Space Exploration

Destination Jupiter


The Juno mission was launched on Aug 5, 2011 and settled into orbit around Jupiter just this last summer on July 5, 2016. Then in February of this year NASA announced that Juno would not enter into a lower (closer) orbit of Jupiter as planned due to a concern with the spacecraft's main engine. The good news is that this decision was made to protect the mission and the impact to mission science objectives was minimal to zero. Since then Juno has been busy snapping pictures and learning a lot about our nearest gas giant neighbor.

Great, so we have a pretty amazing piece of technology orbiting Jupiter. Why are we doing this? It can be hard to boil down the science in such a way that the general public can fully understand, but in the case of Juno NASA has done just the form of a free iBook from Apple called Destination Jupiter. The book does a great job of explaining the origins of the mission, the science we are tying to answer by going there and telling the story of how the mission came to be. This entire narrative is told along side some amazing graphics and photos in a way that makes you feel like you were right there with the team all those years during the mission development, launch and cruise phase all the way to Jupiter (you know, without having to endure the painfully cold vacuum of space).


But wait, there's more! Not only was there a book written but the Juno mission has inspired a lot of artists to create music to commemorate the mission, like Trent Reznor and Brad Paisley. Apple is currently running a promotional banner in the iTunes Music Store that features all of the music inspired by the Juno mission in a single place (see the image below). So go check out the iTunes Store and the Destination Jupiter banner and get a little bit of art to go with your science!


Goodbye EO-1

Last week I had to say goodbye to an old friend, a 17 year-old spacecraft called Earth Observing-1 (EO-1).

"EO-1 was a technology validation mission for testing cutting-edge advancements that have been and are being implemented on current and future satellite missions. The satellite launched in 2000 with 13 new technologies, including three new instruments, that had never been flown previously. Among its many accomplishments, the satellite was an innovator for detecting Earth’s biochemical constituents in unprecedented detail, a pathfinder for using artificial intelligence software for streamlined satellite communication and a precursor for extremely close flying between orbiting satellites."

For me, the EO-1 mission was the start of my career. I was fresh out of college with a B.S. in Aerospace Engineering and I had just landed a job with a very small company in Lanham, Maryland that provided engineering services for NASA at Goddard Space Flight Center. Within a few months of starting work I received my first major work assignment...ascent maneuver design work on the EO-1 mission. My main task on EO-1 was to figure out how to get the spacecraft from the orbit that the launch vehicle initially puts it in on launch day to the orbit it wants to be in operationally. EO-1 was a technology demonstrator mission and one of the technologies it was testing out was autonomous formation flying. If you have ever seen the Blue Angles or the Thunderbirds at an air show then you have seen formation flying...except this is with spacecraft. EO-1 was supposed to fly very close (about 1 minute behind) Landsat-7, a spacecraft that in 2000 was already in orbit above the Earth.

This image shows LandSat-7 in the lead with EO-1 imaging the same swath of the Earth 1-minute later

This image shows LandSat-7 in the lead with EO-1 imaging the same swath of the Earth 1-minute later

One minute may not seem all that close, but remember these are very expensive spacecraft and there isn't anyone sitting in the cockpit in orbit with them. Up until this point in time, if you wanted to move one of these spacecraft it would take days if not weeks of planning before the orbit maneuver was executed and the spacecraft was moved. With the technology we were demonstrating on EO-1 we were going to let the computer on-board EO-1 do all the maneuver calculations and execute the maneuver...all without anyone on the ground having to do anything. This was a first for NASA!

So my first task was to work with a very small team to come up with the sequence of maneuvers that would move EO-1 from the orbit it starts in after launch to a very tight formation flying orbit behind Landsat-7. Getting all of the orbit parameters just right to achieve the tight orbit we needed with Landsat-7 was no easy task and we needed to do it quickly and with as little propellant as know, so the spacecraft could continue to fly for 17 years! This work lead to my first professionally published paper.

The orbit ascent maneuver design wasn't my only task on EO-1. I helped out a bit with the on-orbit software the would perform the autonomous maneuver calculations as well, but my main task was leading the operation team that help operate the spacecraft from the ground (when the spacecraft wasn't testing out its autonomous capabilities). This involved writing a lot of scripts (computer code) that would generate products needed by other systems that supported the EO-1 spacecraft. Things like ground stations that would track EO-1 and help us communicate with the spacecraft. Ground stations needed to know where to point and for that they needed to know where EO-1 was in orbit above the Earth. So we had to generate specifically formatted files to tell the ground stations what they needed to know. I also had to write scripts to tell the spacecraft how to maneuver. It was one thing to figure out how long to turn on the spacecraft thrusters for, but then you had to tell the spacecraft in its own language how to do that. So we needed computer code to take a maneuver design (point the spacecraft here and burn for this long) and turn it into commands the spacecraft would understand.

