European Space Agency

Making sense of Luna 25

At the outset, let’s hope the unfortunate demise of Russia’s Luna 25 mission to the moon will finally silence the social media brigade that’s been calling it a competitor to India’s Chandrayaan 3 – although I wouldn’t put it past some to thump their chests over the latter succeeding where the former couldn’t. To understand why it never made sense to claim CY 3 and Luna 25 were in a race, I highly recommend Jatan Mehta’s points.

With this behind us: there are several interesting ways to slice what happened to Luna 25, beyond the specific technical points of failure on the spacecraft. Two seem particularly notable, to my mind.

First, since it became clear that Luna 25 had erred with an orbit-lowering manoeuvre on August 19, Roscosmos, the Russian space agency, couldn’t communicate with it until the moon was over Russia, which in turn narrowed the window Roscosmos had to troubleshoot and fix the issue. The reason Russia had this problem is because it went to war, provoking stringent sanctions from many countries worldwide, including negating opportunities to make use of a global communications network to stay in touch with Luna 25.

On the other hand, the Indian Space Research Organisation (ISRO) will have assistance from the European and American space agencies to keep track of Chandrayaan 3.

The second is that, against the backdrop of the war and the consequent sanctions, Russia’s reputation as a space power is at stake. Luna 25 was in the works for more than two decades (initially under the name ‘Luna-Glob’) before it launched. When Russian’s lander-based Fobos-Grunt mission to Mars failed in 2012 – it couldn’t perform an orbit-raising manoeuvre around earth and fell back – the country decided that it wouldn’t be able to provide a lander as agreed to ISRO’s Chandrayaan 2 mission by 2015, so ISRO decided to develop its own lander (whose abilities will be tested for the second time come August 23).

(This legacy is yet another reason the coincidental attempts by Luna 25 and Chandrayaan 3 to soft-land on the moon was never a race.)

Fobos-Grunt’s failure together with other commitments further delayed the launch of Luna 25. One of these commitments was a lander for the European Space Agency’s (ESA’s) ExoMars mission, to deliver a rover named ‘Rosalind Franklin’ on Mars. But ESA terminated the deal in 2022 after Russia invaded Ukraine, postponing the mission to at least 2028. Finally, by the late 2010s, Luna 25 was ready.

Taken together, Russia wasn’t able to successfully undertake an interplanetary mission since Phobos 2 in 1989, shortly before the collapse of the Soviet Union. Due to the events of yesterday, this dubious record is now extended to 34 years – an unexpected turn of events for the country that launched the world’s first satellite. It also continues to delay the intended purpose of Luna 25 according to a Roscosmos statement: to “ensure Russia’s guaranteed access to the moon’s surface”.

Russia has also staunchly denied allegations that its economy is groaning under the weight of the sanctions imposed by the West, but its ability to recover from the failure and plan the next mission will surely be affected by limitations on what components it can import.

As the world’s spacefaring countries are getting the moon back in their collective sight, the US and China are leading the line-drawing on this occasion. But Russia – whose Luna 25 was ultimately intended as a statement that the country’s space power status is not on the decline – drew one of its own and paid a price for it.

(To whomever this message appeals, I hope filmmakers in India take note, since they have often villainised the notion of ISRO seeking or receiving help from other agencies in films and TV shows.)

Could there be life on Europa? NASA okays mission to find out

The Wire
June 19, 2015

Artist concept of NASA’s Europa mission spacecraft approaching its target for one of many flybys. Credit: NASA/JPL-Caltech

On Thursday, NASA okayed the development of a probe to Jupiter’s moon Europa, currently planned for the mid-2020s, to investigate if it has conditions suitable for life. The milestone parallels the European Space Agency’s JUICE (Jupiter Icy Moons Explorer) mission, also planned for the mid-2020s, which will study the icy moons of the Solar System’s largest planet.

The NASA mission has tentatively been called Clipper, and its proposal comes on the back of tantalizing evidence from the Galileo mission that Europa could have the conditions to harbour life. Galileo conducted multiple flybys of the moon in the 1990s and revealed signs that it could be harbouring a massive subsurface ocean – with more than twice as much water as on Earth – under an ice shell a few kilometres thick. It also found that the ocean-floor could be rocky, there were tidal forces acting on the water-body, and that the thick ice shell could be host to plate tectonics like on Earth.

These characteristics make a strong case for the existence of habitable conditions on Europa because they mimic similar conditions on Earth. For example, plate tectonics on Earth moves a jigsaw of landmasses on the surface around. Their resulting interactions are responsible for moving minerals on the surface into the ground and dredging new deposits upward, creating an important replenishment cycle that feeds many lifeforms. A rocky seafloor also conducts heat efficiently toward and away from the water, and tidal forces provide warmth through friction.

