WASHINGTON — NASA has done a good job implementing the recommendations of its latest planetary science decadal survey despite past budget problems, but needs to improve some programs, a recent report concluded.
The midterm assessment of the 2011 planetary science decadal survey, prepared by a National Academies committee and published Aug. 7, found that NASA was able to make progress on both flagship and smaller missions recommended by the survey even with funding cuts in the early years of the decade.
“The committee concluded that despite significant cuts to the Planetary Science Division’s budget early in this decade, NASA has made impressive progress at meeting the decadal survey’s goals,” the committee noted in its final report, a reference to a nearly 20 percent cut in planetary science funding in 2013 to less than $1.3 billion. Its budget has subsequently risen significantly, to $2.2 billion in 2018.
The progress includes work on two flagship-class missions prioritized in the report, a Mars rover mission to cache samples for later return to Earth and a spacecraft to orbit Jupiter’s icy moon Europa. Those concepts have become the Mars 2020 and Europa Clipper missions, respectively, after undergoing redesigns to reduce their projected budgets from the decadal report.
The committee, though, did note concerns about the potential cost of Europa Clipper, a multi-billion-dollar mission. “NASA should continue to closely monitor the cost and schedule associated with the Europa Clipper to ensure that it remains executable” without affecting other missions, the committee recommended. “If the [lifecycle cost] exceeds this range, NASA should de-scope the mission.”
The committee was more skeptical about a third flagship-class mission in the early stages of development, a Europa lander mission. The mission has enjoyed funding well above any administration requests largely due to the advocacy of Rep. John Culberson (R-Texas), who chairs the House appropriations subcommittee that funds NASA and is the most prominent congressional supporter of the mission.
A Europa lander, the committee noted, was not prioritized in the latest decadal survey, which called it a “far term” mission that did not receive a detailed cost and technical assessment at the time. “The midterm committee, although it lacks an official cost estimate, believes the mission cost to be in the multiple billions of dollars range,” it concluded.
“Given its cost and its potential impact on the rest of the planetary science program, the committee concluded that the mission should be vetted within the decadal survey process,” the report stated.
The committee also raised concerns about the future of Mars exploration. NASA’s only Mars exploration under development is Mars 2020, although the agency has started studies of a so-called “lean” sample return architecture announced last August. That would require two more missions, one to collect the cached samples and launch them into Mars orbit, and another to collect the sample canister in Mars orbit and return it to Earth.
The committee concluded NASA should continue to study that Mars sample return architecture, but argued that with no other missions on the books, the sample return missions could be vulnerable to failures of existing Mars orbits that serve as communications relays. No other Mars science missions are under development as well.
“There is a risk that ongoing and soon-to-be landed assets on Mars will be left without telecommunications support because of the aging orbiters. The system is fragile and aging,” the committee stated. “There is currently no vision for a program beyond sample return, either for scientific investigation or to prepare for future human exploration.”
The committee recommended that NASA create a Mars Exploration Program (MEP) “architecture, strategic plan, management structure, partnerships (including commercial partnerships), and budget that address the science goals for Mars exploration” outlined in the decadal survey. “This approach of managing the MEP as a program, rather than just as a series of missions, enables science optimization at the architectural level.”
Another recommendation of the committee was to increase the cadence of the Discovery and New Frontiers programs of low- and medium-cost competitively selected planetary science missions. Budget cuts earlier in the decade affected the pace of competitions in both programs, and NASA has struggled to catch up even with increased funding in recent years.
The committee concluded that, to meet the mission cadence recommended in the decadal survey, NASA select three missions in upcoming competitions expected to take place in 2019 and 2021. NASA selected two missions, Lucy and Psyche, in its previous Discovery competition that concluded in January 2017.
The report also offered advice for the next decadal survey in the planetary sciences, which will likely begin by mid-2020 for publication in the spring of 2022. That survey will need to take into account both new science objectives, particularly in astrobiology, as well as new technologies and capabilities, such as smallsats.
