Posted on by Elizabeth Howell

Proposed Balloon Ride Would Let You See The Blackness Of Space

Artist's conception of World View's planned balloon mission some 19 miles (30 kilometers) up. Credit: World View Enterprises Inc.

Doesn’t that look fun? A startup company is proposing to send customers 19 miles (30 kilometers) into the air via balloon, where they can linger for two hours and look at the curvature of the Earth and experience a black sky. While it’s not high enough to qualify as a spaceflight, the listed ticket price may be a little more affordable for space enthusiasts: $75,000.

Don’t get too excited yet — the project appears to be in very early stages, and no “first flight” date is listed yet. But there are some interesting notes for those looking for space and science experience in the company.

  • Among the members of its executive is Alan Stern, the principal investigator for the New Horizons Pluto mission and NASA’s former associate administrator for the science mission directorate. (He’s also the CEO of the Golden Spike company that wants to offer commercial human missions to the moon.)
  • The executive also includes Jane Poynter and Taber MacCallum, who were both members of Biosphere 2. More recently, they also took on senior positions in Inspiration Mars, a Dennis Tito-led project that aims to send humans past Mars. (The target launch date for that is Jan. 5, 2018.)
  • The company proposing to build it is Paragon Space Development Corp. (which Poynter and MacCallum co-founded.) Paragon’s customers for thermal, environment and life support systems include a lot of name brands (including NASA). Paragon is also doing work for the Inspiration Mars project as well as Mars One, which aims to send colonists on a one-way trip to the Red Planet by 2023.
Artist's conception of World View's passenger capsule that will be carried aloft during a proposed balloon flight. Credit: World View Enterprises Inc.
Artist’s conception of World View’s passenger capsule that will be carried aloft during a proposed balloon flight. Credit: World View Enterprises Inc.

“Seeing the Earth hanging in the ink-black void of space will help people realize our connection to our home planet and to the universe around us, and will surely offer a transformative experience to our customers,” stated Poynter, who is CEO of World View. “It is also our goal to open up a whole new realm for exercising human curiosity, scientific research and education.”

World View’s announcement came after the Federal Aviation Administration “determined that World View’s spacecraft and its operations fall under the jurisdiction of the office of Commercial Space Flight,” the company added.

More information on their mission is available on the World View website. It’s a bit of a different track than Virgin Galactic and XCOR, who are offering rides into suborbital space for prices of $250,000 and $95,000, respectively. Neither company has an operational spacecraft yet, but they are in flight testing. Reports indicate they are hoping to get flights going next year.

Posted on by Nancy Atkinson

New Horizons: I Spy Pluto and Charon!

New Horizons LOng Range Reconnaissance Imager (LORRI) composite image showing the detection of Pluto’s largest moon, Charon, cleanly separated from Pluto itself. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

The New Horizons spacecraft is still about 880 million kilometers (550 million miles) from Pluto, but on July 1 and 3, 2013, the spacecraft’s LOng Range Reconnaissance Imager (LORRI) was able to detect not only Pluto, but its largest moon, Charon, visible and cleanly separated from Pluto itself. Charon orbits about 19,000 kilometers (12,000 miles) away from Pluto, and seen from New Horizons, that’s only about 0.01 degrees away.

“The image itself might not look very impressive to the untrained eye, but compared to the discovery images of Charon from Earth, these ‘discovery’ images from New Horizons look great!” said New Horizons Project Scientist Hal Weaver. “We’re very excited to see Pluto and Charon as separate objects for the first time from New Horizons.”

The frame on the left in the grouping of images above is an average of six different LORRI images, each taken with an exposure time of 0.1 second. The frame to the right is the same composite image but with Pluto and Charon circled; Pluto is the brighter object near the center and Charon is the fainter object near its 11 o’clock position. The circles also denote the predicted locations of the objects, showing that Charon is where the team expects it to be, relative to Pluto. No other Pluto system objects are seen in these images.

These images are just a hint of what’s to come when New Horizons gets closer to the Pluto system. On July 14, 2015, the spacecraft is scheduled to pass just 12,500 kilometers (7,750 miles) above Pluto’s surface, where LORRI will be able to spot features about the size of a football field.

“We’re excited to have our first pixel on Charon,” said New Horizons Principal Investigator Alan Stern, “but two years from now, near closest approach, we’ll have almost a million pixels on Charon –and I expect we’ll be about a million times happier too!”

Pluto has five known moons (and naming them has been a bit controversial). Will New Horizons find even more?

Source: New Horizons

Posted on by David Dickinson

Searching for Pluto: A Guide to the 2013 Opposition Season

Pluto & Charon as you'll never see them... imaged by Hubble in 1994. (Credit: NASA/ESA/ESO).

So you’ve seen all of the classic naked eye planets. Maybe you’ve even seen fleet-footed Mercury as it reached greatest elongation earlier this month. And perhaps you’ve hunted down dim Uranus and Neptune with a telescope as they wandered about the stars…

But have you ever seen Pluto?

Regardless of whether or not you think it’s a planet, now is a good time to try. With this past weekend’s perigee Full Moon sliding out of the evening picture, we’re reaching that “dark of the Moon” two week plus stretch where it’s once again possible to go after faint targets.

This year, Pluto reaches opposition on July 1st, 2013 in the constellation Sagittarius. This means that as the Sun sets, Pluto will be rising opposite to it in sky, and transit the meridian around local midnight.

