NASA’s Mars Reconnaissance Orbiter also serves as a communications relay, but may reach the end of its life before a new set of Mars missions arrives there in the early 2020s. (credit: NASA/JPL-Caltech)
by Cody Knipfer
Monday, June 5, 2017
The next several years are poised to be a significant period in the exploration of Mars, with several new spacecraft expected to launch, land, and operate on the Martian surface by the early 2020s. Among them are NASA’s InSight lander, set to land in 2018; the ESA-Russian ExoMars Rover, due to land in 2021; and NASA’s Mars 2020 rover, also expected to arrive in 2021. SpaceX also intends to land its first Red Dragon spacecraft on Mars in 2020, with a follow-on possible in the years after. Assuming their continued functionality, NASA’s existing rovers, Curiosity and Opportunity, will be among this fleet exploring the Martian surface.
If all goes to plan, up to six vehicles, not including China’s planned Mars rover, will be simultaneously operating on Mars—a situation which presents an unprecedented opportunity for groundbreaking science, and an unprecedented strain on the network that NASA uses to communicate with its spacecraft. The increased bandwidth required to efficiently transmit the data these vehicles will surely produce necessitates a robust in-space telecommunications infrastructure servicing the planet.
|This wave of missions presents an unprecedented opportunity for groundbreaking science, and an unprecedented strain on the network that NASA uses to communicate with its spacecraft.|
Sufficient telecommunications capacity between Mars and Earth has long been an important element of the exploration of the planet. Highly constrained by their volume, the mass of their science instruments, and their power supplies, landers and rovers on the Martian surface are significantly restricted in the data they can send directly to Earth. They therefore rely on nearby spacecraft in Mars orbit, which carry substantially more powerful and capable communications equipment, to serve as more efficient relays for communicating with Earth. Indeed, more than 90 percent of data received from vehicles on Mars has been relayed through spacecraft orbiting the planet.
The importance of this relay is apparent in examples such as NASA’s Curiosity rover, which can send less than 500 bits per second of data directly to the Earth-based Deep Space Network. Conversely, data provided from Curiosity to orbiting spacecraft can be sent back to Earth at rates up to 2 megabits per second, some 4,000 times faster than a direct link between the rover and Earth. According to NASA calculations, the amount of data the rover can send to an orbiter during an eight-minute window of communication is roughly equivalent to what the rover would be able to transmit to Earth over the span of 20 hours. Relying on direct transmissions from the Martian surface to Earth is not conducive to a vigorous exploration program.
Troublingly, the telecommunications infrastructure that exists at Mars today is aging, and plans to replenish it in time to meet upcoming bandwidth needs are slipping. This poses a considerable challenge to the operations and science activities planned in the coming years. NASA has determined that it will be “very difficult to meet [entry, descent, and landing] coverage requirements for [Mars] 2020, ExoMars, and 1-2 Red Dragon landings over a 1-2 month period” and that “surface relay support will also be challenging, given number of potential simultaneous surface users.”
In effect, NASA risks a “communications crunch” at Mars in the early 2020s. The agency may find itself lacking the relay capacity it needs to fully support the transfer of data back to scientists on Earth. This essay examines the issue, offering a condensed history of the telecommunications infrastructure at Mars, a look at NASA’s present plan for, and challenges facing, replenishing that infrastructure, and a short analysis of the situation and its implications.
The Mars telecommunications network today
Arriving at Mars in 2001, the Mars Odyssey spacecraft established the telecommunications relay that serves as a link between vehicles on the Martian surface and the Earth. Mars Global Surveyor later joined the network, having been repurposed as a part-time communications satellite following the completion of its primary science mission. The two spacecraft successfully relayed signals from the Spirit and Opportunity rovers prior to and after their entry, descent, and landing in 2004.
|While Mars Odyssey and Mars Reconnaissance Orbiter have demonstrated their longevity, there is, according to Fuk Li, Director of the Mars Exploration Directorate at JPL in 2015, “real concern that the aging spacecraft might fail.”|
The Mars Reconnaissance Orbiter, which arrived at the planet in 2006, took over the bulk of telecommunications relay operations that were being conducted by Mars Global Surveyor, which ceased operation in late 2006. Since then, Mars Odyssey, Mars Reconnaissance Orbiter, and ESA’s Mars Express, which entered orbit in 2003, have supported data and communications relay for Spirit and Opportunity, NASA’s Phoenix lander, the Curiosity rover, and ESA’s Schiaparelli lander.
