Exoplanet-Hunting TESS Satellite to be Launched by SpaceX

A conceptual image of the Transiting Exoplanet Survey Satellite. Image Credit: MIT
A conceptual image of the Transiting Exoplanet Survey Satellite. Image Credit: MIT

The search for exoplanets is heating up, thanks to the deployment of space telescopes like Kepler and the development of new observation methods. In fact, over 1800 exoplanets have been discovered since the 1980s, with 850 discovered just last year. That’s quite the rate of progress, and Earth’s scientists have no intention of slowing down!

Hot on the heels of the Kepler mission and the ESA’s deployment of the Gaia space observatory last year, NASA is getting ready to launch TESS (the Transiting Exoplanet Survey Satellite). And to provide the launch services, NASA has turned to one of its favorite commercial space service providers – SpaceX.

The launch will take place in August 2017 from the Cape Canaveral Air Force Station in Florida, where it will be placed aboard a Falcon 9 v1.1 – a heavier version of the v 1.0 developed in 2013. Although NASA has contracted SpaceX to perform multiple cargo deliveries to the International Space Station, this will be only the second time that SpaceX has assisted the agency with the launch of a science satellite.

This past September, NASA also signed a lucrative contract with SpaceX worth $2.6 billion to fly astronauts and cargo to the International Space Station. As part of the Commercial Crew Program, SpaceX’s Falcon 9 and Dragon spacecraft were selected by NASA to help restore indigenous launch capability to the US.

James Webb Space Telescope. Image credit: NASA/JPL
Artist’s impression of the James Webb Space Telescope, the space observatory scheduled for launch in 2018. Image Credit: NASA/JPL

The total cost for TESS is estimated at approximately $87 million, which will include launch services, payload integration, and tracking and maintenance of the spacecraft throughout the course of its three year mission.

As for the mission itself, that has been the focus of attention for many years. Since it was deployed in 2009, the Kepler spacecraft has yielded more and more data on distant planets, many of which are Earth-like and potentially habitable. But in 2013, two of four reaction wheels on Kepler failed and the telescope has lost its ability to precisely point toward stars. Even though it is now doing a modified mission to hunt for exoplanets, NASA and exoplanet enthusiasts have been excited by the prospect of sending up another exoplanet hunter, one which is even more ideally suited to the task.

Once deployed, TESS will spend the next three years scanning the nearest and brightest stars in our galaxy, looking for possible signs of transiting exoplanets. This will involve scanning nearby stars for what is known as a “light curve”, a phenomenon where the visual brightness of a star drops slightly due to the passage of a planet between the star and its observer.

By measuring the rate at which the star dims, scientists are able to estimate the size of the planet passing in front of it. Combined with measurements the star’s radial velocity, they are also able to determine the density and physical structure of the planet. Though it has some drawbacks, such as the fact that stars rarely pass directly in front of their host stars, it remains the most effective means of observing exoplanets to date.

Number of extrasolar planet discoveries per year through September 2014, with colors indicating method of detection:   radial velocity   transit   timing   direct imaging   microlensing. Image Credit: Public domain
Number of extrasolar planet discoveries on up to Sept. 2014, with colors indicating method of detection. Blue: radial velocity; Green: transit; Yellow: timing, Red: direct imaging; Orange: microlensing. Image Credit: Alderon/Wikimedia Commons

In fact, as of 2014, this method became the most widely used for determining the presence of exoplanets beyond our Solar System. Compared to other methods – such as measuring a star’s radial velocity, direct imaging, the timing method, and microlensing – more planets have been detected using the transit method than all the other methods combined.

In addition to being able to spot planets by the comparatively simple method of measuring their light curve, the transit method also makes it possible to study the atmosphere of a transiting planet. Combined with the technique of measuring the parent star’s radial velocity, scientists are also able to measure a planet’s mass, density, and physical characteristics.