The committee in particular recommended that NASA sponsor 8 to 10 concept studies of missions for potential consideration in the next decadal survey. That includes revisiting a previous study of an “ice giants” mission to Uranus and/or Neptune, citing different scientific objectives in a 2017 study versus those outlined in the decadal survey as well as concerns that “the scientific payload proposed in the study carries significant risk of failing to make the measurements” outlined in the decadal.
Plans to cache samples for later return to Earth created planetary protection complications for NASA’s Mars 2020 mission, including a dispute between the planetary protection office and mission managers, according to a new report. Credit: NASA/JPL-Caltech
WASHINGTON — NASA’s approaches to planetary protection are outdated in an era of more ambitious missions and emergence of private space exploration ventures and thus need to be revised, a new report concludes.
The report, prepared by a committee of the National Academies of Science, Engineering and Medicine at the request of NASA and published July 2, found that existing policies developed for the Apollo lunar landings and the Viking missions to Mars decades ago don’t fit more advanced missions under development, including Mars sample return and exploration of “ocean worlds” in the outer solar system.
Those policies are intended in part to comply with Article 9 of the Outer Space Treaty, which requires countries to avoid “harmful contamination and also adverse changes in the environment of the Earth resulting from the introduction of extraterrestrial matter.” NASA developed policies to avoid contamination of potentially habitable worlds by its spacecraft, and to avoid contaminating the Earth’s environment with any materials those spacecraft return.
The committee concluded that while the central tenets of planetary protection policy, including its basis in the Outer Space Treaty and use of international cooperation, remain viable today, “the current planetary protection policy development process is inadequate to respond to progressively more complex solar system exploration missions, especially in an environment of significant programmatic constraints.”
An example of this cited in the report is the Mars 2020 mission under development. That spacecraft must comply with existing planetary protection standards for all spacecraft going to the Martian surface, but also with samples that rover will cache for later return to Earth. “Thus, Mars 2020 becomes the first-ever mission to have to deal with samples returned from Mars and, therefore, moves NASA into a new planetary protection regime,” the report noted.
That created a clash between the mission and NASA’s planetary protection officer, according to the report, over the level of sterilization needed to comply with planetary protection requirements. “Although the long-running disagreement was eventually resolved by a NASA headquarters decision, the committee found the failure to exercise a dispute resolution process sooner to be a troubling symptom of either a gap in NASA’s policy or a breakdown in utilizing policies that were available,” the report states.
NASA has since moved its planetary protection office from the Science Mission Directorate to the Office of Safety and Mission Assurance and hired a new person to lead the office. The report endorses that shift and calls on NASA to “expeditiously complete” that move.
Lisa Pratt, the Indiana University astrobiologist hired early this year to take the job, endorsed moving her office to the Office of Safety and Mission Assurance. “That’s not just symbolic. It’s a really change in the way we’ll be operating,” she said at an April meeting of the Mars Exploration Program Analysis Group. “That is a group that has a very clear process and protocol, and we’ll be gradually — probably over a period of about two years — figuring out how to make planetary protection fit into that office.”
Missions like Mars 2020 and Europa Clipper, which will make multiple flybys of Jupiter’s icy moon Europa, require a reconsideration of how NASA handles planetary protection policy development, the committee concluded. It called for the development of a “planetary protection strategic plan” that includes elements such as how to secure expert advice from outside the agency, forecast future missions that will have planetary protection issues and identifying research and technology development priorities for planetary protection.
The report also recommended a change in a 40-year-old policy, presidential directive NSC-25, that governs how to approve missions that could have “large-scale environmental effects.” That is primarily used for the approval of missions with nuclear power sources but can also govern missions that plan to return samples or even astronauts from potentially habitable worlds.
“Although NSC-25 prescribes an interagency review process, it does not adequately capture the full range of federal agencies that, today, would have a legitimate role in reviewing planetary protection plans for returned astronauts and samples,” the report states. It recommends that the administration, likely through the National Space Council and other venues, update that policy to support Mars sample return and eventual human missions.
