My Week at NASA

Originally Published: April 29

One of my friends asked me about my work this week at NASA.

Well, here are some highlights under the rubric, #myWeekatNASA:

1) I testified to the House Science Committee this week, with approximately a dozen members present during this highly bi-partisan hearing. It was all about “finding Earth elsewhere”, an objective that was added to NASA’s mission-statement.

2) I commissioned an independent review of the approximately $3B next-generation telescope (WFIRST) that is early in its development. This review was recommended by the National Academies. Sometimes, the best thing we can do to get new science we are all excited about, is to scrutinize how we do it.

3) This week, NASA put Cassini into an orbit inside of Saturn’s rings. This allows to do science we have never done – truly bold move, though, that is part of Cassini’s Grand Finale!

4) We were getting ready this week to ship the biggest space telescope ever built, the James Webb Space Telescope, to NASA Johnson for cryo-test. This is a critical test before finally launching in 2018.

5) We spent a week doing under-flights of the new GOES-16 NOAA/NASA spacecraft using one of our highly equipped NASA airplanes. These measurements are critical for calibration of this next-generation weather satellite.

6) I spent time focused on one of the most epic science shows this year, the August 21, 2017 eclipse ( – can’t wait.

7) This week, we integrated NASA’s GOLD mission into a commercial communications satellite, a novel type of partnership between NASA and commercial entity, increasing the science/dollar spent by NASA. GOLD focuses on the boundary of our atmosphere/ionosphere to space.

8) We launched a novel long-duration balloon from New Zealand this week. This balloon is floating at around 100,000 feet and looking at the signatures of high-energy cosmic rays interacting with the Earth atmosphere.

9) We had some amazing science news this week: another set of new exoplanet observations and also the discovery that tropical storms emit gamma-rays, and many more…

10) And, of course, we are all excited to celebrate Peggy Whitson, the first woman to command the space station, who broke the record this week for the longest duration in orbit of a US astronaut.

Worlds Beyond Our Solar System

Originally Published: April 9, 2017

A few weeks ago, NASA announced a stunning news-story which became one of the biggest NASA science stories ever: over 3 billion interactions with NASA’s online content, hundreds of newspapers (including New York Times) carried the story on the front-page, tens of thousands of articles were written in the worldwide press, and a Google Doodle topped it all off (…/seven-earth-size-exoplanets-discov…).

The story is compelling: Based on NASA Spitzer observations, Trappist-1 is a newly discovered mini-solar system with 7 rocky planets, 3 of which in the habitable zone where water can pool on the surface. This post is about things that happened since, and that shows how exoplanet research is becoming increasingly inter-disciplinary.


A couple of weeks after the initial announcement, Kepler on its K2 mission provided 74 days of monitoring of the Trappist-1 system and its cosmic neighborhood (…/nasas-kepler-provides-another-peek-…/). Within 2.5 hours, the first tweet came out indicating a result: An astronomer had found a second pass of planet H, the outer-most planet. Within weeks, that result was already summarized online as part of the arXiv e-print series ( planet H is at the snow-line, beyond which water can exist only in its frozen state. Many of the other results of the initial paper were also confirmed. Obviously, these results (as well as others mentioned below) will have to go through review before the results are fully accepted.

The data also provided important additional information about the activity of the star. Just like our Sun, Trappist-1 has magnetic activity that leads to flares. In fact, astronomers know that this type of dwarf star tends to have a very violent past when it comes to stellar activity – possibly providing an important ingredient whether or not life can persist on this planet.

One researcher told me that using the data about the magnetic field known from this star, it seems that the field is such that the planets sit in a subsonic part of its stellar wind, and not the super-sonic part as all planets here in the solar system. If this is correct, the Trappist-1 planets have a fundamentally different space weather environment than the Earth with stellar wind coming towards them from all directions, not just from the direction of its star.

There is another result that is important in this context, and this one is from our neighborhood – from MAVEN, currently orbiting Mars. Based on their data of atmospheric loss of specific components, the team concluded that Mars lost most of its atmosphere and its water during its history, making it far less hospitable than the Earth. According to the authors, the culprit for this loss is the absence of a global-scale magnetic field that suppresses such loss to space. Do Trappist-1 planets have magnetic fields? We don’t know at this point.