So for several years leading up to the EO-1 launch in 2000 I worked on all of these things and then we launched. After launch I lead the team that used the maneuver strategy we designed to actually maneuver the spacecraft into its operational orbit. After EO-1 was safely behind Landsat-7 I also helped with the day to day orbit maintenance maneuver design and the efforts for testing out the autonomous algorithms on-board. After the autonomous maneuvers technology was successfully demonstrated I helped to train the operational team that would take over from there, doing the day to day things to support maneuver operations going forward.

EO-1 was an amazing start to my career. If you had told me as a kid that would be maneuvering a several hundred million dollar spacecraft right out of college I would have called you crazy. But I was in the right place at the right time I got to learn under some of most experienced and truly wonderful people I have ever had the privilege of working with. So EO-1 was more than just a spacecraft to me, it was the start of an amazing adventure that I am still on today. In fact, just last year as I was taking one of my last tests to get my Masters degree I had a question about the maneuver design for the EO-1 mission. I never in a million years thought I would be asked a test question about space that was based on my work.

EO-1 was "turned off" on March 30th 2017. This means the spacecraft was taken out of its operational orbit and put into an orbit that atmospheric drag will slowly and naturally cause to become lower and lower until in burns up in the atmosphere around 2056. So EO-1 may no longer be operational, but its kind of nice to think it will still be up there in orbit long after I retire. Thanks EO-1 and Godspeed...

The Sonic Booms Are Back

The Falcon 9 first stage returning to the launch site (Image from SpaceX) 

The Falcon 9 first stage returning to the launch site (Image from SpaceX) 

Yesterday wasn't the first time we have heard sonic booms in central Florida since the Space Shuttle stopped flying, but it was the first time we have heard sonic booms because of something that launch ed off of Launch Complex 39A (where the Apollo moon mission were launched from and it was also one of the Space Shuttle launch pads).

When the Space Shuttle's returned to Earth they would glide back unpowered and land like an airplane. But even though they were flying like an airplane, they were still bleeding off a lot of speed because they had just returned from space. During their descent through the atmosphere they would slow down but even as they would approach the Space Coast they would still be flying faster than the speed of sound...hence the sonic booms. For those of us that followed the Space Shuttle mission closely we would all breathe a sigh of relief when we heard those sonic booms because it meant our astronauts were almost home.

Fast forward a few years and the sonic booms were heard once again, but this time it was because of the Falcon 9 first stage flying back. SpaceX is trying to make as much of their Falcon 9 rocket as reusable as possible, so they after they launch the rocket and the 1st stage is jettisoned from the rocket the 1st stage flies back to the launch site so it can be used again. The 1st stage is also flying faster than the speed of sound, so we again hear sonic booms on the Space Coast.

NASA Audio & Ring Tones


I came across an awesome website the other day. It's a NASA website that has a ton of small sound bytes that are perfect for ringtones or alerts for your cell phone or tablet. And trust me, there are some really cool audio clips in here. Here are a few that stood out for me:

These are just a few of the dozens of sound clips available for download. Be sure to read the instructions page for how to get these onto your iOS device here and enjoy!

Traveling to a Planet Orbiting Another Star

Proxima Centauri imaged by Hubble (photo from NASA) 

Proxima Centauri imaged by Hubble (photo from NASA) 

This month Sky & Telescope published a couple of articles that when combined pretty much blew my mind. The first news story was about the initial discovery of a planet orbiting the star Proxima Centauri. Proxima Centauri is the small red M dwarf star and is the nearest star to our solar system. This new world has been named Proxima Centauri b, has a mass of at least 1.3 times that of Earth and is thought to be a rocky planet. Its orbit is also within the so called "habitable zone" of the star, meaning that theoretically the temperature ranges on the planet's surface could support liquid water (which is widely accepted as something that is needed to support life).

Ok, so that's cool right? Maybe this planet orbiting a star a really long way away from us could support life or even have life currently living on the surface. But what if we could directly image this planet and its atmosphere? Yeah, that may actually be possible here in the next several years. The ESPRESSO spectrograph at the ESO's Very Large Telescope facility in Chile will be operational in 2017 and may just have the capability of determining the composition of Proxima Centauri b's atmosphere.

Just when you thought things couldn't any more futuristic and Sci-Fi crazy...what if I told you it might be possible to travel to this star system and this possible life-harboring planet? Not only is it theoretically possible to send a very small spacecraft there, but it is actively being developed. This Popular Science article talks about a project originally funded by Kickstarter that is beginning to develop an extremely small (just 1 or 2 gram) spacecraft that could potentially harness the power of the Sun and accelerate up to 20% of the speed of light. That would reduce the travel time to Proxima Centauri to just 20 years.

If you put all of this together then we will soon be able to directly image the atmosphere of a planet orbiting a very nearby star that has the potential for alien life and then send a very small probe within our lifetimes to investigate. It wasn't too long ago that we weren't even sure there were other planets beyond our solar system out there. We really do live in the future...

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