Tag: spaceflight

A map of Pluto

9:11 pm

Our best map of Pluto for many decades to come

The New Horizons science team has released the best maps of both Pluto and Charon possible from the images taken during the spacecraft’s fly-by of the ninth planet last year.

The new maps include global mosaics of Pluto and Charon, assembled from nearly all of the highest-resolution images obtained by New Horizons’ Long-Range Reconnaissance Imager (LORRI) and the Multispectral Visible Imaging Camera (MVIC). These mosaics are the most detailed and comprehensive global views yet of the Pluto and Charon surfaces using New Horizons data.

The new collection also includes topography maps of the hemispheres of Pluto and Charon visible to New Horizons during the spacecraft’s closest approach. The topography is derived from digital stereo-image mapping tools that measure the parallax – or the difference in the apparent relative positions – of features on the surface obtained at different viewing angles during the encounter. Scientists use these parallax displacements of high and low terrain to estimate landform heights.

You will also notice large areas of both Pluto and Charon that remain very fuzzy and unclear. What exactly is there will remain a mystery for many decades to come.

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Dream Chaser test vehicle undergoing tow tests

8:58 pm

Capitalism in space: Sierra Nevada’s Dream Chaser engineering test vehicle underwent tow tests today.

Rolling on two main landing gear wheels and a nose skid, the Dream Chaser traveled down a runway Monday in Sierra Nevada’s latest tow test at Edwards Air Force Base, which is co-located with NASA’s Armstrong Flight Research Center. Once cut free from its tow vehicle, the Dream Chaser slowed to a stop, allowing engineers to gather data on the craft’s brakes, steering system, and guidance, navigation and control sensors that will line the spaceplane up for landing, according to Eric Cain, a Sierra Nevada engineer who described Monday’s test on the company’s Twitter account.

More tests are planned in the coming months, including additional tow tests and a “captive carry” flight with the Dream Chaser suspended under a helicopter.

This is the same engineering test vehicle that underwent tow tests and flew successfully once, though its landing gear failed up upon touchdown. They have replaced that landing gear, which was borrowed from the Air Force and was never intended to be the spacecraft’s wheels. Thus, they need to go through these tests all over.

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NASA communications satellite damaged during launch prep

8:20 am

A NASA TDRS communications satellite, scheduled for a August 3 launch on a ULA Atlas 5 rocket, was damaged on July 14 while it was undergoing final preparations for launch.

Though the issue apparently involves one of the satellite’s main antennas, it is unclear what happened exactly or how extensive the damage was. Furthermore, this article about the incident notes that an earlier incident had also occurred during shipping.

It is understood this latest incident is not related to a ‘close call’ that NASA was investigating earlier in the flow. That incident involved the spacecraft’s shipping container – containing environmental instrumentation – which slid a couple of feet on the trailer it was being winched on to.

If I was a customer who might want to buy the launch services of ULA, I would demand detailed information about why these incidents happened, including what measures are being taken to prevent them from occurring again.

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Luxembourg parliament adopts draft space law

9:57 am

Capitalism in space: The Luxembourg parliament yesterday adopted a draft space law that will allow that country to authorize, under the Outer Space Treaty, future private enterprise missions in space, including mining on the Moon and the asteroids.

The press release makes the following claim:

The Grand Duchy is thus the first European country to offer a legal framework ensuring that private operators can be confident about their rights on resources they extract in space. The law will come into force on August 1, 2017. Its first article provides that space resources are capable of being owned. The country’s law also establishes the procedures for authorizing and supervising space exploration missions.

In reading the actual law [pdf], however, I do not think this really does what they claim. All the law does is simply state that “Space resources are capable of being appropriated.” That’s it. They are essentially saying that any private profit-oriented mission that launches under Luxembourg’s authorization will have their blessing to take as much from any planetary body as they desire. No property rights are delineated, including the borders of any territory owned, which is not surprising since the Outer Space Treaty forbids Luxembourg from doing so.

In fact, I think this illustrates for us all the future as we colonize the solar system, assuming the Outer Space Treaty is not revised or dumped. Like pirates, nations (or their citizens) will grab as much as they can, and will then use force to protect those holdings from any one else. Everyone will have to do this, because there will be no legal framework to establish their claims.

Since it appears, at least for the present, that no one wants to change the Outer Space Treaty, expect the future in space to be a brutal legal nightmare for all involved.

