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NAC Adopts Finding To Redirect the Asteroid Redirect Mission -- to Mars - UPDATE

Marcia S. Smith
Posted: 10-Apr-2015
Updated: 25-Apr-2015 04:57 PM

Update, April 25, 2015:   NAC sent a letter to NASA Administrator Bolden with the final wording of its findings and recommendations on April 16.

Original story, April 10, 2015:  The NASA Advisory Council (NAC) today unanimously adopted a finding that it thinks NASA should change the Asteroid Redirect Mission (ARM) into a mission that would go all the way to Mars and thus be more closely aligned with the goal of sending humans there.  NAC chairman Steve Squyres stressed that it is a finding, not a recommendation, and requires no action from NASA. 

NASA's existing concept for ARM responds to Obama Administration policy and NAC recommendations at odds with Administration policy have little value, he explained, since NASA must implement what it is told to do.

As currently conceived, ARM involves sending a robotic spacecraft to an asteroid, descending to the surface of the asteroid to grab a boulder laying on its surface and moving the boulder from the asteroid's native orbit to an orbit around the Moon ("cis-lunar space") where it will be visited by astronauts in an Orion spacecraft to obtain a sample and return it to Earth. The mission is described by NASA and the Obama Administration as part of its "Journey to Mars" wherein humans will be sent to orbit Mars in the 2030s and someday land on the planet.

NAC members are appointed by the NASA Administrator, so the group is comprised of individuals hand-picked by Administrator Charlie Bolden to candidly share their views on NASA's programs and plans. The members of NAC are among the most prestigious and experienced members of the aeronautics and space communities and rarely shy about expressing their opinions.

NAC meets quarterly and ARM has been the subject of intense debate over the past several meetings. Their concerns center on two issues: cost and the extent to which ARM is really needed to achieve the goal of sending humans to Mars (its "extensibility").   

First, they are skeptical of the $1.25 billion cost estimate.  That estimate is only for the robotic portion of the ARM mission and does not include launch.   Squyres, a highly respected space scientist from Cornell, points out that NASA already has a robotic asteroid sample return mission, OSIRIS-REx, under development for launch next year.  OSIRIS-Rex has a less complicated set of objectives and its pricetag is $800 million, so Squyres wonders how ARM can be accomplished for just $425 million more.  ARM involves development of high-power SEP, a spacecraft, and a mechanism for grabbing and containing the boulder.   NAC members are worried that if the ARM cost escalates, other NASA programs will have to pay the price.  

That leads them to ask the further question of whether the cost is worth what will be gained towards the longer term goal of sending humans to Mars.   They agree on the need to develop SEP and they agree that astronauts need to develop experience working in cis-lunar space.  They simply do not see the value of moving "the rock" as part of a human Mars exploration program.

Squyres is the principal investigator for the two Mars Exploration Rovers -- Spirit and Opportunity -- that landed on Mars in 2004 (Opportunity is still operating) so is more expert than most about Mars.  He also chaired the most recent National Research Council Decadal Survey on planetary exploration.   He has forcefully argued at NAC for NASA to reconsider its plans for ARM to make it more relevant to the long term humans-to-Mars goal.

Today NAC agreed that ARM should focus on a full demonstration of high power SEP, which is widely regarded as a sine qua non to support human missions to Mars.  They believe instead of going to an asteroid, it should go all the way to Mars and back.

During discussion yesterday, a suggestion was made that it could go to Phobos, one of the two moons of Mars, and collect a sample of that instead of an asteroid.  That idea is not contained in the finding they adopted today.  Instead it says only that ARM should fly "to Mars orbit and then back to the Earth-Moon system and into a distant retrograde lunar orbit."

"Distant retrograde lunar orbit" is a phrase NASA uses to define the location in lunar orbit where it wants to relocate the boulder.  It is a point of equilibrium in the Earth-Moon system that provides a stable location where spacecraft -- with or without humans on board -- can operate for long periods of time without expending much fuel.  It is a roughly nine day journey from Earth, so astronauts on an Orion spacecraft could travel there, conduct operations for several days, and return to Earth within the 21-22 day lifetime of the Orion spacecraft now under development.   By including that destination in their finding, the NAC members appear to be signalling their agreement with NASA that it is a useful location for future operations even if they do not agree on the need to move a space boulder there.

The wording of the finding agreed to today is as follows:

High-performance solar electric propulsion (SEP) will likely be an
important part of an architecture to send humans to Mars.  NASA's
current plan is to demonstrate a large SEP stage by using it to
maneuver a boulder that has been lifted from the surface of a small
asteroid, and to move the boulder to cis-lunar space.

Maneuvering a large test mass is not necessary to provide a valid in-
space test of a new SEP stage.  We therefore find that a SEP mission
will contribute more directly to the goal of sending humans to Mars if
the mission is focused entirely on development and validation of the
SEP stage.  We also find that other possible motivations for acquiring
and maneuvering a boulder (e.g. asteroid science, planetary defense)
do not have value commensurate with their probable cost.

Instead of relocating a boulder from an asteroid, we suggest that a
more important and exciting first use of this new SEP stage would be a
round trip mission to Mars, flying it to Mars orbit, and then back to the
Earth-Moon system and into a distant retrograde lunar orbit.

Although NASA does not need to act on the NAC finding, because of the stature of the NAC members it could influence other policy-makers.  ARM has won little support in Congress or the space community since it was announced two years ago.  Congress has not prohibited NASA from pursuing ARM, but has said NASA should spend its money only on activities that it would be developing anyway for other purposes.  NASA divides its funding for ARM into two categories --"direct" and "leveraged" -- to show that split.  NASA is requesting its first direct funding for ARM formulation studies in FY2016:  $38 million in the Human Exploration and Operations Mission Directorate, out of a total $220 million request for ARM.  For more detail on ARM funding, see table 2 in SpacePolicyOnline.com's fact sheet on NASA's FY2016 budget request.

 


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