Another issue highlighted in the report is the rise of commercial ventures that plan missions with planetary protection issues. That includes the inaugural launch of SpaceX’s Falcon Heavy rocket in February, which placed its payload — a Tesla Roadster sports car — into a heliocentric orbit that goes beyond the orbit of Mars, but does not pose a collision risk to the planet for the foreseeable future.
Planetary protection did not factor into the approval for that launch, according to the report. “While the Federal Aviation Administration approved the launch, there is no evidence that any formal discussion of planetary protection considerations took place.”
Pratt hinted that was the case in her April talk. “We had a demonstration that sort of slipped through our fingers in terms about thinking about planetary protection,” she said then.
The report recommended that both private and government missions be subjected to the same planetary protection requirements, but also that NASA “make appropriate efforts to take into account the views of the private sector in the development of planetary protection policy.”
Mars Helicopter will fly to Mars on the Mars 2020 rover mission and perform a series of flight tests over a 30-day period. Credit: NASA artist’s concept.
WASHINGTON — NASA announced May 11 that it will fly a small helicopter as a technology demonstration on its next Mars rover, despite concerns from some on the project that it could be a distraction.
In a statement issued late May 11, the space agency said it will include the Mars Helicopter on the Mars 2020 rover mission, where it will perform a series of test flights over the course of a month.
“The idea of a helicopter flying the skies of another planet is thrilling,” NASA Administrator Jim Bridenstine said in the statement. “The Mars Helicopter holds much promise for our future science, discovery, and exploration missions to Mars.”
Both Bridenstine and Rep. John Culberson (R-Texas), chairman of the appropriations subcommittee that funds NASA, highlighted the fact that, if successful, Mars Helicopter will be the first heavier-than-air vehicle to fly on another world. “This exciting and visionary achievement will inspire young people all over the United States to become scientists and engineers, paving the way for even greater discoveries in the future,” Culberson said.
Mars Helicopter weighs about 1.8 kilograms and has a cubical fuselage similar in size to a softball. It will be attached to the belly pan of the Mars 2020 rover and placed on the surface upon finding a suitable site after the rover’s February 2021 landing. The rover will then drive a safe distance from the helicopter before flight tests begin.
Up to five flights are planned over the 30-day test campaign, starting with a flight where the helicopter will ascent to an altitude of three meters and hover for 30 seconds. Later flights will last up to 90 seconds and travel as far as a few hundred meters. The helicopter will recharge its lithium-ion batteries between flights with solar cells.
The helicopter faces a number of technical challenges, including being able to generate lift in atmospheric densities equivalent to an altitude of 30 kilometers on Earth, more than double the altitude record for a conventional helicopter.
“To make it fly at that low atmospheric density, we had to scrutinize everything, make it as light as possible while being as strong and as powerful as it can possibly be,” said Mimi Aung, Mars Helicopter project manager at the Jet Propulsion Laboratory, in the statement. The helicopters blades will rotate at up to 3,000 revolutions per minute, 10 times the rate of a terrestrial helicopter.
Mars Helicopter will also have to be able to fly autonomously, given the long communications lag with the Earth. “We have an autonomous capability that will be able to receive and interpret commands from the ground, and then fly the mission on its own,” Aung said.
NASA sees Mars Helicopter as demonstrating the ability of such vehicles to serve as scouts for future rover missions. That could be useful, for example, for later missions to help spot samples cached by Mars 2020 in order to collect them for return to Earth.
“The ability to see clearly what lies beyond the next hill is crucial for future explorers,” said Thomas Zurbuchen, NASA associate administrator for science, in the statement. Such views are provided now by orbiting spacecraft. “With the added dimension of a bird’s-eye view from a ‘marscopter,’ we can only imagine what future missions will achieve.”