With NASA’s okay, the Europa mission moves to the “formulation stage”, when mission scientists and engineers will start technology development. The agency’s fiscal year 2016 budget includes $30 million for just this, according to a May 26 statement, out of a total of $18.29 billion that Congress has awarded it. NASA has already also asked for $285 million through 2020 for the Europa mission, with the overall mission expected to cost $2 billion notwithstanding delays at the time of a launch planned for 2022.

The same statement also announced the scientific payload that would accomplish the mission. Out of 33 proposals submitted, NASA selected nine – all geared toward exploring the ice- and water-related properties of the moon. They could also be pressed into observing other moons in the Jovian neighbourhood – many of which are icy and have curious surface and atmospheric characteristics resembling Europa’s. These include another of Jupiter’s moons, Ganymede, and Saturn’s Dione, Enceladus, Hyperion, Iapetus, Phoebe and Tethys.

ESA’s JUICE mission – part of its broader Cosmic Vision strategy for a class of long-term missions in the 2020s – is planned to launch in 2022 and reach Jupiter by 2030. At one point, it will enter into orbit around Ganymede. If NASA’s Clipper is at Europa by then, what the two probes find could be complementary, and be compared to infer finer details.

Some more questions concerning Herschel…

The Herschel Space Observatory, a.k.a. Herschel, was the largest space telescope at the time of its launch and still is. With a collecting area twice as large as the Hubble Space Telescope’s, and operating in the far-infrared part of the spectrum, Herschel could look through clouds of gases and dust in the farthest reaches universe and pick up even really faint signals from distant stars and nebulae.

To do this, it depends on three instruments – PACS, SPIRE and HIFI – that are cooled to fractions of degrees above absolute zero, much colder than anything you could find in the solar system. At these temperatures, the instruments are at their most sensitive. The frigidity it achieved using liquid helium, a superfluid coolant that constantly boils off as it removes heat from the instruments. By the end of this month (March, 2013), all the helium will have boiled off, leaving PACS, SPIRE and HIFI effectively blind.

I wrote an article in The Hindu on March 28, a run-of-the-mill news piece that had to leave out some interesting bits of information I’d gathered from the lead scientist, mission manager, and project scientist I’d spoken to. I’ve attached my questions and their answers that contain said bits of information. I think they’re important because

Here are the answers (My questions are in bold).

Herschel was foreseen to run out of helium in early 2013. Considering its unique position in space, why wasn’t a “warm” experiment installed on-board?

MATT GRIFFIN – Lead Scientist, SPIRE Instrument, Herschel Space Observatory

Herschel was designed to operate in the far infrared part of the spectrum – wavelengths typically hundreds of time longer than the wavelengths of visible light. For the far infrared, extreme cooling is always required. For a telescope operating at shorter wavelengths (about ten times longer in wavelength than visible light) a “warm mission” is feasible. This could have been done with Herschel, but it would have required that the surface of the telescope be made far more precise and smooth. That would have made it very much more expensive, leaving less money available for the rest of the spacecraft and the instruments.

Any space mission must be built within a certain budget, and it is usually best to design it to be as effective as possible for a certain wavelength range. Herschel actually covers a very wide range – from 55 to nearly 700 microns in wavelength. That’s more than a factor of ten, which is very impressive. To make a warm mission possible would have meant making the telescope good enough to work at ten times shorter wavelength, and adding a fourth instrument.

Herschel was and is the only space telescope observing in the submillimeter and far infrared part of the spectrum. After it goes blind, are there any plans to replace it with a more comprehensive telescope? Or how far do you think the loss of data because of its close-of-ops will be offset by upcoming ground-based telescopes such as the ALMA?

GORAN PILBRATT – Project Scientist, European Space Research and Technology Centre, Noordwijk

There are currently no concrete ESA (or anywhere else) plans for a replacement or follow-up mission. What many people hope for is the Japanese SPICA mission, which may fly beyond 2020 with an ESA telescope and a European instrument called SAFARI, both based on Herschel experience. Time will tell. Of course the NASA JWST will be important to almost every astronomer which it finally flies. In the meantime ALMA and also the flying SOFIA observatory are of interest. There is also a lot of follow-up observing to be done with many different ground-based telescopes based on Herschel data. This is already happening.

LEO METCALFE – Mission Manager, ESA Centre, Madrid

After the anticipated exhaustion of the Liquid Helium cryogen which keeps the Herschel instruments cold, scientific observations with Herschel will cease. However, the data gathered during the 4-years of operations, stored in the Herschel Science Archive (HSA) at ESAC, will remain available to the worldwide astronomical community for the foreseeable future. Until the end of 2017 ESA, for much of the time in collaboration with the instrument teams and NASA Herschel Science Centre, will actively support users in the exploitation of the data.