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First Starliner manned flight delayed to late 2018

9:24 pm

Boeing has revealed that the first manned flight of its commercial Starliner capsule will likely be delayed a few more months to late 2018.

The latest confirmed schedules from NASA show the uncrewed mission, dubbed the Orbital Flight Test (OFT), slated for No Earlier Than June 2018, followed quickly in August 2018 by the crewed flight test.

However, comments made by Chris Ferguson last month at the Paris Air Show seem to indicate that the crewed flight test is moving from its August timeframe. According to Mr. Ferguson, Director of Crew and Mission Operations for Boeing’s Commercial Crew Program, the first Starliner crewed test flight is aiming for “last quarter of 2018” – which would be a shift of two to five months into the October to December 2018 timeframe.

The unmanned test flight, however, remains set for a June 18, 2018 launch.

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Commercial space has won

1:12 pm

Today the Senate Subcommittee on Space, Science, and Competitiveness, chaired by Senator Ted Cruz (R-Texas), held the third of a series of hearings on the future regulatory framework required for American commercial space to prosper.

My previous reviews of the past two hearings can be found at these links:

In today’s hearing the witnesses in general once again called for a variety of reforms that would simplify the regulatory process for private enterprise. Dr. Moriba K. Jah, associate professor from University of Texas at Austin, suggested removing NOAA’s veto power on remote sensing, something that the proposed House bill I analyzed in my Federalist op-ed actually does). Jeffrey Manber of Nanoracks suggested giving the private sector a certain date when ISS will be decommissioned so that they can more easily obtain investment capital for building the privately-built space facilities that will replace it. Tim Ellis of Relativity, a company trying to build rocket engines manufactured entirely by 3D printing, called for more American spaceports, accessible by private companies, as well as a simplification of the FAA permitting process. Robert Cabana, Director at the Kennedy Space Center, talked about the need for government facilities to provide the infrastructure for private companies, as the center has done for the private launch sites and manufacturing facilities they have helped get established at Kennedy since the retirement of the shuttle.

Tim Hughes from SpaceX topped them all.
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White House rejects House proposal to create a military “Space Corps”

11:01 pm

The White House today objected to a House defense policy bill that included a number of provisions, including the creation of a separate “Space Corps.”

Proposals to build the “Space Corps,” to prohibit a military base closure round, levy notification requirements for military cyber operations, develop a ground-launched cruise missile — and to “misuse” wartime funds for enduring needs — were some of the Trump administration targets.

The White House stopped short of threatening a veto, however, and said it looks forward to working with Congress to address the concerns. Still, the list will provide ammunition to Democrats and Republicans who hope to pick off provisions of the 2018 National Defense Authorization Act when it comes to the House floor on Wednesday.

The idea at this time of establishing a separate military division devoted to space military operations is absurd, a waste of money, and would only create an additional bureaucracy that no one needs right now. However, in reading this op-ed by retired Air Force colonel M.V. “Coyote” Smith, one of the early proponents of this idea, I am not surprised to learn that one of the key good reasons for creating such a force is the Outer Space Treaty. As Smith notes,

Created at the height of the moon race between the two principle [sic] Cold War antagonists and others, the Outer Space Treaty was designed to prevent either power from claiming sovereignty over the entire moon upon arriving first. It succeeded. Unfortunately, it forbids any national appropriation of real estate and resources in space.

This prevents the issuance of property deeds and the awarding of resource rights to any part of the planets, moons and asteroids, without a potential legal contest. This also frustrates commercial and private entities whose business plans require legal clarity.

Thus, the limitations of the Outer Space Treaty forces the need for a military force to protect the rights of any American individual or businesses in space. As I said today in my op-ed for The Federalist:

The Outer Space Treaty poses limits on property rights. It also does not provide any mechanism for peacefully establishing sovereignty for any nation on any territory in space. Yet national sovereignty and territorial control is a given in all human societies. If we do nothing to establish a peaceful method for creating sovereignty and national territories in space, nations are going to find their own way to do it, often by force and violence.

Thus, no one should be surprised by this first proposal. It might be too soon, but it probably is not as soon as many critics claim. Unless we get the Outer Space Treaty revised to allow the establishment of internationally recognized borders, the need by everyone for a military in space to defend their holdings will become essential. And what a messy process that will be.

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Lunar landers/rovers for sale!

10:40 pm

Moon Express, one of the five finalists trying to win the Google Lunar X-Prize (GLXP) before it expires at the end of this year, announced today its long range plans, focused on building low cost lunar landers rovers, and sample return missions that could be purchased and launched for a tenth the cost of a typical government mission.

