The Next Four Mars Landers

Planetary geologist Phil Horzempa returns with a new post on Mars landers planned through 2018.

It doesn't seem to be widely known, but, China appears to be planning to send a lander to Mars in 2016.  As with most Chinese space projects, hard facts are scarce.  A presentation gives some sketchy details of the mission.  From this report we are able to glean the general outline of the mission and the fact that China actually has plans for a Mars exploration program. 

Figure 1.  Chinese orbiter and lander aeroshell.

This diagram shows the lander aeroshell and the orbiter that will carry it to Mars (Figure 1). Upon arrival at the Red Planet, the orbiter/lander combination will enter a capture orbit while still attached to each other, as was done during the Viking missions.  The dual craft will then enter a lower orbit from which the lander will descend to the surface (Figure 2).  As shown in the diagram, the orbiter will serve as a relay for the lander before it maneuvers into a lower science orbit. 

Figure 2. Chinese plan to land from orbit

The Entry, Descent and Landing (EDL) sequence is shown in Figure 3.   Not much detail is revealed, but in brief, it seems to be a typical EDL sequence followed by most Mars landers.  This report indicates that the landing will be semi-soft.  The only clue as to what the lander may look like is shown in a cut-away diagram of the aeroshell.  (Figure 4)   Apparently, it will be battery-powered, with a 3 – 5 day life on the surface.  The lander will have a mass of only 40 – 100 lb.  This will leave little capability for any science instruments.  The available diagrams do not clearly indicate whether there will be a separate lander within the aeroshell, or if the aeroshell structure itself will double as a lander.

Figure 3.  Chinese entry, descent, and landing sequence.

Figure 4. Chinese Mars demonstration lander.

In addition, the report indicates 3 candidate landing sites for this mission.  They are all at about 45 degrees N  latitude, which may be dictated by the orbit of the carrier spacecraft.  All 3 sites are targeted for the plains of Mars possibly to find terrain that is as amenable as possible to a safe landing (Figure 5). 

Figure 5. Possible Chinese landing sites

 Even though this may be a simple hard lander, it would still be a great leap forward for China's space program.   This report also outlines a long-term Mars program that includes a Rover and Sample Return.  (Figure 6)  The unmanned Chang'e lunar program has shown that China is willing, and able, to follow through on fulfilling long-range plans.  If it does the same with its proposed Mars program, then we could see another major player in the exploration of the Red Planet. 

Figure 6. Proposed Chinese Martian exploration program.

In fact, China may be laying the groundwork for its Mars program in the Chang'e program.  Later this year, the Chang'e-3 mission should deliver a rover to the Moon's surface.  In 2017, the Chang'e-5 spacecraft is set to return samples from the Moon.  In preparation for that mission, the Chinese have recently announced that they will conduct an Entry Vehicle test flight in 2015.  This qualification mission will fly a copy of Chang'e-5's entry capsule attached to a bus derived from the Chang'e-2 lunar orbiter.  The mission profile is not clear, but it can be imagined that the bus/capsule combination will fly out to at least the Moon's orbit before returning to the Earth.  This will allow the capsule's thermal protection system to be tested at velocities encountered by spacecraft returning from the Moon or Mars.

 As to whether the 2015 bus/capsule spacecraft will perform a return from lunar distances without approaching the Moon (as in the Soviet Zond 4 mission) or whether it will loop the Moon (as with the Soviet's Zond 5) is an open question.  Not only will this test the Chang'e-5's capsule design, but it will serve as a pathfinder for China's 2016 Mars EDL capsule and future Martian sample-return craft.

The 2018 Mars window will see the launch of the joint ESA/Roscosmos Exomars 2018 rover/lander.  A recent status report has revealed new details of the Russian Descent Module.    This lander is set to deliver ESA's rover to the surface of Mars.  The report shows the Russian surface platform to be a 4-legged (or 3-legged) rocket-powered lander.  This is very similar to the design of the Viking and Phoenix soft-landers, as well as the descent stage of the Soviet advanced Luna landers, e.g., Luna 16. 

 The design of the Russian lander appears to be somewhat fluid .  In an earlier post , Van showed a version of the lander that appears in several illustrations from this newest report.  (Figure 7 to 10)   The lander option in the upper-right of this diagram is especially intriguing.  It shows a descent module with legs that are folded upward after landing.   This would lower the platform so that the rover could more easily egress from the lander.