That said, there is no comparable mission in the currently approved ESA programme considering launches into the early 2020s. The Japanese Aerospace Exploration Agency (JAXA) mission SPICA is of comparable size to Herschel and will operate out to wavelengths a little over 210 microns – in the far-infrared, but only barely reaching what would generally be termed the sub-millimetre region. It may be launched before 2020.

Because of absorption of infrared radiation by the Earth’s atmosphere, ground based telescopes have limited capacity to compete with orbital systems over much of the Herschel wavelength range.

However, the Atacama Large Millimeter Array (ALMA) in the Chilean Andes overlaps in its wavelength coverage with the sub-millimeter parts of the Herschel range, but a typical map size for Alma might be on the order of, say, 10 arcseconds (the full Moon spans about 1800 arcesconds, to give some scale), while a typical Herschel map might cover an area 10 arcminutes (600 arcseconds) on a side. Instead of large area coverage, ALMA provides extremely high spatial resolutions (down to small fractions of an arcsecond), far finer than Herschel could achieve.

So ALMA is well suited to the detailed follow-up of Herschel observations of single high-interest sources, rather than providing comparable coverage to Herschel.

There must be a lot of data left to be analysed that was gathered by Herschel. While creating a legacy archive, will you also be following some threads of investigation over others?

MATT GRIFFIN – Lead Scientist, SPIRE Instrument, Herschel Space Observatory

Although Herschel’s life was limited, it was designed to make observations very quickly and efficiently, and it has collected a huge amount of data. It will be very important during the next few years, in what we call the Post-Operations period, to process all the data in the best and the most uniform way, and to make it available in an easy-to-use archive for future astronomers.

This means that the real scientific power of Herschel is still to be realised, as its results will be used for many years in the future. Only a small fraction of the data from Herschel has so far been fully investigated.

It is clear that when the data are fully explored, and when Herschel’s observations are followed up with other telescopes, a great deal more will be learned. This is especially true for the large surveys that Herschel has done – surveys of many thousands of distant galaxies, and surveys of clouds of gas and dust in our own galaxy in which stars are forming. In the coming years, although Herschel will no longer operate, its scientific project will continue – to understand the birth processes of stars and galaxies.

When did you start working with the Herschel mission? How has your experience been with it? What does the team that worked on Herschel move on to after this?

LEO METCALFE – Mission Manager, ESA Centre, Madrid

In 1982 the Far Infrared and Sub-millimetre Telescope (FIRST) was proposed to ESA. This mission concept evolved and eventually was named Herschel, in honour of the great German/English astronomer William Herschel.

The build-up of the ESA team for Herschel started in earnest in the early 2000s. I came on board as Herschel Science Operations Manager in 2007, with the main task of integrating and training the ESA Science Operations Team and the wider Science Ground Segment (SGA – which includes the external-to-ESA Instrument Control Centres) to be a smoothly functioning system in time for launch, which took place in May 2009.

So my experience of Herschel began with the recruitment of many of the operational team members and the integration of the Science Ground Segment (SGS) focussed on the pre-launch end-to-end testing of the entire observatory system, with data flowing from the spacecraft then on the ground in the test facility at ESTEC in the Netherlands, and continued through a series of pre-flight simulations which put the SGS through all the procedures they would need to follow during operations.

As a result we “hit the ground running” after launch, and the operations of the SGS have been smooth throughout the mission. Those operations have spanned the Launch and Early Orbit (LEOP) Phase, the in-flight Commissioning Phase, the Performance Verification, Science Demonstration, and Routine Operations Phases of the mission, and have included the recovery from the early failure of the prime chain of the HIFI instrument, and the handling of various lesser contingencies caused by ionising radiation induced corruptions of on-board instrument memory, among others.

It has been a fast paced and exciting mission which in the end has returned data from almost 35000 individual science observations. It’s going to be hard to adjust to not having an active spacecraft up there.

Concerning what happens to the team(s) that have worked on Herschel: The ESA team that supervised the construction of the Spacecraft already moved on to other missions soon after Herschel was launched.

The Science Operations Team at the Herschel Science Centre at HSC/ESAC in Spain, together with the Instrument Control Centres (ICCs) formed by the teams that built the scientific instruments (distributed through the ESA member states) and the Mission Operations Centre at ESOC in Germany, have been responsible for the operation of the Spacecraft and its instruments in flight. Those teams will now run down.

