Wednesday, August 29, 2012

Majoring in 'The Right Stuff'

It's back-to-school time, people! Let's say you're a rising high school senior, with long-term plans to travel to the moon. Where should you go to college?

Starfleet Academy: don't bother applying for a few hundred years.
Source: Wikipedia.

For the purpose of this blog post, I'll assume you meet a few depressing historical requirements. For example- you better be graduating from high school in the early 1950s, you'll need to be American, male, and have 20/20 vision. And you ought to learn to fly this:

A T-38; astronauts' jet trainer.
Source: Wikipedia.

A total of 24 men have orbited the moon; 12 of them walked on it. What lessons can we learn from their college choices?

1. Your best bet is a service academy. Not the Coast Guard Academy or the Air Force Academy, though. The Air Force Academy didn't exist till 1954, so most Apollo astronauts missed out on it by a couple years. The most popular college among the 24 is the Naval Academy (6 graduates traveled to the moon) or second to that, West Point (4 graduates traveled to the moon). But, if you can't secure a Congressional nomination to a service academy, don't worry, there are other options...

2. Hoosiers travel to the moon and get in-state tuition. After the Naval Academy and West Point, the third most popular college choice is Indiana's Purdue University. The first and last men to walk on the moon were Boilermakers: Neil Armstrong and Gene Cernan.

3. No need to be fancy, y'all. Counting the service academies, 21 out of the 24 men attended public schools. No Harvard, Yale, or Stanford grad has ever walked on the moon. Only one Ivy Leaguer traveled to the moon. That would be Pete Conrad, Princeton grad and Commander of Apollo 12. His first word upon stepping off the ladder onto the lunar surface: "Whoopie!"

4. It's okay to be a late bloomer. One Apollo 13 astronaut, Fred Haise, started out at community college before transferring to University of Oklahoma. Apollo 14 Command Module Pilot Stuart Roosa attended three different colleges before graduating cum laude from Colorado State at age 27. Even if college wasn't a priority, Stu was keeping busy: his first job out of high school was as a smokejumper for the U.S. Forest Service.

5. If it isn't NCAA Division 1 in football, don't bother. This is true unless the word "Technology" appears in your school's name. One of the 24 was an MIT grad, another a Cal Tech grad. Also, this rule doesn't apply if you are Pete Conrad. (Whoopie!) But otherwise, the better your school is at football, the better your chances are of going to the moon. An Auburn grad, a University of Texas grad, a Georgia Tech Grad, and two former University of Michigan students traveled to the moon.

The stars at night, are big and bright (*clap clap clap clap*)
Source: Scientific American.

So here's the full list of undergrad alma maters. First, the men who walked on the moon:

1. Neil Armstrong - Purdue U.
2. Buzz Aldrin - U.S. Naval Academy
3. Pete Conrad - Princeton U.
4. Alan Bean - University of Texas at Austin
5. Alan Shepard - U.S. Naval Academy
6. Ed Mitchell - Massachusetts Institute of Technology
7. Dave Scott - University of Michigan for one year, then the U.S. Military Academy
8. Jim Irwin - University of Michigan
9. John Young - Georgia Tech
10. Charles Duke (an N.C. native!!) - U.S. Naval Academy
11. Gene Cernan - Purdue University
12. Harrison Schmitt - California Institute of Technology

Second, the men who traveled to the moon:

1. Frank Borman - U.S. Military Academy
2. Jim Lovell - University of Wisconsin-Madison for two years, then the U.S. Naval Academy
3. Bill Anders - U.S. Naval Academy
4. Thomas Stafford - U.S. Naval Academy
5. Michael Collins - U.S. Military Academy
6. Ronald Evans - University of Kansas
7. Ken Mattingly - Auburn University
8. Al Worden - U.S. Military Academy
9. Fred Haise - Mississippi Gulfcoast Community College, then University of Oklahoma
10. Jack Swigert - University of Colorado at Boulder
11. Richard Gordon - University of Washington - Seattle
12. Stuart Roosa - Oklahoma State University, University of Arizona, Colorado State University

I considered lying and making up a 25th astronaut who attended my alma mater (University of North Carolina at Chapel Hill- go Tar Heels!). But I kept things honest. After all, UNC played its part in the moon landings. 23 of the 24 astronauts were trained in celestial navigation at UNC's Morehead Planetarium

Nothing finer than to be in Carolina!
Source: UNC.

Sources: Wikipedia, Morehead Planetarium; Andrew Chaiken's A Man on the Moon.