The potential addition of Mars Helicopter, though, has not necessarily been warmly accepted by the main Mars 2020 mission. At a meeting of the National Academies’ Space Studies Board May 3, Ken Farley, project scientist for Mars 2020, said he and others on the mission had concerns about flying that technology demonstration.
“I am not an advocate for the helicopter, and I don’t believe the Mars 2020 project has been an advocate for the helicopter,” he said at the meeting. The major issue, he said, was that adding Mars Helicopter could disrupt science operations of the main rover during that 30-day test period even as the mission was working to find efficiencies elsewhere to maximize its overall performance.
He added, though, that Mars 2020 has worked to accommodate the helicopter, and was not concerned about any technical risk to the mission from it. “Everybody agrees it will not put the mission at risk,” he said. “All the decisions that are being made have to honor that.”
NASA is expected to make a decision later this month on whether to include a small helicopter as a technology demonstration on the Mars 2020 mission. Credit: NASA artist’s concept.
WASHINGTON — NASA is expected to make a decision later this month on whether to include a small helicopter as a technology demonstration on the Mars 2020 rover despite concerns by scientists that it might distract from the rover’s science mission.
Mars 2020 is scheduled to pass a project development milestone known as Key Decision Point D later this month. That review will formally clear the mission to enter its assembly, test and launch phase, with launch scheduled for July 2020.
Speaking at a meeting of the National Academies’ Space Studies Board here May 1, Steve Jurczyk, NASA acting associate administrator, said the review, scheduled for late May, will also give the agency the opportunity to decide whether to include a small helicopter on the rover. That helicopter has been under development for several years, including flying it in a chamber at Mars atmospheric conditions.
Ken Farley, the project scientist for Mars 2020, said later at the meeting that the project expects NASA Headquarters to make a decision “very shortly” about adding the helicopter. “I expect that there will be an announcement soon,” he said in a May 3 presentation about Mars 2020.
The helicopter is being developed at the Jet Propulsion Laboratory independently of the Mars 2020 mission, but there has been coordination to ensure that the helicopter could be added to the rover. “The Mars 2020 project has done everything that is necessary to accommodate that helicopter,” he said.
If added, the helicopter would operate for only about 30 days early in the rover’s mission, Farley said. It is intended to primarily be a technology demonstration to show how such a vehicle could be a scout for future rovers or carry out additional science.
If NASA did decide to add the helicopter, it would be only after determining that its inclusion would not significantly increase the overall risk of the mission. “Everybody agrees it will not put the mission at risk,” he said. “All the decisions that are being made have to honor that.”
That doesn’t mean, though, that the project supports adding the helicopter even if it doesn’t increase the mission’s risk. “I am not an advocate for the helicopter, and I don’t believe the Mars 2020 project has been an advocate for the helicopter,” he said. That opposition is based on the belief that the helicopter will be a distraction, taking away from the rover’s primary science work, at least for a short time.
“This comes right out of science time,” Farley said. “I have personally been opposed to it because we are working very hard for efficiencies and spending 30 days working on a technology demonstration does not further those goals directly from the science point of view.”
Improving the efficiency of the rover’s operations on the Martian surface, compared to those of the Curiosity rover, is a major area of emphasis for Mars 2020 given its ambitious science goals, which include collecting samples for later return to Earth. At the meeting, he said mission designers were working to reduce the “operational timeline” between the time the rover returns data to Earth and new commands are sent to the cover. The goal is a five-hour turnaround, he said, about half as long as with Curiosity operations.
While waiting for its latest review and a decision on the helicopter, the Mars 2020 mission is addressing some technical issues. One is a fracture of the heat shield intended to protect the spacecraft when entering the Martian atmosphere. JPL announced April 26 that the heat shield, originally developed for the Mars Science Laboratory (MSL) mission that landed Curiosity on Mars in 2012, cracked during testing earlier in the month at a Lockheed Martin facility.
“We’re too early to know exactly what happened,” Farley said, but noted that the heat shield was a “pathfinder” for the one flown on MSL and was not the exact same design. “Our intention, I believe, going forward is to build a new heat shield using the actual design that MSL used.”