A fraction of the people will continue to work in the Herschel project through its almost 5-year Post-operations Phase mentioned already above, while the remainder have or will seek positions with upcoming missions like Rosetta, Gaia, BepiColombo, Solar Orbiter, Euclid … or in some cases may move on to other phases of their careers outside the space sector.

We are talking about people who are highly experienced software engineers, or PhD physicists or astronomers. Generally they are highly employable.

EOM

claimtoken-5162301aad18f

EUCLID/ESA: A cosmic vision looking into the darkness

I spoke to Dr. Giuseppe Racca and Dr. Rene Laureijs, both of the ESA, regarding the EUCLID mission, which will be the world’s first space-telescope launched to study dark energy and dark matter. For the ESA, EUCLID will be the centerpiece of their Cosmic Vision program (2015-2025). Dr. Racca is the mission’s project manager while Dr. Laureijs is a project scientist.

Could you explain, in simple terms, what the Lagrange point is, and how being able to study the universe from that vantage point could help the study?

GR: Sun-Earth Lagrangian point 2 (SEL2) is a point in space about 1.5 million km from Earth in the direction opposite to the sun, co-rotating with the Earth around the Sun. It is a nice and calm point to make observations. It is not disturbed by the heat fluxes from the Earth but at the same time is not too far away to allow to send to Earth the large amount of data from the observation. The orbit around SEL2 that Euclid will employ is rather large and it is easy to reach (in terms of launcher capability) and not expensive to control (in terms of fuel required for the orbit corrections and maintenance manoeuvres).

Does Euclid in any way play into a broader program by ESA to delve into the Cosmic Frontier? Are there future upgrades/extensions planned?

RL: Euclid is the second approved medium class mission of ESA’s Cosmic Vision programme. The first one is Solar Orbiter, which studies the Sun at short distance. The Cosmic Vision programme sets out a plan for Large, Medium and Small size missions in the decade 2015-2025. ESA’s missions Planck, which is presently in operation in L2, and Euclid will study the beginning, the evolution, and the predicted end of our Universe.

GR: A theme of this programme is: “How did the Universe originate and what is it made of?” Euclid is the first mission of this part of Cosmic Vision 2015-2025. There will be other missions, which have not been selected yet.

What’s NASA’s role in all of this? What are the different ways in which they will be participating in the Euclid mission? Is this a mission-specific commitment or, again, is it encompassed by a broader participation agreement?

GR: The NASA participation in the Euclid mission is very important but rather limited in extent. They will provide the Near-infrared detectors for one of the two Euclid instruments. In addition they will contribute to the scientific investigation with a team of about 40 US scientists. Financially speaking NASA contribution is limited to some 3-4% of the total Euclid mission cost.

RL: The Euclid Memorandum of Understanding between ESA and NASA is mission specific and does not involve a broader participation agreement. First of all, NASA will provide the detectors for the infrared instrument. Secondly, NASA will support 40 US scientists to participate in the scientific exploitation of the data. These US scientists will be part of the larger Euclid Consortium, which contains nearly 1000 mostly European scientists.

Do you have any goals in mind? Anything specific or exciting that you expect to find? Who gets the data?

GR: The goals of the Euclid mission are extremely exciting: in few words we want to investigate the nature and origin of the unseen Universe: the dark matter, five times more abundant than the ordinary matter made of atoms, and the dark energy, causing the accelerating expansion of the Universe. The “dark Universe” is reckoned today to amount at 95% of the total matter-energy density. Euclid will survey about 40% of the sky, looking back in cosmic time up to 10 billion years. A smaller part (1% of the sky) will look back to when the universe was only few million years old. This three dimensional survey will allow to map the extent and history of dark matter and dark energy. The results of the mission will allow to understand the nature of the dark matter and its position as part of an extension of the current standard model. Concerning the dark energy we will be able to distinguish between the so called “quintessence” or a modification necessary to current theories of gravity, including General Relativity.

RL: Euclid goals are to measure the accelerated expansion of the universe which tells us about Dark Energy, to determine the properties of gravity on cosmic scales, to learn about the properties of dark matter, and to refine the initial conditions leading to the Universe we see now. These goals have been chosen carefully, the instrumentation of Euclid is optimised to reach these goals as best as possible. The Euclid data opens the discovery space for many other areas in astronomy: Euclid will literally measure billions of stars and galaxies at visible and infrared wavelengths, with a very high image quality, comparable to that of Hubble Space Telescope. The most exiting prospect is the availability of these sharp images, which will certainly reveal new classes of objects with new science. The nominal mission will last for 6 years, but the first year of data will become already public 26 months after the start of the survey.

When will the EUCLID data be released?

GR: The Euclid data will be released to the public one year after their collection and will be made available to all researchers in the world.