Figure 7. ExoMars and Russian platform entry module.

Figure 8. Possible designs for Russian-designed lander.

Figure 9. Detail of one possible design for the Russian supplied lander.

Figure 10. Entry, descent, and landing plan for the ExoMars rover and Russian lander.

However, a variety of options are still being considered by the lander contractor NPO Lavochkin. As Van reported in that earlier post,  the Russians plan to have a full complement of science instruments on their Descent Module.  Even if there were no rover on this mission, the Russian instruments would make this a productive mission. 

What makes the ExoMars 2018 project a dicey proposition is the fact that the last Soviet/Russian rocket-powered landing occurred with the Luna 24 Moon landing in 1976.  The Russians have no recent experience with this type of machine.  (Note that the Soviets soft-landed on Venus as recently as 1985, but the lander deceleration was entirely through atmospheric drag.)  However,  the upcoming mission of Luna 25, in 2016, is set to fly a controlled soft-landing on the Moon.  If successful, this may help ease any concerns about Russian capabilities.  Mars' environment is different than that of the Moon, but the final maneuvers leading to a soft-landing on these worlds is similar.  Thus was the American lunar Surveyor soft-lander a pathfinder for the later Viking spacecraft. 

ESA has indicated that its 2016 EDM (Entry, Descent and Landing Demonstrator Module) lander will play a role in preparing for its following ExoMars effort.  To quote ESA's website, “ EDM will land on Mars to prove key technologies for the 2018 mission.”  This is telling, and brings up the issue of how, exactly, the tasks required for building this lander will be divided between ESA and Roscosmos.   How much of the technology developed for ESA's EDM mission will feed-forward to Russia's 2018 Mars lander?  Will ESA share its software and/or hardware developed for the EDM?   In ESA's latest Quarterly report, there is this quote, “ESA will provide the computer to manage all operations except surface platform operations.  The surface platform, being a Russian responsibility, will be operated using a Russian-supplied computer.  The Rover will also feature an ESA-provided computer dedicated to Rover operations.”   Safely landing on Mars is perhaps the most difficult maneuver in the field of planetary exploration and reliable software is an important aspect. This division of computer labor could be a source of concern.

ESA's EDM Mars lander, referred to above, will use yet another landing technology.  In lieu of airbags or landing legs or a sky crane, it will utilize a crushable structure to attenuate the force of impact.   (Figure 11)   The EDM will also use a set of 9 thrusters (3 clusters of 3 rocket engines each).  They will not be throttled as were those on Surveyor, Viking, and the MSL Sky Crane.  That capability is expensive to develop.  Instead, the EDM will operate its thrusters in pulse mode, the same method utilized by the Phoenix lander in 2008.

Figure 11. ESA's Entry, Descent and Landing Demonstrator Module (EDM)

This brings us to Phoenix-2, aka, Insight, NASA's contribution to the international fleet of landers in 2016.  It is now in Phase B, with construction set to begin in 2014. However, every project has growing pains and one is revealed through comments in NASA's newest budget proposal.  Specifically, the document states, “If: Growth of lander avionics and payload electronics continues to strain volume of thermal enclosure, Then: The heritage design of the thermal enclosure and aeroshell is at risk. The project cannot grow the size of the thermal enclosure.  Instrument teams are working to close trade studies that will establish the baseline for payload electronics configuration, and spacecraft team members are working closely with instrument teams to identify and analyze overall configuration options.”  One of the cost-saving aspects of Insight is the use of the proven Phoenix lander design.  However, it appears that they are having difficulties in stuffing 11 pounds of instruments into a 10-lb bag, so to speak. 

We will see four spacecraft utilizing four different landing designs heading to the Red Planet in 2016 and 2018.  It will be fascinating to see the results of this fleet of ships.  

WFIRST-2.4

Last February, I wrote about proposals to use two surplus spy telescope assemblies for planetary science (Brother, Can You Spare $1B for a Planetary Space Telescope?).  Since then, one study team has completed a study on uses of one of the telescopes for astrophysics studies.  (Another team will report soon on the best proposals for possibly using the second telescope assembly.)  The proposal goes by the more formal Astrophysics Focused Telescope Assets (AFTA) or informally at WFIRST-2.4.  ('WFIRST' is the acronym for a proposed dark energy telescope and 2.4 refers to the 2.4 m mirror of the telescope.)

