could build on prior deep space missions by human crews in Earth-Moon space and to NEOs. It would leave a legacy of better understanding of both Mars and Phobos, along with a foundation for human missions to the surface of Mars. Achieving that legacy through such a mission would require meeting some unique challenges not needed for subsequent Mars surface missions.\u201d<\/p>\n However, given the sad fact NASA\u2019s continued funding uncertainty provides its own challenge for missions which may be two decades away, any outline of a human mission to Mars remains tightly locked up in fancy powerpoints and videos.<\/p>\n It is also possible that by the time a crewed mission to Mars is ramped up, new propulsion concepts may be available to improve the approach.<\/p>\n Either way, a crewed mission to Mars requires political support via solid funding over several Presidencies, many of whom would no longer be in office by the time the mission was carried out. That may prove to be the biggest challenge of all.<\/p>\n Images: Via L2 content, NASA and John Frasanito & Associates inc.)<\/p>\n (To join L2, support NSF and access 4,500+ gbs of content \u2013 click here: http:\/\/www.nasaspaceflight.com\/l2\/)<\/p>\n","protected":false},"excerpt":{"rendered":" As NASA managers continue to work through the evaluations into an exploration roadmap for the agency, the end goal of sending humans to Mars is starting to show a level of consistency. Per documentation, the key Design Reference Mission (DRM) evaluations are pointing to the \u201cFlexible Path\u201d approach of visiting a Martian moon, prior to […]<\/p>\n","protected":false},"author":1,"featured_media":30392,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[9151,9034,367,8568,9095,640,2317,9025,624],"class_list":["post-40221","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","tag-fsps","tag-hlv","tag-mars","tag-mav","tag-mtv","tag-orion","tag-phobos","tag-sep","tag-sls"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/40221"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=40221"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/40221\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media\/30392"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=40221"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=40221"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=40221"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}See Also<\/h4>\n
\n
![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z314.jpg\" "\\"Z3\\"")
\u201cKey features could include demonstration of in-space hardware elements designed for Mars missions while accomplishing scientific and exploration objectives both at Mars and on Phobos.\u201d<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z412.jpg\" "\\"Z4\\"")
A Phobos mission \u2013 used as a precursor to a crewed mission to Mars \u2013 may be the main initial focus by proxy, primarily from two standpoints; a learning curve for a future mission to Mars, and the Mars science that can be gained from Phobos.<\/p>\n
\nPart 1: Battle of the Heavy Lift Launchers \u2013 Monster 200mt vehicle noted
\nPart 2: Manned mission to construct huge GEO and deep space telescopes proposed
\nPart 3: NASA Flexible Path Evaluation of 2025 human mission to visit an asteriod<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z58.jpg\" "\\"Z5\\"")
Currently, there is no agreed baseline approach for setting up a mission to Mars, with the Flexible Path noting the requirement of 10-15 HLV launches \u2013 via the use of chemical (LH2\/LOX) rockets, while the video shows a launch campaign using seven HLVs, sporting nuclear propulsion stages.<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z65.jpg\" "\\"Z6\\"")
Via the mission campaign outlined in the video, the first two HLV launches are focused on sending up the two major elements known as propulsive stages. These stages are placed into Low Earth Orbit (LEO), in order to wait for the rest of the vehicle elements to arrive for rendezvous.<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z75.jpg\" "\\"Z7\\"")
According to the video, these two vehicles both arrive at Mars, with the cargo lander separating from its propulsion stages ahead of a decent to the Martian surface aided by three large parachutes and six descent engines \u2013 as much as this is all via a notional design via NASA Glenn teams.<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z84.jpg\" "\\"Z8\\"")
As noted by NASA, power requirements for human-tended surface outposts and bases are expected to range from 25 to 100 kWe during the early build-up phases. As the base becomes fully operational with in-situ resource production and closed-loop life support, power requirements could approach 1 MW.<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z92.jpg\" "\\"Z9\\"")
This vehicle includes a Deep Space Hab and the Orion the crew will eventually splashdown in upon their return to Earth.<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z101.jpg\" "\\"Z10\\"")
Arriving at the Red Planet aft first \u2013 to allow for deceleration \u2013 the MTV carries out a propulsive Mars Orbit Capture manuever.<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z117.jpg\" "\\"Z11\\"")
Under this mission profile, the crew spend 500+ days exploring Mars (Surface Exploration Phase) via EVAs both on foot and via the use of SEVs \u2013 stationed at a Martian base consisting of the two landers, and other erected support structures, including \u2013 per the video \u2013 an inflatable habitat linked by an airlock and hooked up to one of the landers.<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z121.jpg\" "\\"Z12\\"")
This lander hosts their means of leaving the Martian surface, as they launch via what is again a notional vehicle known as the Mars Ascent Vehicle (MAV).<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z132.jpg\" "\\"Z13\\"")
Again, the above mission is likely to occur after a mission to one of the Martian moons, with the Flexible Path citing a shorter duration stay for a Phobos mission that also includes a unique return element in the flight profile, specifically a fly-by of Venus.<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z141.jpg\" "\\"Z14\\"")
\u201cOur choice to include a short-stay human visit to Phobos as a step toward humans-on-Mars is outside the framework of missions extensively analysed by recent agency Mars mission planning, which have focused on Mars surface missions themselves.<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2012\/01\/Z151.jpg\" "\\"Z15\\"")
\u201cA human Mars Orbit\/Phobos Mission represents an intermediate step between human exploration missions in near Earth space and human missions to explore the surface of Mars. Key features could include demonstration of in-space hardware elements designed for Mars missions while accomplishing scientific and exploration objectives both at Mars and on Phobos.<\/p>\n