NuSTAR

In just a few days (it looks like the launch date is March 21, but the date is “under review” as of this writing), the next NASA Small Explorer (SMEX) mission is set to launch. NuStar (Nuclear Spectroscopic Telescope Array) is the next orbital telescope that will collect high energy X-ray data and is the first on-orbit telescope to use a new generation of hard X-ray optics. Among its mission objectives are locating massive black holes, study the population of compact objects (such as collapsed stars and stellar mass black holes) located in the center of the Milky Way, create maps of of the material from young supernova remnants to better understand how stars explode and create elements, and discover what causes the relativistic jets that emanate from supermassive black holes.

Following a 1-month on-orbit checkout period, NuSTAR will begin its 2-year primary science mission; its main objectives taking an estimated 18 months (including the start-up month) with the six remaining months devoted to targeted observations, some of which will be determined after the mission has already begun. While the mission length is scheduled for two years, the telescope contains no consumables and can essentially function as long as it remains in orbit, which is in excess of five years. This extra time can be worked into extended missions working on Guest Observer proposals.

NuSTAR will work from an altitude of about 575 – 600 km (350 – 370 miles) in a low-earth orbit, inclined just 6° from the equator. This will allow it to have a view of about 80% of the sky at any given time.

The craft itself looks unlike any you’ve probably seen before. While it will launch in a stowed position, once in orbit the two main components will extend apart via a 10-meter mast, which will give the telescope a 10.15-meter focal length.

Artist's concept of NuSTAR

Artist's concept of NuSTAR on orbit. NuSTAR has a 10-m (30') mast that deploys after launch to separate the optics modules (right) from the detectors in the focal plane (left). The spacecraft, which controls NuSTAR's pointings, and the solar panels are with the focal plane. NuSTAR has two identical optics modules in order to increase sensitivity. Image Credit: NASA/JPL-Caltech

I can’t help but see some resemblance between NuSTAR and the “Satellite of Love” from Mystery Science Theatre 3000.

Satellite of Love from Mystery Science Theatre 3000

Satellite of Love from Mystery Science Theatre 3000

But I digress….

What’s also interesting to me about NuSTAR is the way it will be launched. Rather than a ground-based launch, the Pegasus XL rocket is carried up to 40,000 feet (12.19 kilometers) on the underside of a L-1011 Stargazer carrier aircraft, contracted through Orbital Sciences Corporation. Once dropped, it will fall for about five seconds before the rocket engines ignite, taking it up to an orbit altitude and trajectory.

Stay tuned for a successful launch of NuSTAR this month. I can’t wait to see the images it will produce and what mysteries it will unravel.


Waiting For Curiosity

Even though there’s still just under five months remaining until the Mars Science Laboratory Curiosity rover lands on Mars’ surface, I almost find myself counting down the days. I woke up early to watch the launch of MSL live on NASA-TV last November and have followed the updates on its progress since then. One of the neat features you can find on the MSL website is the “Where Is Curiosity?” page, where simulated views of its progress from Earth to Mars are updated daily over its 36-week journey.

Watching the slight change in the images from day to day gave me an idea: these images could be made into a cool animation! So I hopped over to the Jet Propulsion Laboratory/California Institute of Technology’s Solar System Simulator website, fiddled around with the various options, and then started collecting images for each day that the mission has been elapsed up until today. I put them together into a little video, added some music, and now I offer it to you for your interplanetary enjoyment.

In the top left, you can watch the days tick by. The MSL is labeled in green in the center of the video. If you’re interested in reading some of the details related to distance traveled and the speed of the craft, you’ll want to watch the video in HD and full-screen.

You’ll probably notice that around 14 seconds into the video (specifically, beginning with the frame for January 14), the perspective changes slightly. I’m not exactly sure what causes it, but its the way the simulator changed the images it spit out starting with that date. I’m going to contact the designer with JPL/Caltech and see if they can help me out with different perspectives. I hope to update it from time-to-time between now and August, to put Curiosity’s progress in perspective.


Exciting Kepler News – Part 1: Mini-Planetary System

 

There were two exciting Kepler (the NASA mission tasked with discovering planets outside of our solar system) news releases today. I’ll cover them in two separate posts. This is Part 1; stay tuned for Part 2.

KOI-961 Artist Concept

(Click to englarge / Image credit: NASA/JPL-Caltech)

Announced today was the discovery of the three smallest exoplanets (planets orbiting a star other than the Sun) ever discovered. These planets are orbiting a red dwarf star, currently1 named KOI-961 (KOI = Kepler Object of Interest). These planets are all smaller than our home planet, having a radius of .78, .73, and .57 that of Earth’s. (The smallest is about the size of Mars.) Though the planets are thought to be rocky, they orbit KOI-961 very closely, making them too hot to have any likelihood of being habitable.

The planets, currently 2 named KOI-961.01, KOI-961.02, and KOI-961.03, circle their host star at a fair clip, completing an orbit in less than two Earth-days. The star, KOI-961, has much less mass than our Sun. Its diameter is 1/6 the size of the Sun (which is only about 70% larger than Jupiter).

The discovery announced today came from a team of scientists, led by astronomers from the California Institute of Technology (Caltech). They made their discovery by analyzing publicly-released data from the Kepler mission. Studying KOI-961, they were able to greatly refine the preliminary estimated size of the red dwarf, and subsequently verify the presence of the three small exoplanets.

KOI-961 exoplanet comparisons

(Click to enlarge / Image Credit: NASA/JPL-Caltech)

If you’re interested in further details about how Caltech made the discovery, I highly recommend you read their press release.

So let’s take a step back and ponder about what this latest discovery means. Coupled with the many frequent previous Kepler discoveries, we’re starting to create a big picture in which planets are ubiquitous throughout the Universe. Red dwarfs are the most common type of star in at least our own galaxy, and if one red dwarf has a planetary system, it’s likely more do… maybe even most do. We’re discovering planets around different types of stars; those similar to the Sun and those considerably different. Planets of different sizes and compositions as well. Not just large gas giants with little hope for containing life, but smaller, rocky worlds. Other Earth-sized worlds. Other Earth-like orbits. Other… Earths.

The speed at which we’re making these otherworldly discoveries is astounding and encouraging. It wasn’t long ago, I sat wondering if there were other planets out there, beyond our solar system, and if they might be discovered in my life. Today, I’m overwhelmed trying to keep up with all of the new exoplanet discoveries!

This is an exciting era to live in.


  1. I say currently, because once Kepler exoplanets are confirmed, the star generally gets the designation Kepler followed by a number, and the exoplanets are named after the star, followed by a letter designation. For example, Kepler-22b orbits the star Kepler-22. The designation “b” indicates it was the second expolanet discovered in that system.
  2. See the first footnote!