The primary goal for the astrophysics mission is to study key questions about the structure of the universe and the nature and role of dark energy and dark matter.  (Together, these invisible components make up the vast majority of the universe's mass.)  

However, the team also examined uses of the mission for exoplanet studies.  Here, the mission could conduct distinct surveys.  Using the same camera-spectrometer as the astrophysics study, the telescope would spend long periods staring towards the center of our galaxy.  The instrument would occasionally catch an exoplanet transiting in front of a background star.  The gravity of the planet would distort the image of the background star, revealing the mass of the planet.  Operating in this mode, the telescope would be expected to detect an estimated 3,000 or more planets.  Where the Kepler telescope specialized in detecting planets close to their stars, this mission would specialize in detecting planets further out (including those floating in space between stars).  

The study team also is proposing that the telescope be equipped with a coronagraph.  This instrument would use a shade to block the bright light of nearby stars, permitting direct imaging of Neptune and Jupiter-class planets.

Phil Horzempa has written an excellent summary of the exoplanet capabilities of this proposed mission at the Space Review (Exoplanet capabilities of WFIRST-2.4).  (Phil also has contributed to this blog.)  I encourage you to read his story.

In the meantime, here are a couple of slides from a summary presentation on the proposal to whet your appetite.  You can see the entire presentation here or read the study team's report here.

If the mission flies, it would be launched sometime in the early 2020s.  The team did not make its cost estimate available.  Later this month, NASA's administrator will decide whether or not NASA will continue to study this option.

One of the exciting capabilities of WFIRST 2.4 is that it would have a much wider view than the Hubble Space Telescope while retaining Hubble's resolution.  The following two images show how two WFIRST 2.4 images would cover the same area that would require 432 Hubble images.

Implementing Missions Within Budget -- Good News

A few years ago, cost overruns in NASA’s science program were a significant news story.  (See, for example, this post from 2009.)  The major culprits were the two largest missions, the James Webb Space Telescope and the Mars Science Laboratory.  Smaller missions, however, had their share of cost overruns, too.  At one point, for example, NASA cancelled the Dawn mission to the asteroids Vesta and Ceres because of overruns in that mission’s budget.  (Fortunately, NASA reconsidered and re-instated the mission.)

For the last several years, Congress’ General Accounting Office annually has reviewed budget performance on selected NASA missions.  The most recent report got me to relook at cost overruns in NASA’s Planetary Science program.  The news is good, but as so often happens, the good news appears to come with a tradeoff.

The missions of the Discovery program have visited a wide-range of solar system destinations.  These missions also have had a range of cost under- and overruns.  Image from Historic Spacecraft and used under a creative commons license. 

Let’s start by looking at the trends.  Prior to about 2002, some planetary missions came in under budget, others were less than 10% over budget, and two were more than 20% over budget.  (Two of the four missions that came in under budget failed.)  Then, in the mid-2000’s, all missions were more than 19% over their initial estimates.  The Curiosity Mars Science Laboratory began development in 2004 with a planned launch in 2009 (later slipped to 2011).  This mission had the largest absolute and percentage cost overrun since the mid-1990s.   It was towards the end of this period that then NASA science administrator Alan Stern made eliminating cost overruns a central focus.

Trends in NASA planetary mission cost under- and overruns.  Points in red indicate missions in the Discovery and Mars Scout programs (<$500M for the spacecraft) and all other missions are in blue.  Data used is shown at the end of this post.

Following this period, cost overruns in planetary missions all but disappeared.  For missions launched in the last few years, four missions have stayed within their initial budgets and a fifth was less than 10% over budget.

(I was unable to find any information on the Mars Phoenix, Pluto New Horizon, or the Mars Reconnaissance Orbiter missions’ performance against initial cost estimates. The lack of news probably indicates that these missions stayed within budget.)