The GLXP mission won’t be the last lunar voyage for Moon Express, if all goes according to plan. Its deal with Rocket Lab covers up to five launches, and Moon Express wants at least two more to occur in the next few years, Richards revealed during a news conference today.

The first post-GLXP mission, scheduled to launch in 2019, will set up a robotic research outpost near the lunar south pole and prospect for water and other resources. Then, in 2020, Moon Express will launch the first commercial lunar sample-return mission. That effort, Richards said, should prove out the company’s technologies and its business model, which is centered around creating low-cost access to the moon’s surface for a variety of customers. The core piece of hardware to make all of that happen is a single-engine lander called the MX-1, which will launch on the GLXP flight. Moon Express aims to mass-produce the MX-1, sell it as a stand-alone lunar explorer and have it serve as a building block for three larger, more capable spacecraft — the MX-2, the MX-5 and the MX-9, Richards said today.

The MX-2 combines two MX-1s into a single package, boosting the MX-1’s payload capacity in Earth-moon space and potentially enabling missions to Venus or the moons of Mars. As their names suggest, the MX-5 and MX-9 incorporate five engines and nine engines, respectively, and broaden the exploration envelope even further, Richards said. All of these spacecraft will be available in orbiter, lander and deep-space variations, and the MX-5 and MX-9 vehicles will also come in a sample-return configuration.

Moon Express has not revealed how much it will charge for any of these spacecraft. However, company representatives have said that, together, the MX-1 and Electron can deliver a lunar mission for less than $10 million (that’s “cost,” not retail). Electron flights currently sell for about $5.5 million apiece, putting the lander’s raw cost at $4.5 million or less.

Essentially, they are taking the revolution in satellite technology that is making everything smaller and cheaper and applying it to planetary exploration. They are then offering this technology as a very cheap and fast option for scientists and governments. Based on these numbers, a mission to the Moon could cost a customer less than $20 million, which is nothing compared to a typical NASA mission. Even India’s Mars Orbiter was several times more expensive than this.

While I consider NASA’s planetary program second to none, and one of the best things it does, Moon Express is demonstrating, as has SpaceX with launch services, that private enterprise, if given the chance, can do it better.

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Juno images of Great Red Spot released

5:42 pm

The Juno science team has released the images taken by Juno as it flew past Jupiter’s Great Red Spot on June 11.

The three images at the link were all processed by citizen scientists, who took the raw images provided immediately and enhanced the colors. Not surprisingly, the images reveal that there are storms within storms within storms inside the Spot, which itself is a storm, the largest in the solar system.

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Mars rover update: July 12, 2017

2:49 pm

Summary: Curiosity looks at some big dune ripples, then creeps up hill. Opportunity tests its wheels.

Curiosity

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

The interior of a dune ripple

Since my last update on June 23,, Curiosity has worked its way around and, for a few days, even into the small sandy field at the base of Vera Rubin ridge. The scientists noticed that the sandy here had a series of large ripples, and they wanted to take a close look at at least one. The image on the right, cropped to show here, was taken shortly after they had the rover drive through one ripple in order to expose its interior. You can see the robot arm directly above the cut created by the rover’s wheels. On the cut’s wall several distinctly different toned layers are visible. A close look reveals that they are wavy, and probably indicate numerous and repeated overlays as the wind brushes a new layer of dust on top of old layers, time after time. The different tones indicate a change in the material’s composition, which could reveal something about some past events in either Mars’ weather or geology.

In order to decipher this information, however, they will need to be able to date the layers, and figure out when each tonal change happened. I am not sure Curiosity can do this, especially since they have not scooped up any of this dust for later analysis.

They are now approaching Vera Rubin Ridge, and should climb up onto in the coming weeks. At that point they will move off the Murray Formation, where they have been since March 2016, made up of dried and ancient crushed mud, and up onto a lighter, yellowish layer of rock, dubbed the Hematite Unit. This October 3, 2016 press release. gives a good outline of the geology of these regions.
» Read more

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Africa and space

10:07 am

Link here. Prompted by the launch last week of Ghana’s first satellite from ISS, this article take a look at what other African countries are doing to become players in the new colonial movement, noting efforts being done by Nigeria, South Africa, Ethopia, Angola, and Kenya.

Overall, no African country is doing very much in space. The fact that this African-centered news outlet feels compelled to note this, however, suggests that the competitive urge might be stirring there.