With TESS, it will be possible to study the mass, size, density and orbit of exoplanets. In the course of its three-year mission, TESS will be looking specifically for Earth-like and super-Earth candidates that exist within their parent star’s habitable zone.

This information will then be passed on to Earth-based telescopes and the James Webb Space Telescope – which will be launched in 2018 by NASA with assistance from the European and Canadian Space Agencies – for detailed characterization.

The TESS Mission is led by the Massachusetts Institute of Technology – who developed it with seed funding from Google – and is overseen by the Explorers Program at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Further Reading: NASA, SpaceX

 

NASA’s Next Exoplanet Hunter Moves Into Development

A conceptual image of the Transiting Exoplanet Survey Satellite. Image Credit: MIT
A conceptual image of the Transiting Exoplanet Survey Satellite. Image Credit: MIT

NASA’s ongoing hunt for exoplanets has entered a new phase as NASA officially confirmed that the Transiting Exoplanet Survey Satellite (TESS) is moving into the development phase. This marks a significant step for the TESS mission, which will search the entire sky for planets outside our solar system (a.k.a. exoplanets). Designed as the first all-sky survey, TESS will spend two years of an overall three-year mission searching both hemispheres of the sky for nearby exoplanets.

Previous sky surveys with ground-based telescopes have mainly picked out giant exoplanets. In contrast, TESS will examine a large number of small planets around the very brightest stars in the sky. TESS will then record the nearest and brightest main sequence stars hosting transiting exoplanets, which will forever be the most favorable targets for detailed investigations. During the third year of the TESS mission, ground-based astronomical observatories will continue monitoring exoplanets identified by the TESS spacecraft.

“This is an incredibly exciting time for the search of planets outside our solar system,” said Mark Sistilli, the TESS program executive from NASA Headquarters, Washington. “We got the green light to start building what is going to be a spacecraft that could change what we think we know about exoplanets.”

“During its first two years in orbit, the TESS spacecraft will concentrate its gaze on several hundred thousand specially chosen stars, looking for small dips in their light caused by orbiting planets passing between their host star and us,” said TESS Principal Investigator George Ricker of the Massachusetts Institute of Technology..

Artistic representations of the only known planets around other stars (exoplanets) with any possibility to support life as we know it. Credit: Planetary Habitability Laboratory, University of Puerto Rico, Arecibo.
Artistic representations of known exoplanets with any possibility to support life. Image Credit: Planetary Habitability Laboratory, University of Puerto Rico, Arecibo.

All in all, TESS is expected to find more than 5,000 exoplanet candidates, including 50 Earth-sized planets. It will also find a wide array of exoplanet types, ranging from small, rocky planets to gas giants. Some of these planets could be the right sizes, and orbit at the correct distances from their stars, to potentially support life.

“The most exciting part of the search for planets outside our solar system is the identification of ‘earthlike’ planets with rocky surfaces and liquid water as well as temperatures and atmospheric constituents that appear hospitable to life,” said TESS Project Manager Jeff Volosin at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Although these planets are small and harder to detect from so far away, this is exactly the type of world that the TESS mission will focus on identifying.”

Now that NASA has confirmed the development of TESS, the next step is the Critical Design Review, which is scheduled to take place in 2015. This would clear the mission to build the necessary flight hardware for its proposed launch in 2017.

“After spending the past year building the team and honing the design, it is incredibly exciting to be approved to move forward toward implementing NASA’s newest exoplanet hunting mission,” Volosin said.

TESS is designed to complement several other critical missions in the search for life on other planets. Once TESS finds nearby exoplanets to study and determines their sizes, ground-based observatories and other NASA missions, like the James Webb Space Telescope, would make follow-up observations on the most promising candidates to determine their density and other key properties.

The James Webb Space Telescope. Image Credit: NASA/JPL
The James Webb Space Telescope. Image Credit: NASA/JPL

By figuring out a planet’s characteristics, like its atmospheric conditions, scientists could determine whether the targeted planet has a habitable environment.