I hope that the President’s budget office and Congress – which decide whether to reward NASA with funds for new missions or not – take note of this recent accomplishment.  NASA’s Planetary Science Division recognized a problem and appears to have dealt with it.  Unfortunately, I fear that that NASA’s reputation in the near term will be stained by the large overruns in the two flagship programs, MSL and JWST.  Space News reported in January, that future astronomy missions may be limited to approximately $1B, ending a long run of >$1B flagship astronomy missions.  I also wonder how much of the President’s budget office’s refusal to allow development of a Europa mission (estimated $2B) stems from reluctance to trust NASA again on a large science mission.

I also worry about a possible consequence of managing to budget.  Boldly doing new things brings with it the risks of busting budgets.  Look at the string of missions starting in the mid-2000’s that exceeded budgets by 19%+: the Mars Spirit and Opportunity rovers, the Mercury MESSENGER orbiter, the Kepler exoplanet telescope, the Dawn asteroid mission, and the Curiosity rover.  All required new designs and often significant technology development to achieve their goals.

The easiest way to stay within budget is to push the envelope as little as possible.  The Mars MAVEN mission returns to the Red Planet and reuses substantial portions of the Mars Reconnaissance Orbiter’s spacecraft design.  The recently completed lunar GRAIL gravity mapping mission largely reused the spacecraft design of the similar GRACE terrestrial mission.  The 2020 Mars rover mission will reuse the design of the Mars Curiosity rover.  The recently selected Mars InSight lander largely reuses the design of the Phoenix lander. 

InSight’s competitors for selection, by contrast, would have required new designs to either hop across the surface of a comet or to land on a Titan lake.  When NASA selected the InSight mission, its managers emphasized that the science potential of the three were all high, but that the InSight mission had the lowest development risk.

Out of the last nine NASA planetary missions launched or selected for future launch, only two would go to a destination other than the moon or Mars.  This followed a previous string of missions to comets, asteroids, Mercury, and Pluto as well as Mars and the moon.

Managing the tension between fiscal responsibility and doing new things is difficult, but perhaps doable.  The New Frontiers program Jupiter Juno and Pluto New Horizons missions both will boldly go to new destinations.  Both also appear to have done so while staying within their development budgets.  However, both also are among the more expensive missions on the list below.  Perhaps bolder missions require larger budgets.

Or perhaps significant new designs would benefit from longer early design phases than is typically done.  After design began, the Juno mission was delayed approximately two years because of other budget issues at NASA.  At one meeting I listened to, it was stated that the design team put the extra time to good use maturing the design and reducing implementation (and budget) risk. 

It's also likely that NASA and principal investigators have become better at understanding the kinds of missions that are capable in cost-capped programs such as the Discovery program.  The early Discovery missions came in under or near budget.  Then there were a string of more ambitious Discovery missions that came in significantly above their initial estimates.  The last four Discovery and Mars Scout missions appear to have returned to staying within their budgets.

In two years or so, there will be a mid-term assessment of NASA’s performance against the recommendations of the Planetary Decadal Survey that established NASA’s planetary exploration goals.  The budget assumptions in that Survey turned out to be wildly optimistic, and therefore NASA’s capacity to fund missions to new targets was greatly diminished.  I hope that the mid-term update to the Survey will address the proper balance between fiscal responsibility and enabling more frequent exploration of the rest of the solar system beyond the moon and Mars.

In the meantime, NASA’s management team is to be commended for managing recent missions to budget.  Absorbing the budget cuts being imposed on the Planetary Science Division would be much harder to do if one or more of the current missions in development were seriously over budget.

Backup: Mission Cost Data Used

Whenever possible, I used mission cost data from either the National Academies Press Principal-Investigator-Led Missions in the Space Sciences (2006) report or data from the Series of Government Accounting Office assessing NASA’s management of selected projects (downloadable from this link).  For the GAO reports, I compared the earliest firm project cost data with the last reported cost data to compute change.  When these sources failed, I used Wikipedia or press accounts.  For several missions, I was unable to learn whether there had been any significant cost overruns (absence of news probably means there wasn’t any), and I left those columns blank.  It was not always clear from the data sources whether or not mission costs included launch costs.

If any of you have better data for any mission, please send it to me and I’ll correct this post.

If the Mars Science Laboratory is excluded from the list, there is no relationship between final cost and percentage change compared to initial estimated costs.  Because MSL’s cost lies well outside the range of the other missions, it should not be used in an analysis of trends with these much less expensive missions.