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The confusing Iranian space program

10:06 am

Link here. While written as an op-ed outlining the chaotic state of the Iranian space effort, the article highlights two pieces of interesting information.

First, Iran wants to create its own GPS satellite system, which the article refers to as a “pointing, navigation, and timing” (PNT) system.

Mojtaba Saradeghi, a deputy director of the Iran Space Agency (ISA), recently told Iranian media that the ISA plans to develop an indigenous PNT capability. Saradeghi said that the PNT programme is a long-term one and that the ISA is still figuring out how it will be funded.

This announcement is almost certainly pure bluster, instigated by the agreements signed last week between Israel and India, one of which involved working together to develop their own atomic clocks used in GPS satellites.

Second, Iran has decided that instead of launching an already built smallsat they will put it on display in a museum. The smallsat, Mesbah, was built in partnership with Italy back in the early 2000s but never launched because it was seized by Russia and Italy in 2006 due to international sanctions. Though negotiations are on-going now to get it released with the easing of sanctions, the head of the Iran Space Agency, Mohsen Bahrami, on July 2 still said it was going to be mothballed if they get it back.

This incoherence fits with other recent announcements by Iran. They have repeatedly been promising that a number of satellites will be launched in the coming months, but those launches seem to never happen. In addition, they announced in early June that they were shutting down any further work on a human space mission, citing cost.

I would not be surprised it missile tests continue, however. Iran is a corrupt theocracy and semi-dictatorship, and it is typical of these kinds of top-down governments to focus their effort on military technology.

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China begins 200-day simulated self-sufficient space station experiment

9:32 am

The new colonial movement: Four Chinese students yesterday began a 200 day experiment, living in a simulated ground-based space station that will attempt to be self-sufficient for the entire time.

The underlying but unstated goal is revealed by this quote:

But the 200-day group will also be tested to see how they react to living a for period of time without sunlight. The project’s team declined to elaborate. “We did this experiment with animals… so we want to see how much impact it will have on people,” Liu, the professor, said.

They aren’t just testing the self-sufficiency of a future interplanetary spaceship. They are also testing the self-sufficiency of a lunar base, which must undergo 14 days of darkness each lunar day. I wonder if the facility is also subjected to no sunlight during these tests.

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Creating space dirt

9:50 am

Space engineers who need to simulate the surface of planets, moons, and asteroids in order to test their rovers, drills, and landers for future missions are demanding better alien dirt.

James Carpenter just needed some fake Moon dirt. Carpenter, a lunar-exploration expert at the European Space Agency (ESA) in Noordwijk, the Netherlands, works on a drill designed to hunt for buried ice on the Moon. His team recently ordered half a tonne of powdery material to replicate the lunar surface from a commercial supplier in the United States. But what showed up was not what the team was expecting. “The physical properties were visibly different,” says Carpenter.

His experience underscores a longstanding problem with artificial space soils, known as simulants: how to make them consistently and reliably. But now there is a fresh effort to bring the field into line. Last month, NASA established a team of scientists from eight of its research centres to analyse the physical properties and availability of existing simulants. And, for the first time, an asteroid-mining company in Florida is making scientifically accurate powders meant to represent the surfaces of four classes of asteroid. It delivered its second batch to NASA on 28 June.

The article is worth reading in its entirety, as it describes an engineering problem that I am sure most space geeks, including myself, never thought even existed.

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XCOR layoffs due to loss of ULA contract

9:32 am

Capitalism in space: The layoffs at XCOR this week that essentially shut the company down were the due to ULA cancelling its upper stage engine contract with the company.

The primary impetus for the layoffs, Acting CEO and XCOR Board member Michael Blum told me, is the loss of a contract for engine development that the company had with United Launch Alliance. “The proceeds should have been enough to fund the prototype of Lynx [the company’s planned spacecraft], but ULA decided they’re not going to continue funding the contract. So we find ourselves in a difficult financial situation where we need to raise money or find joint developments to continue.” ULA declined to comment.

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NASA and JAXA approve replacement of failed Japanese X-ray space telescope

10:39 am

NASA and JAXA have agreed to build a replacement for the Japanese Hitomi X-ray space telescope that failed after only a few weeks in orbit in March 2016.