NASA’s MAVEN spacecraft joined the trio in 2014, bolstering the on-orbit telecommunications network with a Jet Propulsion Laboratory-developed Electra UHF radio specially designed to relay data received from vehicles on the Martian surface. ESA’s Trace Gas Orbiter, which arrived with the Schiaparelli lander in 2016, also carries two Electra radios. With these additions, there are currently five spacecraft capable of supporting Mars-Earth telecommunications.
With the anticipated arrival and landing of several spacecraft at Mars in the early 2020s, the question is how long these spacecraft can continue their data relay function. In 2014, ESA extended Mars Express’ mission to the end of 2018—at which point the spacecraft will be 15 years old. MAVEN is currently serving an extended mission through late 2018, though it only carries enough propellant for operational life through 2024. According to JPL engineering estimates, Mars Odyssey could continue operations until at least 2025, while Mars Reconnaissance Orbiter has enough propellant to remain operational in orbit through 2034.
While Mars Odyssey and Mars Reconnaissance Orbiter have demonstrated their longevity, there is, according to Fuk Li, Director of the Mars Exploration Directorate at JPL in 2015, “real concern that the aging spacecraft might fail.” Jim Watzin, Director of NASA’s Mars Exploration Program, echoed these concerns in late 2016, noting that most of the spacecraft orbiting Mars will have reduced capabilities, if not failed outright, by 2020. Indeed, one of Mars Odyssey’s four reaction wheels has already failed. Even if they remain operational come 2020, Mars Odyssey will be 19 years old while Mars Reconnaissance Orbiter will be 15—aged platforms carrying outdated communications technology. As John Grunsfeld, former head of NASA’s Science Mission Directorate, noted, a result of this limitation is that “[r]ight now most of what happens on Mars stays on Mars, because we don’t have the bandwidth to get the data back.”
Meanwhile, ESA’s Trace Gas Orbiter is expected to serve as the primary data relay for the ExoMars rover, set to land in 2021, but has a nominal end of mission in 2022. MAVEN’s elliptical orbit and fixed antenna makes it a less-than-ideal platform for data relay; NASA intends to maximize use of the spacecraft for its primary research mission instead of turning it over to communications support. According to Li, “[w]e never wanted to use MAVEN for relay operations unless there was a sudden emergency.”
Obviously, there exists an increasing need for follow-on relay capacity.
Past and present plans for follow-on capacity
NASA, cognizant of the issue, has proposed various plans for, if not made substantial progress on, a follow-on Mars orbiter that would satisfy the increasing need for data relay from Mars.
|In 2014 NASA began looking at concepts for a new Mars orbiter that would satisfy Mars telecommunications demand through the 2020s.|
In the early 2000s, NASA had plans for a “Mars Telecommunications Orbiter,” which would have arrived at the planet in 2009. A dedicated data relay satellite with an expected ten-year mission, the spacecraft would have orbited at an altitude of 5,000 kilometers and remained in near-continuous contact with Earth. The spacecraft would have also experimented with laser optical communications between Mars and Earth.
However, with NASA focused on the Constellation program, including a return to the Moon, and with fewer spacecraft bound for Mars than had been previously expected, the agency opted to cancel the projected-$500 million mission in 2005. According to Doug McCuistion, NASA’s Mars program director at the time, “[t]he need for [data relay] has diminished in the immediate term, but that doesn’t mean we have abandoned the idea.”
With Constellation’s cancellation and NASA’s reorientation to Mars, the need to renew the telecommunications infrastructure at the planet came back in focus.