There is debate as to when the initial budget for MSL became firm and therefore should be used as the basis for comparison.  I used as the initial cost the budget from the 2009 GAO report.

Lower cost missions from the Discovery and now-cancelled Mars Scout programs (<$500M without launch cost, Principal Investigator-led missions) are highlighted in blue.

Mission Launch Final Cost Change from initial planned cost NEAR 1996 $234.4 -10.8% Mars Pathfinder 1996 $273.2 -4% Mars Global Surveyor 1996 298.8 29.2% Lunar Prospector 1998 69.4 10.3% Mars Climate Orbiter 1998 $276.0 -21.8% Mars Polar Lander 1999 $110.0 Stardust 1999 $209.1 1.50% Genesis 2001 $272.3 25.7% Mars Odyssey 2001 $438.2 4.6% CONTOUR 2002 $140.7 -8.8% Mars Exploration Rovers 2003 $809.9 25.3% MESSENGER 2004 $422.5 34.6% Deep Impact 2005 $332.0 19.1% Mars Reconnaissance Orbiter 2005 $720 New Horizons 2006 $700 Kepler 2007 $604.6 21.5% Dawn 2007 $465.0 24.7% Phoenix 2007 $480 Lunar Reconnaissance Orbiter 2009 $590.4 9.3% Juno 2011 $1,107.0 0.0% GRAIL 2011 $487.2 -1.8% Mars Science Laboratory 2011 $2,523.3 53.7% LADEE 2013 $262.9 0.0% MAVEN 2013 $671.2 0.0% OSIRIS-Rex 2016 TBD InSight 2016 TBD Mars 2020 rover 2020 TBD TBD – Mission cost estimates to be determined.

NASA's Planetary Science Budget Reportedly to be Hit -- Again

The sequester will hit NASA again, with large reported cuts to the Planetary Science program.  NASA's managers have stated for several months that further cuts to the planetary program were likely.  The sequester requires automatic cuts to most federal budgets of approximately 5%.  Congress has given the administration the freedom to apply the cuts disproportionately to lower priority programs within agencies to protect higher priority programs.  For NASA, the planetary program is lower priority, and cuts as large as 15% reportedly are being proposed.  

Mark Sykes, editor of the Planetary Exploration Newsletter, has received advanced information (leaks) on the proposed cuts to the budget for the remainder of fiscal year 2013 (which ends in October).  In recent years, Congress has rarely completed new budgets on time. Agencies have operated under continuing resolutions for months into the following fiscal year, so these budget levels, if they stand, could continue well into FY14.

The administration is expected to release its proposed sequester-adjusted budget for NASA later this month.  It has to notify Congress of the proposed cuts, but it's not clear to me whether Congress can object or if it would formally do so.  (Several representatives and senators have issued statements warning the administration not to disproportionately cut the Planetary Science program, but this is not formal Congressional action.)  The cuts reduce planetary spending substantially below to the recently passed NASA planetary budget for FY13 that was signed into law by President Obama.

The only good news in the budget changes is that $67M would be spent to further studies on a mission to Europa.  However, the President's proposed budget for FY14 has no money for this program, so this could be a one year project.  (As I understand the rules of the sequester, whole programs in enacted budgets cannot be eliminated, so the administration may not have had the freedom to cut the Europa mission studies.)

To pay for the Europa studies, the sequester-adjusted budget would cut the Discovery program (missions <$500M) by 33% and the New Frontiers program (missions ~$1B) by 7%.  The Discovery program cuts would, I think, delay the start of the competition for the next mission from early next year to sometime in the future.  (I don't know if the cuts are large enough to impact to delay the current Discovery mission in development -- the Mars InSight geophysical station -- or not.  Sykes does not mention any slip.)  The research and analysis budget that supports the scientific community that analyzes planetary data would be cut by 9% and could cause scientists without funding to leave the field.  (All cut percentages are relative to the current approved Planetary Science budget for FY13 that was passed by Congress.)


Cuts to programs could have potentially larger impacts than the simple percentages imply because they must be applied in the few months remaining in this fiscal year.


You can read the full details of the proposed cuts at the Planetary Exploration Newsletter site.  (I read this newsletter regularly and recommend it to you.)