But finding it won’t be easy. Pluto currently shines at magnitude +14, 1,600 times fainter than what can be seen by the naked eye under favorable sky conditions.  Compounding the situation is Pluto’s relatively low declination for northern hemisphere observers.  You’ll need a telescope, good seeing, dark skies and patience to nab this challenging object.

Wide Field
Pluto in Sagittarius; a wide field field of view with 10 degree finder circle. The orbital path of Pluto and the ecliptic is also noted. The red inset box is the field of view below. All graphics created by the author using Starry Night.

Don’t expect Pluto to look like much. Like asteroids and quasars, part of the thrill of spotting such a dim speck lies in knowing what you’re seeing. Currently located just over 31 Astronomical Units (AUs) distant, tiny Pluto takes over 246 years to orbit the Sun. In fact, it has yet to do so once since its discovery by Clyde Tombaugh from the Lowell observatory in 1930. Pluto was located in the constellation Gemini near the Eskimo nebula (NGC 2392) during its discovery.

And not all oppositions are created equal. Pluto has a relatively eccentric orbit, with a perihelion of 29.7 AUs and an aphelion of 48.9 AUs. It reached perihelion on September 5th, 1989 and is now beginning its long march back out of the solar system, reaching aphelion on February  19th, 2114.

Medium field
A medium field finder for Pluto with a five degree field of view. The current direction of New Horizons is noted. The yellow inset box is the field of view below.

Pluto last reached aphelion on June 4th, 1866, and won’t approach perihelion again until the far off date of September 15th, 2237.

This means that Pluto is getting fainter as seen from Earth on each successive opposition.  Pluto reaches magnitude +13.7 when opposition occurs near perihelion, and fades to +15.9 (over 6 times fainter) when near aphelion. It’s strange to think that had Pluto been near aphelion during the past century rather than the other way around, it may well have eluded detection!

This all means that a telescope will be necessary in your quest, and the more powerful the better. Pluto was just in range of a 6-inch aperture instrument about 2 decades ago. In 2013, we’d recommend at least an 8-inch scope and preferably larger to catch it. Pluto was an easy grab for us tracking it with the Flandrau Science Center’s 16-inch reflector back in 2006.

Small field
A one degree field of view, showing the path of Pluto from June 23rd of this year until December 2nd. Stars are labeled down to 7th magnitude, unlabeled stars are depicted down to 10th magnitude.

Pluto is also currently crossing a very challenging star field.  With an inclination of 17.2° relative to the ecliptic, Pluto crosses the ecliptic in 2018 for the first time since its discovery in 1930. Pluto won’t cross north of the ecliptic again until 2179.

Pluto also crossed the celestial equator into southern declinations in 1989 and won’t head north again til 2107.

But the primary difficulty in spotting +14th magnitude Pluto lies in its current location towards the center of our galaxy. Pluto just crossed the galactic plane in early 2010 into a very star-rich region. Pluto has passed through some interesting star fields, including transiting the M25 star cluster in 2012 and across the dark nebula Barnard 92 in 2010.

Narrow field
A one degree narrow field of view, showing the path of Pluto from June 24th to August 6th. Stars are depicted down to 14th magnitude.

This year finds Pluto approaching the +6.7 magnitude star SAO 187108 (HIP91527). Next year, it will pass close to an even brighter star in the general region, +5.2 magnitude 29 Sagittarii.  Mid-July also sees it passing very near the +10.9 magnitude globular cluster Palomar 8 (see above). This is another fine guidepost to aid in your quest.

So, how do you pluck a 14th magnitude object from a rich star field? Very carefully… and by noting the positions of stars at high power on successive nights. A telescope equipped with digital setting circles, a sturdy mount and pin-point tracking will help immeasurably. Pluto is currently located at:

Right Ascension: 18 Hours 44′ 30.1″

Declination: -19° 47′ 31″

Heavens-Above maintains a great updated table of planetary positions. It’s interesting to note that while Pluto’s planet-hood is hotly debated, few almanacs have removed it from their monthly planetary summary roundups!

You can draw the field, or photograph it on successive evenings and watch for Pluto’s motion against the background stars.  It’s even possible to make an animation of its movement!

Pluto will once again reach conjunction on the far side of the Sun on January 1st 2014. Interestingly, 2013 is a rare year missing a “Plutonian-solar conjunction.” This happens roughly every quarter millennium, and last occurred in 1767. This is because conjunctions and oppositions of Pluto creep along our Gregorian calendar by about a one-to-two days per year.

An Earthly ambassador also lies in the general direction of Pluto. New Horizons, launched in 2006  is just one degree to the lower left of 29 Sagittarii. Though you won’t see it through even the most powerful of telescopes, it’s fun to note its position as it closes in on Pluto for its July 2015 flyby.

Let us know your tales of triumph and tragedy as you go after this challenging object. Can you image it? See it through the scope? How small an instrument can you still catch it in? Seeing Pluto with your own eyes definitely puts you in a select club of visual observers…

Still not enough of a challenge?  Did you know that amateurs have actually managed to nab Pluto’s faint +16.8th magnitude moon Charon? Discovered in 35 years ago this month in 1978, this surely ranks as an ultimate challenge. In fact, discoverer James Christy proposed the name Charon for the moon on June 24th, 1978, as a tribute to his wife Charlene, whose nickname is “Char.”  Since it’s discovery, the ranks of Plutonian moons have swollen to 5, including Nix, Hydra and two as of yet unnamed moons.