Tuesday, August 21, 2012

Drama on Lake Tenzig!

I was wondering why Russian space capsules are shaped differently than U.S. space capsules. Here's what I mean by that. Take a look at the Vostok I, right Yuri Gagarin's historic flight:

Vostok I.
Source: sciencephoto.com. 

It's shaped like a sphere, right? And here is Freedom 7, right after Alan Shepard's splashdown.

Recovering Freedom 7.
Source: History.com.

See how Freedom 7 is shaped like a cone? The difference persisted for several decades, with the Soviet Voskhod and the (now Russian) Soyuz re-entry crafts shaped roughly like spheres, and the American Mercury, Gemini ,and Apollo crafts looking like stubby ice cream cones. I wondered why. You have two space-faring societies trying to accomplish roughly the same missions in space. Many of their engineers shared the same training, as both the Soviets and the Americans ended up with German rocket scientists after World War Two. Shouldn't any differences in spacecraft design be relatively minor?

It turns out there are a number of practical reasons why U.S. and Soviet space capsules had different shapes. For example, the crafts landed differently. U.S. Mercury, Gemini, and Apollo missions all splashed down in the Atlantic or Pacific.

Spashdown site for the Mercury, Gemini, and a few Apollo missions.
Source: Wikipedia.

But Soviet and Russian spacecraft all land in Asia, set down on the ground. The ice cream cone design sits well in the water. It'll float, pointy end up. That's not a concern if you're landing in a desert in the middle of Kazakhstan. No need to make sure your spacecraft is seaworthy. It's just a spaceship, not a boat.

The Soviet Union, and then Russia, has landed 122 manned spacecraft in Central Asia. Every single one landed on solid ground... with one exception. Soyuz 23 landed in the middle of a lake. And that landing very nearly killed the crew!

The Soyuz 23 crew:
Manning the first combination spacecraft/submarine/icebreaker.
Source: Videocosmos.

Despite the preference for ground landings, Soyuzes are designed to survive water landings. The problem was the weather at Lake Tenzig on that particular day.

Lake Tenzig in the "winter."
Source: Ramsar Convention on Wetlands.

Soyuz 23 landed in northern Kazakhstan in mid-October, which apparently is winter there. Weather conditions at the landing site were awful. It was nighttime, -8 degrees Fahrenheit, in the middle of a blizzard. The lake was fogged in. The craft landed 5 miles offshore,and its landing shattered the surrounding ice. Its parachute soaked through, and the weight of the wet parachute flipped the capsule upside down so that the hatch was submerged. That was when Soyuz 23 became the first space-faring submarine. Its air intake valve was also underwater, so the astronauts had only the time-limited air supply that came with them from space. The cosmonauts cut off most of their instruments to conserve power and thus managed to keep the CO2 scrubbers running. That way, they could keep breathing for a while... though they must have been pretty chilly.


Cosmonauts Zudov and Rozdestvensy awaiting rescue.
Source: Videocosmos.

Since the lake was only partially frozen, and surrounded by bogs, neither boats nor amphibious vehicles could reach the craft. Rescue was delayed eight hours, till dawn, when helicopters could be safety brought in to tow the ship (with the cosmonauts still in it) to shore. The situation was bad enough that the rescue crew was surprised that the cosmonauts were still alive. Soyuz 23 Mission Engineer Valery Rozhdestvensky  recalled, "when I got to see our photos and how they dragged the capsule - then I really was frightened - the only time in my life I was really frightened."

Soyuz 23, towed to shore.
Source: Epizodspace.

What a rough night. Neither of the Soyuz 23 cosmonauts ever flew in space again. As for other reasons behind the different spacecraft designs: I'll talk more about that in my next blog post...

Sources: Wikipedia; Videocosmos; Epizodspace.

Wednesday, August 15, 2012

1978: A Space Odyssey

In 1972, the last Apollo lunar mission left the moon (that would be Apollo 17 if you believe Tom Hanks or Apollo 18 if you prefer alien attacks to facts). Since then, we've put a couple space stations in orbit, launched 135 space shuttle missions, and now humans even have a pet robot the size of a pickup truck living on Mars!

President Obama on the phone to JPL, discussing America's pet robot.
Source: JPL.

Which is all really awesome- and I am so excited to follow Curiosity's progress as it explores! But... don't you wish it was actual people who landed on Mars last weekend? How great would that have been?

Curiosity- our very own UFO over Mars!
Source: NASA.

