NASA Continues Journey to Mars Planning

The Trump Administration has said very little about its plans for NASA's human spaceflight program other than terminating the Asteroid Redirect Mission (ARM), but NASA continues to shape its architecture for sending people to Mars in the 2030s.  The status of that planning was presented to a NASA Advisory Council (NAC) committee today.

Bill Gerstenmaier and Jim Free of NASA's Human Exploration and Operations Mission Directorate (HEOMD) spoke to NAC's Human Exploration and Operations committee this morning.  Two of Gerstenmaier's slides summarized current plans for launches of the Space Launch System (SLS), Orion, and associated systems -- including a lunar "gateway" -- from 2018 to 2030 and beyond.  All would culminate in a human mission to orbit Mars in 2033.

 
Screengrab from NASA presentation to NASA Advisory Council HEO Committee March 28, 2017.  

 

Screengrab from NASA presentation to NASA Advisory Council HEO Committee March 28, 2017.  

One interesting feature is that the first two Exploration Mission launches, EM-1 and EM-2, are separated on the slide by the launch of the Europa Clipper mission. That is notionally expected in 2022.  The schedule fits with NASA's official plan to launch EM-1 in 2018 and its commitment date to launch EM-2 in 2023, but the agency is working toward an internal deadline of 2021 for the EM-2 launch and Congress is providing additional funding to achieve it.  The slide suggests that NASA does not want to go too far in promising the earlier launch date.   The slide also shows EM-1 as a 25-60 day mission to a Distant Lunar Retrograde Orbit, not a crewed mission, which NASA is currently studying.

Another feature is the lunar "gateway" NASA recently has begun discussing.  Free emphasized today that the gateway would not be another International Space Station (ISS) in lunar orbit.  It would be smaller and human-tended, not permanently inhabited -- a location from which to stage missions to Mars and possibly to the lunar surface. 

"Robust international partnerships" and "commercial capabilities" are essential ingredients of the plan, he added. 

The humans-to-Mars mission in 2033 could involve a Venus flyby, they said.  It would be an "out and back" mission, but the crew would remain in Mars orbit for a period of time. That differentiates it from the Inspiration Mars mission proposed by Dennis Tito several years ago.  In that scenario, two people would have made a slingshot flyby of Mars, not enter orbit.  Tito's original idea was for a privately funded mission that would launch in 2018, but within a year Tito decided that it would need to be a public-private partnership with NASA shouldering 70 percent of the cost.  The conceptual launch date slipped to 2021 when Mars and the Earth were not as well aligned and the spacecraft would have needed a gravity assist from Venus.  House Science, Space, and Technology Committee chairman Lamar Smith (R-TX) was a strong supporter of the idea.  Little has been heard about it recently, but this NASA concept is sure to prompt comparisons.

NASA describes the path to Mars in terms of phases and the Asteroid Redirect Crewed Mission (ARCM) at one time was to signal the end of Phase 1 when experience was gained in cis-lunar space (the Earth-Moon region).  President Trump has proposed terminating the Asteroid Redirect Mission (ARM), however, and NASA is reconfiguring its plans accordingly.   ARM comprises ARCM and the Asteroid Redirect Robotic Mission (ARRM).  ARRM was to launch first and robotically relocate a boulder from the surface of an asteroid into lunar orbit where ARCM astronauts would visit it to obtain a sample for return to Earth.  The mission had few supporters in Congress and the proposal to terminate it is not likely to generate much opposition.

However, ARM involved the development of high power solar electric propulsion (SEP) and that part of the program is expected to continue.  The "40 kw Power/Prop bus" shown on the slides reflects that effort.  High power SEP is useful for many types of missions in Earth orbit and deep space. Michele Gates, ARM program director, is on the NAC/HEO committee's schedule tomorrow (Wednesday) to give a briefing on in-space power and propulsion.

Concern has been expressed over the low launch rate for SLS for fear that launch teams will lose their proficiency.  A launch rate of, at most, one per year has been projected.  Today, however, Free said that the latest plan is for one crewed SLS/Orion launch per year beginning in 2023 plus one cargo SLS launch per year beginning in 2027, which would increase the cadence to two per year in support of the human spaceflight program. Some SLS supporters believe that additional uses of SLS will materialize, such as for science missions, that could further increase the launch rate, although the cost per launch is not yet known.

The key to all of this is how much support the Trump Administration will provide for such activities.  The President's budget blueprint is for a status quo NASA human spaceflight program.  Funding for SLS/Orion would remain essentially at its current level.  During a signing ceremony last week for the NASA Transition Authorization Act, Rep. John Culberson (R-TX), who chairs the House Appropriations subcommittee that funds NASA, told the President that just as President Eisenhower is remembered for creating the interstate highway system, he (Trump) would be remembered for creating an interplanetary highway system.  Trump's response was "Well that sounds exciting. First we want to fix our highways.  We have to fix our highways."

Quelle:  Space and Technology Policy Group