Be sure to join the hunt for Pluto this coming month. Its an uncharted corner of the solar system that we’re going to get a peek at in just over two years!

Posted on by Ken Kremer

New Horizons Spacecraft ‘Stays the Course’ for Pluto System Encounter

The Pluto and Charon Binary Planet System imaged by the Hubble Space Telescope. NASA’s New Horizons spacecraft will pass through in 2015 using the original baseline trajectory . Credit: Hubble Space Telescope

Following an intense 18 month study to determine if NASA’s New Horizons spacecraft faced potentially destructive impact hazards during its planned 2015 flyby of the Pluto binary planet system, the mission team has decided to ‘stay the course’ – and stick with the originally planned trajectory because the danger posed by dust and debris is much less than feared.

The impact assessment study was conducted because the Pluto system was discovered to be much more complex – and thus even more scientifically compelling – after New Horizons was launched in January 2006 from Cape Canaveral in Florida.

Two years ago researchers using the iconic Hubble Space Telescope discovered two new moons orbiting around Pluto, bringing the total to 5 moons!

It was feared that debris hitting the moons could have created dangerous dust clouds that in turn would slam into and damage the spacecraft as it zoomed past Pluto at speeds of some 30,000 miles per hour (more than 48,000 kilometers per hour) in July 2015.

“We found that loss of the New Horizons mission by dust impacting the spacecraft is very unlikely, and we expect to follow the nominal, or baseline, mission timeline that we’ve been refining over the past few years,” says New Horizons Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory, in a statement.

After both the team and an independent review board and NASA thoroughly analyzed the data, it was determined that New Horizons has only a 0.3 percent chance of suffering a mission destroying dust impact event using the baseline trajectory.

Hubble Space Telescope view of Pluto and its known moons.
Hubble Space Telescope view of Pluto and its known moons.

The 0.3 percent probability of mission loss is far less than some earlier estimates.

This is really good news because the team can focus most of its efforts on developing the flyby encounter science plan when New Horizons swoops to within about 12,500 kilometers (nearly 7,800 miles) of Pluto’s surface.

Pluto forms a “double planet” system with Charon, its largest moon. Charon is half the size of Pluto.

But the team will still expend some effort on developing alternative trajectories – known as SHBOTs, short for Safe Haven by Other Trajectories, just in case new information arises from the ships camera observations that would force a change in plans as New Horizons sails ever closer to Pluto.

“Still, we’ll be ready with two alternative timelines, in the event that the impact risk turns out to be greater than we think,” says Weaver.

Indeed the team, led by Principal Investigator Alan Stern, of the Southwest Research Institute is finalizing the encounter plan this month and plans a rehearsal in July of the most critical nine-day segment of the baseline flyby trajectory.

New Horizons will perform the first reconnaissance of Pluto and Charon in July 2015. The “double planet” is the last planet in our solar system to be visited by a spacecraft from Earth.

And New Horizons doesn’t’ stop at Pluto. The goal is to explore one or more of the icy Kuiper Belt Objects (KBO’s) further out in the Solar System.

The team will use the Pluto flyby to redirect New Horizons to a KBO that is yet to be identified.

And don’t forget to “Send Your Name to Mars” aboard NASA’s MAVEN orbiter- details here. Deadline: July 1, 2013. Launch: Nov. 18, 2013

Ken Kremer

…………….
Learn more about Pluto, Mars, Curiosity, Opportunity, MAVEN, LADEE and NASA missions at Ken’s upcoming lecture presentations

June 23: “Send your Name to Mars on MAVEN” and “CIBER Astro Sat, LADEE Lunar & Antares Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM

Posted on by David Dickinson

U.S. To Restart Plutonium Production for Deep Space Exploration

A marshmellow-sized Pu-238 pellet awaits a space mission. (Credit: The Department of Energy).

The end of NASA’s plutonium shortage may be in sight. On Monday March 18th,  NASA’s planetary science division head Jim Green announced that production of Plutonium-238 (Pu-238) by the United States Department of Energy (DOE) is currently in the test phases leading up to a restart of full scale production.

“By the end of the calendar year, we’ll have a complete plan from the Department of Energy on how they’ll be able to satisfy our requirement of 1.5 to 2 kilograms a year.” Green said at the 44th Lunar and Planetary Science Conference being held in Woodlands, Texas this past Monday.

This news comes none too soon. We’ve written previously on the impending Plutonium shortage and the consequences it has for future deep space exploration. Solar power is adequate in most cases when you explore the inner solar system, but when you venture out beyond the asteroid belt, you need nuclear power to do it.

Production of the isotope Pu-238 was a fortunate consequence of the Cold War.  First produced by Glen Seaborg in 1940, the weapons grade isotope of plutonium (-239) is produced via bombarding neptunium (which itself is a decay product of uranium-238) with neutrons. Use the same target isotope of Neptunium-237 in a fast reactor, and Pu-238 is the result. Pu-238 produces 280x times the decay heat at 560 watts per kilogram versus weapons grade Pu-239  and is ideal as a compact source of energy for deep space exploration.

Since 1961, over 26 U.S. spacecraft have been launched carrying Multi-Mission Radioisotope Thermoelectric Generators (MMRTG, or formerly simply RTGs) as power sources and have explored every planet except Mercury. RTGs were used by the Apollo Lunar Surface Experiments Package (ALSEP) science payloads left on by the astronauts on the Moon, and Cassini, Mars Curiosity and New Horizons enroute to explore Pluto in July 2015 are all nuclear powered.