It turns out, we came pretty close to launching a manned mission to Mars and Venus soon after the Apollo lunar program ended- back in the late 1970s!

Illustration of a test of Apollo hardware, for a manned Venus mission.
Source: Wikipedia.

There were a few different proposals for how the mission could have proceeded. The easiest, simplest idea was a manned flyby of Venus, spending four months to travel there, zipping by the planet less than 2,000 miles above its surface, and then spending four months travelling back to Earth. 

The most ambitious idea was for a triple-planet flyby: 

- Leave Earth orbit on November 28, 1978.
- Fly by equatorial Venus, on the "day" side of the planet, on May 11, 1979.
- Fly by Mars on November 25, 1979.
- Fly by southern Venus, passing from "day" into "night" on January 29, 1980.
- Land on Earth on January 31, 1981.

The four astronauts in the crew would observe Mars and Venus as they passed by, releasing weather balloons to travel into Venus's atmosphere, and launching a swarm of probes to land on Mars.The entire mission would last 800 days. For comparison, there's one human, Cosmonaut Sergei Krikalev, who has spent over 800 days in space. But it wasn't all at the same time- he flew six different missions. The record for the single longest duration spaceflight is held by Cosmonaut Valeri Polyakov, who lived on the Mir Space Station for over 437 days.

But, using existing 1970s (or for that matter, 2012) propulsion technology, an 800 day trip would be necessary.

The mission profile for a triple-planet flyby, launching in 1978.
Source: Wired Science.

During a November 1978 launch window the three planets would have been aligned for relatively quick and low-energy flybys. So when the manned triple-planet flyby was cancelled, NASA took advantage of this fortuitous alignment of the planets to launch Pioneer Venus 1 and Pioneer Venus 2 instead. NASA also launched a manned space station, Skylab, using much of the Apollo technology and drawing on ideas that would have been applied to the manned triple-planet flyby.

Skylab, as viewed by a Skylab Command and Service Module.
Source: Wikipedia.

The triple-planet flyby spacecraft would have relied on Apollo technology as much as possible, along with new technology being developed for the space shuttle. One plan envisioned a Saturn V rocket (scaled up slightly) being used to launch modules into orbit 25,000 miles above Earth, to be assembled into the triple-planet flyby spacecraft. The spacecraft's operations would be powered mainly by solar panels, like Skylab was; or radioisotopes, depending on the mission duration. The spacecraft itself would be propelled towards Venus using a rocket design based on a Saturn V. Then, a rocket like that found on the Apollo command module would be used for course corrections. Once the spacecraft left Earth orbit, that command module engine would be the only propellant needed: Sir Isaac Newton takes care of the rest, slingshoting the craft from planet to planet.

Here's a mock-up of the spacecraft.

The manned triple-flyby spacecraft.
Source: Wired Science.

(A) are the "radioisotope power supply systems," which deploy outside the body of the craft after the craft arrives in Earth orbit. 

(B) is the vehicle used to re-enter Earth's atmosphere at the end of the mission (the cone on top is similar to the Apollo Command Module; attached to that is a craft similar to the Apollo service module). 

(C) is an access tunnel between the living quarters of the space ship and the re-entry vehicle and the pressurized space around it. 

(D) is the main crew quarters (located as far away as possible from the radioisotope power supply).

(E) is an emergency shelter, with radiation shielding, in the crew compartment. It would be used to protect astronauts during solar flares. The walls of the emergency shelter would consist of the crew's water supply. 

(F) is a two-man centrifuge. Engineers considered equipping the entire craft with artificial gravity (by rotating all or part of the craft) but instead, to save weight, there's just the small centrifuge.

A manned probe above Mars: what could have been and could still be!
Source: Wired Science.

The spacecraft and potential mission plans were pretty well planned out. If you'd like to read more about them, David Portree's Wired Science article After EMPIRE: Using Apollo Hardware to Explore Venus and Mars is a fascinating source. He also wrote an interesting article on NASA plans to use space shuttle hardware for a 1990s Mars mission.

Why didn't the plans for a manned Mars and Venus flyby become reality? A few different factors, including the tragic Apollo 1 fire, slowed the Apollo program down to the point where funding for such a large-scale project became unlikely. The energy spent planning the manned flyby was probably also in large part a response to fears that the USSR might try to make a manned Venus or Mars flight before the U.S. could. This of course did not come to pass. Too bad, right?

Oh well. At least there's this guy:

Curiosity, hanging out all by himself on Mars.
Source: Universe Today.

