Mars visions, then and now



In my continual efforts to tame the paper jungle in my office, I’ve come across my notes from a “robotic and human exploration of Mars strategic roadmap committee meeting,” held February 8-10, 2005, at the Carnegie Institution of Washington. Given that yet another “humans to Mars summit” took place last week in Washington, D.C., I thought I’d convey a few highlights of discussion at the 2005 meeting.

Recall that it was on January 14, 2004, when then-President George W. Bush announced his “vision” for space exploration, a plan to “extend a human presence across the solar system.” The goal was to put people on the Moon by 2020 “as the launching point for missions beyond.” At the time, Sean O’Keefe was NASA administrator. Oddly (it seems odd to me, anyway), O’Keefe is speaking today at the Center for Strategic and International Studies on U.S. strategy for civil and military space (O’Keefe is now a “distinguished senior advisor” at CSIS.)

Back to 2005 – here are some of the findings of the roadmap committee – which involved Michael Meyer of the NASA headquarters Mars exploration program office (he’s still there) and Firouz Naderi of the Jet Propulsion Laboratory’s solar system exploration directorate (he’s still there, see below):

  • Human Mars exploration design reference mission development “must be re-initiated immediately. Two to three years will be required for preliminary design development. (The estimate at that time was that this mission would require the launch of 3-8 International Space Station (ISS) masses to low Earth orbit. According to NASA, the ISS weighs about 925,000 pounds, equivalent to the mass of about 320 automobiles.)
  • Use the ISS as a test bed for Mars exploration.
  • Mars sample return (MSR) is a capstone human exploration precursor mission. It could set the stage for a round-trip human exploration mission…”minus environmental control and life support systems and biology and the scale problem.”
    • “One or more MSR missions must precede human exploration.” (The thinking then was that if we can’t execute an MSR mission, then we certainly can’t execute a human mission.)

In 2005, nuclear-fission-powered propulsion was being considered for the new heavy-lift launch vehicle that would have to be built to get people beyond LEO. (The nuclear option fell by the wayside, thank goodness.) The assumption then was that the Mars Science Laboratory would launch in 2009 (it went up in 2011), to be followed by an MSR mission during the next decade and a large astrobiology field laboratory after that.

There was discussion at the 2005 meeting about the hazard of radiation exposure for a human mission to Mars. This discussion continues. The Wall St. Journal reported earlier this month on new research results showing “that cosmic rays during an interplanetary voyage could cause subtle brain damage, leaving astronauts confused, forgetful and slow to react to the unexpected.”

Back to the present: as Space News reported in a story about last week’s gathering of humans-to-Mars advocates, “While NASA argues there is a growing consensus that the agency’s long-term human spaceflight goal should be landing people on Mars, a recent conference suggested there is less agreement about exactly how NASA should accomplish that goal.” covered last week’s gathering, too, reporting that JPL’s Firouz Naderi (see above) called for “an incremental, multiple-mission approach that envisions getting astronauts to Phobos by 2033, then down to the Martian surface by 2039.” This approach could make humans-to-Mars “technologically and economically feasible,” he said.

The current administration has decided that sending astronauts to an asteroid will precede sending humans to Mars (or back to the Moon, or anyplace else.) Mars sample return, identified by the space science community for decades as a top priority in planetary exploration, remains too expensive to undertake. (Advocates will undoubtedly argue with me about this point, but the reality today is that no organization or group of organizations has taken on this challenge.)

So, at the same time that I am bothered by the very idea of sending people to Mars, with the intent of settling the planet, I am not too bothered, as I think a human mission to Mars is much further off into the future than advocates believe it is. In the United States, the world’s top spender on space exploration, the 2016 presidential election will bring a transition that is as likely as not to include new national goals in space. And who knows what they’ll be?

Stay tuned.

What to do about hazardous asteroids: many ideas…



At the 4th international Planetary Defense Conference (April 13-17, Frascati, Italy), proposals were aired for ground-and space-based systems designed to detect asteroids that pose a risk of Earth impact and different methods of deflecting or destroying asteroids found to be on an impact course with Earth.