Plutonium powered RTGs are the only technology that we have currently in use that can carry out deep space exploration. NASA’s Juno spacecraft will be the first to reach Jupiter in 2016 without the use of a nuclear-powered RTG, but it will need to employ 3 enormous 2.7 x 8.9 metre solar panels to do it.

The plutonium power source inside the Mars Science Laboratory's MMRTG during assembly at the Idaho National Laboratory. (Credit: Department of Energy?National Laboratory image under a Creative Commons Generic Attribution 2.0 License).
The plutonium power source inside the Mars Science Laboratory’s MMRTG during assembly at the Idaho National Laboratory. (Credit: Department of Energy/Idaho National Laboratory image under a Creative Commons Generic Attribution 2.0 License).

The problem is, plutonium production in the U.S. ceased in 1988 with the end of the Cold War. How much Plutonium-238 NASA and the DOE has stockpiled is classified, but it has been speculated that it has at most enough for one more large Flag Ship class mission and perhaps a small Scout class mission. Plus, once weapons grade plutonium-239 is manufactured, there’s no re-processing it the desired Pu-238 isotope. The plutonium that currently powers Curiosity across the surface of Mars was bought from the Russians, and that source ended in 2010. New Horizons is equipped with a spare MMRTG that was built for Cassini, which was launched in 1999.

Technicians handle an RTG at the Payload Hazardous Servicing Facility at the Kennedy Space Center for the Cassini spacecraft. (Credit: NASA).
Technicians handle an RTG at the Payload Hazardous Servicing Facility at the Kennedy Space Center for the Cassini spacecraft. (Credit: NASA).

As an added bonus, plutonium powered missions often exceed expectations as well. For example, the Voyager 1 & 2 spacecraft had an original mission duration of five years and are now expected to continue well into their fifth decade of operation. Mars Curiosity doesn’t suffer from the issues of “dusty solar panels” that plagued Spirit and Opportunity and can operate through the long Martian winter. Incidentally, while the Spirit and Opportunity rovers were not nuclear powered, they did employ tiny pellets of plutonium oxide in their joints to stay warm, as well as radioactive curium to provide neutron sources in their spectrometers. It’s even quite possible that any alien intelligence stumbles upon the five spacecraft escaping our solar system (Pioneer 10 & 11, Voyagers 1 & 2, and New Horizons) could conceivably date their departure from Earth by measuring the decay of their plutonium power source. (Pu-238 has a half life of 87.7 years and eventually decays after transitioning through a long series of daughter isotopes into lead-206).

New Horizons in the Payload Hazardous Servicing Facility at the Kennedy Space Center. Note the RTG (black) protruding from the spacecraft. (Credit: NASA/Uwe W.)
New Horizons in the Payload Hazardous Servicing Facility at the Kennedy Space Center. Note the RTG (black) protruding from the spacecraft. (Credit: NASA/Uwe W.)

The current production run of Pu-238 will be carried out at the Oak Ridge National Laboratory (ORNL) using its High Flux Isotope Reactor (HFIR). “Old” Pu-238 can also be revived by adding newly manufactured Pu-238 to it.

“For every 1 kilogram, we really revive two kilograms of the older plutonium by mixing it… it’s a critical part of our process to be able to utilize our existing supply at the energy density we want it,” Green told a recent Mars exploration planning committee.

Still, full target production of 1.5 kilograms per year may be some time off. For context, the Mars rover Curiosity utilizes 4.8 kilograms of Pu-238, and New Horizons contains 11 kilograms. No missions to the outer planets have left Earth since the launch of Curiosity in November 2011, and the next mission likely to sport an RTG is the proposed Mars 2020 rover. Ideas on the drawing board such as a Titan lake lander and a Jupiter Icy Moons mission would all be nuclear powered.

Engineers perform a fit check of the MMRTG on Curiousity at the Kennedy Space Center. The final installation of the MMRTG occured the evening prior to launch. (Credit: NASA/Cory Huston).
Engineers perform a fit check of the MMRTG on Curiosity at the Kennedy Space Center. The final installation of the MMRTG occurred the evening prior to launch. (Credit: NASA/Cory Huston).

Along with new plutonium production, NASA plans to have two new RTGs dubbed Advanced Stirling Radioisotope Generators (ASRGs) available by 2016. While more efficient, the ASRG may not always be the device of choice. For example, Curiosity uses its MMRTG waste heat to keep instruments warm via Freon circulation.  Curiosity also had to vent waste heat produced by the 110-watt generator while cooped up in its aero shell enroute to Mars.

Cutaway diagram of the Advanced Stirling Radioisotope Generator. (Credit: DOE/NASA).
Cutaway diagram of the Advanced Stirling Radioisotope Generator. (Credit: DOE/NASA).

And of course, there are the added precautions that come with launching a nuclear payload. The President of the United States had to sign off on the launch of Curiosity from the Florida Space Coast. The launch of Cassini, New Horizons, and Curiosity all drew a scattering of protesters, as does anything nuclear related. Never mind that coal fired power plants produce radioactive polonium, radon and thorium as an undesired by-product daily.

An RTG (in the foreground on the pallet) left on the Moon by astronauts during Apollo 14. (Credit: NASA/Alan Shepard).
An RTG (in the foreground on the pallet) left on the Moon by astronauts during Apollo 14. (Credit: NASA/Alan Shepard).