“TESS should discover thousands of new exoplanets within two hundred light years of Earth,” Ricker said. “Most of these will be orbiting bright stars, making them ideal targets for characterization observations with NASA’s James Webb Space Telescope.”

“The Webb telescope and other teams will focus on understanding the atmospheres and surfaces of these distant worlds, and someday, hopefully identify the first signs of life outside of our solar system,” Volosin said.

TESS will use four cameras to study sections of the sky’s north and south hemispheres, looking for exoplanets. The cameras would cover about 90 percent of the sky by the end of the mission.

This makes TESS an ideal follow-up to the Kepler mission, which searches for exoplanets in a fixed area of the sky. Because the TESS mission surveys the entire sky, TESS is expected to find exoplanets much closer to Earth, making them easier for further study.

In addition, Ricker said TESS would provide precision, full-frame images for more than 20 million bright stars and galaxies.

“This unique new data will comprise a treasure trove for astronomers throughout the world for many decades to come,” Ricker said.

Now that TESS is cleared to move into the next development stage, it can continue towards its goal of being a key part of NASA’s search for life beyond Earth.

“I’m still hopeful that in my lifetime, we will discover the existence of life outside of our solar system and I’m excited to be part of a NASA mission that serves as a key stepping stone in that search,” Volosin said.

Further Reading: NASA

Is Our Solar System Weird?

This artist’s view shows an extrasolar planet orbiting a star (the white spot in the right).
This artist’s view shows an extrasolar planet orbiting a star (the white spot in the right). Image Credit: IAU/M. Kornmesser/N. Risinger (skysurvey.org)

Is our Solar System normal? Or is it weird? How does the Solar System fit within the strange star systems we’ve discovered in the Milky Way so far?

With all the beautiful images that come down the pipe from Hubble, our Solar System has been left with celestial body image questions rivaling that of your average teenager. They’re questions we’re all familiar with. Is my posture crooked? Do I look pasty? Are my arms too long? Is it supposed to bulge out like this in the middle? Some of my larger asteroids are slightly asymmetrical. Can everyone tell? And of course the toughest question of all… Am I normal?

The idea that stars are suns with planets orbiting them dates back to early human history. This was generally accompanied by the idea that other planetary systems would be much like our own. It’s only in the last few decades that we’ve had real evidence of planets around other stars, known as exoplanets. The first extrasolar planet was discovered around a pulsar in 1992 and the first “hot jupiter” was discovered in 1995.

Most of the known exoplanets have been discovered by the amazing Kepler spacecraft. Kepler uses the transit method, observing stars over long periods of time to see if they dim as a planet passes in front of the star. Since then, astronomers have found more than 1700 exoplanets, and 460 stars are known to have multiple planets. Most of these stellar systems are around main sequence stars, just like the Sun. Leaving us with plenty of systems for comparison.

Artist's impression of the solar system showing the inner planets (Mercury to Mars), the outer planets (Jupiter to Neptune) and beyond. Credit: NASA
Artist’s impression of the solar system showing the inner planets (Mercury to Mars), the outer planets (Jupiter to Neptune) and beyond. Credit: NASA

So, is our Solar System normal? Planets in a stellar system tend to have roughly circular orbits, just like our Solar system. They have a range of larger and smaller planets, just like ours. Most of the known systems are even around G-type stars. Just like ours.….and we are even starting to find Earth-size planets in the habitable zones of their stars. JUST LIKE OURS!

Not so fast…Other stellar systems don’t seem to have the division of small rocky planets closer to the star and larger gas planets farther away. In fact, large Jupiter-type planets are generally found close to the star. This makes our solar system rather unusual.

Computer simulations of early planetary formation shows that large planets tend to move inward toward their star as they form, due to its interaction with the material of the protoplanetary disk. This would imply that large planets are often close to the star, which is what we observe. Large planets in our own system are unusually distant from the Sun because of a gravitational dance between Jupiter and Saturn that happened when our Solar System was young.