The X-ray Astronomy Recovery Mission, or XARM, could launch as soon as March 2021, filling a potential gap in astronomers’ X-ray vision of the universe, according to the Japan Aerospace Exploration Agency, or JAXA. NASA has agreed to a junior partner in XARM — pronounced “charm” — and supply X-ray telescopes and a spectrometer instrument for the Japanese-led mission, according to Paul Hertz, directory of NASA’s astrophysics division.

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China planning its own commercial sea launch platform

10:35 am

The new colonial movement: According to one Chinese official, China is developing its own ocean-going launch platform for placing commercial payloads into orbit.

Tang Yagang, vice head of the aerospace division of the No.1 institute of the China Aerospace Science and Technology Corporation (CASTC), said that the technology is not difficult and a sea launch platform can be built based on modifying 10,000-tonne freighters.

China will use solid carrier rockets which rely less on launch facilities and feature mature technology, Tang said, adding that key technology for the carrier rockets will be tested at sea this year and the service is expected to be available for international users in 2018.

This pronouncement suggests that the platform is already mostly built, and that the first test launches will occur this year.

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ESA unveils dual orbiter mission to Mercury

10:31 am

After twenty years of development, the European Space Agency this week finally unveiled the completed dual orbiters that it hopes to launch on a seven year journey to Mercury in October 2018.

The 4,100-kilogram BepiColombo consists of two orbiters that will launch together — the ESA-managed Mercury Planetary Orbiter (MPO) and the JAXA-owned Mercury Magnetospheric Orbiter (MMO). The two spacecraft will be delivered to the orbit around Mercury stacked on top of each other by the Mercury Transfer Module (MTM). During the seven-year journey, the MMO will be shielded from the sun by the MMO Sunshield and Interface Structure (MOSIF), which will also serve as a mechanical and electrical interface between the two orbiters.

“MPO focuses on the planet, the surface and the interior size,” said Reininghous. “The orbit is a polar one — 480km times approximately 1500km — a little bit elliptical but extremely close to the planet as such with a return period of 2.3 hours. The data return is estimated at 1.5 gigabit per year.”

The MMO will focus on the planetary environment including the planet’s atmosphere, according to Reininghous. “The orbit is also polar but far more elliptical — 590 km times approximately 11,700 km. It has a period of 9.3 hours. The data return is approximately 10 percent of what we expect from the MPO.”

The European orbiter is much larger and more expensive, with Japanese probe budget being about a tenth the cost.

According to ESA, the mission took so long to build because in 2004, after about seven years of development, ESA suddenly realized that its orbiter’s thermal protection was inadequate, and required a complete redesign. To me, this is either outright incompetence (they knew from the start they were going to Mercury) or a clever way to extend the funding so that it provides an entire lifetime’s work for its builders. Think about it. Twenty-one years from concept to launch, then seven years to fly to Mercury, and then one to two years in orbit. That’s more than thirty years for this single mission.

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Roskosmos completes investigation into deadly post launch debris fire

10:21 am

Russia’s space agency Roskosmos has completed its investigation into the brush fire that caused two deaths at the impact site of the first stage of Soyuz rocket on June 14.

The report reveals several interesting details. First, it appears that the impact sites for abandoned first stages of Russian rockets are considered “planned.” This is not hyperbole. If the launch proceeds as intended, it should be possible to calculate with some accuracy where the abandoned first stage will hit the ground.

Second, it appears the deaths occurred when high winds caused the flames from the impact brush fire to engulf the two workers, one of whom died immediately, with the second dying several weeks later in the hospital.

Third, the agency will do more thorough reconnaissance of impact sites, before and after impact, before sending crews there. It will also augment the equipment and crews, depending on need.

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Pablum from Pence on space

12:31 pm

If you want to waste about about 25 minutes of your life, you can listen to the speech that Vice President Mike Pence gave today at the Kennedy Space Center here, beginning at the 49:30 minute mark.

My advice is that you don’t do it. Pence said nothing. He handed out a lot of empty promises and cliches, without any specifics or details of any kind. He confirmed for me what I have suspected of Pence for several years, that despite the fact that he lives and breathes a conservative and honorable personal life, as a politician he is a hack.

He made a big deal about the recreation of the National Space Council, which he now leads. However, as this article by Eric Berger properly noted the people who seem to be exerting the most influence on that council, on Trump, and on Pence are from the big space companies that have spent more than a decade and a half spending about $40 billion trying to build a big rocket (SLS) to fly a single unmanned test flight of the Orion capsule.