The mission is also developing improved parachutes, work Farley said was driven by the failure of similar parachutes on NASA’s Low-Density Supersonic Decelerator project. “It raised doubts about whether supersonic parachutes were fully understood,” he said.
That work feature testing of parachutes on sounding rockets, such as a March 31 launch from NASA’s Wallops Flight Facility. “Testing has not yet reached the most extreme conditions that it will be tested to, but so far, so good on that,” he said.
Another pending decision for Mars 2020 is the selection of a landing site. A workshop in October will bring together scientists to discuss the merits of the three finalists: Columbia Hills, Jezero Crater and Northeast Syrtis. That workshop will produce a ranked list of the three to deliver to NASA’s associate administrator for science, Thomas Zurbuchen, who will make the final decision.
“This is going to be a challenge,” Farley said of the upcoming workshop. “In many ways it feels to me like most people’s opinions are completely locked in and it becomes almost a religious preference.”
Farley said that one alternative is a compromise landing site, dubbed “Midway,” that is roughly halfway between Jezero and NE Syrtis, which are only 40 to 50 kilometers apart. Midway is similar in geology to NE Syrtis and is in driving range from Jezero.
“We have to do further investigation to see whether that is desirable and whether it’s feasible,” he said. If it is, “Maybe we can have our cake and eat it, too.”
The Space Launch System and its associated ground systems contributed to growing cost and schedule issues with NASA’s major programs, according to a May 1 GAO report. Credit: NASA
WASHINGTON — NASA’s cost and performance on major programs has “deteriorated” significantly in the last year according to a report May 1 by the U.S. Government Accountability Office.
The report, its tenth annual assessment of the agency’s major human and robotic programs under development, found that those programs had an average launch delay of 12 months, the largest GAO had measured over the last decade, and cost growth of at least 18.8 percent.
That cost increase is much less than annual cost growth of more than 45 percent seen earlier in the decade. However, it marks the end of several years of declining cost growth. The report added it could not accurately gauge cost growth because of a lack of an updated cost estimate for the Orion spacecraft, which accounts for 22 percent of overall agency development costs.
“The cost and schedule performance of NASA’s portfolio of major projects has deteriorated since last year,” the report stated.
The GAO attributed most of the cost and schedule growth in the last year to four projects: the Space Launch System, Exploration Ground Systems, Mars 2020 and Space Network Ground Segment Sustainment (SGSS), an upgrade to ground systems used to communicate with NASA spacecraft. Those projects accounted for $638 million of a net cost increase of $646.7 million among NASA projects in development in 2017, and 59 of 91 months overall schedule delay.
All four of those programs suffered “technical challenges compounded by risky programmatic decisions,” according to the report. Examples of the programmatic decisions that contributed to the cost and schedule problems, particularly in the case of human spaceflight programs, include providing low cost and schedule reserves and use of “aggressive” internal schedules that “could exacerbate delays and lead to cost overruns.”
In the case of Mars 2020, its cost overruns are more modest — $12.9 million in the last year — and the mission remains on schedule for a mid-2020 launch. The report blamed issues with a technology demonstration instrument on the mission, as well as higher costs for integrating another instrument.
SGSS has suffered repeated problems, the GAO said, including “incomplete understanding of its requirements” by the contractor and project management issues. Those problems have continued, the report noted, even as the scope of the project decreased.
Steve Jurczyk, NASA acting associate administrator, acknowledged that there were “serious challenges” with SGSS in a May 1 presentation to a joint meeting of the Aeronautics and Space Engineering Board and Space Studies Board of the National Academies. “The good news is that they’ve turned it around,” he said, citing improved project management and contractor performance.
However, he added that the administration’s 2019 budget request to cancel SGSS and consider commercial alternatives. “That leaves us in a very challenging position,” he said, with only one of four antennas upgraded. He said the agency is performing an independent study of SGSS and alternatives.