In July 2014, NASA issued a request for information (RFI) seeking ideas on “potential commercialization options for the provision of Mars telecommunications proximity link services.” Under such an approach, a commercial provider would own and operate the orbiter while NASA would contract to purchase relay services over a period of time. Speaking to the RFI, Grunsfeld said that “we are looking to broaden participation in the exploration of Mars to include new models for government and commercial partnerships… [d]epending on the outcome, the new model could be a vital component in future science missions and the path for humans to Mars.” However, little has been publicly announced regarding NASA plans to pursue this potential approach since the release of the RFI.
Concurrently, NASA began looking at concepts for a new Mars orbiter that would satisfy Mars telecommunications demand through the 2020s. At a February 2015 meeting of the Mars Exploration Program Analysis Group, Watzin announced NASA’s plan to launch a new telecommunications satellite to Mars in 2022. Speaking at a NASA Advisory Council subcommittee meeting two months later, he said that the need to refurbish the Mars telecommunications infrastructure is “very real,” further noting that the proposed orbiter could carry an optical communications payload to speed data relay. As the year went on, more potential features for the spacecraft were offered, such as a solar-electric propulsion system, remote sensing instruments, and a sample rendezvous capture and return capability, transforming it from “simply” a telecommunications package to an orbiter capable of fulfilling a multi-mission role.
Notably, despite the year’s ongoing discussions regarding the orbiter, the mission wasn’t yet part of NASA’s budget. Nor would it be until the White House submitted its fiscal year (FY) 2017 budget request; the agency did not request funding for the mission in its FY16 request. Recognizing this, Watzin acknowledged that while the orbiter deserved “serious study… I’m not saying we’re going to do this.”
Nonetheless, in April 2016, NASA issued a solicitation seeking industry input on possible designs for the orbiter, calling on it to substantially increase bandwidth communications. By June, JPL had awarded $400,000 contracts to Boeing, Lockheed Martin, Northrop Grumman, Orbital ATK, and Space Systems Loral to study concepts for the mission. In an October teleconference held by the Mars Exploration Program Analysis Group, Watzin highlighted ongoing studies on the potential of using a commercial spacecraft bus for the orbiter, with initial results “looking very, very encouraging.” Such an approach would allow NASA to “have a very healthy and vigorous competition to select a bus, and expect very little or limited development on that.”
Yet during that same teleconference, Watzin conceded that the agency had made little progress on the mission, saying that “[s]omewhat disappointingly, we are still in a situation where we have no missions beyond 2020 on the books that are approved or budgeted.” While the agency was continuing to study the mission, and continuing “to work on concepts and approaches that will allow us to get that orbiter in place as quickly as possible,” he noted that “[i]t’s a difficult environment to get new missions into the program right now.” Still, with a “focused beginning of the program,” Watzin felt it was possible to support a launch by 2022.
The President’s proposed FY17 budget, issued in February 2016, requested $10 million to begin early conceptual work on the orbiter. Yet, with Congress passing a series of Continuing Resolutions through the year, NASA continued to be funded at the FY16 level until May 2017—seven months after FY17 notionally began. The Consolidated Appropriations Act of 2017, signed into law on May 5, provided the Mars Exploration Program $647 million for FY17, a boost of $62.6 million over the President’s request of $584.5M million. Per the Planetary Society’s Casey Dreier, this additional money would serve to double the amount of study funding provided to the Mars orbiter mission.
|To date, despite ongoing studies, NASA has not yet formally approved any Mars mission, including the orbiter, beyond the Mars 2020 rover.|
In a March 2016 presentation to the NASA Advisory Council’s Planetary Science Subcommittee, Watzin laid out the notional project lifecycle for the orbiter. It envisioned the spacecraft launching in 2022 and arriving at Mars in 2023; initial Phase A studies would take place throughout 2017 using allocated FY17 funds. His presentation noted that “Phase A start in 2017 is essential, given that an orbiter arriving at Mars at the earliest opportunity would join Odyssey in its 22nd year of service and MRO in its 18th.” He suggested that this schedule was “aggressive, but very, very doable… [w]e’ve got to get started on this.”