Finally, a submitted paper by Wolf ( does the first analysis of a climate model for the Trappist-1 planets. Needless to say, there are lots of assumption in there, put the paper points out that – under several assumptions – planet E has the best chance to be a habitable world. To me, the paper indicates how many observations about the planets’ atmospheres we need to make to actually nail down some of the very hard questions about the habitability of these strange worlds.

In summary, the Trappist-1 discovery announced a few weeks ago is already spurring research that goes far beyond the initial observations. The follow-up studies give an indication that to answer the fundamental question: “Is there life out there?”, is a fundamental question that will require scientific breakthroughs from many different science fields, including ones who currently are not deeply engaged in this exciting research.

This demonstrates the nature of great research: it’s not just about answering questions that have been asked in the past, it is about asking entirely new questions that will have impact for a long time to come!

Ambitious Science Driving Innovative Technology

Originally Published: February 12, 2017

It took nearly 100 years for predictions about frame-dragging, a direct consequence of Einstein’s theory of general relativity published in 1915, to be confirmed using a sophisticated analysis of three spacecraft in orbit about the Earth. The Earth is very, very slowly dragging space with its rotation, subtly changing satellite orbits, as predicted by two Austrian scientist in 1918, and finally confirmed at the <10% level around 2010.


It also took more than 100 years for the ground-based Laser Interferometer Gravitational-wave Observatory (LIGO) to make the first observations (announced almost exactly 1 year ago!) and to confirm one of the most fundamental predictions of the same theory – the existence of gravitational waves. This prediction has ignited more interest in space-born detections of these waves by spacecraft such as LISA, the Laser Interferometer Space Antenna, which will open up a whole new window into the universe.

An artist’s rendering of LISA Pathfinder on its way to Earth-sun L1.

It will have taken 60+ years for NASA’s Solar Probe mission to launch in 2018 in order to test the fundamental predictions made by Parker in his profound 1957 paper that almost was rejected by reviewers. It just seemed too unlikely – why would the Sun eject supersonic plasma that fills space? Now, we are finally building the spacecraft to examine the solar wind where it matters most, at its source.

NASA’s Solar Probe Plus undergoes preparation for testing Engineers at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, prepare the developing Solar Probe Plus spacecraft for thermal vacuum tests that simulate conditions in space.

Sometimes, doing the best science takes a lot of time! It turns out that the most important physical effects we seek to confirm are extra-ordinarily subtle or tough to access.

To do the frame-dragging experiment, we had to learn how to launch spacecraft, how to shoot lasers at them and to measure times and positions at highest accuracy. It took a deep understanding of radiation pressure forces and also of the Earth gravity field and levels we could only imagine in the 1900s.


The engineering challenges for LIGO almost seem hopeless: detect motions of scales of 1/1000 of an atomic nucleus. Build 4 km long vacuum chambers, and do so twice, 3000 km apart, but in precise coordination. It seems hopeless when you start, but it leads to the best science and it launches a storm of innovation to make it reality.

So, what does it take to get so close to the Sun that you can observe the waves that accelerate the solar wind? You need to be at 10 solar radii, with nearly 50,000 more heat hitting the spacecraft surface than near Earth. To survive this heat, one has to invent a thermal protection system that not only can survive, but do so that the sensitive science measurements next to them are still possible. The spacecraft has to be on auto-pilot for some of the most important phases. It is really, really hard!

Looking at history, it turns out, that we always need to invent some totally new and innovative technologies to enable new ambitious science. This interplay between ambitious science and innovative technologies is one of the most impactful aspects of NASA’s science program. Projects like LISA, the James Webb Space Telescope, or Solar Probe are like science moon shots: We invent all the steps of the path till we finally get the desired goal!

This science-driven technology development not only enables scientific leadership, it also feeds an innovation engine with impacts that are well beyond the realm of the initial question and application space. We know about the economic impact of the Apollo program, and we are in awe about the broad applicability of space technologies for National defense, our technological leadership and also our economy. And in rare cases, our observations we make in space change everything, even the way we think! There is nothing more profound than that.