Other delays and cost increases, the GAO report, are due to technical problems found during integration and testing of spacecraft. That includes the James Webb Space Telescope, whose launch has now been delayed to around May 2020, with a potential overrun of its $8 billion cost cap. NASA’s ICESat-2 spacecraft, an Earth science mission, has also suffered several months of delays because of problems with its main instrument, a laser altimeter.
Some problems, the GAO said, are not directly to blame on the projects themselves. That includes delays in the launch of the GRACE-Follow On and ICON missions because of launch vehicle problems, and a change in scope in a synthetic aperture radar mission being jointly developed by NASA and the Indian space agency ISRO as a result of discussions by an interagency working group.
Some of the schedule issues, the report said, may be due to workforce issues. The GAO cited several cases where projects have run into delays because of “experienced workforce shortages” and difficulty retaining key workers. NASA’s workforce, the report noted, is aging, with 56 percent of its employees age 50 or older, an increase of seven percentage points in five years.
The GAO said NASA was at risk of growing cost and schedule overruns because of those projects and others, citing previously-reported schedule risks for NASA’s commercial crew program. New programs, like Europa Clipper and a proposed follow-on lander, and the Wide-Field Infrared Survey Telescope (WFIRST), will also be ramping up.
“The composition of the portfolio in the coming years is expected to include similarly large and complex projects, putting NASA at risk of continued cost increases and schedule delays,” the GAO concluded. While NASA is taking steps to prevent similar problems, like a recent effort to reduce the scope and cost of WFIRST, the report argued those measures may not be sufficient.
“But even with these efforts, NASA’s cost and schedule performance may be further tested in upcoming years as some expensive, complex projects linger in the portfolio longer than expected,” the report stated.
An illustration of the Mars Science Laboratory spacecraft entering the Martian atmopshere. A spare heat shield from that mission, planned for use on Mars 2020, cracked during recent tests. Credit: NASA/JPL-Caltech
WASHINGTON — Development of a NASA mission to collect samples on Mars for later return to Earth has suffered a setback, although one that project officials said should not affect its 2020 launch date.
In a statement released late April 26, NASA’s Jet Propulsion Laboratory said a structure that is part of the heat shield for the Mars 2020 spacecraft cracked during testing earlier in the month at a Lockheed Martin facility near Denver.
The fracture in the composite structure is located near the outer edge of the shield and spans its circumference, according to the JPL statement. It was detected April 12 after the heat shield underwent a week of testing at the Lockheed facility where it was subjected to forces 20 percent above those expected in a normal entry into the Martian atmosphere.
Mars 2020 project officials at JPL are working with Lockheed Martin to determine the cause of the cracking. JPL said the structure will be repaired to support other spacecraft testing, but will not be flown. A new heat shield will be built for use on the mission.
The heat shield that cracked was one of two built more than a decade ago for the Mars Science Laboratory (MSL) mission, which landed the Curiosity rover on the surface of Mars in August 2012. The shield underwent testing in 2008 and was as a spare for the one used on the MSL mission.
Mars 2020 is based on the MSL design, using the same approach for entry, descent and landing that was successful for that earlier mission. Mars 2020 makes use of spare hardware from MSL but with some changes, such as more durable wheels on its rover and a different suite of instruments.
JPL didn’t disclose the cost of repairing the damaged heat shield structure and building a replacement. It did state that it should have no effect on the mission’s planned July 2020 launch.
Mars 2020 is intended to be the first phase of a multi-mission effort to return samples of Martian rock and soil to the Earth. The rover will cache those samples in containers, which will be collected by a later mission that will then launch them into Martian orbit. Another spacecraft will capture the sample canister in orbit and return it to the Earth.
There are no firm plans, though, for those later sample return missions after Mars 2020. In August 2017, NASA announced it was developing a “lean architecture” for sample return that focused on only the key capabilities needed for sample return. That approach would minimize the development of additional infrastructure, like a new communications and imaging orbiter that was previously under consideration.