Said launches aren’t without hazards, albeit with risks that can be mitigated and managed. One of the most notorious space-related nuclear accidents occurred early in the U.S. space program with the loss of an RTG-equipped Transit-5BN-3 satellite off of the coast of Madagascar shortly after launch in 1964. And when Apollo 13 had to abort and return to Earth, the astronauts were directed to ditch the Aquarius Landing Module along with its nuclear-powered science experiments meant for the surface of the Moon in the Pacific Ocean near the island of Fiji. (They don’t tell you that in the movie) One wonders if it would be cost effective to “resurrect” this RTG from the ocean floor for a future space mission. On previous nuclear-equipped launches such as New Horizons, NASA placed the chance of a “launch accident that could release plutonium” at 350-to-1 against  Even then, the shielded RTG is “over-engineered” to survive an explosion and impact with the water.

But the risks are worth the gain in terms of new solar system discoveries. In a brave new future of space exploration, the restart of plutonium production for peaceful purposes gives us hope. To paraphrase Carl Sagan, space travel is one of the best uses of nuclear fission that we can think of!

Posted on by Jason Major

New Horizons’ Pluto Stamp is One Step Closer to Becoming a Reality

Concept art for a New Horizons postage stamp. Image Credit: Dan Durda/Southwest Research Institute

A little over a year ago Alan Stern, principal investigator on the New Horizons mission, announced the team’s plans to have a Forever Stamp issued by the US Postal Service commemorating the New Horizons spacecraft along with its targets, Pluto and Charon. Thousands signed the petition, and today the team announced a long-awaited update to all of its supporters: it’s definitely a maybe!

In an email sent out to petition signers as well as on its Facebook page, the New Horizons team noted that the stamp — conceptualized by planetary scientist and artist Dan Durda — has cleared its first major hurdle in the USPS approval process and will be submitted for review and consideration before their Advisory Committee.

Pending that approval, it will then be put on the agenda for the meeting of the Citizens’ Stamp Advisory Committee.

After that point, since no notification is made to the applicant about a stamp’s approval by the Postmaster General until a public announcement is issued it’s likely that we won’t know if there will actually be a New Horizons stamp until the spacecraft is on final approach to Pluto in July 2015. Hopefully the USPS will see the benefit to having a stamp actually ready for purchase by that time and plan accordingly, but one never knows. Until then, cross your fingers and keep an eye out for a Forever Stamp featuring the “First Spacecraft to Explore Pluto!”

“This is a chance for us all to celebrate what American space exploration can achieve though hard work, technical excellence, the spirit of scientific inquiry, and the uniquely human drive to explore.”

– Alan Stern, New Horizons Principal Investigator

USPS Forever Stamps can be used to mail a one-ounce letter regardless of when the stamps are purchased or used and no matter how prices may change in the future. Forever Stamps are always sold at the same price as a regular First-Class Mail stamp. Forever Stamps can be used for international mail, but since all international prices are higher than domestic US prices, additional postage is necessary.

Posted on by Nancy Atkinson

New Horizons May Need to ‘Bail Out’ to Dodge Debris, Rings and Moons in the Pluto System

Artist’s concept shows the New Horizons spacecraft during its 2015 encounter with Pluto and its moon, Charon. Credit: JHUAPL/SwRI

Since the New Horizons spacecraft left Earth back in 2006, there are a few things we know about the Pluto system now that we didn’t know then. For instance, it was discovered Pluto has two additional small moons – P4 and P5 — and Alan Stern, New Horizons Principal Investigator, said Pluto may have a large system of moons to be discovered as the spacecraft gets closer. There are also comets, possibly more dwarf planets and other objects out in the Kuiper Belt region where Pluto orbits.

“That’s exciting,” Stern said, “but this is a mixed story.”

Stern told Universe Today that while the spacecraft possibly could come upon an undiscovered moon or Kuiper Belt Object and they would have to alter course, the biggest issue is tiny debris which may be coming from impacts on the smaller moons.

“We could have 100 moons the size of P4 and they would not be a significant hazard,” Stern said via email. “The hazard is from ejecta coming off these satellites when they are cratered, because the ejecta escapes their feeble gravity and gets into orbit around Pluto.”

At a press conference at the American Astronomical Society’s Division for Planetary Sciences meeting, Stern said that with all the debris in the Kuiper Belt, objects are definitely getting impacted. “If hits occur on Pluto and Charon, they have enough gravity that ejecta just flies across the planet and creates secondary craters. But the ejecta on smaller moons puts shards and debris into the Pluto system.”

Stern said the ejecta speeds from these moons would be comparable to orbital speeds. That means the debris can orbit at any inclination, and there could be a cloud of debris around the system, creating a hazard for the spacecraft.

This worries Stern and his team.

“My spacecraft is going very fast and even a strike from something as small as a BB would be fatal,” he said. “There’s almost no place the spacecraft could get hit and it would be OK.”

Stern said current knowledge of the density of debris of the system can’t prove the spacecraft won’t get hit, and they won’t be able to find out more until they get closer.

“We’re going somewhere new and have no direct evidence of debris that could pose an impact hazard,” he said. “We don’t know what we are going to find and we might have to change our course.”

Stern and his team are looking at some alternative plans, and developing them now is crucial.

“When we plan an encounter for a mission like this, it literally takes tens of thousands of man-hours by experts to put that sequence together and test it,” he said. “We have to plan them now in order to complete that planning. We can’t complete them in the last couple of months or weeks.”

The plans being considered are called SHBOT: Safe Haven Bail Out Trajectory. They currently have nine different possible trajectories, depending on what they find as they get closer.