Broad and lasting impacts are not coming from playing it safe, they come from ambitious science driving innovative technology. Note that we have a NASA science program that has a variety of tools with different objectives. But, when it comes to breakthrough science, playing it safe intellectually does not cut it!

Final point: intellectual ambition is not proportional to the cost of a system. In fact, the most entrepreneurial solutions are the ones that pair intellectual ambition with nearly impossible financial constraints!

Science: An International Language

Originally Published: February 4, 2017

Last week, I did my first trip abroad as Associate Administrator of Science at NASA, visiting both Switzerland and France.

My first talk was to an audience of about 600+ at the University of Bern, my alma mater. I started my presentation by announcing that we were making history today since I was the first NASA Associate Administrator to give a science talk in German (pic below from U Bern). I had prepared for over four hours to ensure that i knew all the words. During this chat, I discussed the impact that science has in the world. From benefiting humanity on Earth, to the importance of fundamental research, the science that NASA does on a daily basis is critical.


I also gave a lunch talk in Swiss German three days later where I focused on the power of innovation and leadership in organizations. The next day, I finally gave a talk to a French audience. Even though I took some questions in French, I did not dare give my talk in French just having arrived in Paris the day before.

I studied French for 10 years. French is the only subject area in my entire education I did not pass. The only comfort for me as a teenager: Einstein also failed French. In fact, French was my first true foreign language and I despised learning it, not realizing how powerful languages would become in my life. Only a few years later, I lived in a French speaking town and later I shared an apartment with a friend who spoke French.

For many scientists, foreign languages are much more difficult to learn than math or science. But, I have become a strong proponent and actively encourage students to do so. When learning a foreign language two things happen. First, one learns to communicate to more and different people on this Earth. Second, and equally important, learning a new language makes one think of one’s own language. We learn about its origins, its defining characteristics, and also about culture in new and different ways as language and culture are deeply interrelated.

Why is this important? From decades of observations and experiences, I am convinced that the ability to communicate fluently across cultural boundaries is directly linked to the richness of ones personal experiences and also to career success. If we only talk to people who think and talk like us, even when speaking in our native language, we never fully realize the power of what we do to truly make the world better.

My Home on Earth

Originally Published: Jan. 21, 2017

I spent the weekend home in Ann Arbor, with my family. I made that decision after receiving a message from the people running my apartment-house in DC telling me to stay away from windows and off balconies during the Inauguration related events.

In fact, I was glad to spend time in Ann Arbor and I even had time to visit some friends and former colleagues at the University of Michigan and do an interview for Gary Krenz’s Bicentennial activities. The interview made me think because of a question he asked that was very hard to answer. It was a question about “my home” and how I feel about it.


See, as an immigrant, the concept of “home” is a lot tougher to define than for others. Consider my brother, who sent me the picture attached to this post. He grew up in the same house he now lives with his beautiful family. Looking at this picture from this weekend – who would not agree that he has a beautiful and amazing home. You ask him where his home is, it takes him 2 seconds to give you the answer.

For me, it is a lot longer answer. I grew up there as well, and I have a lot of positive feelings about the town of Heiligenschwendi. But, I love Bern as well, where I lived over 10 years. I got my education there, tons of great memories, and lots of friends – I grew up there. I even lived the better part of one year in Bern with my US family. If I organize a trip to Switzerland, I first think about where to stay in Bern, my former home.

And then, I moved to Ann Arbor, the place I built my career, made friends, and – most importantly – the place where I met my wife, where my two children were born. I also found the most supportive environment any young researcher could hope for, an environment that enabled what I do now. I lived in four places in Ann Arbor and was an owner of two houses at different moments in time.

Right now, we are getting ready to sell our house where my family lived in for 13+ years, and we are thinking about which town we want to make our home in the future.