For a summary of PDC presentations on the Jet Propulsion Laboratory’s proposed space-based near-Earth object survey telescope, called NEOCAM; the B612 Foundation’s proposed Sentinel space-based NEO survey telescope; and a comparative analysis of the two proposals conducted at the request of the White House Office of Science and Technology Policy, see this report in Space News. You can also watch the archived webcast of PDC talks by Amy Mainzer/NEOCAM, Hal Reitsema/Sentinel, and Bhavya Lal/Science and Technology Policy Institute (these three talks start at about 45:00).

A paper published by the NEOCAM team reports on the team’s simulations of NEOCAM operations. See my blog post of February 23 for details. For information on Sentinel, see this abstract (undated), posted in the B612 Foundation’s online newsroom under “scientific papers.”

As Reitsema explained in his PDC talk, the Sentinel project has now coupled itself with the Large Synoptic Survey Telescope (LSST ) project, due to come on line in 2022 (if work stays on schedule).

On an LSST “frequently asked questions” page hosted by the University of Washington, this information is offered on LSST’s schedule and cost:

The LSST is scheduled for first engineering light in 2014 and for early science operations beginning in 2015. Full science operations will begin in 2016. [Calendar years] The LSST project will cost $390M through first light, including all construction, hardware, software, data management, and a 30% contingency. [2006 $] This work-based cost estimate has remained constant within 15% since the beginning of the project phase in 2003. Significant milestones have already been reached, including the casting of the primary/tertiary mirror. The LSST survey will last for ten years.”

This information is out of date.

The National Science Foundation and the Department of Energy are the primary sponsors of the project. In July 2012, NSF reported that LSST would cost about $665 million. In March of this year, LSST Director Steve Kahn reported to the Space Studies Board’s Committee on Astronomy and Astrophysics that LSST would cost $681 million, with construction scheduled to be complete by September 30, 2022, and full science operations planned to begin in 2023. LSST operating costs are estimated at $37 million a year (2013 U.S. dollars) over a 10-year period.

On to asteroid impact “mitigation” ideas – I put mitigation in quote marks because some of my colleagues have questioned the labeling of asteroid deflection or destruction concepts as impact mitigation options. Impact mitigation is more a matter of disaster planning and response, in the event that an Earth impact should occur….

There’s a lot yet to be learned about hitting or moving an asteroid. (And it should be noted that most of what’s known about asteroid deflection is a product of computer modeling. Keith Holsapple of the University of Washington observed at the conference that modeling results can be iffy.) One message I took home from PDC 2015 is that there’s no all-purpose asteroid deflection approach. Every asteroid is different, and every close approach and impact hazard is different, so deflection options will have to be developed case by case.

PDC 2015 offered considerable discussion of “the nuclear option” – that is, using nuclear “devices” to disrupt or destroy an asteroid on a certain impact course with Earth. A contingent from the Department of Energy weapons labs (Livermore, Los Alamos, Sandia), along with university researchers and NASA specialists, offered a range of perspectives on the nuclear option as well as kinetic-impactor concepts. As Paul Miller of Lawrence Livermore National Lab noted, “composition plays a central role in how an asteroid reacts to a kinetic impactor or nuclear deflection.” Dan Scheeres of the University of Colorado raised the question of how shape and topography might affect a kinetic deflection attempt. Laser ablation or nuclear blasts are sensitive to surface topography. Ion beam deflection is not affected by these factors, as ions implant into the surface and do not “reflect,” he said. Kirsten Howley of Livermore addressed the importance of the composition of the asteroid and the spectrum of the device in the case of a stand-off (off-surface) nuclear deflection attempt.

Dave Dearborn of Livermore said the kinetic impactor option looks like a good choice when the asteroid is small and the impact warning time is long. In the case of a large asteroid and a short warning time, the stand-off nuclear option might be the only viable option, he said. Galen Gisler of Los Alamos National Lab agreed with Dearborn, adding that for small asteroids, “kinetic impact is surprisingly effective and would be even more effective for volatile-rich bodies.”