Screenshot from Stern’s presentation, depicting the nine SHBOT trajectories.

The team is also using every available tool — including sophisticated computer simulations of the stability of debris orbiting Pluto, giant ground-based telescopes, stellar occultation probes of the Pluto system, and even the Hubble Space Telescope — to search for debris in orbit.

Stern told Universe Today that they use the cameras on New Horizons itself every summer when they “wake up” the spacecraft. “LORRI (Long Range Reconnaissance Imager) has already seen Pluto for about 6 years!” he said, “But we won’t pass HST resolution till we’re about 10 weeks out, in April 2015. That’s when we turn on the heavy effort to look for more moons, rings, etc.”

They are looking at the pluses and minuses for each of the plans so they can be tested and be just as “bullet-proof” as the original, nominal flight plan.

In addition to saving the spacecraft, these alternative trajectories also need to preserve the science mission as much as possible. Most of the alternate courses bring the spacecraft farther away from the Pluto system, but one actually brings it closer to Charon, as the path there may be clearer there because of Charon’s gravity and clearing effect.

The spacecraft will start science observations in January 2015, with closest approach to the system currently set for on July 14, 2015 (“Bastille Day,” Stern said, “when we storm the gates of the Pluto system!”)

During the final 50 days of approach, when the spacecraft is taking pictures and sending them back to Earth to be analyzed, the team may discover something and have to fire the spacecraft engines, putting them on one of the SHBOT trajectories. But the last opportunity to actually change course is 10 days before encounter.

“After that we are in too close and we would run out of fuel and not complete the maneuver,” Stern said.

So, while the Mars Science Laboratory team had “Seven minutes of terror” during the perilous landing on Mars, Stern said they have something similar. “We don’t have seven minutes of terror; we have seven weeks of suspense.”

Posted on by Jason Major

What Has the Kuiper Belt Taught Us About The Solar System?

Over 4 billion miles (6.7 billion km) from the Sun, the Kuiper Belt is a vast zone of frozen worlds we still know very little about. Image: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI)

Today marks the 20th anniversary of the discovery of the first Kuiper Belt Object, 1992QB1. KBOs are distant and mostly tiny worlds made up of ice and rock that orbit the Sun at incredible distances, yet are still very much members of our Solar System. Since 1992 over 1,300 KBOs have been found, and with NASA’s New Horizons spacecraft speeding along to its July 2015 rendezvous with Pluto and Charon (which one could argue are technically the first KBOs ever found) and then onwards into the Belt, we will soon know much more about these far-flung denizens of deep space.

But how has the discovery of the Kuiper Belt — first proposed by Gerard Kuiper in 1951 (and in a fashion even earlier by Kenneth Edgeworth) — impacted our current understanding of the Solar System? New Horizons Principal Investigator Alan Stern from the Southwest Research Institute recently discussed this on his mission blog, “The PI’s Perspective.”

First, Stern lists some of the surprisingly diverse physical aspects of KBOs that have been discovered so far:

  • Some are red and some are gray;
  • The surfaces of some are covered in water ice, but others (like Pluto) have exotic volatile ices like methane and nitrogen;
  • Many have moons, though none with more known moons than Pluto;
  • Some are highly reflective (like Pluto), others have much darker surfaces;
  • Some have much lower densities than Pluto, meaning they are primarily made of ice. Pluto’s density is so high that we know its interior is about 70% rock in its interior; a few known KBOs are more dense than Pluto, and even rockier!

But although these features are fascinating in themselves, just begging for further exploration, Stern notes that there are three very important lessons that the Kuiper Belt has taught us about the Solar System:

1. Our planetary system is much larger than we had ever thought.

“In fact, we were largely unaware of the Kuiper Belt — the largest structure in our solar system — until it was discovered 20 years ago,”  Stern writes. “It’s akin to not having maps of the Earth that included the Pacific Ocean as recently as 1992!”

2. Planetary locations and orbits can change over time.

“This even creates whole flocks of migration of planets in some cases. We have firm evidence that many KBOs (including some large ones like Pluto), were born much closer to the Sun, in the region where the giant planets now orbit.”

3. Our solar system, and likely others as well, was very good at making small planets.

“Today we know of more than a dozen dwarf planets in the solar system, and those dwarfs already outnumber the number of gas giants and terrestrial planets combined. But it is estimated that the ultimate number of dwarf planets we will discover in the Kuiper Belt and beyond may well exceed 10,000. Who knew?”

And with a little jab at the whole Pluto-isn’t-a-planet topic, Stern asks: “And which class of planet is the misfit now?”

Read: Was Pluto Ever REALLY a Planet?

The discovery of the Kuiper Belt has shown us that our solar system — and very likely planetary systems across the galaxy, even the Universe — aren’t neat and tidy things that can be easily summed up with grade-school models or chalkboard diagrams. Instead they are incredibly diverse and dynamic, continually evolving and consisting of countless, varied worlds spanning enormous distances… yet still connected through the ever-present effects of gravity (not to mention the occasional-yet-unavoidable collision.)

“What an amazing set of paradigm shifts in our knowledge the Kuiper Belt has brought so far. Our quaint 1990s and earlier view of the solar system missed its largest structure!”

– Alan Stern, New Horizons Principal Investigator

Read more about the New Horizons mission here.

 The first KBO identified, 1992 QB1 (European Southern Observatory)

Posted on by Ray Sanders

Help Support a ‘New Horizons’ U.S. Postage Stamp!