Eventually, he'll have some more friends on Mars!

Sources: Wired Science; more Wired Science; even more Wired Science; Wikipedia; JPL; Vintage Space.

Monday, August 6, 2012

Curiosity Landed!! In one piece!!

YAY!!!!!!! Happy birthday, Neil Armstrong! You got an extra-nice present this year: a new rover safely set down on the surface of Mars!

Curiosity's first photo on Mars!!
Source: Nasa!

The boyfriend and I watched the landing footage at the Adler Planetarium tonight. It was a packed house! Two full auditoriums, plus an overflow room. It's exciting to see folks so interested in this mission!

My view of the landing!

It takes roughly 14 minutes for radio signals to travel from Mars to Earth. So for me the spookiest part of the evening came 14 minutes before the landing was announced. At that point, hundreds of millions of miles away, Curiosity was already down on the ground, for better or worse. But we wouldn't find out how the landing went for 14 more minutes.

I was so nervous... even more so when NASA Associate Administrator John Grunsfeld started acting super confident about 10 minutes before the landing was confirmed. He was announcing that everything was going to go great and we were headed for a perfect landing! Come on, buddy, don't jinx it!

My very amateur video of the reaction at JPL and and at Adler Planetarium!

However, it turns out he was right- it was a flawless landing!! Calm weather on Mars, a completely error-free performance by Curiosity, and even the Odyssey orbiter cooperated in uploading data from Curiosity to Earth, so we were able to get confirmation right away!

YAY, Curiosity, NASA, and JPL!

Sources: NASA, JPL, Mars, Adler Planetarium, and that amazing lil rover! Thank you guys!!

Sunday, August 5, 2012

Shields Up!

How do we protect spacecraft from catastrophic collisions with space junk?

The flecks of black on Mir's far right solar panel are damage from micrometeorites.
Source: Wikipedia.

Space junk includes everything from discarded rockets to tools that slip out of astronauts' hands during spacewalks. There are over 20,000 pieces of trash bigger than a baseball in Earth orbit; 500,000 pieces that are bigger than a marble, and millions of additional smaller pieces. The amount of trash in orbit is increasing as a rate of about 4% a year... and each piece is travelling at up to 17,500 miles per hour!

Space junk: the debris added by the 2009 Iridium-Kosmos collision is shown in red.
Source: The Space Review.

The U.S. tracks tens of thousands of pieces of orbital debris. Sometimes it can provide advance warning to allow a craft to maneuver out of a potential collision. But we can't prevent every collision that way.

So how do we protect spacecraft from being slowly pulverized by tiny pieces of high-speed trash? The U.S. and Russia have developed deflector shields: strong, lightweight material (like Kevlar) assembled in staggered layers, able to dissipate some incoming particles.

Beware, Romulans and Russian communications satellites with degrading orbits.
Source: WikiSciFi.

Every International Space Station module comes with some shielding, but one module in particular, the Zvezda module, is extra-protected. This is necessary because it contains the Station's life support systems. If Zvezda was crippled, it could render the Station uninhabitable.

Debris impact risk on the Station.
The Zvezda module is on the far left of this diagram, in blues and greens.
Source: Wikipedia. 

Zvezda is covered in "Debris Protection Panels," which astronauts clamped around the outside of the module after it was launched into space.

Astronauts installing the panels on the Zvezda Module in 2007.
Source: NASA.
These panels are only about an inch thick, but they'll stop micrometeorites and the smallest pieces of debris from breaching Zvezda's walls.

Zvezda. Debris panels don't keep the inside tidy.
Source: Wikipedia.

An even more heavy-duty shield was built to protect the Stardust spacecraft- a probe designed to literally fly into the tail of a comet. Here's one of Stardust's shields:

See the various layers of material, each slightly separated from the other.
Source: Wikipedia.

Stardust was an incredibly successful spacecraft. It encountered two comets and became the first spacecraft to scoop up a sample of comet debris and send it back to Earth. It functioned for over twelve years, and its shields never failed!

Stardust!
The rectangular boxes in front and the large circle in the middle are the shields.
Source: NASA.

It's neat to think that we have deflector shields on our spacecraft, just on Star Trek. But, shields provide limited protection. They won't save you from the Kessler Syndrome: low Earth orbit becoming so cluttered with junk that collisions cascade out of control. In short order, every spacecraft in orbit would be pulverized!

Sources: Lockheed Martin; Space Daily; NASA; Wired Science; Space.com.