New trade tree for manned mars missions

Roadmap to a human Mars mission

“…The main risks are linked to the entry, descent and landing phase (EDL), the long and complex assembly of giant spaceships in low Earth orbit and the use of nuclear thermal engines for which the technology readiness level (TRL) is low. This methodological problem has been highlighted in several studies showing that there are other options allowing important reductions of the risks [19,20,21,22]. The main idea is to downscale the entire mission by means of several simplifications [21]:…”

“…The scope of this paper is not to determine the details of the human Mars mission but to lay out the most important elements that can be shared by a class of scenarios respecting the recommendations presented in the previous section (see also [19] In human space flight, for safety reasons, the qualification of systems is very strict. In order to achieve the human rated certification, a long list of procedures and tests have to be followed from the design and construction up to the integration into the space vehicle [12,15].…”

“…The interplanetary vehicles can be sent to Mars after simple (or eventually no) assembly in low Earth orbit and the use of chemical propulsion systems [19,21].…”

Robust, affordable, semi-direct Mars mission

“…Another significant challenge concerns the development of entry, descent, and landing systems for heavy vehicles. Several studies recommended making the choice of the EDL systems a major parameter of the trade tree [10,19]. Aerocapture and EDL issues are discussed in the next sections.…”

“…For all these reasons, the most difficult, uncertain, and, possibly, the most expensive part of the Mars program is likely to be developing EDL systems appropriate for a manned mission. A reasonable recommendation is, therefore, to examine the parameters of the EDL phase and investigate ways to reduce the overall complexity [19]. One critical parameter is entry velocity.…”