However, the half-year long delay in FY17 funding for the mission’s Phase A studies likely did little to enable the “focused beginning of the program” for which Watzin had hoped. A presentation given to the National Academies of Sciences’ Space Studies Board in March 2017 failed to indicate whether the orbiter had undergone the Mission Concept Review that had previously been planned for the end of FY16. Nor has an announcement of opportunity for science instruments, a significant step in mission development, been issued, though the project lifecycle Watzin laid out suggested it would occur in in the first half of 2017.
Moreover, President Trump’s FY18 budget request, issued in late May 2017, offers only $2.9 million for the “Mars Future Missions” budget line item under which the orbiter’s planning falls—$7 million less than the FY17 funding request and $9.1 million less than the notional FY18 estimate NASA had produced in 2016.
A chart from a presentation showing the various options for a 2022 Mars orbiter mission, of varying degrees of capability and cost. (credit: NASA)
A coming communications crunch?
To date, despite ongoing studies, NASA has not yet formally approved any Mars mission, including the orbiter, beyond the Mars 2020 rover. This, coupled with the Administration’s current reticence to supply more funding for early-stage planning of such a mission, risks further slippage on the hoped-for schedule of a 2022 launch.
A review of past Mars orbiters’ lifecycles offers some insight into the average schedule of spacecraft development. Technology and advanced concept work on Mars Odyssey, which launched in 2001, began in 1995 (initially as a component of the cancelled Mars Surveyor 2001 program.) Advanced concept work on Mars Express, which launched in 2003, began in 1996. F0r the Mars Reconnaissance Orbiter, launched in 2005, this work began in 2000. MAVEN, which launched in 2013, was selected in 2008 from proposals submitted in response to an announcement of opportunity issued in August 2006. Though of varying cost and complexity, these missions each took at least five years from selection and advanced concept work to launch.
With 2017 nearly halfway over, the 2022 Mars orbiter’s timeline now stands at an equivalent point as the beginning of these past programs. Further delays to starting the orbiter’s development could push its launch back to the next Earth-Mars launch window in 2024, in which case the spacecraft would arrive at the planet in 2025 or 2026. Per a chart in Watzin’s 2017 presentation, NASA expects ExoMars and Red Dragon to make use of the Mars relay between 2021 and 2022. Mars 2020 will be in its primary mission between 2021 and 2023 and first extended mission between 2023 and 2025. A delayed arrival in 2025–26 would have the orbiter doing nothing to support the at-risk telecommunications relay until well into Mars 2020’s first extended mission.
Several competing pressures are at play behind the orbiter’s development that will affect the date it ultimately launches.
As with all things, one is budgetary. While Congress has offered NASA’s planetary science budget considerable increases above the presidential request in the past few years, that extra money have largely gone to missions that have experienced cost overruns. Funding necessary for the Mars 2020 rover, which is expected to cost $2.1 billion, is significantly higher than initial estimates of $1.5 billion. The two-year postponement of InSight’s launch, from 2016 to 2018, cost the agency an additional $153.8 million. A result of that extra cost, according to David Schurr, deputy director of NASA’s Planetary Science Division, is that “there may be fewer opportunities for new missions in future years, from fiscal years 2017–2020… [t]he plan is for planetary science to cover these costs over the next four years.” A new Mars orbiter is among the victims of that overrun. Meanwhile, ramped-up funding for NASA’s ambitious Europa mission, which Congress expects will launch in 2022, risks crowding out the budget (see “What price Europa”, The Space Review, June 1, 2015) for other possible missions in the planetary science portfolio, such as the orbiter.
|The Mars Exploration Program Analysis Group study proposed a range of concepts for the orbiter of different size, complexity, and cost that would achieve the decadal survey’s goals at varying degrees.|
The other is the scope of the orbiter itself. With it likely to be the only NASA spacecraft aside from Mars 2020 to arrive at the planet in the first half of the decade, the scientific community hopes it can fulfill several of the priorities laid out in the 2013–2022 Planetary Science Decadal Survey. These scientific priorities present a challenging decision that NASA will have to make regarding the orbiter’s cost and timeline.