On April 26, ESA and NASA signed a “statement of intent” to study potential cooperation in aspects of the Mars sample return architecture. The signing of the agreement took place during an international Mars sample return workshop in Berlin.
The announcement offered few details about any roles ESA might play, other than that a decision on a European role in future sample return missions would be made at ESA’s next ministerial meeting in late 2019. “The challenges of going to Mars and back demand that they are addressed by an international and commercial partnership – the best of the best,” David Parker, director of human and robotic exploration at ESA, said in the statement.
At an April 4 meeting of NASA’s Mars Exploration Program Analysis Group (MEPAG) in Crystal City, Virginia, scientists discussed sample return planning, including a study by a group called the International Mars Sample Return Objectives and Sample Team. That study, focused on the scientific objectives of Mars sample return, assumed that the effort would be carried out by more than just NASA.
“It’s going to be an international endeavor. We want everybody involved,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program, at the MEPAG meeting.
Development of Mars 2020 remains on schedule despite uncertainty about when future phases of the overall Mars sample return effort will launch. Credit: NASA/JPL-Caltech
WASHINGTON — With few new missions in development, NASA’s Mars Exploration Program is shifting towards operations of ongoing missions as well as technology development to support an eventual sample return effort.
NASA’s fiscal year 2019 budget proposal requests $601.5 million for the program, which includes several missions currently in operation and the Mars 2020 rover under development. That figure is down from the $647 million it received in fiscal year 2017, reflecting the progress on Mars 2020.
The 2019 budget proposal includes an additional $22.3 million to cover operations of the InSight Mars lander spacecraft, which is part of the agency’s Discovery program of planetary science missions separate from the Mars Exploration Program. InSight is scheduled to launch May 5, landing on Mars Nov. 26.
Mars 2020, the only other Mars spacecraft in development, accounts for $348 million of the $601.5 million in the request. The project is set to undergo a system integration review the week of Feb. 26, said Jim Watzin, director of the Mars Exploration Program at NASA Headquarters, at a Feb. 20 meeting of the Mars Exploration Program Analysis Group (MEPAG). That review keeps the mission on schedule for a July 2020 launch.
Mars 2020 is designed to cache Martian rock and regolith samples for later return to Earth. The agency, though, has yet to formally start development of the missions that would follow Mars 2020 to retrieve the samples from the Martian surface and return them to Earth.
The budget proposal includes a line for “Mars Future Missions” with a request for $50 million in 2019. The funding is earmarked to support work on key technologies needed for any future sample return missions.
“One of the highlights in the planetary science budget was the addition of planning for a potential Mars sample return mission,” Watzin said at the MEPAG meeting. “This is really great news for us to begin taking a serious look at this.”
NASA unveiled a general architecture for what it calls “lean sample return” in August 2017. That calls for the launch of a lander and rover to collect the samples cached by Mars 2020 and place them into a container that would be launched into orbit by an ascent vehicle. An orbiter would rendezvous with and grab that container and return it to Earth.
Many of the details of how those missions would be developed, and even their requirements, are still under study. “Fundamentally, we’re going to have to maintain some flexibility in our requirements for the mission,” Watzin said. “We may not be able to do everything that everyone wanted on that particular mission, and we will be trading cost and risk and performance as an essential part of the trade space as we look at this.”
Technology development work is already in progress, he said, to address key issues associated with both the sample retrieval lander and sample collection orbiter. A particular focus has been on the technologies needed for the Mars ascent vehicle rocket and the ability of the orbiter to rendezvous with the sample canister launched by that rocket.
Those efforts have made some progress, Chad Edwards of the Mars Exploration Program said at the MEPAG meeting. That includes a decision on the design of the ascent vehicle, which will be a single-stage rocket using hybrid propulsion, a paraffin-based solid fuel known as SP7 along with mixed oxides of nitrogen liquid oxidizer. That vehicle would be able to place a sample container weighing 12 kilograms into a 350-kilometer orbit around the planet.