“Existing devices can deflect essentially all NEOs,” Dearborn noted, so there’s no need to develop new nuclear devices for planetary defense. He also noted that nuclear warheads are not an option for planetary defense as they are designed to withstand reentry into Earth’s atmosphere.

Philip Lubin of the University of California-Santa Barbara said directed-energy deflection is a very practical option. “I think it’s ridiculous not to have planetary defense [systems] pre-deployed,” he asserted. Young people “enjoy blowing up everything they can,” he said, so why not place directed-energy deflection systems in space for planetary defense and, while they’re waiting for an asteroid target, let them be used to blow up space debris?

Brent Barbee of NASA Goddard Space Flight Center reported on a study being led by Iowa State University’s Asteroid Deflection Research Center of suborbital asteroid interception and fragmentation for very-short-warning-time impact scenarios. This concept involves a high-altitude interception by a Minuteman III missile.

Bob Weaver of Los Alamos described a mission concept for a hypervelocity asteroid impact vehicle (HAIV) to intercept NEOs as small as 50 meters. This concept involves a two-body spacecraft, with one performing a subsurface nuclear explosive detonation (that is, contact versus stand-off) within 10 meters of the NEO center. Modeling shows that a low-density impactor would not go deep enough. This “leading impactor” needs to be redesigned to be a “penetrator.” Bong Wie of Iowa State’s Asteroid Deflection Research Center said he is seeking funding to develop an emergency asteroid defense project, involving a non-nuclear multiple kinetic impactor vehicle that would vaporize or pulverize or vaporize 50-150 meter objects.   “A lot of people would not like to have nuclear testing in space,” he said.

Brian Kaplinger of the Florida Institute of Technology raised the possibility of errors in modeling NEO orbits, composition, porosity, and shape, noting that “not all dependencies can be adequately resolved in any simulation.”

There were many more talks at PDC 2015. I offer just a few highlights. While talks at the conference revealed a lot of progress on planetary defense mission concepts and designs since PDC 2013, it appears that the nearest-term possibility for a planetary defense demonstration mission might be the NASA-ESA Asteroid Impact Deflection and Assessment project (AIDA) – including NASA’s Asteroid Impact Mission (AIM) demonstration and ESA’s Double Asteroid Redirection Test (DART). This mission concept study, begun in 2011, has just proceeded to Phase A this year, with a proposed launch date of 2022.

The current schedule for the robotic segment of NASA’s Asteroid Redirect Mission (ARM) – which will collect a multi-ton boulder from the surface of a large near-Earth asteroid and include a demonstration of the “enhanced gravity tractor” method for planetary defense – calls for a launch in 2020, asteroid rendezvous in 2022, and planetary defense demonstration in 2023. This schedule is contingent on many factors, perhaps the most important one being whether ARM survives the annual budget process over the next few years and a presidential transition in 2017.

Stay tuned.

Planetary defense: it’s a global thing



I spent the week of April 13-17 in Frascati, Italy, attending the 4th international Planetary Defense Conference (PDC) – a biennial gathering of experts concerned with protecting Earth from future asteroid impacts. Here I’ll offer some highlights of the week’s discussions.

First, the good news: of the more than 12,000 known near-Earth objects (NEOs) – asteroids and comets predicted to come within 0.3 astronomical units (28 million miles/45 million kilometers) of Earth on a future orbit around the Sun – none pose a risk of impact with Earth (See the Jet Propulsion Laboratory’s NEO impact risk table). Of these 12,000 NEOs, 1,574 are currently deemed “potentially hazardous” – predicted to come within 0.05 AU (4.65 million mi./7.5 million km) of Earth on a future orbit. These numbers will change, of course as new NEOs are found and further observations of known objects improve the accuracy of predictions of future orbital movements.