I will always think of Ann Arbor as my home, as a place close to my heart for which I feel a sense of belonging. I feel the very same way about Bern and Heiligenschwendi, and – if I am lucky – I will find another place or two that I associate with my life, my love, my family and friends and also with opportunity to have impact. But, the point is that I have more than one home and – because of that – I think about this more than the 70%+ of people who live within 5 miles to where they grew up.

So, what is my home? I am lucky to have had more than one during my lifetime! But, my home is where my family and my friends are!

Living and Working in the District of Columbia

Originally Published: Jan. 14, 2017

Living in D.C., I get a unique front-window view on US politics and learn about the country in a new and unprecedented way.

Right now, the entire city is buzzing about the inauguration and the peaceful change of power that is typical of presidential transitions since the beginning of the US. Last week, the entire county listened to current president and his associates reflect on his last 8 years of presidential politics. We watched the vice-president’s tearful reaction when he was surprised by his friend, the president, awarding him the medal of freedom, with distinction. Yes, this change is filling the news worldwide. But there are things you only see in DC.


Here are two visual impressions of this transition. The right hand picture shows the inside of the White House’s Eisenhower Executive Office Building on Friday, Jan. 13. It felt like the last day of summer camp: empty boxes everywhere, and full boxes stacked in hallways, friends hugging and taking pictures. There were lines of political employees looking for “single point checkout”, where they can turn in their batches and government furnished cell-phones. And the White House gift store had a long line, as so many dedicated and loyal members of the U.S. government looked back to the past years and thought about what is next. I talked to some of them – they really, really care about the jobs they are leaving.

The picture on the left hand side shows the view out of the door of my apartment building. I live on Pennsylvania, about 10 blocks from the White House and right by the parade that will happen next week. The porta potties are in preparation of the hundreds of thousands of participants of the Inaugural Parade, and also the big march the day thereafter. There are bleachers, TV antennas, camera towers, and elevated platforms everywhere. In fact, a whole bunch of people have been working on these for weeks. As inauguration approaches, more and more security personnel show up. My apartment building sent a letter last week that told us to stay off the balconies and away from windows during Inauguration Day. This is real life in D.C., enabled by a cadre of civil servants, security personnel and police officers that enable one of these very things that make our country what it is.

Thanks to everybody who was part of the previous government in whatever role and thanks for those who are setting their personal goals aside for service as part of the next administration. It’s these selfless and unsung heroes that make the government work!

Selecting New Science Missions

Originally Published: Jan. 7, 2017

Sensing the environment of black holes and the origin of high-energy cosmic rays, exploring the early building blocks of the outer solar system, and a journey to the metal-world of a planetary core – these are the science investigations NASA announced this week, my first three selections as an Associate Administrator.


Imagine sitting in a room for many hours and listening the the sales pitches of mission finalists. Each pitch is exactly an hour and highly regulated with respect to its contents and participants of the pitch. The team is nervous and worried, trying to interpret every move you make, where you look and second-guess what each question means that you ask. This is what I did during December – eight times over.

Selecting a mission is hard. It is all about the future, about the new science that will be learned. But it also about professional aspirations of some of the hardest working members of the entire science community, the investigators and their teams. Finally, it is about the intellectual and economic capacity of the US as a space-faring nation.


I made selections resulting in three teams having the weeks of their lives, and others having bitter disappointments. I delivered all phone calls personally – to the winners and to the ones I had to give bad news. In all cases there were two things about which I was absolutely certain: First, the selections were done with the highest level of integrity and to benefit science and the US. Second, each call was made with my best attempt to directly relate to the principal investigator. As opposed to many others in my job previously, I too received many calls with bad news, and I too got a few good ones. Both, the good and the bad calls I received changed my life. The only reason I get to make these calls now is, ironically, due to the fact that I received three such negative calls approximately a dozen years ago. For me, sometimes the answers that were hardest to receive, had the most positive impact in my professional life!


As for the selections announced this week – I only wish I had been able to select even more missions. Most importantly, can’t wait to see these missions become reality – this will be so exciting!

NASA press releases:

NASA Selects Mission to Study Black Holes, Cosmic X-ray Mysteries

NASA Selects Two Missions to Explore the Early Solar System