55 Cancri. Image credit: NASA/JPL
55 Cancri. Image credit: NASA/JPL

Although our Solar System is slightly unusual, there are some planetary systems that are downright quirky. There are planetary systems where the orbits are tilted at radically different angles, like Kepler 56, and a sci-fi favorite, the planets that orbit two stars like Kepler 16 and 34. There is even a planet so close to its star that its year lasts only 18 hours, known 55 Cancri e.

And so, the Kepler telescope has presented us with a wealth of exoplanets, that we can compare our beautiful Solar System to. Future telescopes such as Gaia, which was launched in 2013, TESS and PLATO slated for launch in 2017 and 2024 will likely discover even more. Perhaps even discovering the holy grail of exoplanets, a habitable planet with life…

And the who knows, maybe we’ll find another planet… just like ours.

What say you? Where should we go looking for habitable worlds in this big bad universe of ours? Tell us in the comments.

And if you like what you see, come check out our Patreon page and find out how you can get these videos early while helping us bring you more great content!

The Search for Alien Life Could Get A Boost From NASA’s Next-Generation Rocket

Artist's conception of NASA's Space Launch System with Orion crewed deep space capsule. Credit: NASA

In three years, NASA is planning to light the fuse on a huge rocket designed to bring humans further out into the solar system.

We usually talk about SLS here in the context of the astronauts it will carry inside the Orion spacecraft, which will have its own test flight later in 2014. But today, NASA advertised a possible other use for the rocket: trying to find life beyond Earth.

At a symposium in Washington on the search for life, NASA associate administrator John Grunsfeld said SLS could serve two major functions: launching bigger telescopes, and sending a mission on an express route to Jupiter’s moon Europa.

The James Webb Space Telescope, with a mirror of 6.5 meters (21 feet), will in part search for exoplanets after its launch in 2018. Next-generation telescopes of 10 to 20 meters (33 to 66 feet) could pick out more, if SLS could bring them up into space.

“This will be a multi-generational search,” said Sara Seager, a planetary scientist and physicist at the Massachusetts Institute of Technology. She added that the big challenge is trying to distinguish a planet like Earth from the light of its parent star; the difference between the two is a magnitude of 10 billion. “Our Earth is actually extremely hard to find,” she said.

Much like our solar system, Kepler-62 is home to two habitable zone worlds. The small shining object seen to the right of Kepler-62f is Kepler-62e. Orbiting on the inner edge of the habitable zone, Kepler-62e is roughly 60 percent larger than Earth. Image credit: NASA Ames/JPL-Caltech.
Much like our solar system, Kepler-62 is home to two habitable zone worlds. The small shining object seen to the right of Kepler-62f is Kepler-62e. Orbiting on the inner edge of the habitable zone, Kepler-62e is roughly 60 percent larger than Earth. Image credit: NASA Ames/JPL-Caltech.

While the symposium was not talking much about life in the solar system, Europa is considered one of the top candidates due to the presence of a possible subsurface ocean beneath its ice. NASA is now seeking ideas for a mission to this moon, following news that water plumes were spotted spewing from the moon’s icy south pole. A mission to Europa would take seven years with the technology currently in NASA’s hands, but the SLS would be powerful enough to speed up the trip to only three years, Grunsfeld said.

And that’s not all that SLS could do. If it does bring astronauts deeper in space as NASA hopes it will, this opens up a range of destinations for them to go to. Usually NASA talks about this in terms of its human asteroid mission, an idea it has been working on and pitching for the past year to a skeptical, budget-conscious Congress.

But in passing, John Mather (NASA’s senior project scientist for Webb) said it’s possible astronauts could be sent to maintain the telescope. Webb is supposed to be parked in a Lagrange point (gravitationally stable location) in the exact opposite direction of the sun, almost a million miles away. It’s a big contrast to the Hubble Space Telescope, which was conveniently parked in low Earth orbit for astronauts to fix every so often with the space shuttle.