My pessimism here might be misplaced. We still do not know who will be on this space council. Furthermore, the Trump administration has been very good at doing a lot of public relations and soft stroking of its opponents in order to put them off guard prior to hitting them hard, where it hurts. This might be what Pence was doing here.

Nonetheless, the lack of any substance in Pence’s remarks makes me fear that he will be easily influenced by the big players who simply want the federal cash cow to continue sending them money, whether or not they ever build anything.

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New Horizons’ next target might be smaller than predicted

10:43 am

The uncertainty of science: Because all attempts to observe an occultation of a star on June 3 by New Horizons’ next target failed, astronomers now think Kuiper Belt object 2014 MU69 is much smaller than previously believed.

The discovery observations using Hubble and other ground-based telescopes had estimated its size as between 12 to 25 miles in diameter. The null result from the June 3 event suggests it is smaller than that.

More occultations are upcoming, so stay tuned.

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Team Indus needs to raise $40 million for Google mission

9:48 am

Capitalism in space: Team Indus, one of five remaining competitors for the Google Lunar X-Prize, announced today that they are now looking for the last half of the total $80 million they need to fly their mission by December.

While hardware and technology aspects have been met, Team Indus is discussing raising finances of roughly ₹120-130 crore ($15-20 million) to meet its total mission costs of around ₹520 crore ($80 million), co-founder Rahul Narayan said on Wednesday. The startup is also offering branding opportunities for their products and services on what will be the first Indian private Moon mission, he told journalists.

Team Indus is part of aerospace innovations company Axiom Research Labs, Bengaluru. It is the lone Indian entry in the global contest, the Google Lunar XPrize worth over $20 million.

It appears that they have so far raised $40 million, and need at least $40 million more to fly the mission. It also appears that if they raise only $20 million they will fly anyway with the hope that they win the $20 million prize to make up the difference.

It is very late in the game to raise this money, which means their success remains a very touch-and-go prospect. What improves their chances however is how they are now selling themselves, not as a Google X-Prize contestant, which is nothing more than a publicity stunt, but as a smallsat construction company that can build satellites for anyone at a low cost. This is very smart.

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Israel and India sign three new space agreements

9:33 am

The new colonial movement: India and Israel have inked three new development agreements between their different government space agencies.

Prime Minister Narendra Modi’s historic visit to Israel has deepened cooperation in space technology between the two countries as the two sides on Wednesday signed three agreements relating to space. The first memorandum of understanding was between Indian Space Research Organisation (Isro) and Israel Space Agency for cooperation in electric propulsion for small satellites, second was on cooperation in GEO-LEO optical links and third pact was on cooperation in atomic clocks (which are satellite components meant to provide precise locational data).

The third agreement is especially interesting. It indicates that India no longer wants to work with the German company that built its most recent GPS satellites because that company’s atomic clocks all had problems. Unlike the ESA, India has decided that such failures should not be rewarded with more work.

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XCOR shuts down

9:24 am

Capitalism in space: XCOR, the company that was going to fly tourists on the Lynx reusable suborbital plane by 2013, has laid off its last remaining employees.

Though years ago I predicted this failure accurately, I do not celebrate it. I would have much preferred to have been dead wrong, and to have seen Lynx built and flying, making money from space tourism. At the same time, I am also utterly realistic about the realities of capitalism. To have big successes you need to also have sad failures. XCOR unfortunately belongs to the latter.

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Will Dawn head to another asteroid?

4:31 pm

NASA is still reviewing the proposal by the Dawn science team that they send the spacecraft to another asteroid in its last years before its fuel runs out.

The spacecraft has continued operations despite problems with its reaction wheels, used for attitude control. After suffering the loss of two of its four reaction wheels earlier in the mission, a third wheel malfunctioned in April. The spacecraft went into safe mode briefly, but controllers resumed operations with hydrazine thrusters taking over for the failed wheel. That failure will eventually lead to the end of the mission when the spacecraft runs out of hydrazine. “It does reduce our lifetime because we have to use hydrazine at a faster rate,” Raymond said at the SBAG meeting in June.

That lifetime, she said, is dependent on the spacecraft’s orbital altitude. Dawn has spiraled out to a higher orbit during its extended mission, which reduces the amount of hydrazine needed for attitude control. “The lifetime is now highly dependent on orbital altitude because we need to use the jets to fight the gravity gradient torques,” she said. In its current high orbit, Raymond said that Dawn had sufficient hydrazine, as well as xenon propellant used for the ion engine, to operate at least through the end of 2018.

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