A Mars Exploration Program Analysis Group study on the orbiter, conducted throughout 2015, identified several scientific and technological missions the orbiter could potentially conduct beyond replenishing telecommunications capacity. These included surface and atmosphere reconnaissance, location and quantification of in situ resources for future missions, a demonstration (or actual return) of surface-launched sample rendezvous and capture, and infusion and demonstration of solar electric propulsion (SEP) technology. Watzin’s 2017 presentation acknowledged that “the importance of Mars Sample Return expressed by the Decadal Survey… has been and remains the highest scientifically endorsed priority by both of last two decadal surveys.” Mars 2020, with its sample-collection mission, represents “the critical first element of Mars sample return and should be viewed primarily in the context of sample return.” The Survey noted that “important multi-decade efforts like Mars Sample Return can only come about if [its] recommendations are… followed.”
The Mars Exploration Program Analysis Group study proposed a range of concepts for the orbiter of different size, complexity, and cost that would achieve the decadal survey’s goals at varying degrees. Class 1, “MRO Class,” would be simply a telecommunications, recon, and science orbiter with conventional chemical propulsion. Class 2, “MRO Upgrade,” would carry out the above mission, also feature SEP, allow for up to three times the telecommunications capacity of MRO, and conduct sample rendezvous demonstrations. Class 3, “New Class,” would be a multi-function flagship SEP orbiter with up to ten times the telecommunications capacity of Mars Reconnaissance Orbiter that would carry out all the above functions, in addition to possible Mars sample return.
The study determined that “a demonstration of rendezvous and capture or actual return of a retrieved container/cache to Earth vicinity would likely require SEP capability.” However, it noted that “the major limitation to exploiting the full capabilities of a SEP mission is likely to be payload cost.”
Two years later, without a formally approved mission and limited budget, and with a possible telecommunications gap approaching, NASA will need to decide how to balance its scientific interests and fiscal limitations with its Mars relay requirements. Expediting mission development at lower cost will be a tough concession for the scientific community to make. Waiting for a favorable budgetary environment for a flagship-class mission and/or drawing out spacecraft development to accommodate a larger scientific payload puts the data return of Mars 2020, the next Mars flagship mission, in jeopardy. A win-win scenario appears increasingly further from reach.
It is entirely possible that Congress will allocate enough funds for the mission in its FY18 budget to allow development to begin in earnest. However, as mentioned earlier, other missions in NASA’s portfolio have garnered greater congressional attention and, therefore, funding. Of course, considering the present political environment, it’s also possible that Congress will fund the government at FY17 levels well into the start of FY18 through continuing resolutions.
NASA might pursue international cooperation on the orbiter to defray costs or the burden of development. In its April 2016 study solicitation, the agency expressed interest in implementing the mission “in concert with its international partners to the greatest extent possible.” Likewise, the Mars Exploration Program Analysis Group study noted that “there are many possible contributions by international partners, both for spacecraft subsystems and for the payload elements needed to meet the recommended mission measurement objectives.” To date, however, NASA has not publicly announced any progress toward securing international involvement in a possible orbiter.
Alternatively, NASA could pursue the commercialization approach it investigated through its 2014 RFI. Whether industry would be ready or willing to participate in such an approach within the early 2020 timeframe, however, isn’t certain. Of the growing commercial space sector, only SpaceX has expressed interest in sending a spacecraft it owns and operates to Mars in the early 2020s. It is doubtful, considering the nature of the Red Dragon mission and SpaceX’s focus on launch vehicles, crew and cargo spaceccraft, and low Earth orbit small satellites, that the company would seek to pursue development ofn an in-house telecommunications relay capable of meeting Mars-Earth bandwidth needs. The company could perhaps offer to provide a rideshare to a third party offering a relay satellite, though that would surely necessitate a significant rescoping of the mission. SpaceX has expressed no intent to do so.
Whatever the case, and whatever course of action NASA decides to take (or not take), the telecommunications relay at Mars is aging, several surface spacecraft are progressing toward launch, and the clock is ticking—perhaps toward a coming communications crunch at Mars.