An Artist's Conception of the James Webb Space Telescope. Credit: ESA.
An Artist’s Conception of the James Webb Space Telescope. Credit: ESA.

While NASA works on the funding and design for larger telescope mirrors, Webb is one of the two new space telescopes it is focusing on in the search for life. Webb’s infrared eyes will be able to peer at solar systems being born, once it is launched in 2018. Complementary to that will be the Transiting Exoplanet Survey Satellite, which will fly in 2017 and examine planets that pass in front of their parent stars to find elements in their atmospheres.

The usual cautions apply when talking about this article: NASA is talking about several missions under development, and it is unclear yet what the success of SLS or any of these will be until they are battle-tested in space.

But what this discussion does show is the agency is trying to find many purposes for its next-generation rocket, and working to align it to astrophysics goals as well as its desire to send humans further out in the solar system.

Life After Kepler: Upcoming Exoplanet Missions

Artist's depiction of TESS. Image Credit: TESS team.

Last week I held an interview with Dr. Sara Seager – a lead astronomer who has contributed vastly to the field of exoplanet characterization. The condensed interview may be found here. Toward the end of our interview we had a lengthy conversation regarding the future of exoplanet research. I quickly realized that this subject should be an article in itself.

The following is a list of approved missions that will continue the search for habitable worlds, with input from Dr. Seager about their potential for finding planets that might harbor life.

Transiting Exoplanet Survey Satellite (TESS)

Slated to launch in 2017, TESS will search for exoplanets by looking for faint dips in brightness as the unseen planet passes in front of its host star. With a price tag of $200 million, TESS will be the first space-based mission to scan the entire sky for exoplanets.

While the Kepler space telescope confirmed hundreds of exoplanets (with thousands of candidates yet to be confirmed) it stared 3000-light-years deep into a single patch of sky.  TESS will scan hundreds of thousands of the brightest and closest stars in our galactic neighborhood.

“TESS will find many planets,” explained Seager in our interview. “The ones we’re highlighting it will find are rocky planets transiting small stars.” One of the missions goals is to find earth-like exoplanets in the habitable zone – the band around a star where water can exist in its liquid state.

The team hopes that TESS will find up to 1000 exoplanets in the first two years of searching. This will give astronomers a wealth of new worlds to study in more detail.

While the stars Kepler examined were faint and difficult to study in follow-up observations, the stars TESS will focus on are bright and close to home. These stars will be prime targets for further scrutiny with other space based telescopes.

“We plan to have a pool of planets, maybe a handful of them, that we can follow up with the James Webb Space Telescope … which will look at the atmospheres of those transiting planets, looking for signs of life,” Seager said.

ExoplanetSat

While slightly under the radar, ExoplanetSat will monitor bright stars using nano-satellites. Each nano-satellite will be capable of monitoring a single, bright, sun-like star for two years.

The current design of ExoplanetSat. Image Credit: Pong et al. 2010
The current design of ExoplanetSat. The telescope is approximately the size of a loaf of bread. Image Credit: Pong et al. 2010 (SPIE 7731).

“The way that we describe this mission is not that we will find earth,” Seager said. “But if there is a transiting earth-like planet around a bright sun-like star, we will find it.”

Currently no planned mission has the capability to survey the brightest stars in the sky. TESS will observe stars of magnitude 5 through 12 – the dimmest our eyes can see and fainter.

The brightest stars are too widely spaced for a single telescope to continuously monitor. The best method is to monitor the brightest sun-like stars in a targeted star search instead.

The mission is pretty far along in terms of funding. It has already received a few million dollars and is about one million short of launching the first prototype.

After a successful demonstration the goal is to launch a fleet of nano-satellites to observe enough bright stars to find a number of interesting exoplanets.  One day we may be able to look at a bright star in our night sky and know it has a planet.