Concept art for a New Horizons postage stamp. Image Credit: Dan Durda/Southwest Research Institute

[/caption]Today the New Horizons mission team, along with Principal Investigator Alan Stern have unveiled their proposal for a U.S Postage stamp, to honor the first mission to Pluto.

The current concept art for the stamp was done by Dan Durda, a space scientist and artist at The Southwest Research Institute. Durda’s work has appeared on the New Horizons website and in other locations. If the stamp is approved, it would be the successor to a U.S. postage stamp issued in 1990 that labeled Pluto as “Not Yet Explored.”

“You can help make this happen.” says Stern.

Since it can take several years for a proposed stamp to be approved by the U.S. post office, the mission team launched an internet petition today. The team plans to submit petitioners’ names along with their formal proposal, with the hopes that the stamp will be approved and printed in time to celebrate the New Horizons fly-by of Pluto in 2015.

Stern added, “We’re asking people to sign the petition, because the post office considers not just the merits of a new stamp proposal, but also whether it is supported by a significant number of people. This is a chance for us all to celebrate what American space exploration can achieve though hard work, technical excellence, the spirit of scientific inquiry, and the uniquely human drive to explore.”

Artist's impression of New Horizons' encounter with Pluto and Charon. Credit: NASA/Thierry Lombry
You can help by signing the petition urging the post office’s Citizen Stamp Advisory Committee to recommend a New Horizons stamp to the postmaster general.

The New Horizons team encourages people signing the petition to also tell their friends, family members, Facebook friends, Google plusketeers, and Twitter followers to sign as well!

The text of the petition reads as follows:

Greetings,

I just signed the following petition addressed to: Citizens’ Stamp Advisory Committee.

—————-
The nation has an opportunity to honor a truly exemplary accomplishment of humankind in general, and the U.S. space program in particular, with a new U.S. postage stamp in 2015 honoring the flyby and reconnaissance of the Pluto system by NASA’s New Horizons spacecraft.

New Horizons lifted off in January 2006 aboard a U.S. Atlas V rocket, the fastest spacecraft ever launched. In fact, New Horizons crossed the orbit of the Moon in just nine hours – almost 10 times quicker than the Apollo lunar missions. Since then, New Horizons has been speeding toward Pluto – more than three billion miles from Earth — covering nearly one million miles a day!

New Horizons will make its closest approach to Pluto and its family of moons on July 14, 2015, 50 years to the day after Mariner 4 made the first successful flyby of Mars.

With the New Horizons flyby of Pluto, the U.S. space program will complete the first era of planetary reconnaissance, a profoundly inspiring feat of lasting historical significance. Moreover, the Pluto flyby will represent the first exploration of the Kuiper Belt, the first exploration of a double planet, the first exploration of an ice dwarf planet, and the farthest object ever explored in space.

Join the mission team in asking the U.S. Postal Service to commemorate the historic achievements of New Horizons by signing this petition in support of a new postage stamp, supplanting the 1990 U.S. stamp that described Pluto simply as “Not Yet Explored.”

The petition urges the Citizen Stamp Advisory Committee to recommend to the Postmaster General a stamp in honor of New Horizons.

Let’s celebrate what humans can achieve though hard work, technical excellence, scientific inquiry and the uniquely human spirit of exploration.
—————-

Sincerely,

[Your name]

Sign the petition at: http://www.change.org/petitions/usps-honor-new-horizons-and-the-exploration-of-pluto-with-a-usps-stamp

If you’d like to learn more about the New Horizons mission, visit: http://pluto.jhuapl.edu/index.php

Source: New Horizons Mission Updates

Posted on by Ray Sanders

Dr. Alan Stern Answers Your Questions!

Dr. Alan Stern preparing for a high-altitude test flight in A two-seater, NASA WB-57 aircraft. Photo Credit: SOuthwest Research Institute.

[/caption]Some of you may know, we recently launched a new “Ask” feature here at Universe Today. Our inaugural launch features Dr. Alan Stern, Principal Investigator for the New Horizons mission to Pluto and the Kuiper Belt. We collected your questions in our initial post and passed them along to Dr. Stern who graciously took the time to answer them.

Here are the questions picked by you, the readers, and Dr. Stern’s responses. We’d like to thank our readers for making this kick-off a success, as well as Dr. Stern for his participation.


1.) Many sci-fi authors have dreamed of putting some sort of telescope on the surface of Pluto to take advantage of the relative darkness and extreme cold encountered on this distant dwarf planet. How feasible would it be, judging from what we’re learning from the New Horizons expedition, to actually land a spacecraft, or a telescope, on Pluto’s surface? If such a telescope where deployed, how much more effective, if at all, could it be than an instrument like the JWST?

Alan Stern:“Space astronomy has revolutionized the way we look at the universe and is fundamental to modern astrophysics.” There are benefits to getting telescopes out of the atmosphere, and even benefits to getting out of Earth orbit, as in the case of Kepler and someday maybe JWST.

With regard to taking advantage of Pluto’s cold temperature – we’ve gotten really good at cooling down space telescopes. “There would be a benefit to placing a radio telescope on the far side of the Moon, but there’s no real practical reasons to place a telescope on Pluto—particularly given the cost of getting there, other than it being cool.”