Space agency officials from around the world reported at the PDC on the status of their plans for planetary defense – ranging from work with emergency management agencies in case of an unavoidable asteroid impact with Earth to plans for launching multiple spacecraft to an asteroid on an impact course with Earth to deflect it off its orbital path toward us. Collaboration and coordination is improving among the various agencies, programs, and projects focused on finding, tracking, and characterizing NEOs and identifying those that are potentially hazardous to Earth, in part due to the formation of the International Asteroid Warning Network (IAWN). NASA’s NEO Observations Program, the European Space Agency’s Space Situational Awareness Programme-NEO Segment, and the NEO Dynamic Site (NEODyS), among others, are participating in IAWN.

NASA’s NEO Observations Program* head Lindley Johnson said the NASA program’s updated program objective is to discover at least 90 percent of NEOs larger than 140 meters “as soon as possible.” Primary assets supported by NASA to find and track NEOS are the Pan-STARRS (Panoramic Survey Telescope & Rapid Response System) facility in Hawaii, the Catalina Sky Survey in Arizona, and NASA’s space-based NEOWISE infrared telescope. Primary assets supported by NASA to characterize NEOs are the Arecibo Observatory in Puerto Rico, the Goldstone station of NASA’s Deep Space Network, the Infrared Telescope Facility, and the Spitzer Space Telescope. The NASA program currently has an annual budget of $40 million. The President’s budget request for the program in fiscal year 2016 is $50 million.

Gerhard Drolshagen, co-manager of the NEO segment of the European Space Agency’s Space Situational Awareness (SSA) Programme –NEO Segment , said SSA Programme funding for 2013-2016 is 50 million euro. (The SSA Programme is responsible for space weather and space debris as well as for NEO observations.) One of ESA’s new NEO projects is NEOSTel. The agency has funded detailed design work for this automated, ground-based “fly-eye” telescope system to survey the sky for NEOs. Completion of the project, which ultimately will include four telescopes, will cost about 10 million euro, Drolshagen said.

Meanwhile, ESA’s NEO Coordination Centre is working on more closely integrating the European Asteroid Research Network (EARN) and the NEO Dynamic Site (NEODyS) with its own database, he noted. EARN maintains an online database of physical and dynamical properties of NEOs. According to the NEODyS web site, the NEO segment of ESA’s SSA Programme will “progressively assume larger responsibility for the operations of NEODyS…. The NEODyS service is expected to be federated, together with others including the Spaceguard Central Node and the EARN Asteroid Database, in a new comprehensive SSA-NEO information service.”

Boris Shustov of the Institute of Astronomy at the Russian Academy of Sciences reported on Russian assets involved in NEO observations. Telescopes in the International Scientific Optical Network (managed by the Keldysh Institute of Applied Mathematics at the Russian Academy of Sciences) devote some time to NEO observations. Next year, a new wide-angle 1.6 meter telescope, AZT-33VM, located at the boundary of Mongolia, will see first light. This telescope will be suited to detecting large (greater than 50 meters) distant asteroids.

Alan Harris, European Union coordinator for the EU’s NEOshield Project, reported on the start-up of NEOshield-2. NEOShield was set up to carry out a detailed analysis of open questions relating to realistic options for preventing NEO impacts with Earth. This March, work began on NEOshield-2. The EU granted $4 million to NEOshield. It has granted $6 million to NEOshield-2, for work to September 2017.

Makoto Yoshikawa of the Japan Aerospace Exploration Agency (JAXA) reported on the creation of the Asia-Pacific Asteroid Observation Network. Current members include Japan, South Korea, Thailand, Malaysia, Macau, Indonesia, Mongolia, Taiwan, and China.

NASA, ESA, JAXA, and others indicated they would like to build their own space-based NEO survey telescopes – if they had the budget for it. None do.

Stay tuned for PDC 2015, Part 2 – in which I will discuss reports from two teams working on concepts for a space-based NEO survey telescope.

* My work is funded in part by the NEO Observations Program. However, no one at NASA asked me to write this blog post.