Direct Imaging Missions

Disentangling a faint, barely reflective, exoplanet from its overwhelmingly bright host star in a direct image seems nearly impossible. A common analogy is looking for a firefly next to a searchlight across North America. Needless to say, very few exoplanets have been seen directly.

Because of the difficulties NASA is fostering a study and soliciting applications with a single goal in mind: create a mission that will directly image exoplanets under a price cap of one billion dollars.

Seager is working with a team that plans to utilize a star shade – “a specially shaped screen that will fly far from the telescope and block out the light from the star so precisely that we will see any planets like earth.”

The shade isn’t circular but shaped like a flower. Light waves would bend around a circle and create spots brighter than the planets themselves. The flower-like shape avoids this while blocking out the starlight – making a planet that is one ten billionth as bright as its host star visible.

The star shade and the telescope have to be aligned perfectly at 125,000 miles away. Once aligned, the system will observe a distant star, and then move to another distant star and re-align. This is technologically speaking, unchartered territory.

While this mission may not occur in full tomorrow, or even years from tomorrow, astronomers’ synapses are firing. We’re coming up with new techniques that will advance technology and find earth-like worlds.

Etc.

Above is a list of only a handful of future exoplanet missions – all at various stages in their production – with some still on the drawing board and others having received full funding and preparing for launch. With creativity and advancing technology we’ll detect a true-earth analogue in the near future.

 

New Exoplanet-Hunting Mission to launch in 2017

Artist's rendition of TESS in space. (Credit: MIT Kavli Institute for Astrophysics Research).

Move over Kepler. NASA has recently green-lighted two new missions as part of its Astrophysics Explorer Program.

These come as the result of four proposals submitted in 2012. The most anticipated and high profile mission is TESS, the Transiting Exoplanet Survey Satellite.

Slated for launch in 2017, TESS will search for exoplanets via the transit method, looking for faint tell-tale dips in brightness as the unseen planet passes in front of its host star. This is the same method currently employed by Kepler, launched in 2009. Unlike Kepler, which stares continuously at a single segment of the sky along the galactic plane in the direction of the constellations Cygnus, Hercules, and Lyra, TESS will be the first dedicated all-sky exoplanet hunting satellite.

The mission will be a partnership of the Space Telescope Science Institute, the MIT Lincoln Laboratory, the NASA Goddard Spaceflight Center, Orbital Sciences Corporation, the Harvard-Smithsonian Center for Astrophysics and the MIT Kavli Institute for Astrophysics and Space Research (MKI).

TESS will launch onboard an Orbital Sciences Pegasus XL rocket released from the fuselage of a Lockheed L-1011 aircraft, the same system that deployed IBEX in 2008 & NuSTAR in 2012. NASA’s Interface Region Imaging Spectrograph (IRIS) will also launch using a Pegasus XL rocket this summer in June.

An Orbital Sciences Pegasus XL rocket attached to the fuselage of an L1011 for the launch of IBEX. (Credit: NASA).
An Orbital Sciences Pegasus XL rocket attached to the fuselage of an L1011 for the launch of IBEX. (Credit: NASA).

“TESS will carry out the first space-borne all-sky transit survey, covering 400 times as much sky as any previous mission. It will identify thousands of new planets in the solar neighborhood, with a special focus on planets comparable in size to the Earth,” said George Riker, a senior researcher from MKI.

TESS will utilize four wide angle telescopes to get the job done. The effective size of the detectors onboard is 192 megapixels. TESS is slated for a two year mission. Unlike Kepler, which sits in an Earth-trailing heliocentric  orbit, TESS will be in an elliptical path in Low Earth Orbit (LEO).

TESS will examine approximately 2 million stars brighter than 12th magnitude including 1,000 of the nearest red dwarfs. Not only will TESS expand the growing catalog of exoplanets, but it is also expected to find planets with longer orbital periods.

One dilemma with the transit method is that it favors the discovery of planets with short orbital periods, which are much more likely to be seen transiting their host star from a given vantage point in space.