Other work includes studying whether to use electric or chemical propulsion to maneuver to rendezvous with the sample canister. “This becomes a trade between mass and time,” he said, with electric propulsion offering lower mass versus the shorter maneuvering times chemical propulsion can provide.
“All of these technologies are on track to support a launch of the sample retrieval lander and sample return orbiter as early as 2026,” Edwards said. However, the administration’s budget proposal does not commit to a specific date for launching those missions. The budget projections included in the proposal keep the future missions line at $50 million a year through 2023, almost certainly insufficient to support development of spacecraft whose combined cost is likely to be well above a billion dollars.
Jim Green, director of NASA’s planetary science division, said at the Planetary Science Advisory Committee meeting Feb. 21 said future funding would depend on how the Mars sample return architecture takes shape, including potential roles by commercial and international partners.
“Without a go-forward architecture for which we can actually get a rudimentary budget, money is not just be given to us to have it lay around,” he said. “We have a lot of work to do to be able to scope out what elements of the program are going to be executed, and who’s going to do what, before we can create a budget.”
Current missions and other concepts
The remainder of the Mars Exploration Program budget goes to support ongoing missions, development of an instrument that will fly on the European Space Agency’s ExoMars 2020 lander, and other science and technology work.
“All of our missions are healthy, but many of them are getting long in the tooth,” Watzin said at a Feb. 22 meeting of the Planetary Science Advisory Committee. The youngest, the Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter, has been at Mars since September 2014. The oldest, the Mars Odyssey orbiter, arrived at Mars in October 2001.
Those spacecraft, while healthy, are not without their problems. Engineers have been working for about a year on problems with the drill on the Curiosity rover, ultimately developing an alternative way to use the drill to work around those problems. The first operation of the drill using that alternative technique should take place within days, he said.
The Mars Reconnaissance Orbiter (MRO), which has been in orbit for nearly 12 years, recently suffered a voltage problem with its batteries that put the spacecraft into a standby mode for several days. That kept it from performing observations or serving as a communications relay for the Curiosity and Opportunity rovers. The importance of MRO, and its age, led NASA to study concepts for a Mars orbiter mission that could launch in 2022 to take over MRO’s imaging and communications roles, but those plans are no longer being pursued.
“We have healthy fuel reserves on board, so now the challenge before us is to see how long we can extend the life and usefulness of this mission,” Watzin said of MRO.
NASA is moving ahead with plans to alter the orbit of the MAVEN orbiter to have it serve as a communications relay. Watzin said the spacecraft, now in its extended mission, will lower the apoapsis, or most distant point, of the spacecraft’s orbit in 2019 from its current 6,200 kilometers to 4,000 to 4,500 kilometers. That lower orbit will put MAVEN into a better position to be a relay while allowing it to continue its science mission.
While large missions beyond Mars 2020 are not under consideration other than future sample return missions, Mars smallsat missions are being studied. Watzin described at the MEPAG meeting one concept called Mars Micro Orbiter under development by a team led by Mike Malin of Malin Space Science Systems. The spacecraft is a 12-unit cubesat that would launch as a secondary payload and use onboard propulsion to travel to and enter orbit around Mars to perform global environmental monitoring. The mission will undergo a preliminary design review in March, he said, although he didn’t discuss its status beyond that.
Another concept under development over the last several years is a small helicopter that could fly on a rover mission like Mars 2020, serving as an aerial scout. Tests of the concept, including flying it in a chamber at Mars atmospheric conditions, have been promising, Watzin said.
NASA has not made a decision to include it on Mars 2020, though. “There’s certainly a chance,” he said at the MEPAG meeting when asked if it could fly on that mission. A decision would likely come in a month or two, he added.
Green said the decision to add the helicopter to Mars 2020 will depend on both its technical progress and “an adequate budget” to complete its development. “It’s going through its reviews. So far, it’s doing well,” he said. “It has a ways to go.”