2.) Kuiper objects differentiate strongly in color suggesting compositional or perhaps formation differences. Interestingly the color distribution correlates with the two different cold and hot Kuiper populations. Assuming the spectral analysis capability of New Horizon works for identifying the follow up Kuiper objects beyond Pluto-Charon, and given the putative possibility of choosing between several such targets, what type of target would the mission aim for? Would it try to cover as much diversity of objects as possible or is there a certain class of objects that could be important to concentrate on?

A.S: “We have to find Kuiper belt objects within our spacecraft’s fuel supply.” Stern elaborated, stating, “Predictions from our computer models tell us to expect to be able to have perhaps six possible candidates, to choose from, but so far we’ve just begun to search for these and though we’re finding KBOs, none we’ve found are yet are within the fuel supply.”

Stern also added, “Keep in mind our search for candidates isn’t easy – these are 27th magnitude objects which are roughly 50,000 times fainter than Pluto. What we’ll use to select between candidates once we have them are color, orbits, moons, rotational speeds – basically what combination of properties give us the most science for our fuel budget. The longer we wait after the Pluto flyby in July 2015 to make a decision, the more fuel will be consumed, so the “sweet spot” would be to have preliminary candidates in early 2015.”
(UT Note: New Horizons will perform its Pluto flyby in mid-2015 ).

3.) Given the limited funds available, Which do you recommend (Europa or Enceladus) as a suitable target for a mission in the 2025 time-frame in terms of value for money, scientific return, and practicality, and what kind of mission do you propose (lander vs. orbiter) ?

A.S: “Every scientist has their own judgment of what would make a good outer system flagship mission, or the best world to perform a series of missions that would equal a flagship mission.” Dr. Stern’s opinion is to explore Titan first, with Enceladus as a secondary target of that mission and Europa last, stating “Titan is the belle of the ball”, citing Titan’s active liquid cycle and thick atmosphere. Stern also added that he believes a mission to Titan would provide the most science per budget dollar.

4.) Four of the craft escaping the Solar System – Pioneers 10 & 11 and Voyagers 1 & 2 – have on board some sort of “message” to any possible extraterrestrials in the unlikely event they find it. Why was not some sort of message like that included on New Horizons, which may be the last (in our lifetimes) craft to also escape the Solar System?

A.S “There are several mementos onboard New Horizons, but no Voyager-like message.” Dr. Stern discussed a promise he made to his team that New Horizons would not be canceled and that he wanted his team focused on the science of the mission. Stern also pointed out that the process of deciding what to place on the Voyager plaques became mired in political correctness, (should the humans have been clothed? What cultures and races should be represented, etc.)

By separating the “icing from the cake”. Stern and his team have been able to concentrate on their main objective—to execute the New Horizons mission for about twenty cents on the dollar, as compared to the Voyager missions. Stern concluded with, “I’m proud that we got this done and that New Horizons is operating perfectly now way out there between Uranus and Neptune and flying almost a million kilometers per day toward the Pluto system.”

5.) Are any present or foreseeable technologies being considered for exploring the depths of our four “gas giant” planets?

A.S “There are no serious proposals to put a probe into one of the giant planets now, or even any call for such in the recent decadal survey for planetary missions. Keep in mind, though, that the Juno mission (now en route to Jupiter ) will use powerful remote sensing techniques to probe Jupiter from orbit around it to greater depths than the Galileo probe (which actually entered Jupiter’s atmosphere).”

6.) Why was it considered “urgent” to get to Pluto before the atmosphere refroze?

A.S “We have three “Group 1″ objectives for New Horizons. Map the surface, map the composition, and assay the atmosphere.” Stern referred to the objectives as a “three legged stool” in that no one objective could be omitted and still justify the mission, adding “so we need to accomplish that.. we need to get there before the atmosphere collapses”. Stern also referred to Pluto’s atmosphere as “very different from any other planet yet studied”, hence its inclusion as one of the three “Group 1” objectives.

7.) The Dawn mission to Vesta has shown us a body that was much less round than expected. Do you think it is possible that New Horizons will surprise us about Pluto, to the same degree? Please compare the expectations of the New Horizons fly by, to the early images of Vesta from Dawn.

A.S “With New Horizons being the first mission to Pluto, we will be surprised—after all, we’re always surprised on first reconnaissance flybys”. Stern added, “With Mariner 10, we discovered Mercury was all core, with Voyager we discovered volcanos and geysers across the outer solar system, and of course we were surprised when craters and river valleys were discovered by early Mars probes.”

Regarding Pluto, Stern stated “Pluto is the first discovered and soon to be reconnoitered of the most plentiful class of planets, while I’m not big on making predictions, I will say that what we will find will certainly be, well, wonderful.”

9.) Can new horizons now take more detailed photos of Pluto than HST? If not, when does it get close enough?

A.S “Great question! We actually thought about that a lot when designing New Horizons. One of our instruments, LORRI (Long-Range Reconnaissance Imager – http://pluto.jhuapl.edu/spacecraft/sciencePay.html) will provide us with views better than HST around April of 2015, and we expect to have about twenty weeks (10 weeks before, 10 weeks after the Pluto flyby) when we “own” the Pluto system — and I can guarantee the best images we hope to make should be as good as Landsat images of Earth!”

That wraps up our interview with Dr. Alan Stern. Once again, we at Universe Today would like to thank Dr. Stern for his gracious participation. If you’d like to learn more about the New Horizons mission to Pluto and The Kuiper Belt, visit: http://pluto.jhuapl.edu/index.php

Next month, we’ll be having an “Ask an Astronaut” feature with Mike Fossum, Commander of Expedition 29 on the International Space Station. Stay tuned!