TESS will also serve as a logical progression from Kepler to later proposed exoplanet search platforms. TESS will also discover candidates for further scrutiny by as the James Webb Space Telescope to be launched in 2018 and the High Accuracy Radial Velocity Planet Searcher (HARPS) spectrometer based at La Silla Observatory in Chile.

Artist's conception of NICER on the exterior of the International Space Station. (Credit: NASA).
Artist’s conception of NICER on the exterior of the International Space Station. (Credit: NASA).

Also on the board for launch in 2017 is NICER, the Neutron Star Interior Composition Explorer to be placed on the exterior of the International Space Station. NICER will employ an array 56 telescopes which will collect and study X-rays from neutron stars. NICER will specialize in the study of a particular sub-class of neutron star known as millisecond pulsars. The X-ray telescopes are in a configuration utilizing a set of nested glass shells looking like the layers of an onion.

Observing pulsars in the X-ray range of the spectrum will offer scientists tremendous insight into their inner workings and structure. The International Space Station offers a unique vantage point to do this sort of science. Like the Alpha Magnetic Spectrometer (AMS-02), the power requirements of NICER dictate that it cannot be a free-flying satellite. X-Ray astronomy must also be done above the hindering effects of the Earth’s atmosphere.

NICER will be deployed as an exterior payload aboard an ISS ExPRESS Logistics Carrier. These are unpressurized platforms used for experiments that must be directly exposed to space.

Another fascinating project working in tandem with NICER is SEXTANT, the Station Explorer for X-ray Timing And Navigation Technology. This project seeks to test the precision of millisecond pulsars for interplanetary navigation.

“They (pulsars) are extremely reliable celestial clocks and can provide high-precision timing just like the atomic signals supplied through the 26-satellite military operated Global Positioning System (GPS),” said NASA Goddard scientist Zaven Arzoumanian. The chief difficulty with relying on this system for interplanetary journeys is that the signal gets progressively weaker the farther you travel from the Earth.

“Pulsars, on the other hand, are accessible in virtually every conceivable flight regime, from LEO to interplanetary and deepest space,” said NICER/SEXTANT principle investigator Keith Gendreau.

Both NICER and TESS follow the long legacy of NASA’s Astrophysics Explorer Program, which can be traced all the way back to the launch Explorer 1. This was the very first U.S. satellite launched in 1958. Explorer 1 discovered the Van Allen radiation belts surrounding the Earth.

(from left) William Pickering, James Van Allen, and Wernher von Braun hold aloft a mock up of Explorer 1 shortly after launch. (Credit NASA/JPL-Caltech.
(From left) William Pickering, James Van Allen, and Wernher von Braun hold aloft a mock up of Explorer 1 shortly after launch. (Credit NASA/JPL-Caltech).

“The Explorer Program has a long and stellar history of deploying truly innovative missions to study some of the most exciting questions in space science,” stated NASA associate administrator for science John Grunsfeld. “With these missions, we will learn about the most extreme states of matter by studying neutron stars and we will identify many nearby star systems with rocky planets in the habitable zones for further study by telescopes such as the James Webb Space Telescope.”

Of course, Grunsfeld is referring to planets orbiting red dwarf stars, which will be targeted by TESS. These are expected have a habitable zone much closer to their primary star than our own Sun. It has even been suggested by MIT scientists that the first exoplanets visited by humans on some far off date might be initially discovered by TESS. The spacecraft may also discover future targets for follow up spectroscopic analysis, the best chance of discovering alien life on an exoplanet in the next 50 years. One can imagine the excitement that a positive detection of a chemical exclusive to life as we know it such as chlorophyll in the spectra of a far of world would generate. More ominously, detection of such synthetic elements as plutonium in the atmosphere of an exoplanet might suggest we found them… but alas, too late.

But on a happier note, it’ll be exciting times for space exploration to see both projects get underway. Perhaps human explorers will indeed one day visit the worlds discovered by TESS… and use navigation techniques pioneered by SEXTANT to do it!